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HomeMy WebLinkAboutSouthold Stormwater Management Program Plan TOWN OF SOUTHOLD Albert Krupski, Town Supervisor �4i► Louisa P. Evans, Town Justice Jill Doherty, Town Councilman Greg Doroski, Town Councilman Brian O. Mealy, Town Councilman Anne Smith, Town Councilman Denis Noncarrow, Town Clerk Paul DeChance, Town Attorney Daniel J. Goodwin, Highway Superintendent Stormwater Management Program Plan Revised February 7, 2025 This Stormwater Management Program Plan (SWMP Plan) incorporates the efforts of the Town of Southold (Town) to meet the Phase II Stormwater Permit requirements for municipal separate storm sewer systems (MS4s). Background In 1972, Congress enacted the Clean Water Act (CWA). Under the CWA, the discharge of pollutants to waters of the United States from any point source is unlawful unless the discharge is covered under a National Pollutant Discharge Elimination System (NPDES) permit. The CWA has been amended multiple times since its enactment implementing additional program requirements. Through delegation by the federal government, New York State is administering these program requirements through the New York State Department of Environmental Conservation (NYSDEC). On March 20, 2009 the Town received official notice from the NYSDEC that the Town had been formally designated as an MS4 operator that would be required to obtain coverage under the New York State Department of Environmental Conservation SPDES General Permit for Stormwater Discharges from Municipal Separate Storm Sewer Systems (MS4s), Permit No. GP-0-08-002. The Town submitted a Notice of Intent (NOI) to NYSDEC on September 29, 2009, thereby gaining coverage under the GP-0- 08-002. This general permit has been modified and updated and the Town is currently regulated under GP-0-24-001. A copy of GP-0-24-001 and the current NOI on file with NYSDEC is included in Appendix A. 1 General Permit GP-0-24-001 Introduction GP-0-24-001 regulates stormwater discharges from MS4s. In short, the permit allows the Town to discharge stormwater from its regulated MS4s to water bodies provided that the Town maintains a certain level of responsibility to ensure that pollutants are prevented from entering the water bodies via the regulated MS4s to the maximum extent practicable. The permit is lengthy and complex. This introduction is not intended to provide detailed explanations of the permit and its requirements. It is intended to provide the reader some basic information that will assist them in reviewing the permit and the sections of it that apply to the Town. This information is listed below: • An MS4 is a conveyance or system of conveyances (including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, man-made channels, or storm drains): 0 owned or operated by a State, city, town, village, borough, county, parish, district, association, or other public body (created by or pursuant to State law) having jurisdiction over disposal of sewage, industrial wastes, stormwater, or other wastes, including special districts under State law such as a sewer district, flood control district or drainage district, or similar entity, or an Indian tribe or an authorized Indian tribal organization, or a designated and approved management agency under section 208 of the CWA, that discharges to surface waters of the State; o designed or used for collecting or conveying stormwater; o which is not a combined sewer; and o which is not part of a Publicly Owned Treatment Works (POTW) as defined at 40 CFR 122.2. • A storm sewershed is the catchment area that drains into the storm sewer system based on the surface topography in the area served by the storm sewer • Surface Waters include fresh water wetlands and tidal wetlands and are not necessarily standing water • The Town contains an Automatically Designated Area as defined in the permit and has a number of MS4s located within the Automatically Designated Area • All Town MS4s that lie outside of the Automatically Designated Area are within the Additionally Designated Area as defined in the permit • The Town is regulated as a traditional land use control MS4 • The MS4s owned and operated by Suffolk County, New York State and the Village of Greenport are regulated separately from the Town and these entities are responsible for their own infrastructure and programs Town of Southold - Regulatory Designation According to Appendix B of GP-0-24-001 "Designation Criteria for Identifying Regulated Municipal Separate Storm Sewer Systems (MS4s), January 2010, revised January 2023", only a sub-set of small MS4s, referred to as "regulated" small MS4s, are covered by the Federal stormwater regulations. A small MS4 can be designated as a regulated MS4 through automatic designation by the USEPA or by meeting designation criteria developed by the NPDES permitting authority, which is the NYSDEC in New York State (NYS). 2 The USEPA's automatic designation criteria are based strictly on population and density. An area is automatically designated if the population is at least 50,000 and has an overall population density of at least 1,000 people per square mile based on the 2000 and 2010 census. Appendix B of GP-0-24-001 also states that under Criterion 3, automatically designated areas are extended to town, village, or city boundaries, but only for town, village or city implementation of minimum control measure 4 construction site stormwater runoff control and minimum control measure 5 post-construction stormwater management in development and redevelopment. This criterion designates all Town MS4s located outside of the automatically designated area as regulated, but only for the implementation of these two minimum control measures. The Town's regulatory boundaries are defined as the storm sewersheds served by the Town MS4s. General Permit GP-0-24-001 Requirements This Phase II Permit requires the Town to develop a SWMP Plan that satisfies the requirements for each of six required program components, known as Minimum Control Measures (MCMs). These six MCMs listed in the Phase II Permit are as follows: 1. Public Education and Outreach Program 2. Public Involvement/Participation 3. Illicit Discharge Detection and Elimination 4. Construction Site Stormwater Runoff Control 5. Post-Construction Stormwater Management 6. Pollution Prevention and Good Housekeeping The Town MS4s located within the automatically designated area are subject to all six MCMs. The Town MS4s outside of the automatically designated area are only subject to MCMs 4 and 5. Staffing The Town Engineer serves as the Stormwater Program Coordinator to oversee the development, implementation and enforcement of the Stormwater Management Program; coordinate all elements of the program to ensure compliance with GP-0-24-001; and develop and submit the Annual Report. The current Stormwater Program Coordinator is: 3 Michael Collins, P.E. Town Engineer michael.collins(a)-town.southold.ny.us Office of the Engineer 53095 Main Road Southold, New York 11971 (631) 765-1560 A Staffing Plan can be found in Appendix B identifying the titles responsible for implementing the elements of this SWMP Plan. SWMP Plan Availability This SWMP Plan, including all Appendices, can be accessed by Town staff and the public from the Engineering Department section of the Town website under the "Stormwater Management Program" webpage. The link to this webpage is https://www.southoIdtownny.gov/567/Stormwater-Management-Program. Comprehensive System Mapping A SPDES Sewersheds map meeting all of the comprehensive system mapping requirements of GP-0-24-001 can be accessed by Town staff and the public on the Southold Town website via the "Maps and Trails" button. The link to this webpage is httos://www.southoldtownny.gov/401/Maips-and-Trails. Legal Authority As a continuing permittee, adequate legal authority is maintained in accordance with Part IV.E.2 through Chapter 234 Stormwater Management and Erosion & Sediment Control and Chapter 235 Illicit Discharges, Activities and Connections to Municipal Separate Storm Sewer System of the Town Code. These local laws and a certification from the Town Attorney that these laws are equivalent to the NYSDEC model local laws is included in Appendix C. Enforcement Response Plan A written Notice of Violation as per §234-8 Section 3A and a Stop Work Order as per §234-8 Section 3B will be issued for all violations of Chapter 234. The Stop Work Order will remain in place until the violation has been corrected to the satisfaction of the Town Engineer. Penalties will be assessed in accordance with §234-8 Section 3D. A written Notice of Violation as per §235-12A will be issued for all illicit connections or discharges to the Town's MS4. The Notice of Violation will compel the immediate cessation of any illicit discharge and the immediate removal of any illicit connection, as well as any remediation activities deemed necessary by the Town Engineer. Penalties will be assessed in accordance with §235-12B. 4 Enforcement Tracking Instances of non-compliance with Chapters 234 & 235 will be documented in this SWMP Plan under Appendix D. The enforcement case documentation will include, at a minimum, the following: i. The name of the owner/operator of the facility or site of the violation; ii. The location of the stormwater source; iii. A description of the violation; iv. A schedule for returning to compliance; V. A description of the enforcement response used, including escalated responses if repeat violations occur or violations are not resolved in a timely manner; vi. All accompanying documentation of the enforcement response; vii. Any referrals to different departments or agencies; and viii. The date the violation was resolved Recordkeeping, Reporting and Stormwater Management Program Evaluation The Town will keep all records required by GP-0-24-001 for a period of five (5) years after they are generated. All records will be incorporated into the appropriate sections of the SWMP Plan. All reports required by GP-0-24-001 will be submitted to the NYSDEC electronically. The Annual Report will be submitted to the NYSDEC by April 1st of each reporting period, which runs from January 3rd of the year prior to the submission of the Annual Report to January 2nd of the year in which the Annual Report is submitted. Twice a year, the Town will submit Interim Progress Certifications to NYSDEC verifying that the activities included in GP-0-24-001 have been completed by the dates specified in the permit using a form provided by NYSDEC. An Interim Progress Certification will be submitted: i. For the period of January 3rd through June 30t" of the same year by October 1 St of the same year; and ii. For the period of July 1st through January 2nd of the following year by April 1st of the following year in conjunction with the Annual Report. All reports will be signed and certified in accordance with Part X.J. of GP-0-24-001. Copies of the reports submitted to NYSDEC will be incorporated into Appendix E of the SWMP Plan. Once every five (5) years, the Town will evaluate the Stormwater Management Program for compliance with the terms and conditions of GP-0-24-001, including the effectiveness or deficiencies of components within the SWMP Plan, and the status of achieving the requirements outlined in GP-0-24-001. 5 Stormwater Management Program Plan MCM 1 : Public Education and Outreach Program The Town will develop and implement an education and outreach program to increase public awareness of pollutant generating activities and behaviors. This MCM is designed to inform the public about the impacts of stormwater on water quality, the general sources of stormwater pollutants, and the steps the general public can take to reduce pollutants in stormwater runoff. Illicit Discharges Education Information related to the prevention of illicit discharges has been made available to municipal employees, businesses and the public through publication on the Town website. This information can be accessed from the Engineering Department section under the Stormwater Management Program on the webpage titled "Illicit Discharges". The link to this webpage is https://www.southoldtownny.gov/2216/Illicit-Discharges. The residents of the Town will be notified and reminded of the availability of this information annually as part of the Public Notice announcing the special informational meeting discussed in the Town SWMP Plan under MCM2. Impaired Waters Education Information related to the legal and programmatic efforts that the Town is making to address discharges to impaired waterbodies has been made available on the Town website. This information can be accessed from the Engineering Department section under the Stormwater Management Program on the webpage titled "Impaired Waters". The link to this webpage is https://www.southoldtownny.gov/2217/Impaired-Waters. The residents of the Town will be notified and reminded of the availability of this information annually as part of the Public Notice announcing the special informational meeting discussed in the Town SWMP Plan under MCM2. 6 Stormwater Management Program Plan MCM 2: Public Involvement/Participation The Town will provide opportunities to involve the public in the development, review, and implementation of the SWMP. Public Involvement/Participation As the Stormwater Program Coordinator, the Town Engineer serves as the local point of contact for public concerns regarding the Town's SWMP and compliance with GP-0-24-001: Michael Collins, P.E. Town Engineer michael.collins(a)town.southold.ny.us Office of the Engineer 53095 Main Road Southold, New York 11971 (631) 765-1560 Annually, at a special informational meeting to be held between January 15th and February 15th (inclusive), the public will be provided with an opportunity to comment on and ask questions about the Town SWMP. This meeting will also provide the public an opportunity to comment on and ask questions about the draft Annual Report. Public Notice and Input Requirements A Public Notice announcing the special informational meeting will be published in the local paper at least 72 hours prior to the meeting date. This notice will also contain links to the webpage where the Town SWMP and the draft Annual Report can be viewed or downloaded so that the public has the opportunity to review the documents, ask questions and provide comments prior to the special informational meeting. The draft Annual Report will be posted on the Town website at least one week prior to the special informational meeting. The posting will include information on how to submit comments or questions about the draft Annual Report prior to its submission to NYSDEC. All records pertaining to the implementation of this MCM are contained in Appendix F. 7 Stormwater Management Program Plan MCM 3: Illicit Discharge Detection and Elimination The Town is required to develop, implement and enforce a program which systematically detects, tracks down and eliminates illicit discharges to the MS4. This MCM is designed to manage the MS4 so it is not conveying pollutants associated with flows other than those directly attributable to stormwater runoff. Illicit Discharge Detection As the Stormwater Program Coordinator, the Town Engineer will receive all complaints related to illicit discharges. Within thirty (30) days of an illicit discharge, the Town will document each report of an illicit discharge in the SWMP Plan with the following information: i. Date of the report; ii. Location of the illicit discharge; iii. Nature of the illicit discharge; iv. Follow up actions taken or needed (including response times); and V. Inspection outcomes and any enforcement taken. The monitoring locations used to detect illicit discharges are identified in the Monitoring Locations Inventory included in Appendix G. All aspects associated with the detection, sampling, track down and elimination of illicit discharges to the Town's MS4 systems will be conducted by the Town Engineer. Monitoring locations will be inspected during dry weather at least once every five (5) years following the most recent inspection according to the following procedures: i. Monitoring location inspections, including any sampling results, will be documented using the Monitoring Locations Inspection and Sampling Field Sheet found in Appendix D of GP-0-24-001; ii. If a physical indicator not related to flow, potentially indicative of an intermittent or transitory discharge, is identified during an initial inspection, the monitoring location will be re-inspected within thirty (30) days of the initial inspection utilizing techniques described in Chapter 12.6 of the Center for Watershed Protection Illicit Discharge Detection and Elimination: A Guidance Manual for Program Development and Technical Assistance, October 2004 (CWP 2004). A copy of CWP 2004 is included in Appendix G. If the same physical indicators persist, the Town will initiate illicit discharge track down procedures; 8 iii. Monitoring locations which have inspections resulting in a suspect or obvious illicit discharge characterization and for which the source of the illicit discharge is not clear or discernable will be sampled. The sampling requirement is based on the number and severity of physical indicators present in the flow to better inform track down procedures; iv. Sampling will be completed with field test kits or field instrumentation that are sufficiently sensitive to detect the parameter below the sampling action level used and are not subject to 40 CFR Part 136 requirements for approved methods and certified laboratories. Sampling and analytical procedures will follow Chapter 12 of the CWP 2004; V. The Town will initiate track down procedures: a. Within two (2) hours of discovery of an obvious illicit discharge of sanitary wastewater that affects bathing areas during bathing season, shell fishing areas or public water intakes. The Town will also report the illicit discharge orally to the Regional Water Engineer and the Suffolk County Department of Health Services; b. Within twenty-four (24) hours of discovery of an obvious illicit discharge at a flowing monitoring location; and c. Within five (5) days of discovery of a suspect illicit discharge vi. Track down procedures will follow Chapter 13 of the CWP 2004; vii. The Town will eliminate illicit discharges: a. Within twenty-four (24) hours of identification of an illicit discharge that has a reasonable likelihood of adversely affecting human health or the environment; b. Within five (5) days of identification of an illicit discharge that does not have a reasonable likelihood of adversely affecting human health or the environment; and c. Where elimination of an illicit discharge is not possible within the specified timeframes above, the Town will notify the Regional Water Engineer. viii. Enforcement actions will be conducted in accordance with the Enforcement Response Plan. All records pertaining to the implementation of this MCM are contained in Appendix G. 9 Stormwater Management Program Plan MCM 4: Construction Site Stormwater Runoff Control The Town is required to develop, implement and enforce a program to ensure construction sites are effectively controlled in conformance with the NYSDEC SPDES General Permit for Stormwater Discharges from Construction Activity, Permit No. GP-0-25-001, a copy of which is included in Appendix H. This MCM is designed to prevent pollutants from construction related activities, as well as promote the proper planning and installation of post-construction Stormwater Management Practices (SMPs). Public Reporting of Construction Site Complaints As the Stormwater Program Coordinator, the Town Engineer will receive all complaints related to stormwater construction activity. Construction Oversight Program The construction site stormwater runoff control program must address stormwater runoff to the MS4 from sites with construction activities that: i. Result in a total land disturbance of greater than or equal to one acre; or ii. Disturb less than one acre if part of a larger common plan of development or sale Construction sites meeting one of the conditions noted above that discharge to Waters of the State through a Town MS4 will be controlled under the Town's MS4 program and will be required to submit a Stormwater Pollution Prevention Plan (SWPPP) to the Office of the Engineer for review and approval. Construction sites within the Town that discharge to Waters of the State either directly or through a MS4 not owned or operated by the Town are subject to control directly by the NYSDEC. Owners/operators of these sites will be provided with a letter from the Town to provide to NYSDEC stating that the Town will not be taking jurisdiction over the site. SWPPPs will be reviewed by the Town Engineer, who, as a licensed Professional Engineer, meets the definition of a qualified professional. Therefore, the Town Engineer is both qualified to review all aspects of the SWPPP and is exempt from the training requirements for SWPPP reviewers. Each SWPPP with be reviewed for conformance with GP-0-25-001 as follows: i. Erosion and sediment controls will be reviewed for conformance with the NYS Standards and Specifications for Erosion and Sediment Control (Blue Book), November, 2016 version, or equivalent. A copy of the Blue Book is included in Appendix H.; 10 ii. Post-construction SMPs will be reviewed for conformance with the New York State Stormwater Management Design Manual, dated July 31, 2024 (NYS SWMDM 2024), a copy of which is located in Appendix H, including; a. All post-construction SMPs will meet the sizing criteria contained in the NYS SWMDM 2024 and GP-0-25-001. b. Deviations from the performance criteria of the NYS SWMDM 2024 will demonstrate that they are equivalent. c. The SWPPP will include an Operation & Maintenance Plan that includes inspection and maintenance schedules and actions to ensure continuous and effective operation of each post-construction SMP. The SWPPP will identify the entity that will be responsible for the long-term operation and maintenance of each practice. iii. Upon approval, the Town will notify construction site owner/operators that their SWPPP has been accepted using the MS4 SWPPP Acceptance Form, which will be signed by the Town in accordance with Part X.J of GP-0-24-001. Prior to commencement of construction activities, a pre-construction meeting will be held attended by the owner/operator listed on the Notice of Intent, the Town Engineer, and the contractor(s) responsible for implementing the SWPPP for the construction activity. This meeting will serve to: i. Confirm the approved project has received, or will receive, coverage under GP-0- 25-001 or an individual SPDES permit; ii. Verify that contractors and subcontractors selected by the owner/operator of the construction activity have identified at least one individual that has received four (4) hours of NYSDEC endorsed training in proper erosion and sediment control principles from a Soil & Water Conservation District or other endorsed entity; and iii. Review the construction oversight program and expectations for compliance. Construction site inspections will be conducted by the Town Engineer, who, as a licensed Professional Engineer, meets the definition of a qualified professional. Therefore, the Town Engineer is both qualified to conduct construction site inspections and is exempt from the training requirements for site inspectors. All sites with construction activity identified in the Town's inventory of permitted sites will be inspected at least annually during a period of active construction. Construction sites with deficiencies that require attention will be inspected more frequently to confirm that corrective actions are completed in accordance with timeframes established by GP-0-25-001 and the Town's ERP. All inspections will be documented using the Construction Site Inspection Form contained in Appendix D to GP-0- 24-001 Prior to construction site close-out, the Town Engineer will conduct a final construction site inspection and document it using the Construction Site Inspection Form contained in 11 Appendix D to GP-0-24-001. The Town will then sign the completed Notice of Termination in accordance with Part X.J of GP-0-24-001. Compliance with the Construction Oversight Program is expected of all construction site owners and operators. If necessary, enforcement actions will be conducted in accordance with the Enforcement Response Plan. Construction Site Inventory & Inspection Tracking The Town has no construction sites subject to Town control within its municipal boundaries. Construction Site Prioritization The Town has no construction sites to prioritize. 12 Stormwater Management Program Plan MCM 5: Post-Construction Stormwater Management The Town is required to develop, implement and enforce a program to ensure proper operation and maintenance of post-construction SMPs for new or redeveloped sites. This MCM is designed to promote the long-term performance of post-construction SMPs in removing pollutants from stormwater runoff. Applicable Post-Construction SMPs The post-construction SMP program must address stormwater runoff to the MS4 from publicly owned/operated and privately owned/operated post-construction SMPs that meet the following: i. Post-construction SMPs that have been installed as part of any GP-0-25-001 covered construction site or individual SPDES permit (since March 10, 2003); and ii. All new post-construction SMPs constructed as part of the construction site stormwater runoff control program. Post-Construction SMP Inventory & Inspection Tracking The Town has no post-construction SMPs in its inventory. SWPPP Review Post-construction SMP SWPPP review procedures are covered in the description of the Construction Oversight Program contained in the SWMP Plan section for MCM 4: Construction Site Stormwater Runoff Control. Post-Construction SMP Inspection & Maintenance Program The Town has no post-construction SMPs in its inventory. Upon the addition of any SMP to the Town's inventory, this section will be updated to reflect the inspection and maintenance requirements associated with each SMP. 13 Stormwater Management Program Plan MCM 6: Pollution Prevention/Good Housekeeping The Town is required to develop and implement a pollution prevention and good housekeeping program for municipal facilities and municipal operations to minimize pollutant discharges. This MCM is designed to ensure that the Town's own activities do not contribute pollutants to surface waters of the State. Municipal Facilities There are no municipal facilities within the Town's regulated boundaries. Municipal Operations and Maintenance Catch Basin Inspection and Maintenance i. All catch basins will be inspected by the Town Engineer on an annual basis, documenting: a. Date of inspection; b. Approximate level of trash, sediment, and/or debris at time of inspection (no trash, sediment, and/or debris, <50% of the depth of the sump, >50% of the depth of the sump); c. Depth of structure; d. Depth of sump; and e. Date of clean out, if applicable. ii. Based on the catch basin inspection results, catch basins will be cleaned within the following timeframes: a. Within six (6) months of inspection, if the catch basin had trash, sediment, and/or debris exceeding 50% of the depth of the sump; b. Within one (1) year of inspection, if the catch basin had trash, sediment, and/or debris less than 50% of the depth of the sump. iii. Catch basins containing no trash, sediment and/or debris or that have a sump depth of less than or equal to two (2) feet will not be cleaned; iv. Water and materials removed from catch basins will be properly disposed of at a Town recharge basin so that they cannot reenter waters of the State; 14 V. If there are signs/evidence of illicit discharges the Town Engineer will investigate in accordance with the procedures for MCM3. Road & Right of Way Maintenance i. The Town of Southold operates mechanical street sweepers to remove accumulated debris from the road surfaces within the Town Highway network. Annually, from April 1 through October 31, all roads will be swept. Each road is swept in each direction during this period, with the street sweeper completing a minimum of two passes in each direction. The material collected by the street sweeper is transported to the Highway Department yard where it is stockpiled. The stockpiled material is then mechanically screened and reused for suitable and approved purposes; ii. Within six (6) months of MS4 outfall inspection, the Town will initiate actions to repair all MS4 outfall protection and/or bank stability problems identified during the inspection. Repairs will be completed in accordance with the Blue Book; iii. Roads will only be paved, marked or sealed in dry conditions; iv. No herbicides or pesticides are used to maintain Town right of ways; V. Routine snow disposal activities will comply with the Division of Water Technical and Operation Guidance Series 5.1.11, Snow Disposal, a copy of which is included in Appendix I. All records pertaining to the implementation of this MCM are contained in Appendix I. 15 APPENDIX A ISTNEw Department of RK ATE Environmental Conservation FINAL PERMIT for NEW YORK STATE DEPARTMENT OF ENVIRONMENTAL CONSERVATION SPDES GENERAL PERMIT for STORMWATER DISCHARGES from MUNICIPAL SEPARATE STORM SEWER SYSTEMS (MS4s) Permit No. GP-0-24-001 Issued Pursuant to Article 17, Titles 7, S and Article 70 of the Environmental Conservation Law Issuance Date: December 13, 2023 Effective Date: January 3, 2024 Expiration Date: January 2, 2029 Scott Sheeley Chief Permit Administrator Authorized Signature Date Address: NYS DEC Division of Environmental Permits 625 Broadway, 4th Floor Albany, NY 12233 PART I. PERMIT COVERAGE AND LIMITATIONS......................................................................................................1 A. PERMIT AUTHORIZATION.......................................................................................................................................1 B. EXEMPTION AND LIMITATIONS ON COVERAGE............................................................................................................2 PART II.OBTAINING PERMIT COVERAGE................................................................................................................2 PART III.SPECIAL CONDITIONS...............................................................................................................................4 A. DISCHARGE COMPLIANCE WITH WATER QUALITY STANDARDS.......................................................................................4 B. WATER QUALITY IMPROVEMENT STRATEGIES FOR IMPAIRED WATERS............................................................................5 1. List of Impaired Waters(Appendix C).........................................................................................................5 2. Watershed Improvement Strategy Requirements for TMDL Implementation (Part IX.).............................6 3. Impaired waters with an approved TMDL and listed in Appendix C...........................................................7 PART IV.STORMWATER MANAGEMENT PROGRAM(SWMP)REQUIREMENTS......................................................7 A. ADMINISTRATIVE..................................................................................................................................................7 1. Alternative Implementation Options..........................................................................................................7 2. Staffing plan/Organizational chart.............................................................................................................8 B. SWMP PLAN......................................................................................................................................................8 1. Stormwater Program Coordinator..............................................................................................................8 2.Availability of SWMP Plan................................................................................................................................9 3. Timeframes for SWMP Plan Development or Updates....................................................................................9 C. MINIMUM CONTROL MEASURES(MCMS)...............................................................................................................9 D. MAPPING.........................................................................................................................................................10 E. LEGAL AUTHORITY..............................................................................................................................................12 F. ENFORCEMENT MEASURES&TRACKING.................................................................................................................14 1. Enforcement Response Plan.....................................................................................................................14 2. Enforcement Tracking...............................................................................................................................15 PART V.RECORDKEEPING,REPORTING,AND SWMP EVALUATION......................................................................15 A. RECORDKEEPING................................................................................................................................................15 B. REPORTING.......................................................................................................................................................15 1. Report Submittal.......................................................................................................................................15 2. Annual Reports.........................................................................................................................................16 3. Interim Progress Certifications.................................................................................................................16 4. Shared Annual Reporting..........................................................................................................................17 5. Certification..............................................................................................................................................17 6.Annual Report and Interim Progress Certification Content............................................................................17 C. SWMP EVALUATION..........................................................................................................................................17 PART VI.MINIMUM CONTROL MEASURES(MCMS)FOR TRADITIONAL LAND USE CONTROL MS4 OPERATORS...19 A. MCM 1—PUBLIC EDUCATION AND OUTREACH PROGRAM.........................................................................................19 1. Development.............................................................................................................................................19 2. Implementation and Frequency................................................................................................................20 B. MCM 2-PUBLIC INVOLVEMENT/PARTICIPATION.....................................................................................................21 1. Public Involvement/Participation.............................................................................................................21 2. Public Notice and Input Requirements......................................................................................................22 C. MCM 3-ILLICIT DISCHARGE DETECTION AND ELIMINATION.......................................................................................23 1. Illicit Discharge Detection.........................................................................................................................23 2. Illicit Discharge Track Down Program.......................................................................................................27 3. Illicit Discharge Elimination Program.......................................................................................................28 D. MCM 4-CONSTRUCTION SITE STORMWATER RUNOFF CONTROL...............................................................................29 1. Applicable Construction Activities/Projects/Sites.....................................................................................29 2. Public Reporting of Construction Site Complaints..........................................................................................30 I Construction Oversight Program..............................................................................................................J0 4. Construction Site Inventory&Inspection Tracking...................................................................................31 5. Construction Site Prioritization.................................................................................................................32 6 IN/PPP Review..........................................................................................................................................J3 7 Meeting.----------------------------------------J4 /l Construction Site Inspections....................................................................................................................34 9. Construction Site Close-out --------------------------------------'JJ E. yWCyW5— InOomwwna MANAGEMENT.................................................................................35 1 ApplicoblePoxt-{onstructionIMPs-----------------------------------.35 l Post-Construction JMP Inventory&Inspection Tracking.........................................................................36 IIN/PPP Review..........................................................................................................................................J7 4[ SMPInspection& MointenonceProgrom----------------------.37 F. yWCyW6-POLLUTION PREVENTION AND GOOD HOUSEKEEPING.................................................................................39 1 Best Management Practices(BMos)for Municipal Facilities& Operations.............................................J9 lMunicipal Facilities...................................................................................................................................4J 3. Municipal Operations&Maintenance.....................................................................................................51 PART Vi|.MINIMUM CONTROL MEASURES(MCM8FOR TRADITIONAL NON-LAND USE CONTROL&NON- TRADITIONAL MS4 OPERATORS...........................................................................................................................S6 A. yWCyW1-PUBLIC EDUCATION AND OUTREACH PROGRAM.........................................................................................56 1 DevelopmenL----------------------------------------------56 I Implementation and Frequency................................................................................................................58 B. yWCyWZ PUBLIC INVOLVEMENT/PARTICIPATION.....................................................................................................58 1 Public Involvement/Participation.............................................................................................................J8 l Public Notice and Input Requirements.---------------------------------'59 C. yWCyW3 ILuorDIsc*AxoE DETECTION AND ELIMINATION.......................................................................................6O 1 Illicit Discharge Detection.........................................................................................................................60 I Illicit Discharge Track Down Program.......................................................................................................64 I Illicit Discharge Elimination Program.......................................................................................................65 D. yWCyW4'CONSTRUCTION SncInOxMwwTEx RUNOFF CONTROL...............................................................................66 1 Applicable Construction A ----------------------------.67 I Public Reporting of Construction Site Complaints..........................................................................................67 3. Construction Oversight Program..............................................................................................................67 4. Construction Site Inventory&Inspection Tracking...................................................................................68 5. Construction Site Prioritization.................................................................................................................69 6 IN/PPP Review..........................................................................................................................................70 7 Meeting.----------------------------------------72 8. Construction Site Inspections....................................................................................................................71 9. Construction Site Close-out --------------------------------------'7Z E. yWCyW5— InnxMwmTEn MANAGEMENT.................................................................................72 1 Applicable Post-Construction SMPs..........................................................................................................73 I Post-Construction IMP Inventory&Inspection Tracking.........................................................................73 IIN/PPP Review..........................................................................................................................................74 4. IMP Inspection&Maintenance Program...................................................................74 F. yWCyW6-POLLUTION PREVENTION AND GOOD HOUSEKEEPING.................................................................................75 1 Best Management Practices(BMPd for Municipal Facilities& Operations.............................................76 lMunicipal Facilities...................................................................................................................................80 I Municipal Operations& Maintenance.....................................................................................................88 PART V1U. ENHANCED REQUIREMENTS FOR IMPAIRED WATERS.------------------------.93 A. POLLUTANT SPECIFIC ByWPs FOR PHOSPHORUS........................................................................................................93 1 Mapping...................................................................................................................................................9J I Public Education and Outreach................................................................................................................9J |i 3. Public Involvement/Participation.............................................................................................................94 4. Illicit Discharge Detection and Elimination...............................................................................................94 5. Construction Site Stormwater Runoff Control..........................................................................................94 6. Post-Construction Stormwater Management...........................................................................................94 7. Pollution Prevention and Good Housekeeping.........................................................................................94 8. Planned Upgrades to Municipal Facilities in Sewersheds to Impaired Waters.........................................95 B. POLLUTANT SPECIFIC BM PS FORSILT/SEDIMENT.....................................................................................................95 1. Mapping...................................................................................................................................................95 2. Public Education and Outreach ................................................................................................................96 3. Public Involvement/Participation.............................................................................................................96 4. Illicit Discharge Detection and Elimination...............................................................................................96 5. Construction Site Stormwater Runoff Control..........................................................................................96 6. Post-Construction Stormwater Management...........................................................................................96 7. Pollution Prevention and Good Housekeeping.........................................................................................96 8. Planned Upgrades to Municipal Facilities in Sewersheds to Impaired Waters.........................................97 C. POLLUTANT SPECIFIC BMPS FOR PATHOGENS..........................................................................................................98 1. Mapping...................................................................................................................................................98 2. Public Education and Outreach ................................................................................................................98 3. Public Involvement/Participation.............................................................................................................98 4. Illicit Discharge Detection and Elimination...............................................................................................99 5. Construction Site Stormwater Runoff Control..........................................................................................99 6. Post-Construction Stormwater Management...........................................................................................99 7. Pollution Prevention and Good Housekeeping.........................................................................................99 8. Planned Upgrades to Municipal Facilities in Sewersheds to Impaired Waters.......................................100 D. POLLUTANT SPECIFIC BMPS FOR NITROGEN..........................................................................................................ZOO 1. Mapping.................................................................................................................................................100 2. Public Education and Outreach ..............................................................................................................101 4. Illicit Discharge Detection and Elimination.............................................................................................101 5. Construction Site Stormwater Runoff Control........................................................................................101 6. Post-Construction Stormwater Management.........................................................................................101 7. Pollution Prevention and Good Housekeeping.......................................................................................102 8. Planned Upgrades to Municipal Facilities in Sewersheds to Impaired Waters.......................................102 E. POLLUTANT SPECIFIC BMPS FOR FLOATABLES........................................................................................................102 1. Mapping.................................................................................................................................................102 2. Public Education and Outreach ..............................................................................................................103 3. Public Involvement/Participation...........................................................................................................103 4. Illicit Discharge Detection and Elimination.............................................................................................103 5. Construction Site Stormwater Runoff Control........................................................................................103 6. Post-Construction Stormwater Management.........................................................................................103 7. Pollution Prevention and Good Housekeeping.......................................................................................103 8. Planned Upgrades to Municipal Facilities in Sewersheds to Impaired Waters.......................................104 PART IX.WATERSHED IMPROVEMENT STRATEGY REQUIREMENTS FOR TMDL IMPLEMENTATION....................105 A. NYC EAST OF HUDSON PHOSPHORUS IMPAIRED WATERSHED MS4S.........................................................................105 1. Mapping.................................................................................................................................................106 2. Public Education and Outreach on Stormwater Impacts........................................................................106 3. Public Involvement/Participation...........................................................................................................106 4. Illicit Discharge Detection and Elimination.............................................................................................107 5. Construction Site Stormwater Runoff Control........................................................................................107 6. Post-Construction Stormwater Management.........................................................................................108 7. Pollution Prevention/Good Housekeeping..............................................................................................109 8. Planned Upgrades to Municipal Facilities in Watersheds to Impaired Waters......................................110 B. OTHER PHOSPHORUS IMPAIRED WATERSHED MS4S...............................................................................................111 III 1. Mapping.................................................................................................................................................111 2. Public Education and Outreach on Stormwater Impacts........................................................................112 3. Public Involvement/Participation...........................................................................................................112 4. Illicit Discharge Detection and Elimination.............................................................................................112 5. Construction Site Stormwater Runoff Control........................................................................................113 6. Post Construction Stormwater Management.........................................................................................113 7. Pollution Prevention/Good Housekeeping..............................................................................................115 8. Planned Upgrades to Municipal Facilities in Watersheds to Impaired Waters......................................116 C. PATHOGEN IMPAIRED WATERSHEDS MS4S...........................................................................................................116 D. NITROGEN IMPAIRED WATERSHED MS4S.............................................................................................................116 1. Mapping.................................................................................................................................................117 2. Public Education and Outreach on Stormwater Impacts........................................................................117 3. Public Involvement/Participation...........................................................................................................118 4. Illicit Discharge Detection and Elimination.............................................................................................118 5. Construction Site Stormwater Runoff Control........................................................................................118 6. Post-Construction Stormwater Management.........................................................................................118 7. Pollution Prevention/Good Housekeeping..............................................................................................118 8. Planned Upgrades to Municipal Facilities in Watersheds to Impaired Waters......................................119 PART X.STANDARD PERMIT CONDITIONS.........................................................................................................120 A. DUTY TO COMPLY.............................................................................................................................................120 B. NEED TO HALT OR REDUCE ACTIVITY IS NOT A DEFENSE...........................................................................................120 C. PENALTIES......................................................................................................................................................120 D. FALSE STATEMENTS..........................................................................................................................................120 E. REOPENER CLAUSE...........................................................................................................................................120 F. DUTY TO MITIGATE...........................................................................................................................................121 G. REQUIRING ANOTHER GENERAL PERMIT OR INDIVIDUALSPDES PERMIT....................................................................121 H. DUTY TO PROVIDE INFORMATION........................................................................................................................122 i. EXTENSION......................................................................................................................................................122 J. SIGNATORIES AND CERTIFICATION........................................................................................................................123 K. INSPECTION&ENTRY........................................................................................................................................124 L. CONFIDENTIALITY OF INFORMATION.....................................................................................................................125 M. OTHER PERMITS MAY BE REQUIRED....................................................................................................................125 N. PROPERTY RIGHTS............................................................................................................................................125 O. COMPLIANCE WITH INTERSTATE STANDARDS..........................................................................................................125 P. OIL&HAZARDOUS SUBSTANCE LIABILITY..............................................................................................................126 Q. SEVERABILITY...................................................................................................................................................126 APPENDIX A.ACRONYMS AND DEFINITIONS.....................................................................................................127 ACRONYMLIST..........................................................................................................................................................127 DEFINITIONS.............................................................................................................................................................129 APPENDIX B.DESIGNATION CRITERIA FOR IDENTIFYING REGULATED MUNICIPAL SEPARATESTORM SEWER SYSTEMS(MS4S),JANUARY 2010,REVISED JANUARY 2023...............................................................................136 APPENDIX C. LIST OF IMPAIRED WATERS...........................................................................................................137 APPENDIX D.FORMS.........................................................................................................................................147 WORKSCITED....................................................................................................................................................162 iv Part I NOTE All italicized words within this State Pollutant Discharge Elimination System (SPDES) general permit are defined in Appendix A. rare i. Permit Goverage and Limitations A. Permit Authorization This SPDES general permit authorizes the discharge of stormwaterfrom small MS4s. 1 . An MS4 Operator is eligible for coverage under this SPDES general permit if the MS4 is automatically or additionally designated (Appendix 8). Only portions of the MS4 which are located within the automatically or additionally designated areas are subject to, and authorized to discharge by, the requirements of this SPDES general permit (Part IV.C.). 2. This SPDES general permit contains terms and conditions specific for each of the following types of MS4 Operators that are authorized to discharge under this SPDES general permit, in accordance with Part I.A.1: a. Traditional Land Use Control MS4 Operators,- b. Traditional Non-land Use Control MS4 Operators, and c. Non-traditional MS4 Operators. The minimum control measures (MCMs) for traditional land use MS4 Operators are listed in Part VI. The MCMs for traditional non-land use control MS4 Operators and non-traditional MS4 Operators are listed in Part VI I. Part I 11.13, Part VIII, and Part IX. list additional requirements for all MS4 Operators' MS4s discharging to impaired waters. 3. Non-stormwater discharges through outfalls listed in Part 6 of the Official Compilation of Codes, Rules and Regulations of the State of New York (NYCRR) 750-1.2(a)(29)(vi) and 40 CFR 122.34(b)(3)(ii), are authorized by this SPDES general permit provided they do not violate Environmental Conservation Law (ECL) Section 17-0501 . If the Department or MS4 Operator determines that one or more of the discharges are in violation of ECL Section 17-0501, the identified discharges are illicit and the MS4 Operator must eliminate such discharges by following the illicit discharge MCM requirements found in Part VI.C. or Part VII.C, depending on the MS4 Operatortype. Discharges from firefighting activities are authorized only when the firefighting activities are emergencies/unplanned. 1 Part I.B. B. Exemption and Limitations on Coverage 1. The following discharges from MS4 Operators are exempt from the requirements of this SPDES general permit: a. Stormwater discharges associated with an industrial activity provided the discharges are covered by the SPDES Multi-Sector General Permit for Stormwater Discharges Associated with Industrial Activity, GP-0-23-001 (MSGP); and b. Individual SPDES permitted stormwater discharges provided the discharges are in compliance with their individual SPDES permit limitations. 2. The following discharges from MS4 Operators are not authorized by this SPDES general permit: a. Stormwater discharges that may adversely affect an endangered or threatened species, or its designated critical habitat, unless the MS4 Operator has obtained a permit issued pursuant to 6 NYCRR Part 182 or the Department has issued a letter of non-jurisdiction. b. Stormwater discharges which adversely affect properties listed or eligible for listing in the National Register of Historic Places unless the covered entity is in compliance with requirements of the National Historic Preservation Act and has coordinated with the appropriate State Historic Preservation Office any activities necessary to avoid or minimize impacts. c. Stormwater discharges, the permitting of which is prohibited under 40 CFR 122.4 and 6 NYCRR 750-1 .3. d. The discharge of vehicle and equipment washwater from municipal facilities, including tank cleaning operations. 3. All documentation necessary to demonstrate discharge eligibility (Part I.B.1. and Part I.B.2.) must be documented in the Stormwater Management Program Plan (SWMP Plan) (Part IV.B.). Part II. Obtaining Permit Coverage A. MS4 Operators, meeting the eligibility requirements in Part I.A.1. of this SPDES general permit, must submit the notice of intent (NOI) electronically (eNOI) unless the MS4 Operator has obtained a waiver from the electronic submittal requirement (Part II.B.) in order to be authorized to discharge under this SPDES general permit. Access and directions for use, for electronic submission of the NOI, are located on the Department's website. MS4 Operators must submit the eNOI as indicated in Table 1 and in accordance with Part X.J. 2 Part II.A. Table 1. eN01 Submittal for Permit Coverage Type of permit Deadline to submit Effective Date of Form to file coverage complete eN01 Coverage (EDC) With the Department Newly designated 180 days' from The submission of MS4 Operator written notification the complete eNOI eNOI from the Department MS4 Operators Forty-five (45) days continuing coverage from the effective EDP eNOI from GP-0-15-003 date of the permit (EDP) MS4 Operators continuing coverage from GP-0-15-003 are eligible for continued coverage under this SPDES general permit (GP-0-24-001) on an interim basis for up to sixty (60) calendar days from the EDP. During this interim period, an MS4 Operator must comply with the requirements of GP-0-15-003. By submitting the complete eN01, the MS4 Operator certifies that the MS4 Operator has read and agrees to comply with the terms and conditions of this SPDES general permit including the provisions to update the SWMP Plan (Part IV.B.) in accordance with the timeframes set forth in this SPDES general permit. MS4 Operators must document the complete NOI in the SWMP Plan (Part IV.B.). As information in the completed NOI changes, within thirty (30) days, the MS4 Operators must update the information on the NOI and resubmit the completed NOI to the Department. The MS4 Operator must document information from the Department acknowledging previous coverage or designation in the SWMP Plan (Part IV.B.). Where there is a permit condition to develop, newly designated MS4 Operators must create that permit requirement. Where there is a permit condition to develop, MS4 Operators continuing coverage must continue to implement their current SWMP and update the SWMP to comply with the permit requirement. For newly designated MS4 Operators, timeframes for compliance begin on the effective date of coverage (EDC). B. Electronic Submission Waiver 1 . MS4 Operators must submit all NOls electronically unless the MS4 Operator has received a waiver from the Department based on one of the following conditions: a. If the MS4 Operator is physically located in a geographical area (i.e., zip code or census tract) that is identified as under-served for broadband internet In this SPDES general permit, days refer to calendar days. 3 Part H.B. access in the most recent report from the Federal Communications Commission; or b. If the MS4 Operator has limitations regarding available computer access or computer capability. 2. If an MS4 Operator wishes to obtain a waiver from submitting an NOI electronically, the MS4 Operator must submit a request using the Application for Electronic Submittal Waiver to the Department at the following address: NYS DEC Bureau of Water Compliance MS4 NOTICE OF INTENT WAIVER 625 Broadway, 4th Floor Albany, New York 12233-3505 3. A waiver may only be considered granted once the MS4 Operator receives written confirmation from the Department. 4. MS4 Operators must document the eNO1 waiver in the SWMP Plan (Part IV.B.), if applicable. C. MS4 Operators who submit a complete NOI are authorized to discharge stormwater under the terms and conditions of this SPDES general permit. 1. NOI Content The NOI shall include: a. Legal name and address of the MS4 Operator, b. Receiving waterbodies; and c. Municipal Separate Storm Sewer System (MS4) NPDES Permit-Related Information of 40 CFR Part 127 Appendix A. Part III. Speciai conditions A. Discharge Compliance with Water Quality Standards 1. The MS4 Operator must implement the required controls contained in Part III. through Part IX. of this SPDES general permit. The Department expects that compliance with the terms and conditions of this SPDES general permit will assure MS4 discharges meet applicable water quality standards. 2. It shall be a violation of the ECL for any discharge authorized by this SPDES general permit to either cause or contribute to a violation of water quality standards as contained in 6 NYCRR 700-705. 3. The MS4 Operator must take all necessary actions to ensure discharges comply with the terms and conditions of this SPDES general permit. If at any time an MS4 Operator becomes aware (e.g., through self-monitoring or by notification from the Department) that a discharge causes or contributes to the violation of an applicable water quality standard, the MS4 Operator must implement corrective 4 Part III.A. actions and the MS4 Operator must document these actions in the SWMP Plan (Part N.B.). 4. Compliance with this SPDES general permit does not preclude, limit, or eliminate any enforcement activity as provided by Federal and/or State law. Additionally, if violations of applicable water quality standards occur, then coverage under this SPDES general permit may be terminated by the Department in accordance with 6 NYCRR 750-1 .21(e), and the Department may require an application for an alternative SPDES general permit or an individual SPDES permit may be issued. B. Water Quality Improvement Strategies for Impaired Waters 1. List of Impaired Waters (Appendix C) Part VIII. requirements must be implemented in addition to the applicable requirements of the six (6) MCMs in Part VI. or Part VII, depending on the MS4 Operator type. For MS4 Operators whose MS4 outfalls and additionally designated area MS4 outfalls (ADA MS4 outfalls) discharge to waters impaired for phosphorus, silt/sediment, pathogens, nitrogen, or floatables (Appendix C), the MS4 Operator must develop and implement the pollutant specific best management practices (BMPs), listed in Part VIII, targeted towards the pollutant of concern (POC) causing the impairment. For MS4 Operators discharging to waters within a total maximum daily load (TMDL) watershed that does not specify a pollutant load reduction necessary for MS4s and listed in Appendix C, the MS4 Operator must implement the enhanced BMP requirements of Part VIII. for the applicable pollutant of concern of the TMDL. The enhanced BMP requirements in Part VIII. are written to address the POCs listed in Table 2. Table 2. Pollutant Specific BMPs for Impaired Waters listed in Appendix C POC Part VIII. Reference Phosphorus A Silt/Sediment B Pathogens C Nitrogen D Floatables E 5 Part III.B. 2. Watershed Improvement Strategy Requirements for TMDL Implementation (Part IX.) Part IX. requirements must be implemented in addition to the applicable requirements of the six (6) MCMs in Part VI. or Part VII, depending on the MS4 Operator type. a. MS4 Operators discharging to waters within the watersheds listed in Table 3 must implement additional BMPs and applicable retrofit plans as specified in Part IX. to achieve the pollutant load reductions specified in the referenced TMDL or respective implementation plan. Table 3. Approved TMDL Watersheds with MS4 Contribution TMDL POC Part IX. Reference Phase II Phosphorus TMDLs for Reservoirs in the NYC Watershed, June 2000 Total Maximum Daily Load (TMDL) for Phosphorus in Lake Phosphorus A Carmel, October 2016 Total Maximum Daily Load (TMDL) for Phosphorus in Palmer Lake, March 2015 Impaired Waters Restoration Plan for Greenwood Lake — Total Maximum Daily Load for Total Phosphorus, September 2005 Updated Phosphorus Total Maximum Daily Load for Phosphorus B Onondaga Lake, June 2012 Total Maximum Daily Load (TMDL) for Phosphorus in Lake Oscawana, September 2008 None Pathogen C TMDL for Nitrogen in the Peconic Estuary Program Study Area, Including Waterbodies Currently Impaired Due to Low Dissolved Oxygen: the Lower Peconic River and Tidal Nitrogen D Tributaries; Western Flanders Bay and Lower Sawmill Creek; and Meetinghouse Creek, Terry Creek and Tributaries, September 2007 b. Each MS4 Operator is responsible for a waste load reduction as specified in the applicable TMDL or TMDL implementation plan referenced in Part IX. MS4 Operators may form a Regional Stormwater Entity (RSE) to implement stormwater retrofits collectively where compliance with the pollutant reduction requirements would be achieved on a regional basis. The individual load reduction for each participating MS4 Operator is aggregated to create a RSE load reduction. The RSE then designs and installs retrofits where they are most feasible within the boundaries of the RSE. Each participating MS4 6 Part III.B. Operator of an RSE complies if the aggregated RSE pollutant load reduction is met. 3. Imnaired waters with an aaoroved TMDL and listed in AnDendix C Part VIII. and Part IX. requirements must be implemented in addition to the applicable requirements of the six (6) MCMs in Part VI. or Part VII, depending on the MS4 Operator type. An MS4 discharging to a waterbody listed in Appendix C must meet the requirements of Part VII I. for the POC(s) listed in Appendix C. An MS4 discharging to a waterbody listed in Table 3 must meet the requirements of Part IX. for the specific POC identified in the TMDL. Part IV. Stormwater Management Program (SWMP) Requirements MS4 Operators must develop, implement, and enforce a SWMP. The SWMP must be retained in written format, hardcopy or electronic. The written SWMP is referred to as the SWMP Plan (Part N.B.). The MS4 Operator must use the SWMP Plan (Part N.B.) to document developed, planned, and implemented elements of the SWMP. A. Administrative 1. Alternative Implementation Options a. MS4 Operators may utilize other entities or the resources of those entities to assist with any portion of the SWMP development, implementation, or enforcement. These entities may consist of other MS4 Operators, an RSE, a Coalition of MS4 Operators, other public entities (e.g., non-MS4 Operators), or a private third-party contractor. If the MS4 Operator is relying upon another entity for compliance with any portion of this SPDES general permit, there must be an agreement in place that: i. Is legally binding; ii. Is documented in writing; iii. Is signed and dated by all parties including a certification statement that explains that the MS4 Operator is responsible for compliance with this SPDES general permit; iv. Identifies the activities that the entity will be responsible for including the particular MCM, the location and type of work; v. Includes the name, address, and telephone number of the contact person representing the entity; vi. Is kept up-to-date and part of the SWMP Plan; and vii. Is retained by each party for the duration of the permit term. 7 Part N.A. b. In the SWMP Plan, the MS4 Operator must develop and maintain an inventory of entities assisting in permit implementation that includes the following information: i. Name of entity performing permit implementation; and ii. Permit requirement being implemented performed by entity. c. Irrespective of any agreements, each party remains legally responsible for obtaining its own permit coverage, for filing the NOI, and satisfying all requirements of this SPDES general permit for its own discharges. d. Within thirty (30) days signing, alternative implementation agreements (Part IV.A.1.) must be documented in the SWMP Plan (Part IV.B.). e. Annually review and update any alternative implementation agreements in the SWMP Plan, as necessary. 2. Staffing plan/Organizational chart Individual SWMP components may be developed, implemented, or enforced by different titles associated with the MS4 Operator, or other entities as described in Part IV.A.1 . Within six (6) months of the EDC, the MS4 Operator must develop a written staffing plan/organizational chart which includes job titles and other entities as identified in Part IV.A.1 , and the roles and responsibilities for each corresponding to the required elements of the SWMP. The staffing plan must describe how information will be communicated and coordinated among all those with identified responsibilities. All staffing plan/organization charts must be documented in the SWMP Plan (Part IV.B.). B. SWMP Plan The SWMP Plan must contain, at a minimum, all permit requirements implemented to meet the terms and conditions of this SPDES general permit, and documentation required by this SPDES general permit. The SWMP Plan may incorporate by reference any documents that meet the requirements of this SPDES general permit. If an MS4 Operator relies upon other documents to describe how the MS4 Operatorwill comply with the requirements of this SPDES general permit, the MS4 Operator must attach to the SWMP Plan a copy of these documents. The SWMP Plan must identify if any requirements from Part VI. through Part IX. do not require updates and include the rationale behind the determination. The SWMP Plan must identify if any requirements from Part VI. through Part IX. are not applicable and include the rationale behind the determination. 1. Stormwater program Coordinator On the NOI, the MS4 Operator must designate a Stormwater Program Coordinator who must be knowledgeable in the principles and practices of stormwater management, the requirements of this SPDES general permit, and the SWMP. The Stormwater Program Coordinator oversees the development, implementation, and enforcement of the SWMP, coordinates all elements of the 8 Part IV.B. SWMP to ensure compliance with this SPDES general permit; and develops and submits the Annual Report (Part V.13.2.). The name, title, and contact information of the Stormwater Program Coordinator must be documented in the SWMP Plan. 2. Availability of SWMP Plan a. Within six (6) months of the EDC, the MS4 Operator must make the current SWMP Plan, and documentation associated with the implementation of the SWMP Plan, available during normal business hours to the MS4 Operator's management and staff responsible for implementation as well as the Department and United States Environmental Protection Agency (USEPA) staff.2 The completion of this permit requirement must be documented in the SWMP Plan. b. Within six (6) months of the EDC, the MS4 Operator must make a copy of the current SWMP Plan available for public inspection during normal business hours at a location that is accessible to the public or on a public website. The location of the SWMP Plan must be kept current. The completion of this permit requirement must be documented in the SWMP Plan. 3. Timeframes for SWMP Plan Development or Update MS4 Operators must develop and implement their SWMP Plan in accordance with the timeframes set forth in this SPDES general permit. Annually, after the end of the Reporting Year and by April 1, the SWMP Plan must be updated to ensure the permit requirements are implemented. More frequent updates to the SWMP Plan are noted throughout this SPDES general permit in specific permit requirements. C. Minimum Control Measures (MCMs) The MCMs for traditional land use MS4 Operators are listed in Part VI. while those for traditional non-land use control MS4 Operators and non-traditional MS4 Operators are listed in Part VII. Parts 111.13, Part VIII, and Part IX. list additional requirements for all MS4 Operators discharging to impaired waters. MS4 Operators subject to Part VI. For MS4 Operators subject to Part VI. requirements, all MCMs must be implemented within the automatically designated area or an additionally designated area subject to Criterion 1 or 2 of the Additional Designation Criteria (Appendix B). For MS4 Operators subject to Part VI. requirements, MCM 4 and MCM 5 must also be implemented within an additionally designated area subject to Criterion 3 of the Additional Designation Criteria (Appendix B). �4S4 Operators subiect to Part VII. For MS4 Operators subject to Part VII. requirements, all MCMs must be implemented within the automatically designated area or an additionally designated area subject to Criterion 1 or 2 of the Additional Designation Criteria (Appendix B). 2 Part X.F. contains the duty forth e MS4 Operator to provide information. 9 Part N.C. MS4 Operators subject to Part VIII. Part VIII. requirements must be implemented in addition to the applicable requirements of the six (6) MCMs in Part VI. or Part VII, depending on the MS4 Operator type. For all MS4 Operators subject to Part VIII. requirements, all MCMs must be implemented within the automatically designated area. For MS4 Operators subject to Part VI. requirements and subject to Part VIII. requirements, MCM 4 and MCM 5 must also be implemented within an additionally designated area subject to Criterion 3 of the Additional Designation Criteria (Appendix B). MS4 Operators subject to Part IX. Part IX. requirements must be implemented in addition to the applicable requirements of the six (6) MCMs in Part VI. or Part VII, depending on the MS4 Operator type. For all MS4 Operators subject to Part IX. requirements, all MCMs must be implemented within the automatically designated area or an additionally designated area subject to Criterion 1 of the Additional Designation Criteria (Appendix B). D. Mapping The MS4 Operator must develop and maintain comprehensive system mapping to include the mapping components within the MS4 Operator's automatically designated area or an additionally designated area subject to Criterion 1 or 2 of the Additional Designation Criteria (Appendix B), unless otherwise specified. The comprehensive system mapping must be documented in the SWMP Plan. The comprehensive system mapping must be in a readily accessible format, with scale and detail appropriate to provide a clear understanding of the MS4, to serve as a planning tool to allow for prioritization of efforts and facilitate management decisions by the MS4 Operator. Annually, after Phase I (Part IV.D.2.a.) completion, the MS4 Operator must update the comprehensive system mapping including updates to prioritization information of monitoring locations (Part VI.C.1.d. or Part VII.C.1.d, depending on the MS4 Operatortype), construction sites (Part VI.D.5. or Part VII.D.5, depending on the MS4 Operatortype), and municipal facilities (Part VI.F.2.c.i. or Part VII.F.2.c.i, depending on the MS4 Operatortype). 1. Within six (6) months of the EDC, the comprehensive system mapping must include the following information: a. MS4 outfalls (as required for MS4 Operators continuing coverage from previous iterations of this SPDES general permit); b. Interconnections (as required for MS4 Operators continuing coverage from previous iterations of this SPDES general permit); c. Preliminary storm-sewershed boundaries (as required for MS4 Operators continuing coverage from previous iterations of this SPDES general permit); 10 Part IV.D. d. MS4 infrastructure (as required for MS4 Operators continuing coverage from previous iterations of this SPDES general permit that were subject to Part IX.A. or Part IX.D.), including: i. Conveyance system a) Type (closed pipe or open drainage); b) Conveyance description for closed pipes (material, shape, dimensions); c) Conveyance description for open drainage (channel/ditch lining material, shape, dimensions); and d) Direction of flow; ii. Culvert crossings (location and dimensions) iii. Stormwater structures a) Type (drop inlet, catch basin, or manhole); and b) Number of connections to catch basins, and manholes; e. Basemap information: i. Automatically3 and additionally designated areas (based on criterion 3 of Additional Designation Criteria in Appendix B);4 ii. Names and location of all surface waters of the State, including: a) Waterbody classification, b) Waterbody Inventory/Priority Waterbodies List (WI/PWL);6 i) Impairment status; and ii) POC, if applicable; c) TMDL watershed areas;' iii. Land use, including: a) Industrial; b) Residential; c) Commercial; d) Open space; and e) Institutional; iv. Roads; and v. Topography.8 2. The comprehensive system mapping must be updated with the data collected for each phase of mapping within the timeframe for each phase as outlined below: a. Phase I: Within three (3) years of the EDC, the comprehensive system mapping must include the following information: 3Utilizing the Stormwater Interactive Map on the Department's website or the NYS GIS Clearinghouse. 4Utilizing the Stormwater Interactive Map on the Department's website. 5Utilizing the Stormwater Interactive Map on the Department's website or the NYS GIS Clearinghouse. 6Utilizing the Stormwater Interactive Map on the Department's website or the NYS GIS Clearinghouse. 'Utilizing the Stormwater Interactive Map on the Department's website. $Utilizing USGS Quadrangle Map or finer. 11 Part N.D. i. Monitoring locations, with associated prioritization (Part VI.C.1 .d. or Part VII.C.1.d, depending on the MS4 Operatortype); ii. Preliminary storm-sewershed boundaries (for newly designated MS4 Operators); iii. Focus areas (Part VI.A.1 .a. or Part VII.A.1 .a, depending on the MS4 Operatortype); iv. Publicly owned/operated post-construction stormwater management practices (SMPs) (Part VI.E.3. or Part VII.E.3, depending on the MS4 Operator type). The publicly owned/operated post-construction SMPs subject to this requirement are in the automatically designated area or an additionally designated area subject to Criterion 1, 2, or 3 of the Additional Designation Criteria (Appendix B); and v. Municipal facilities, with associated prioritization (Part VI.F.2.c. or Part VII.F.2.c, depending on the MS4 Operatortype). b. Phase II: Within five (5) years of the EDC, the comprehensive system mapping must include the following information: i. MS4 infrastructure, including: a) Conveyance system i) Type (closed pipe or open drainage); and ii) Direction of flow;9 b) Stormwater structures i) Type (drop inlet, catch basin, or manhole); and ii) Number of connections to and from drop inlets, catch basins, and manholes; ii. Privately owned/operated post-construction SMPs which discharge to the MS4 (Part VI.E.2.). The privately owned/operated post-construction SMPs subject to this requirement are in the automatically designated area or an additionally designated area subject to Criterion 1, 2, or 3 of the Additional Designation Criteria (Appendix B). a) If the location of the privately-owned post-construction SMPs cannot be determined without accessing the private property, the MS4 Operator must map the location of the property that the post- construction SMP is located on using street address or tax parcel. E. Legal Authority For MS4 Operators continuing coverage from previous iterations of this SPDES general permit, adequate legal authority must be maintained in accordance with Part IV.E.1. or Part IV.E.2. For a newly designated MS4 Operator, within three (3) years, the MS4 Operator must, to the extent allowable by State and local law, develop and implement 9 Direction of flow can be a written description or indicated as an arrow on the feature. 12 Part N.E. adequate legal authority to control pollutant discharges to implement this SPDES general permit. An MS4 Operator must either be in conformance with Part IV.E.1. or Part VI.E.2: 1 . Adopt the following model local laws and include a copy of the resolution in their SWMP Plan: a. The New York State Department of Environmental Conservation Model Local Law to Prohibit Illicit Discharges, Activities and Connections to Separate Storm Sewer Systems, April 2006 (NYS DEC Model IDDE Local Law 2006); and b. The New York State Department of Environmental Conservation Sample Local Law for Stormwater Management and Erosion & Sediment Control, March 2006 (NYS DEC Sample SM and E&SC Local Law 2006). 2. Enact a legal mechanism or ensure that written policies/procedures are in place with content equivalent to the model local law, with documentation in the SWMP Plan from the attorney representing the MS4 Operator of the equivalence. Equivalent legal mechanisms or written policies/procedures must include the following: a. For illicit discharges: i. A prohibition of: a) Illicit discharges, spills or other release of pollutants; b) Unauthorized connections into the MS4; ii. A mechanism to: a) Receive and collect information related to the introduction of pollutants into the MS4; b) Require installation, implementation, and maintenance of post- construction SMPs; c) Require compliance and take enforcement action; and, d) Access property for inspection. b. To be adequate the legal mechanism must also ensure: i. Applicable construction activities are effectively controlled and include post-construction runoff controls for new development and redevelopment projects; and ii. Post-construction SMPs are properly operated and maintained by requiring the following: a) A stormwater pollution prevention plan (SWPPP) with erosion and sediment controls that meets or exceed the New York State, Standards and Specifications for Erosion & Sediment Control, November 2016 (NYS E&SC 2016) and requires post-construction SMPs for applicable construction activity described in Part VI.D.1 in conformance with the 13 Part IV.E. SPDES General Permit for Stormwater from Construction Activities, GP-0-20-001 (CGP); b) Post-construction SMPs as required by CGP meet the sizing criteria specified in the New York State Stormwater Management Design Manual, January 2015 (NYS SWMDM 2015), and performance criteria, or equivalent, including Operation & Maintenance Plans for long term maintenance; c) Construction site operators to control waste such as discarded building materials, concrete truck washout, chemicals, litter, and sanitary waste, all of which may cause adverse impacts to water quality; and d) Receive and collect information related to compliance with the approved SWPPP including verification of maintenance of post- construction SMPs (if conducted by private entities). F. Enforcement Measures & Tracking 1. Enforcement Response Plan Within six (6) months, the MS4 Operator must develop and implement an enforcement response plan (ERP) which clearly describes the action(s) to be taken for violations that the MS4 Operator has enacted for illicit discharge (Part VI.C. or Part VILC, depending on the MS4 Operator type), construction (Part VI.D. or Part VILD, depending on the MS4 Operator type), and post-construction (Part VI.E. or Part VILE, depending on the MS4 Operator type). The ERP must be documented in the SWMP Plan. The ERP must set forth a protocol to address repeat and continuing violations through progressively stricter responses (i.e., escalation of enforcement) as needed to achieve compliance with the terms and conditions of this SPDES general permit. a. The ERP must describe how the MS4 Operator will use the following types of enforcement responses or combination of responses: i. Verbal warnings; ii. Written notices; iii. Citations (and associated fines); iv. Stop work orders; v. Withholding of plan approvals or other authorizations affecting the ability to discharge to the MS4; and vi. Additional measures, supported in local legal authorities, such as collecting against the project's bond or directly billing the responsible party to pay for work and materials to correct violations. b. Enforcement responses are based on the type, magnitude, and duration of the violation, effect of the violation on the receiving water, compliance history of the operator, and good faith of the operator in compliance efforts. 14 Part IV.F. c. Efforts to obtain a voluntary correction of deficiencies through informal enforcement, such as verbal warnings or written notices, must not exceed sixty (60) days in duration (from the time of the MS4 Operator's initial determination until a return to compliance). 2. Enforcement Tracking The MS4 Operator must track instances of non-compliance in the SWMP Plan. The enforcement case documentation must include, at a minimum, the following: a. Name of the owner/operator of the facility or site of the violation (can be redacted from the publicly available SWMP Plan); b. Location of the stormwater source (e.g., construction project); c. Description of the violation; d. Schedule for returning to compliance; e. Description of enforcement response used, including escalated responses if repeat violations occur or violations are not resolved in a timely manner; f. Accompanying documentation of enforcement response (e.g., notices of noncompliance, notices of violations); g. Any referrals to different departments or agencies; and h. Date violation was resolved. Part V. Recordkeeping, Reporting, and SWMP Evaluation A. Recordkeeping The MS4 Operator must keep records required by this SPDES general permit for five (5) years after they are generated. Records must be submitted to the Department within a reasonable specified time period of a written Department request for such information. Documents can be maintained in electronic format if the manner reasonably assures the integrity of the records, in accordance with NYCRR 750-2.5(e)(1). Records, including the NOI and the SWMP Plan, must be made available to the public at reasonable times during regular business hours. B. Reporting 1. Report Submittal a. Reports must be submitted electronically to the Department using the forms located on the Department's website (http://www.dec.ny.gov/). b. Electronic Submission Waiver ii. MS4 Operators must submit all reports electronically unless the MS4 Operator has received a waiver from the Department based on one of the following conditions: 15 Part V.B. a) If the MS4 Operator is physically located in a geographical area (i.e., zip code or census tract) that is identified as under-served for broadband internet access in the most recent report from the Federal Communications Commission; or b) If the MS4 Operator has limitations regarding available computer access or computer capability. iii. If an MS4 Operator wishes to obtain a waiver from submitting a report electronically, the MS4 Operator must submit a request using the Application for Electronic Submittal Waiver to the Department at the following address: NYS DEC Bureau of Water Compliance MS4 NOTICE OF INTENT WAIVER 625 Broadway,4th Floor Albany, New York 12233-3505 iv. A waiver may only be considered granted once the MS4 Operator receives written confirmation from the Department. v. MS4 Operators must document the electronic submission waiver in the SWMP Plan, if applicable. 2. Annual Reports a. Annually, MS4 Operators must submit an Annual Report to the Department using the form provided by the Department. The completion of this permit requirement must be documented in the SWMP Plan. b. The reporting period for the Annual Report is January 3 of the current year to January 2 of the following year (Reporting Year). c. For MS4 Operators continuing coverage, the Annual Report must be submitted to the Department by April 1 of the year following the end of the Reporting Year. d. For newly designated MS4 Operators, if authorization to discharge is granted: i. Before September 30, the first Annual Report must be submitted by April 1 of the year following the end of the Reporting Year; or ii. After September 30, the first Annual Report must be submitted by April 1 following their first complete Reporting Year. 3. Interim Progress Certification a. Twice a year, MS4 Operators must submit to the Department an Interim Progress Certification that verifies the activities included in this SPDES general permit have been completed by the date specified using the form provided by the Department. The completion of this permit requirement must be documented in the SWMP Plan. 16 Part V.B. b. MS4 Operators located within the watersheds listed in Table 3 must include additional information to identify the activities that have been performed during the reporting period to demonstrate progress made by the MS4 Operatortowards completion of the reduction requirements, prescribed in Part IX. c. An Interim Progress Certification for the period of January 3 through June 30 of the same year must be submitted to the Department by October 1 of the same year. An Interim Progress Certification for the period of July 1 through January 2 of the following year must be submitted to the Department by April 1 of the following year along with the Annual Report. Submission of the Annual Report is not a substitute for submission of the Interim Progress Certification. 4. Sharea Annual Reporting MS4 Operators working together to implement their SWMPs may complete and submit a shared Annual Report to satisfy the reporting requirements specified in Part V.13.2. a. The shared Annual Report must outline and explain group activities, but also include the tasks performed by each individual MS4 Operator. b. On or before the reporting deadline, April 1, each MS4 Operatorwithin the group, must sign the certification section of the Annual Report to take responsibility for the information in the Annual Report, which includes specific endorsement or acceptance of both the shared Annual Report information and Annual Report information on behalf of the individual MS4 Operator. 5. Certification All reports specified within this Part must be signed and certified in accordance with Part X.J. 6. Annual Report and Interim Progress Certification Content The Annual Report and Interim Progress Certifications shall summarize the activities performed throughout the Reporting Year, including: a. The status of compliance with permit requirements; b. Information documented in the SWMP Plan, as specified throughout this SPDES general permit; and c. A certification statement in accordance with 40 CFR 122.22(d). C. SWMP Evaluation Once every five (5) years, the MS4 Operator must evaluate the SWMP for compliance with the terms and conditions of this SPDES general permit, including the effectiveness or deficiencies of components of the individual SWMP Plan, and 17 Part V.B. the status of achieving the requirements outlined in this SPDES general permit. The SWMP evaluation must be documented in the SWMP Plan. 18 Part VI Part VI. Minimum Control Measures (MCMs) for Traditional Land Use Control MS4 Operators In addition to the requirements contained in Part I. through Part V, traditional land use control MS4 Operators must comply with the MCMs contained in this Part. A. MfM1 — Public Education and Outreach Program The MS4 Operator must develop and implement an education and outreach program to increase public awareness of pollutant generating activities and behaviors. This MCM is designed to inform the public about the impacts of stormwater on water quality, the general sources of stormwater pollutants, and the steps the general public can take to reduce pollutants in stormwater runoff. 1. Development a. Focus Areas Within three (3) years of the EDC, the MS4 Operator must identify and document the focus areas in the SWMP Plan. The focus areas to be considered are as follows: i. Areas discharging to waters with Class AA-S, A-S, AA, A, B, SA, or SB (mapped in accordance with Part IV.D.1 .e.ii.a)); ii. Sewersheds for impaired waters listed in Appendix C (subject to Part VIII. requirements; mapped in accordance with Part IV.D.1.c. for MS4 Operators continuing coverage and Part IV.D.2.a.ii. for newly designated MS4 Operators); iii. TMDL watersheds (subject to Part IX. requirements; mapped in accordance with Part IV.D.1 .e.ii.c)); iv. Areas with construction activities; v. Areas with on-site wastewater systems (subject to Part VIII. or Part IX. requirements); vi. Residential, commercial, and industrial areas (mapped in accordance with Part IV.D.1 .e.iii.); vii. Stormwater hotspots; and viii. Areas with illicit discharges. b. Target Audiences and Associated Pollutant Generating Activities Within three (3) years of the EDC, the MS4 Operator must identify and document the applicable target audience(s) and associated pollutant generating activities that the outreach and education will address for each focus area identified by the MS4 Operator in Part VI.A.1.a. in the SWMP Plan. The target audiences are as follows: 19 Part VI.A. i. Residents; ii. Commercial:10 Business owners and staff; iii. Institutions-" Managers, staff, and students; iv. Construction: Developers, contractors, and design professionals; v. Industrial.12 Owners and staff, and vi. MS4 Operator's municipal staff. c. Education and Outreach Topic, Within three (3) years of the EDC, the MS4 Operator must identify and document in the SWMP Plan the education and outreach topics and how the education and outreach topics will reduce the potential for pollutants to be generated by the target audience(s) (Part VI.A.1 .b.) for the focus area(s) (Part VI.A.1.a.). d. Illicit Discharge Education Within six (6) months of the EDC, the MS4 Operator must make information related to the prevention of illicit discharges, available to municipal employees, businesses, and the public and document the completion of this requirement in the SWMP Plan. The information related to the prevention of illicit discharges must include the following: i. What types of discharges are allowable (Part I.A.3.); ii. What is an illicit discharge and why is it prohibited (Part VI.C.); iii. The environmental hazards associated with illicit discharges and improper disposal of waste; iv. Proper handling and disposal practices for the most common behaviors within the community (e.g., septic care, car washing, household hazardous waste, swimming pool draining, or other activities resulting in illicit discharges to the MS4); and v. How to report illicit discharges they may observe (Part VI.C.1 .a.). 2. Implementation and Frequency a. Distribution Method of Educational Messages Once every five (5) years, the MS4 Operator must identify and document in the SWMP Plan which of the following method(s) are used for the distribution of educational messages: i. Printed materials (e.g., mail inserts, brochures, and newsletters); ii. Electronic materials (e.g., websites, email Iistservs); 10 Business, retail stores, and restaurants. 11 Hospitals, churches, colleges, and schools. 12 Factories, recyclers, auto-salvage, and mines. 20 Part VLA. iii. Mass media (e.g., newspapers, public service announcements on radio or cable); iv. Workshops or focus groups; v. Displays in public areas (e.g., town halls, library, parks); or vi. Social Media (e.g., Facebook, Twitter, blogs). b. Frequency Following the completion of Part VI.A.1 .a, Part VI.A.1.b, and Part VI.A.1 .c, within five (5) years of the EDC, and once every five (5) years, thereafter, the MS4 Operator must: i. Deliver an educational message to each target audience(s) (Part VI.A.1.b.) for each focus area(s) (Part VI.A.1 .a.) based on the defined education and outreach topic(s) (Part VI.A.1 .c.); and ii. Document the completion of this requirement in the SWMP Plan. c. Updates to the Public Education and Outreach Program Following the completion of Part VI.A.1.a, Part VI.A.1.b, and Part VI.A.1 .c, annually, by April 1 , the MS4 Operator must: i. Review and update the focus areas, target audiences, and/or education and outreach topics; and ii. Document the completion of this requirement in the SWMP Plan. B. MCM 2 - Public Involvement/Participation The MS4 Operator must provide opportunities to involve the public in the development, review, and implementation of the SWMP. This MCM is designed to give the public the opportunity to include their opinions in the implementation of this SPDES general permit. �. Public Involvement/Participation a. Annually, the MS4 Operator must provide an opportunity for public involvement/participation in the development and implementation of the SWMP. The MS4 Operator must document the public involvement/participation opportunities in the SWMP Plan. The opportunities for public involvement/participation are as follows: i. Citizen advisory group on stormwater management; ii. Public hearings or meetings; iii. Citizen volunteers to educate other individuals about the SWMP; iv. Coordination with other pre-existing public involvement/participation opportunities; 21 Part VI.B. v. Reporting concerns about activities or behaviors observed; or vi. Stewardship activities. b. Annually, the MS4 Operator must inform the public of the opportunity (Part VI.B.1 .a.) for their involvement/participation in the development and implementation of the SWMP and how they can become involved. The MS4 Operator must document the method for distribution of this information in the SWMP Plan. The methods for distribution are as follows: i. Public notice; ii. Printed materials (e.g., mail inserts, brochures and newsletters); iii. Electronic materials (e.g., websites, email listservs); iv. Mass media (e.g., newspapers, public service announcements on radio or cable); v. Workshops or focus groups; vi. Displays in public areas (e.g., town halls, library, parks); or vii. Social Media (e.g., Facebook, Twitter, blogs). c. Within six (6) months of the EDC, the MS4 Operator must identify a local point of contact to receive and respond to public concerns regarding stormwater management and compliance with permit requirements. The name or title of this individual, with contact information, must be published on public outreach and public participation materials and documented in the SWMP Plan. 2. Public Notice and Input Requirements a. Public Notice and Input Requirements for SWMP Plan Annually, the MS4 Operator must provide an opportunity for the public to review and comment on the publicly available SWMP Plan (Part IV.13.2.b.). The public must have the ability to ask questions and submit comments on the SWMP Plan. The completion of this permit requirement must be documented in the SWMP Plan. This requirement may be satisfied by Part VI.B.1. b. Public Notice and Input Requirements for Draft Annual Report i. Annually, the MS4 Operator must provide an opportunity for the public to review and comment on the draft Annual Report. The completion of this permit requirement must be documented in the SWMP Plan. This requirement may be satisfied by either: a) Presentation of the draft Annual Report at a regular meeting of an existing board (e.g., administrative, planning, zoning) or a separate meeting specifically for stormwater, as designated by the MS4 or if requested by the public. The public must have the ability to ask 22 Part VI.B. questions about and make comments on the draft annual report during that presentation; or b) Posting of the draft Annual Report on a public website. The website must provide information on the timeframes and procedures to submit comments and/or request a meeting. However, if a public meeting is requested by two or more persons, the MS4 Operator must hold such a meeting. c. Consideration of Public Input i. Annually, the MS4 Operator must include a summary of comments received on the SWMP Plan and draft Annual Report in the SWMP Plan. ii. Within thirty (30) days of when public input is received, the MS4 Operator must update the SWMP Plan, where appropriate, based on the public input received. C. MCM 3 - Illicit uscharge Detection and Elimination The MS4 Operator must develop, implement, and enforce a program which systematically detects, tracks down, and eliminates illicit discharges to the MS4. This MCM is designed to manage the MS4 so it is not conveying pollutants associated with flows other than those directly attributable to stormwater runoff. . Illicit Discharge Detection a. Public Reporting of Illicit Discharges i. Within six (6) months of the EDC, the MS4 Operator must establish and document in the SWMP Plan an email or phone number (with message recording capability) for the public to report illicit discharges. ii. Within thirty (30) days of an illicit discharge, the MS4 Operator must document each report of an illicit discharge in the SWMP Plan with the following information: a) Date of the report; b) Location of the illicit discharge; c) Nature of the illicit discharge; d) Follow up actions taken or needed (including response times); and e) Inspection outcomes and any enforcement taken. b. Monitoring Locations The monitoring locations used to detect illicit discharges are identified as follows: i. MS4 outfalls;13 3 MS4 outfalls can be found at a municipal facility. 23 Part VI.C. ii. Interconnections-14 and iii. Municipal facility intra connections.15 c. Monitoring Locations Inventory i. Within three (3) years of the EDC, the MS4 Operator must develop and maintain an inventory of the monitoring locations in the SWMP Plan. The following information must be included in the inventory.16 a) Inventory information for MS4 outfalls i) ID; ii) Prioritization (high or low) (Part VI.C.1 .d.); iii) Type of monitoring location (Part VI.C.1.b.); iv) Name of MS4 Operator's municipal facility, if located at a municipal facility;17 v) Receiving waterbody name and class (mapped in accordance with Part IV.D.1 .e.ii.a)); vi) Receiving waterbody WI/PWL Segment ID (mapped in accordance with Part IV.D.1.e.ii.b)); vii) Land use in drainage area; viii)Type of conveyance (open drainage or closed pipe); ix) Material; x) Shape; xi) Dimensions; xii) Submerged in water; and xiii)Submerged in sediment. b) Inventory information for interconnections i) ID; ii) Prioritization (high or low) (Part VI.C.1.d.); iii) Type of monitoring location (Part VI.C.1.b.); iv) Name of MS4 Operator receiving discharge or private storm system; v) Name of MS4 Operator's municipal facility, if located at a municipal facility; and vi) Receiving waterbody name and class (mapped in accordance with Part IV.D.1.e.ii.a)). c) Inventory information for municipal facility intraconnections i) ID; ii) Prioritization (high or low) (Part VI.C.1.d.); 14 Interconnections can be found at a municipal facility. 15 Municipal facility intra connections can be found only at a municipal facility. 16 The information included in the inventory is collected during inspections on the Monitoring Locations Inspection and Sampling Field Sheet (Appendix D) unless otherwise specified by the permit conditions. 7 This information is collected as part of the municipal facility inventory. 24 Part VI.C. iii) Type of monitoring location (Part VI.C.1.b.); iv) Name of MS4 Operator's municipal facility; and v) Receiving waterbody name and class (mapped in accordance with Part IV.D.1 .e.ii.a)). ii. Annually, the MS4 Operator must update the inventory if monitoring locations are created or discovered. d. Monitoring Locations Prioritization i. Within three (3) years of the EDC, the MS4 Operator must prioritize monitoring locations which are included in the monitoring locations inventory (Part VI.C.1.c.) as follows: a) High priority monitoring locations include monitoring locations: i) At a high priority municipal facility, as defined in Part VI.F.2.c; ii) Discharging to impaired waters (subject to Part VIII. requirements; mapped in accordance with Part IV.D.1.e.ii.b)); iii) Discharging within a TMDL watershed (subject to Part IX. requirements; mapped in accordance with Part IV.D.1.e.ii.c)); iv) Discharging to waters with Class AA-S, A-S, AA, A, B, SA, or SIB (mapped in accordance with Part IV.D.1.e.ii.a)); and/or v) Confirmed citizen complaints on three or more separate occasions in the last twelve (12) months. b) All other monitoring locations are considered low priority. ii. Within thirty (30) days of when a monitoring location is constructed or the MS4 Operator discovers it, the MS4 Operator must prioritize those monitoring locations; and iii. Annually, after the initial prioritization (Part VI.C.1.d.i.), the MS4 Operator must update the monitoring location prioritization in the inventory (Part VI.C.1.c.) based on information gathered as part of the monitoring location inspection and sampling program (Part VI.C.1 .e.). The completion of this permit requirement must be documented in the SWMP Plan. e. Monitoring Locations Inspection and Sampling Program Within two (2) years of the EDC, the MS4 Operator must develop and implement a monitoring locations inspection and sampling program. The monitoring locations inspection and sampling program must be documented in the SWMP Plan specifying: i. The monitoring locations inspection and sampling procedures including: 25 Part VI.C. a) During dry weather,18 one (1) inspection of each monitoring location identified in the inventory (Part VI.C.1 .c.) every five (5) years following the most recent inspection; b) Documentation of all monitoring location inspections, including any sampling results, using the Monitoring Locations Inspection and Sampling Field Sheet (Appendix D) or an equivalent form containing the same information and include the completed monitoring location inspections and sampling results in the SWMP Plan (e.g., the completed Monitoring Locations Inspection and Sampling Field Sheets); c) Provisions to sample all monitoring locations which had inspections which resulted in a suspect or obvious illicit discharge characterization. The sampling requirement is based on the number and severity of physical indicators present in the flow to better inform track down procedures (Part VI.C.2.). If the source of the illicit discharge is clear and discernable (e.g., sewage), sampling is not necessary; d) Sampling may be done with field test kits or field instrumentation that are sufficiently sensitive to detect the parameter below the sampling action level used19 and are not subject to 40 CFR Part 136 requirements for approved methods and certified laboratories; e) Provisions to initiate, or cause to initiate'20 track down procedures (Part VI.C.2.a.), in accordance with the timeframes specified in Part VI.C.2.a.iii, for monitoring locations with an overall characterization21 as suspect illicit discharge or obvious illicit discharge or that exceed any sampling action level used; f) Provisions to re-inspect the monitoring location within thirty (30) days of initial inspection if there is a physical indicator not related to flow, potentially indicative of intermittent or transitory discharges, utilizing techniques described in Chapter 12.6 of the Center for Watershed Protection Illicit Discharge Detection and Elimination: A Guidance Manual for Program Development and Technical Assistance, October 2004 (CWP 2004) or equivalent. i) If those same physical indicators persist, the MS4 Operator must initiate illicit discharge track down procedures (Part VI.C.2.a.). $MS4 Operators can reference the Center for Watershed Protection Illicit Discharge Detection and Elimination: A Guidance Manual for Program Development and Technical Assistance, October 2004 (CWP 2004)for other factors to consider when determining when to conduct monitoring location inspection and sampling. 19 Refer to Chapter 12 of the CWP 2004 for parameters, sampling action levels, and procedures. 20 If track down is conducted by individuals or entities other than those conducting the monitoring locations inspections. 21 Reference to the Monitoring Locations Inspection and Sampling Field Sheet, adapted from CWP 2004, Section 6: Overall Monitoring Location Characterization based on the Relative Severity Index of physical indicators for flowing monitoring locations only. 26 Part VI.C. ii. The training provisions for the MS4 Operator's monitoring locations inspection and sampling procedures (Part VI.C.1.e.i.). a) If new staff are added, training on the MS4 Operator's monitoring locations inspection and sampling procedures (Part VI.C.1 .e.i.) must be given prior to conducting monitoring locations inspections and sampling procedures; b) For existing staff, training on the MS4 Operator's monitoring locations inspection and sampling procedures (Part VI.C.1.e.i.) must be given prior to conducting monitoring locations inspections and sampling and once every five (5) years, thereafter; and c) If the monitoring locations inspection and sampling procedures (Part VI.C.1.e.i.) are updated (Part VI.C.1 .e.iv.), training on the updates must be given to all staff prior to conducting monitoring locations inspections and sampling. iii. The names, titles, and contact information for the individuals who have received monitoring locations inspection and sampling procedures training and update annually; and iv. Annually, by April 1 , the MS4 Operator must: a) Review and update the monitoring location inspection and sampling procedures (Part VI.C.1.e.i.) based on monitoring location inspection results (e.g., trends, patterns, areas with illicit discharges, and common problems); and b) Document the completion of this requirement in the SWMP Plan. 2. Illicit Discharge Track Down Program Within two (2) years of the EDC, the MS4 Operator must develop and implement an illicit discharge track down program to identify the source of illicit discharges and the responsible party. The illicit discharge track down program must be documented in the SWMP Plan specifying: a. The illicit discharge track down procedures including: i. Procedures as described in Chapter 13 of CWP 2004 or equivalent; ii. Steps taken for illicit discharge track down procedures; iii. The following timeframes to initiate illicit discharge track down: a) Within twenty-four (24) hours of discovery, the MS4 Operator must initiate track down procedures for flowing MS4 monitoring locations with obvious illicit discharges,22 22 Reference to the Monitoring Locations Inspection and Sampling Field Sheet, adapted from CWP 2004, Section 6: Overall Monitoring Location Characterization based on the Relative Severity Index of physical indicators for flowing monitoring locations only. 27 Part VI.C. b) Within two (2) hours of discovery, the MS4 Operator must initiate track down procedures for obvious illicit discharges of sanitary wastewater that would affect bathing areas during bathing season, shell fishing areas or public water intakes and report orally or electronically to the Regional Water Engineer and local health department; and c) Within five (5) days of discovery, the MS4 Operator must initiate track down procedures for suspect illicit discharges. b. The training provisions for the MS4 Operator's illicit discharge track down procedures (Part VI.C.2.a.). i. If new staff are added, training on the MS4 Operator's illicit discharge track down procedures (Part VI.C.2.a.) must be given prior to conducting illicit discharge track downs; ii. For existing staff, training on the MS4 Operator's illicit discharge track down procedures (Part VI.C.2.a.) must be given prior to conducting illicit discharge track downs and once every five (5) years, thereafter; and iii. If the illicit discharge track down procedures (Part VI.C.2.a.) are updated (Part VI.C.2.d.), training on the updates must be given to all staff prior to conducting illicit discharge track downs. c. The names, titles, and contact information for the individuals who have received illicit discharge track down procedures training and update annually; and d. Annually, by April 1 , the MS4 Operator must: i. Review and update the illicit discharge track down procedures (Part VI.C.2.a.); and ii. Document the completion of this requirement in the SWMP Plan. 3. Illicit Discharge Elimination Program Within two (2) years of the EDC, the MS4 Operator must develop and implement an illicit discharge elimination program. The illicit discharge elimination program must be documented in the SWMP Plan specifying: a. The illicit discharge elimination procedures including: i. Provisions for escalating enforcement and tracking, both consistent with the ERP required in Part IV.F. of this SPDES general permit; ii. Provisions to confirm the corrective actions have been taken; iii. Steps taken for illicit discharge elimination procedures; and iv. The following timeframes for illicit discharge elimination: a) Within twenty-four (24) hours of identification of an illicit discharge that has a reasonable likelihood of adversely affecting human health or the environment, the MS4 Operator must eliminate the illicit discharge; 28 Part VI.C. b) Within five (5) days of identification of an illicit discharge that does not have a reasonable likelihood of adversely affecting human health or the environment, the MS4 Operator must eliminate the illicit discharge,- and c) Where elimination of an illicit discharge within the specified timeframes (Part VI.C.3.a.iv.) is not possible, the MS4 Operator must notify the Regional Water Engineer. b. The training provisions for the MS4 Operator's illicit discharge elimination procedures (Part VI.C.3.a.). i. If new staff are added, training on the MS4 Operator's illicit discharge elimination procedures (Part VI.C.3.a.) must be given prior to conducting illicit discharge eliminations; ii. For existing staff, training on the MS4 Operator's illicit discharge elimination procedures (Part VI.C.3.a.) must be given prior to conducting illicit discharge eliminations and once every five (5) years, thereafter; and iii. If the illicit discharge elimination procedures (Part VI.C.3.a.) are updated (Part VI.C.3.d.), training on the updates must be given to all staff prior to conducting illicit discharge eliminations. c. The names, titles, and contact information for the individuals who have received illicit discharge elimination procedures training and update annually; and d. Annually, by April 1 , the MS4 Operator must: i. Review and update the illicit discharge elimination procedures (Part VI.C.3.a.); and ii. Document the completion of this requirement in the SWMP Plan. D. MCM 4 - Construction Site Stormwater Runoff Control The MS4 Operator must develop, implement, and enforce a program to ensure construction sites are effectively controlled. This MCM is designed to prevent pollutants from construction related activities,23 as well as promote the proper planning and installation of post-construction SMPs. 1. Applicable Construction Activities/Projects/Sites a. The construction site stormwater runoff control program must address stormwater runoff to the MS4 from sites with construction activities that: i. Result in a total land disturbance of greater than or equal to one acre; or 23 Projects that comply with the terms and conditions of the CGP or an individual SPDES permit for stormwater for which they obtained coverage and local erosion and sediment control requirements are effectively controlled. 29 Part VI.D. ii. Disturb less than one acre if part of a larger common plan of development or sale. b. For construction activities where the MS4 Operator is listed as the owner/operator on the Notice of Intent for coverage under the CGP: i. The MS4 Operator must ensure compliance with the CGP; and ii. The additional requirements for construction oversight described in Part VI.D.6 through Part VI.D.9 are not required. 2. Public Reporting of Construction Site Complaints a. Within six (6) months of the EDC, the MS4 Operator must establish and document in the SWMP Plan an email or phone number (with message recording capability) for the public to report complaints related to construction stormwater activity. b. The MS4 Operator must document reports of construction site complaints in the SWMP Plan with the following information: i. Date of the report; ii. Location of the construction site; iii. Nature of complaint; iv. Follow up actions taken or needed; and v. Inspection outcomes and any enforcement taken. 3. Construction Oversight Program Within one (1) year of the EDC, the MS4 Operator must develop and implement a construction oversight program. The construction oversight program must be documented in the SWMP Plan specifying: a. The construction oversight procedures including: i. When the construction site stormwater control program applies (Part VI.D.1 .); ii. What types of construction activity require a SWPPP; iii. The procedures for submission of SWPPPs; iv. SWPPP review requirements (Part VI.D.6.) v. Pre-construction oversight requirements (Part VI.D.7.) vi. Construction site inspection requirements (Part VI.D.8.); vii. Construction site close-out requirements (Part VI.D.9.); viii. Enforcement process/expectations for compliance; and ix. Other procedures associated with the control of stormwater runoff from applicable construction activities. 30 Part VI.D. b. The training provisions for the MS4 Operator's construction oversight procedures (Part VI.D.3.a.). i. If new staff are added, training on the MS4 Operator's construction oversight procedures (Part VI.D.3.a.) must be given prior to conducting any construction oversight activities; ii. For existing staff, training on the MS4 Operator's construction oversight procedures (Part VI.D.3.a.) must be given prior to conducting any construction oversight activities and once every five (5) years, thereafter; and iii. If the construction oversight procedures (Part VI.D.3.a.) are updated (Part VI.D.3.a.), training on the updates must be given to all staff prior to conducting construction oversight. c. The names, titles, and contact information for the individuals who have received construction oversight training and update annually; d. Procedures to ensure those involved in the construction activity itself (e.g., contractor, subcontractor, qualified inspector, SWPPP reviewers) have received four (4) hours of Department endorsed training in proper erosion and sediment control principles from a Soil & Water Conservation District, or other Department endorsed entity; and e. Annually, by April 1, the MS4 Operator must: i. Review and update the construction oversight procedures (Part VI.D.3.a.); and ii. Document the completion of this requirement in the SWMP Plan. 4. Construction Site inventory & inspection i racking a. Within six (6) months of the EDC, the MS4 Operator must develop and maintain an inventory of all applicable construction sites (Part VI.D.1 .a.) in the SWMP Plan. The following information must be included in the inventory.- i. Location of the construction site; ii. Owner/operator contact information, if other than the MS4 Operator, iii. Receiving waterbody name and class (mapped in accordance with Part IV.D.1.e.ii.a)); iv. Receiving waterbody WI/PWL Segment ID (mapped in accordance with Part IV.D.1 .e.ii.b)); v. Prioritization (high or low) (Part VI.D.5.); vi. Construction project SPDES identification number; vii. SWPPP approval date; viii. Inspection history, including dates and ratings (satisfactory, marginal, or unsatisfactory, when available); and 31 Part VI.D. ix. Current status of the construction site/project (i.e., active, temporarily shut down, complete24). b. Annually, the MS4 Operator must update the inventory if construction projects are approved or completed. 5. Construction Site Prioritization a. Within one (1) year of the EDC, the MS4 Operator must prioritize all construction sites which are included in the construction site inventory (Part VI.DA.) as follows: i. High priority construction sites include construction sites: a) With a direct conveyance (e.g., channel, ditch, storm sewer) to a surface water of the State that is: i) Listed in Appendix C with silt/sediment, phosphorus, or nitrogen as the POC; ii) Classified as AA-S, AA, or A (mapped in accordance with Part IV.D.1.e.ii.a)); or iii) Classified with a trout (T) or trout spawning (TS) designation (mapped in accordance with Part IV.D.1 .e.ii.a)); b) With greater than five (5) acres of disturbed earth at any one time; c) With earth disturbance within one hundred (100) feet of any lake or pond (mapped in accordance with Part IV.D.1 .e.ii.b)); and/or d) Within fifty (50) feet of any rivers or streams (mapped in accordance with Part IV.D.1.e.ii.b)); ii. All other construction sites are considered low priority. b. Within thirty (30) days of when a construction site becomes active, the MS4 Operator must prioritize those construction sites; and c. Annually, after the initial prioritization (Part VI.D.5.a.), the MS4 Operatormust update the construction site prioritization in the inventory (Part VI.DA.a.) based on information gathered as part of the construction oversight program (Part VI.D.3.). The completion of this permit requirement must be documented in the SWMP Plan. i. If the prioritization of the construction site changes priority based on information gathered as part of the construction oversight program, the MS4 Operator must comply with the requirements that apply to that prioritization. 24 Construction projects listed on the inventory must be inspected and tracked as described in Part VI.D.8. until a final site inspection has been completed as specified in Part VI.D.9. and the construction site status changes to complete. 32 Part VI.D. 6. SWPPP Review The MS4 Operator must: a. Ensure individual(s), responsible for reviewing SWPPPs for acceptance, receive: i. Four (4) hours of Department endorsed training in proper erosion and sediment control principles from a Soil & Water Conservation District, or other Department endorsed entity. This training must be completed within three (3) years of the EDC and every three (3) years thereafter. ii. Document the completion of this requirement in the SWMP Plan. b. Ensure SWPPP reviewers receive this training (Part VI.D.6.a.) prior to conducting SWPPP reviews for acceptance. i. Individuals without these trainings cannot review SWPPPs for acceptance. ii. Individuals who meet the definition of a qualified professional or qualified inspector are exempt from this requirement. c. Ensure individuals responsible for reviewing SWPPPs review all SWPPPs for applicable construction activities (Part VI.D.1.) and for conformance with the requirements of the CGP, including: i. Erosion and sediment controls must be reviewed for conformance with the NYS E&SC 2016, or equivalent; ii. Individuals responsible for review of post-construction SMPs must be qualified professionals or under the supervision of a qualified professional; and iii. Post-construction SMPs must be reviewed for conformance with the NYS SWMDM 2015 or equivalent, including: a) All post-construction SMPs must meet the sizing criteria contained in the CGP and NYS SWMDM 2015. b) Deviations from the performance criteria of the NYS SWMDM 2015 must demonstrate that they are equivalent. c) The SWPPP must include an O&M plan that includes inspection and maintenance schedules and actions to ensure continuous and effective operation of each post-construction SMP. The SWPPP must identify the entity that will be responsible for the long-term operation and maintenance of each practice. d. In the SWMP Plan, document and update annually the names, titles, and contact information for the individuals who have received the trainings listed in Part VI.D.6.a. e. In the SWMP Plan, document the SWPPP review including the information found in Part III.B. of the CGP; f. Prioritize new construction activities (Part VI.D.5.a.); and 33 Part VI.D. g. Notify construction site owner/operators that their SWPPP has been accepted using the MS4 SWPPP Acceptance Form25 created by the Department and required by the CGP, signed in accordance with Part X.J. 7. Pre-Construction Meeting Prior to commencement of construction activities, the MS4 Operator must ensure a pre-construction meeting is conducted. The date and content of the pre- construction inspection/meeting must be documented in the SWMP Plan. The owner/operator listed on the CGP NOI (if different from the MS4 Operator), the MS4 Operator, contractor(s) responsible for implementing the SWPPP for the construction activity, and the qualified inspector(if required for the construction activity by Part IV.C. the CGP) must attend the meeting in order to: a. Confirm the approved project has received, or will receive26, coverage under the CGP or an individual SPDES permit; b. Verify contractors and subcontractors selected by the owner/operator of the construction activity have identified at least one individual that has received four (4) hours of Department endorsed training in proper erosion and sediment control principles from a Soil & Water Conservation District or other endorsed entity as required by the CGP and Part VI.D.3.d; and c. Review the construction oversight program (Part VI.D.3.) and expectations for compliance. 8. Construction Site Inspections The MS4 Operator must: a. Ensure individuals(s), responsible for construction site inspections, receive: i. Four (4) hours of Department endorsed training in proper erosion and sediment control principles from a Soil & Water Conservation District, or other Department endorsed entity. This training must be complete, within three (3) years of the EDC and every three (3) years thereafter. ii. Document the completion of this requirement in the SWMP Plan. b. Ensure all MS4 Construction Site Inspectors receive this training prior to conducting construction site inspections. i. Individuals without these trainings cannot inspect construction sites. ii. Individuals who meet the definition of a qualified professional or qualified inspector are exempt from this requirement. 25 The MS4 SWPPP Acceptance Form can be found on the Department's website. 26 Preconstruction meetings may occur prior to the issuance of the MS4 SWPP Acceptance Form, however, the MS4 Operator must confirm coverage under the CGP will be applied for by the construction site owner/operator prior to commencement of construction of construction activities. 34 Part VI.D. c. Annually inspect all sites with construction activity identified in the inventory (Part VI.D.4.) during active construction after the pre-construction meeting (Part VI.D.7.), or sooner if deficiencies are noted that require attention. i. Follow up to construction site inspections must confirm corrective actions are completed within timeframes established by the CGP and the MS4 Operator's ERP (Part IV.F.1 .). d. In the SWMP Plan, document and update annually the names, titles, and contact information for the individuals who have received the trainings listed in Part VI.D.8.a. e. Document all inspections using the Construction Site Inspection Report Form (Appendix D) or an equivalent form containing the same information. The MS4 Operator must include the completed Construction Site Inspection Reports in the SWMP Plan. 9. Construction Site Giose-out a. The MS4 Operator must ensure a final construction site inspection is conducted and documentation of the final construction site inspection must be maintained in the SWMP Plan. The final construction site inspection must be documented using the Construction Site Inspection Report Form (Appendix D), or an equivalent form containing the same information, or accept the construction site owner/operator's qualified inspector final inspection certification required by the CGP. b. The Notice of Termination (NOT)27 must be signed by the MS4 Operatoras required by the CGP for projects determined to be complete. The NOT must be signed in accordance with Part X.J. E. MCM 5 — Post-Construction Stormwater Management The MS4 Operator must develop, implement, and enforce a program to ensure proper operation and maintenance of post construction SMPs for new or redeveloped sites. This MCM is designed to promote the long-term performance of post-construction SMPs in removing pollutants from stormwater runoff. 1. Applicable Post-Construction SMPs The post-construction SMP program must address stormwater runoff to the MS4 from publicly owned/operated and privately owned/operated post-construction SMPs that meet the following: a. Post-construction SMPs that have been installed as part of any CGP covered construction site or individual SPDES permit (since March 10, 2003); and 2'The NOT can be found on the Department's website. 35 Part VI.E. b. All new post-construction SMPs constructed as part of the construction site stormwater runoff control program (Part VI.D.). 2. Post-Construction SMP Inventory & Insnection Tracking28 a. The MS4 Operators continuing coverage must: i. Maintain the inventory from previous iterations of this SPDES general permit for post-construction SMPs installed after March 10, 2003; and ii. Develop the inventory for post-construction SMPs installed after March 10, 2003 including post-construction SMPs: a) As they are approved or discovered; or b) After the owner/operator of the construction activity has filed the NOT with the Department (Part VI.D.9.b.). b. The newly designated MS4 Operators must develop and maintain the inventory for post-construction SMPs installed after March 10, 2003 including post-construction SMPs: i. As they are approved or discovered; or ii. After the owner/operator of the construction activity has filed the NOT with the Department (Part VI.D.9.b.). c. Annually, the MS4 Operator must update the inventory of post-construction SMPs to include the post-construction SMPs in Part VI.E.2.a. and Part VI.E.2.b. d. Within five (5) years of the EDC, the following information must be included in the inventory either by using the MS4 Operator maintenance records or by verification of maintenance records provided by the owner of the post- construction SMP: i. Street address or tax parcel; ii. Type,.29 iii. Receiving waterbody name and class (mapped in accordance with Part IV.D.1 .e.ii.a)); iv. Receiving waterbody WI/PWL Segment ID (mapped in accordance with Part IV.D.1 .e.ii.b)); v. Date of installation (if available) or discovery; vi. Ownership; vii. Responsible party for maintenance; 28 Post-construction SMPs can be found at a municipal facility. 29 Post-construction SMP types are defined in the New York State Department of Environmental Conservation Maintenance Guidance: Stormwater Management Practices, March 31, 2017 (NYS DEC Maintenance Guidance 2017). 36 Part VI.E. viii. Contact information for party responsible for maintenance; ix. Location of documentation depicting O&M requirements and legal agreements for post-construction SMP; x. Frequency for inspection of post-construction SMP, as specified in the New York State Department of Environmental Conservation Maintenance Guidance: Stormwater Management Practices, March 31 , 2017 (NYS DEC Maintenance Guidance 2017) or as specified in the O&M plan contained in the approved SWPPP (Part VI.D.6.); xi. Reason for installation (e.g., new development, redevelopment, retrofit, flood control), if known; xii. Date of last inspection; xiii. Inspection results; and xiv. Any corrective actions identified and completed. e. MS4 Operators must document the inventory of post-construction SMPs in the SWMP Plan. 3. SWPPP Review For post-construction SMP SWPPP review requirements, see Part VI.D.6. 4. Post-Construction SMP Inspection & Maintenance Program Within one (1) year of the EDC, the MS4 Operator must develop and implement a post-construction SMP inspection and maintenance program. The post- construction SMP inspection and maintenance program must be documented in the SWMP Plan specifying: a. The post-construction SMP inspection and maintenance procedures including: i. Provisions to ensure that each post-construction SMP identified in the post-construction SMP inventory (Part VI.E.2.) is inspected at the frequency specified in the NYS DEC Maintenance Guidance 2017 or as specified in the O&M plan contained in the approved SWPPP (Part VI.D.6.), if available; a) The MS4 Operator can only accept Level 1 inspections (NYS DEC Maintenance Guidance 2017) by private owners inspecting post- construction SMPs. ii. Documentation of post-construction SMP inspections using the Post- Construction SMP Inspection CheckliSt30 or an equivalent form containing the same information. The MS4 Operator must include the completed 30 The Department developed checklist forms specific to each post-construction SMP designed to assist MS4 Operators in conducting inspections and maintenance activities of standard practices. The Post-Construction SMP Inspection Checklist, March 31, 2017, can be found on the Department's website. 37 Part V.E. post-construction SMP inspections (i.e., the completed Post-Construction SMP Inspection Checklist) in the SWMP Plan; iii. Provisions to initiate follow-up actions (i.e., maintenance, repair, or higher- level inspection) within thirty (30) days of post-construction SMP inspection; and iv. Provisions to initiate enforcement within sixty (60) days of the inspection if follow-up actions are not complete. b. The training provisions for the MS4 Operators post-construction SMP inspection and maintenance procedures (Part VI.E.4.a.). i. If new staff are added, training on the MS4 Operator's post-construction SMP inspection and maintenance procedures (Part VI.E.4.a.) and procedures outlined in the Department endorsed program must be given prior to conducting any post-construction SMP inspection and maintenance; ii. For existing staff, training on the MS4 Operator's post-construction SMP inspection and maintenance procedures (Part VI.E.4.a.) and procedures outlined in the Department endorsed program must be given prior to conducting any post-construction SMP inspection and maintenance and once every five (5) years, thereafter; and iii. If the post-construction SMP inspection and maintenance procedures (Part VI.E.4.a.) are updated (Part VI.E.4.d.), training on the updates must be given to all staff prior to conducting post-construction SMP inspection and maintenance. c. The names, titles, and contact information for the individuals who have received post-construction SMP inspection and maintenance procedures training and update annually; and d. Annually, by April 1 , the MS4 Operator must: i. Review and update the post-construction SMP inspection and maintenance procedures (Part VI.E.4.a.); and ii. Document the completion of this requirement in the SWMP Plan. 38 Part VI.F. F. MCM 6 — Pollution Prevention and Good Housekeeping The MS4 Operator must develop and implement a pollution prevention and good housekeeping program for municipal facilities and municipal operations to minimize pollutant discharges. This MCM is designed to ensure the MS4 Operator's own activities do not contribute pollutants to surface waters of the State. 1. Best Management Practices (BMPs) for Municipal Facilities & Operations Within three (3) years of the EDC, the MS4 Operator must incorporate best management practices (BMPs) into the municipal facility program and municipal operations program to minimize the discharge of pollutants associated with municipal facilities and municipal operations, respectively. The BMPs to be considered are as follows and must be documented in the SWMP Plan: a. Minimize Exposure i. Exposure of materials to rain, snow, snowmelt, and runoff must be minimized, unless not technologically possible or not economically practicable and achievable in light of best industry practices, including areas used for loading and unloading, storage, disposal, cleaning, maintenance, and fueling operations, with the following BMPs: a) Locate materials and activities inside or protect them with storm resistant coverings; b) Use grading, berming, or curbing to prevent runoff of contaminated flows and divert run-on away from these areas; c) Locate materials, equipment, and activities so leaks and spills are contained in existing containment and diversion systems; d) Clean up spills and leaks promptly using dry methods (e.g., absorbents) to prevent the discharge of pollutants; e) Store leaky vehicles and equipment indoors or, if stored outdoors, use drip pans and absorbents; f) Use spill/overflow protection equipment; g) Perform all vehicle and/or equipment cleaning operations indoors, under cover, or in bermed areas that prevent runoff and run-on and also captures any overspray; h) Drain fluids, indoors or under cover, from equipment and vehicles that will be decommissioned, and, for any equipment and vehicles that will remain unused for extended periods of time, inspect at least monthly for leaks; and/or i) Minimize exposure of chemicals by replacing with a less toxic alternative (e.g., use non-hazardous cleaners). ii. No Exposure Certification for High Priority Municipal Facilities 39 Part VI.F. a) Municipal facilities may qualify for No Exposure Certification (Appendix D) when all activities and materials are completely sheltered from exposure to rain, snow, snowmelt and/or runoff. b) High priority municipal facilities (Part VI.F.2.c.i.a)) with uncovered parking areas for vehicles awaiting maintenance may be considered a low priority municipal facility (Part VI.F.2.c.i.c)) if only routine maintenance is performed inside and all other no exposure criteria are met. c) Municipal facilities accepting or repairing disabled vehicles and/or vehicles that have been involved in accidents are not eligible for the No Exposure Certification. d) Municipal facilities must maintain the No Exposure Certification and document in the SWMP Plan. The No Exposure Certification ceases to apply when activities or materials become exposed. b. Follow a Preventive Maintenance Program i. Implement a preventative maintenance program that includes routine inspection, testing, maintenance, and repair of all fueling areas, vehicles and equipment and systems to prevent leaks, spills and other releases. This includes: a) Performing inspections and preventive maintenance of stormwater drainage, source controls, treatment systems, and plant equipment and systems; b) Maintaining non-structural BMPs (e.g., keep spill response supplies available, personnel appropriately trained, containment measures, covering fuel areas); and c) Ensure vehicle washwater is not discharged to the MS4 or to surface waters of the State. Wash equipment/vehicles in a designated and/or covered area where washwater is collected to be recycled or discharged to the sanitary sewer (Part I.B.2.d.). ii. Routine maintenance must be performed to ensure BMPs are operating properly. iii. When a BMP is not functioning to its designed effectiveness and needs repair or replacement: a) Maintenance must be performed before the next anticipated storm event, or as necessary to maintain the continued effectiveness of stormwater controls. If maintenance prior to the next anticipated storm event is impracticable, maintenance must be scheduled and accomplished as soon as practicable; and b) Interim measures must be taken to prevent or minimize the discharge of pollutants until the final repair or replacement is implemented, 40 Part VI.F. including cleaning up any contaminated surfaces so that the material will not be discharged during subsequent storm events. c. Spill Prevention and Response Procedure✓ i. Minimize the potential for leaks, spills and other releases that may be exposed to stormwater and develop plans for effective response to such spills if or when they occur. At a minimum, the MS4 Operator must: a) Store materials in appropriate containers; b) Label containers (e.g., "Used Oil," "Spent Solvents," "Fertilizers and Pesticides") that could be susceptible to spillage or leakage to encourage proper handling and facilitate rapid response if spills or leaks occur; c) Implement procedures for material storage and handling, including the use of secondary containment and barriers between material storage and traffic areas, or a similarly effective means designed to prevent the discharge of pollutants from these areas; d) Develop procedures for stopping, containing, and cleaning up leaks, spills, and other releases. As appropriate, execute such procedures as soon as possible; e) Keep spill kits on-site, located near areas where spills may occur or where a rapid response can be made; f) Develop procedures for notification of the appropriate facility personnel, emergency response agencies, and regulatory agencies when a leak, spill, or other release occurs. If possible, one of these individuals should be a member of the stormwater pollution prevention team (Part VI.F.2.d.i.a)). Any spills must be reported in accordance with 6 NYCRR 750-2.7; and g) Following any spill or release, the MS4 Operator must evaluate the adequacy of the BMPs identified in the municipal facility specific SWPPP. If the BMPs are inadequate, the SWPPP must be updated to identify new BMPs that will prevent reoccurrence and improve the emergency response to such releases. ii. Measures for cleaning up spills or leaks must be consistent with applicable petroleum bulk storage, chemical bulk storage, or hazardous waste management regulations at 6 NYCRR Parts 596-599, 613 and 370-373. iii. This SPDES general permit does not relieve the MS4 Operator of any reporting or other requirements related to spills or other releases of petroleum or hazardous substances. Any spill of a hazardous substance must be reported in accordance with 6 NYCRR 597.4. Any spill of petroleum must be reported in accordance with 6 NYCRR 613.6 or 17 NYCRR 32.3. 41 Part VI.F. d. Erosion and Sediment Controls31 i. Stabilize exposed areas and control runoff using structural and/or non- structural controls to minimize onsite erosion and sedimentation. ii. The MS4 Operator must consider: a) Structural and/or non-structural controls found in the NYS E&SC 2016; b) Areas that, due to topography, land disturbance (e.g., construction), or other factors, have potential for significant soil erosion; c) Whether structural, vegetative, and/or stabilization BMPs are needed to limit erosion; d) Whether velocity dissipation devices (or equivalent measures) are needed at discharge locations and along the length of any channel to provide a non-erosive flow velocity from the structure to a water course; and e) Address erosion or areas with poor vegetative cover, especially if the erosion is within fifty (50) feet of a surface water of the State e. Manage Vegetated Areas and Ooen Soace on Municipal Prooerty i. Maintain vegetated areas on MS4 Operator owned/operated property and right of ways: a) Specify proper use, storage, and disposal of pesticides, herbicides, and fertilizers including minimizing the use of these products and using only in accordance manufacturer's instruction; b) Use lawn maintenance and landscaping practices that are protective of water quality. Protective practices include: reduced mowing frequencies; proper disposal of lawn clippings; and use of alternative landscaping materials (e.g., drought resistant planting); c) Place pet waste disposal containers and signage concerning the proper collection and disposal of pet waste at all parks and open space where pets are permitted; and d) Address waterfowl congregation areas where needed to reduce waterfowl droppings from entering the MS4. f. Salt32 Storage Piles or Pile Containing Salt Enclose or cover storage piles of salt, or piles containing salt, used for deicing or maintenance of paved surfaces, except during loading, unloading, and handling. Implement appropriate measures (e.g., good housekeeping, routine sweeping, diversions, containment) to minimize exposure resulting from adding to or removing materials from the pile. 31 The use of the term"controls" in Part VI.F.1.d. aligns with the use of the term"controls"in the CGP. 32 For purposes of this SPDES general permit, salt means any chloride-containing material used to treat paved surfaces for deicing, including sodium chloride, calcium chloride, magnesium chloride, and brine solutions. 42 Part VLF. g. Waste, Garbage, and Floatable Debris i. Keep all dumpster lids closed when not in use. For dumpsters and roll off boxes that do not have lids and could leak, ensure that discharges have a control (e.g., secondary containment, treatment); and ii. Keep exposed areas free of waste, garbage, and debris or intercept them before they are discharged: a) Manage trash containers at parks and open space (scheduled cleanings; sufficient number); b) Pick up trash and debris on MS4 Operator owned/operated property and rights of way; and c) Clean out catch basins within the appropriate timeframes (Part VI.F.3.c.iii.). h. Alternative Implementation Options When alternative implementation options (Part IV.A.1 .) are utilized, require the parties performing municipal operations as contracted services, including but not limited to street sweeping, snow removal, and lawn/grounds care, to meet permit requirements as the requirements apply to the activity performed. 2. Municipal Facilities33 a. Municipal Facility Program Within three (3) years of the EDC, the MS4 Operator must develop and implement a municipal facility program. The municipal facility program must be documented in the SWMP Plan specifying: i. The municipal facility procedures including: a) The BMPs (Part VI.F.1.) incorporated into the municipal facility program; b) The high priority municipal facility requirements (Part VI.F.2.d.) as applied to the specific municipal facility; and c) The low priority municipal facility requirements (Part VI.F.2.e.) as applied to the specific municipal facility. ii. The training provisions for the MS4 Operator's municipal facility procedures (Part VI.F.2.a.i.). a) If new staff are added, training on the MS4 Operator's municipal facility procedures (Part VI.F.2.a.i.) must be given prior to conducting municipal facility procedures; b) For existing staff, training on the MS4 Operator's municipal facility procedures (Part VI.F.2.a.i.) must be given prior to conducting 33 Municipal facilities that have coverage under a separate SPDES permit(either individual or MSGP)must comply with the terms and conditions of that permit and the requirements set forth in this Part are not applicable. 43 Part VI.F. municipal facility procedures and once every five (5) years, thereafter; and c) If the municipal facility procedures (Part VI.F.2.a.i.) are updated (Part VI.F.2.a.iv.), training on the updates must be given to all staff prior to conducting municipal facility procedures. iii. The names, titles, and contact information for the individuals who have received municipal facility training and update annually; and iv. Annually, by April 1 , the MS4 Operator must: a) Review and update the municipal facility procedures (Part VI.F.2.a.i.); and b) Document the completion of this requirement in the SWMP Plan. b. Municipal Facility Inventory i. Within two (2) years of the EDC, the MS4 Operator must develop and maintain an inventory of all municipal facilities in the SWMP Plan. The following information must be included in the inventory.- a) Name of municipal facility; b) Street address; c) Type of municipal facility; d) Prioritization (high or low) (Part VI.F.2.c.); e) Receiving waterbody name and class (mapped in accordance with Part IV.D.1.e.ii.a)) ; f) Receiving waterbody WI/PWL Segment ID (mapped in accordance with Part IV.D.1.e.ii.b)); g) Contact information; h) Responsible department; i) Location of SWPPP (if high priority; when completed); j) Type of activities present on site; k) Size of facility (acres); I) Date of last assessment; m) BMPs identified; and n) Projected date of next comprehensive site assessment (Part VI.F.2.d.ii.c) or Part VI.F.2.e.ii.c), depending on the municipal facility prioritization (Part VI5.2.c.)). ii. Annually, the MS4 Operator must update the inventory if new municipal facilities are added. 44 Part VI.F. c. Municipal Facility Prioritization i. Within three (3) years of the EDC, the MS4 Operator must prioritize all known municipal facilities as follows: a) High priority municipal facilities include municipal facilities that have one or more of the following on site and exposed to stormwater: i) Storage of chemicals, salt, petroleum, pesticides, fertilizers, anti- freeze, lead-acid batteries, tires, waste/debris; ii) Fueling stations; and/or iii) Vehicle or equipment maintenance/repair. b) Low priority municipal facilities include any municipal facilities that do not meet the criteria for a high priority (Part VI.F.2.c.i.a)) municipal facility. c) High priority municipal facilities (Part IV.F.2.c.i.a)) which qualify for a No Exposure Certification (Part VI.F.1.a.ii.) are low priority municipal facilities. ii. Within thirty (30) days of when a municipal facility is added to the inventory, the MS4 Operator must prioritize those municipal facilities; and iii. Annually, after the initial prioritization (Part VI.F.2.c.i.), the MS4 Operator must update the municipal facility prioritization in the inventory (Part VI.F.2.b.i.) based on information gathered as part of the municipal facility program (Part VI.F.2.a.), including cases where a No Exposure Certification (Part VI.F.1 .a.ii.) ceases to apply. The completion of this permit requirement must be documented in the SWMP Plan. d. High Priority Municipal Facility Requirements i. Municipal Facility Specific SWPPP Within five (5) years of the EDC, MS4 Operators must develop and implement a municipal facility specific SWPPP for each high priority municipal facility (Part VI.F.2.c.i.a)) and retain a copy of the municipal facility specific SWPPP on site of the respective municipal facility. The SWPPP must contain: a) Stormwater Pollution Prevention Team The municipal facility specific SWPPP must identify the individuals (by name and/or title) and their role/responsibilities in developing, implementing, maintaining, and revising the municipal facility specific SWPPP. The activities and responsibilities of the team must address all aspects of the municipal facility specific SWPPP. b) General Site Description A written description of the nature of the activities occurring at the municipal facility with a potential to discharge pollutants, type of 45 Part VI.F. pollutants expected, and location of key features as detailed in the site map (Part VI.F.2.d.i.e)). c) Summary of potential pollutant sources The municipal facility specific SWPPP must identify each area at the municipal facility where materials or activities are exposed to stormwater or from which authorized non-stormwater discharges (Part I.A.3.) originate, including any potential pollutant sources for which the municipal facility has reporting requirements under the Emergency Planning and Community Right-To-Know Act (EPCRA), Section 313. i) Materials or activities include: machinery; raw materials; intermediate products; byproducts; final products or waste products; and, material handling activities which includes storage, loading and unloading, transportation or conveyance of any raw material, intermediate product, final product or waste product. ii) For each separate area identified, the description must include: (a) Activities - A list of the activities occurring in the area (e.g., material storage, equipment fueling and cleaning); (b) Pollutants - A list of the associated pollutant(s) for each activity. The pollutant(s) list must include all materials that are exposed to stormwater; and (c) Potential for presence in stormwater- For each area of the municipal facility that generates stormwater discharges, a prediction of the direction of flow, and the likelihood of the activity to contaminate the stormwater discharge. Factors to consider include the toxicity of chemicals, quantity of chemicals used, produced or discharged, the likelihood of contact with stormwater, and history of leaks or spills of toxic or hazardous pollutants. d) Spills and Releases For areas that are exposed to precipitation or that otherwise drain to a stormwater conveyance to be covered under this SPDES general permit, the municipal facility specific SWPPP must include a list of spills or releases34 of petroleum and hazardous substances or other pollutants, including unauthorized non-stormwater discharges, that may adversely affect water quality that occurred during the last three-year period. The list must be updated when spills or releases occur. e) Site Map 34 This may also include releases of petroleum or hazardous substances that are not in excess of reporting quantities but which may still cause or contribute to significant water quality impairment. 46 Part VI.F. The municipal facility specific SWPPP must include a site map identifying the following, as applicable: i) Property boundaries and size in acres; ii) Location and extent of significant structures (including materials shelters), and impervious surfaces; iii) Monitoring locations (mapped in accordance with Part IV.D.2.a.i.) with its approximate sewershed. Each monitoring location must be labeled with the monitoring location identification; iv) Location of all post-construction SMPs (mapped in accordance with Part IV.D.2.a.iv.) and MS4 infrastructure (mapped in accordance with Part IV.D.2.b.i.); v) Locations of discharges authorized under other SPDES permits; vi) Locations where potential spills or releases can contribute to pollutants in stormwater discharges and their accompanying drainage points; vii) Locations of haul and access roads; viii)Rail cars and tracks; ix) Arrows showing direction of stormwater flow; x) Location of all receiving waters in the immediate vicinity of the municipal facility, indicating if any of the waters are impaired and, if so, whether the waters have TMDLs established for them (mapped in accordance with Part IV.D.1.e.ii.); xi) Locations where stormwater flows have significant potential to cause erosion; xii) Location and source of run-on from adjacent property containing significant quantities of pollutants and/or volume of concern to the municipal facility; and xiii) Locations of the following areas where such areas are exposed to precipitation or stormwater. (a) Fueling stations; (b) Vehicle and equipment maintenance and/or cleaning areas; (c) Loading/unloading areas; (d) Locations used for the treatment, storage or disposal of wastes; (e) Liquid storage tanks; (f) Processing and storage areas; (g) Locations where significant materials, fuel or chemicals are stored and transferred; (h) Locations where vehicles and/or machinery are stored when not in use (i) Transfer areas for substances in bulk; 47 Part VI.F. (j) Location and description of non-stormwater discharges (Part I.A.3.); (k) Locations where spills35 or leaks have occurred; and (I) Locations of all existing structural BMPs. f) Stormwater Best Management Practices (BMPs) The municipal facility specific SWPPP must document the location and type of BMPs implemented at the municipal facility (Part VI.F.1.). The municipal facility specific SWPPP must describe how each BMP is being implemented for all the potential pollutant sources. g) Municipal facility assessments The municipal facility specific SWPPP must include a schedule for completing and recording results of routine and comprehensive site assessments (Part VI.F.2.d.ii.c)). ii. Municipal Facility Assessments a) Wet Weather Visual Monitoring i) Once every five (5) years, the MS4 Operator must conduct wet weather visual monitoring of the monitoring locations (Part VI.C.1.b.) and other sites of stormwater leaving the site that are discharging stormwaterfrom fueling areas, storage areas, vehicle and equipment maintenance/fueling areas, material handling areas and similar potential pollutant generating areas (Part VI.F.2.d.i.e)xiii)). (a) All samples must be collected from discharges resulting from a qualifying storm event. The storm event must be documented using the Storm Event Data Form (Appendix D) and kept with the municipal facility specific SWPPP. The sample must be taken during the first thirty (30) minutes (or as soon as practical, but not to exceed one hour) of the discharge at the monitoring location. (b) No analytical tests are required to be performed on the samples for the purpose of meeting the visual monitoring requirements. (c) The visual examination must document observations of color, odor, clarity, floating solids, settled solids, suspended solids, foam, oil sheen, and any other obvious indicators of stormwater pollution. (d) The visual examination of the sample must be conducted in a well-lit area. 35 A spill includes: any spill of a hazardous substance that must be reported in accordance with 6 NYCRR 597.4 and any spill of petroleum that must be reported in accordance with 6 NYCRR 613.6 or 17 NYCRR 32.3. 48 Part VLF. (e) Where practicable, the same individual should carry out the collection and examination of discharges for the entire permit term for consistency. (f) The MS4 Operator must document the visual examination using the Visual Monitoring Form (Appendix D) and keep it with the municipal facility specific SWPPP to record: (i) Monitoring location ID; (i i) Examination date and time; (iii) Personnel conducting the examination; (iv) Nature of the discharge (runoff or snowmelt); (v) Visual quality of the stormwater discharge including observations of color, odor, clarity, floating solids, settled solids, suspended solids, foam, oil sheen, and other obvious indicators of stormwater pollution; and (vi) Probable sources of any observed stormwater contamination. (vii) Corrective and follow up actions — If the visual examination indicates the presence of color, odor, floating solids, settled solids, suspended solids, foam, oil sheen, or other indicators of stormwater pollution, the MS4 Operator must, at minimum, complete and document the following actions: (1) Evaluate the facility for potential sources; (2) Remedy the problems identified; (3) Revise the municipal facility specific SWPPP; and (4) Perform an additional visual inspection during the first qualifying storm event following implementation of the corrective action. If the first qualifying storm event does not occur until the next visual monitoring period, this follow up action may be used as the next visual inspection. b) The monitoring locations inspection and sampling program must be implemented at the municipal facility (Part VI.C.1.e.). c) Comprehensive Site Assessments i) Once every five (5) years following the most recent assessment, the MS4 Operator must complete a comprehensive site assessment for each high priority municipal facility as identified in the inventory (Part VI.F.2.b.) using the Municipal Facility Assessment Form (Appendix D) or an equivalent form containing 49 Part VI.F. the same information, and document in the municipal facility specific SWPPP and SWMP Plan that: (a) The municipal facility is in compliance with the terms and conditions of this SPDES general permit; (b) Deficiencies were identified and all reasonable steps will be taken to minimize any discharge in violation of the permit, which has a reasonable likelihood of adversely affecting human health or the environment; (i) Within twenty-four (24) hours, the MS4 Operator must prepare a schedule that includes corrective actions and specific interim milestones to be implemented until the corrective action is implemented; or (c) Deficiencies were identified and all reasonable steps will be taken to minimize any discharge in violation of the permit, which does not have a reasonable likelihood of adversely affecting human health or the environment; (i) Within seven (7) days, the MS4 Operator must prepare a schedule that includes corrective actions and specific interim milestones to be implemented until the corrective action is implemented. e. Low Priority Municipal Facility Requirement i. The MS4 Operator must identify procedures outlining BMPs for the types of activities that occur at the low priority municipal facilities as described in Part VI.F.1. A municipal facility specific SWPPP is not required. ii. Municipal Facility Assessments a) Low priority municipal facilities are not required to conduct wet weather visual monitoring. b) The monitoring locations inspection and sampling program must be implemented at the municipal facility(Part VI.C.1 .e.). c) Comprehensive Site Assessments i) Once every five (5) years following the most recent assessment, the MS4 Operator must complete a comprehensive site assessment for each low priority municipal facility as identified in the inventory (Part VI.F.2.b.) using the Municipal Facility Assessment Form (Appendix D) or an equivalent form containing the same information, and document in the SWMP Plan that: (a) The municipal facility is in compliance with the terms and conditions of this SPDES general permit; (b) Deficiencies were identified and all reasonable steps will be taken to minimize any discharge in violation of the permit, which 50 Part VI.F. has a reasonable likelihood of adversely affecting human health or the environment; (i) Within twenty-four (24) hours, the MS4 Operator must prepare a schedule that includes corrective actions and specific interim milestones to be implemented until the corrective action is implemented; or (c) Deficiencies were identified and all reasonable steps will be to minimize any discharge in violation of the permit, which does not have a reasonable likelihood of adversely affecting human health or the environment; (i) Within seven (7) days, the MS4 Operatormust prepare a schedule that includes corrective actions and specific interim milestones to be implemented until the corrective action is implemented. 3. Municipal Operations & Maintenance a. Municipal Operations Program Municipal operations are: street and bridge maintenance; winter road maintenance; MS4 maintenance; open space maintenance; solid waste management; new construction and land disturbances; right-of-way maintenance; marine operations; or hydrologic habitat modification. Within three (3) years of the EDC, the MS4 Operator must develop and implement a municipal operations program. The municipal operations program must be documented in the SWMP Plan specifying: i. The municipal operations procedures including: a) The BMPs (Part VI.F.1.) incorporated into the municipal operations program; b) The municipal operations corrective actions requirements (Part VI.F.3.b.); c) Catch basin inspection and maintenance requirements (Part VI.F.3.c.); d) Roads, bridges, parking lots, and right of way maintenance requirements (Part VI.F.3.d.); and e) All other municipal operations maintenance requirements. ii. The training provisions for the MS4 Operator's municipal operations procedures (Part VI.F.3.a.i.). a) If new staff are added, training on the MS4 Operator's municipal operations procedures (Part VI.F.3.a.i.) must be given prior to conducting municipal operations procedures; 51 Part VI.F. b) For existing staff, training on the MS4 Operator's municipal operations procedures (Part VI.F.3.a.i.) must be given prior to conducting municipal operations procedures and once every five (5) years, thereafter; and c) If the municipal operations procedures (Part VI.F.3.a.i.) are updated (Part VI.F.3.a.iv.), training on the updates must be given to all staff prior to conducting municipal operations procedures. iii. The names, titles, and contact information for the individuals who have received municipal operations training and update annually; and iv. Annually, by April 1 , the MS4 Operator must: a) Review and update the municipal operations procedures (Part VI.F.3.a.i.); and c) Document the completion of this requirement in the SWMP Plan. b. Municipal Operations Corrective Action i. For municipal operations, MS4 Operators must either: a) Ensure compliance with the terms and conditions of this SPDES general permit; or b) Implement corrective actions according to the following schedule and, after implementation, ensure the operations are in compliance with the terms and conditions of this SPDES general permit: i) Within twenty-four (24) hours of discovery for situations that have a reasonable likelihood of adversely affecting human health or the environment; ii) Initiated within seven (7) days of inspection and completed within thirty (30) days of inspection for situations that do not have a reasonable likelihood of adversely affecting human health or the environment; and iii) For corrective actions that require special funding or construction that will take longer than thirty (30) days to complete, a schedule must be prepared that specifies interim milestones that will ensure compliance in the shortest reasonable time. c. Catch Basin Inspection and Maintenance Within three (3) years of the EDC, the MS4 Operator must: i. Identify when catch basin inspection is needed with consideration for: a) Areas with construction activities (mapped in accordance with Part IV.D.2.a.iii.); b) Residential, commercial, and industrial areas (mapped in accordance with Part IV.D.1 .d.iii.); 52 Part VI.F. c) Recurring or history of issues; or d) Confirmed citizen complaints on three or more separate occasions in the last twelve (12) months. ii. Inventory catch basin inspection information including: a) Date of inspection; b) Approximate level of trash, sediment, and/or debris captured at time of clean-out (no trash, sediment, and/or debris, <50% of the depth of the sump, >50% of the depth of the sump); c) Depth of structure; d) Depth of sump; and e) Date of clean out, if applicable (Part VI.F.3.c.iii.). iii. Based on inspection results, clean out catch basins within the following timeframes: a) Within six (6) months after the catch basin inspection, catch basins which had trash, sediment, and/or debris exceeding 50% of the depth of the sump as a result of a catch basin inspection must be cleaned out; b) Within one (1) year after the catch basin inspection, catch basins which had trash, sediment, and/or debris at less than 50% of the depth of the sump as a result of a catch basin inspection must be cleaned out; and c) MS4 Operators are not required to clean out catch basins if the catch basins are operating properly and: i. There is no trash, sediment, and/or debris in the catch basin; or ii. The sump depth of the catch basin is less than or equal to two (2) feet. iv. Properly manage (handling and disposal) materials removed from catch basins during clean out so that: a) Water removed during the catch basin cleaning process will not reenter the MS4 or surface waters of the State; b) Material removed from catch basins is disposed of in accordance with any applicable environmental laws and regulations; and c) Material removed during the catch basin cleaning process will not reenter the MS4 or surface waters of the State. v. Determine if there are signs/evidence of illicit discharges and procedures for referral/follow-up if illicit discharges are encountered. 53 Part VI.F. d. Roads, Bridges, Parking Lots, & Right of Way Maintenance i. Sweeping Within six (6) months of the EDC, the MS4 Operator must develop and implement procedures for sweeping and/or cleaning municipal streets, bridges, parking lots, and right of ways owned/operated by the MS4 Operator. The procedures and completion of permit requirements must be documented in the SWMP Plan specifying: a) All roads, bridges, parking lots, and right of ways must be swept and/or cleaned once every five (5) years in the spring (following winter activities such as sanding). This requirement is not applicable to: i) Uncurbed roads with no catch basins; ii) High-speed limited access highways; or iii) Roads defined as interstates, freeways and expressways, or arterials by the United States Department of Transportation, Federal Highway Administration, Highway Functional Classification Concepts, Criteria and Procedures, 2013. b) Annually, from April 1 through October 31 , roads in business and commercial areas must be swept. This requirement is not applicable to: i) Uncurbed roads with no catch basins; ii) High-speed limited access highways; or iii) Roads defined as interstates, freeways and expressways, or arterials by the USDOT 2013. ii. Maintenance Within five (5) years of the EDC, in addition to the BMPs (Part VI.F.1.), the MS4 Operator must implement the following provisions: a) Pave, mark, and seal in dry conditions; b) Stage road operations and maintenance activity (e.g., patching, potholes) to reduce the potential discharge of pollutants to the MS4 or surface waters of the State; c) Restrict the use of herbicides/pesticide application to roadside vegetation; and d) Contain pollutants associated with bridge maintenance activities (e.g., paint chips, dust, cleaning products, other debris). iii. Winter Road Maintenance Within five (5) years of the EDC, in addition to the BMPs (Part VI.F.1.), the MS4 Operator must implement the following provisions: a) Routinely calibrate equipment to control salt/sand application rates; and 54 Part VI.F. b) Ensure that routine snow disposal activities comply with the Division of Water Technical and Operation Guidance Series 5.1.11, Snow Disposal.36 36 The Division of Water Technical and Operation Guidance Series 5.1.11, Snow Disposal can be found on the Department's website. 55 Part VI Part VII. Minimum Control Measures (MCMs) for Traditional Non-Land Use Control & Non-Traditional MS4 Operators In addition to the requirements contained in Part I. through Part V, traditional non- land use and non-traditional MS4 Operators must comply with the MCMs contained in this Part. These MS4 Operators should consider their public to be: • Employees (i.e., staff, faculty); • User population/visitors; • Students; • Tenants; and • Contractors & developers working for MS4 Operator. A. MCM1 — Public Education and Outreach Program The MS4 Operator must develop and implement an education and outreach program to increase public awareness of pollutant generating activities and behaviors. This MCM is designed to inform the public about the impacts of stormwater on water quality, the general sources of stormwater pollutants, and the steps the general public can take to reduce pollutants in stormwater runoff. .r. Oeveiopment a. Focus Areas Within three (3) years of the EDC, the MS4 Operator must identify and document the focus areas in the SWMP Plan. The focus areas to be considered are as follows: i. Areas discharging to waters with Class AA-S, A-S, AA, A, B, SA, or SB (mapped in accordance with Part IV.D.1 .e.ii.a)); ii. Sewersheds for impaired waters listed in Appendix C (subject to Part VIII. requirements; mapped in accordance with Part IV.D.1 .c. for MS4 Operators continuing coverage and Part IV.D.2.a.ii. for newly designated MS4 Operators); iii. TMDL watersheds (subject to Part IX. requirements; mapped in accordance with Part IV.D.1.e.ii.c)); iv. Areas with construction activities; v. Areas with on-site wastewater systems (subject to Part VIII. or Part IX. requirements); vi. Residential, commercial, and industrial areas (mapped in accordance with Part IV.D.1.e.iii.); vii. Stormwater hotspots; and viii. Areas with illicit discharges. 56 Part VI I.A. b. Target Audiences and Associated Pollutant Generating Activities Within three (3) years of the EDC, the MS4 Operator must identify and document the applicable target audience(s) and associated pollutant generating activities that the outreach and education will address for each focus area identified by the MS4 Operator in Part VI I.A.1.a. in the SWMP Plan. The target audiences are as follows: i. Residents; ii. Commercial:37 Business owners and staff; iii. Institutions.31 Managers, staff, and students; iv. Construction: Developers, contractors, and design professionals; v. Industrial.. Owners and staff; and vi. MS4 Operator's municipal staff. c. Education and Outreach Topics Within three (3) years of the EDC, the MS4 Operator must identify and document in the SWMP Plan the education and outreach topics and how the education and outreach topics will reduce the potential for pollutants to be generated by the target audience(s) (Part VII.A.1 .b.) for the focus area(s) (Part VII.A.1.a.). e. Illicit Discharge Education Within six (6) months of the EDC, the MS4 Operator must make information related to the prevention of illicit discharges, available to municipal employees, businesses, and the public and document the completion of this requirement in the SWMP Plan. The information related to the prevention of illicit discharges must include the following: i. What types of discharges are allowable (Part I.A.3.); ii. What is an illicit discharge and why is it prohibited (Part VII.C.); iii. The environmental hazards associated with illicit discharges and improper disposal of waste; iv. Proper handling and disposal practices for the most common behaviors within the community (e.g., septic care, car washing, household hazardous waste, swimming pool draining, or other activities resulting in illicit discharges to the MS4); and v. How to report illicit discharges they may observe (Part VII.C.1.a.). 37 Business, retail stores, and restaurants. 38 Hospitals, churches, colleges, and schools. 39 Factories, recyclers, auto-salvage, and mines. 57 Part VI I.A. 2. Implementation and Frequency a. Distribution Method of Educational Messages Once every five (5) years, the MS4 Operator must identify and document in the SWMP Plan which of the following method(s) are used for the distribution of educational messages: i. Printed materials (e.g., mail inserts, brochures, and newsletters); ii. Electronic materials (e.g., websites, email listservs); iii. Mass media (e.g., newspapers, public service announcements on radio or cable); iv. Workshops or focus groups; v. Displays in public areas (e.g., town halls, library, parks); or vi. Social Media (e.g., Facebook, Twitter, blogs). b. Frequency Following the completion of Part VII.A.1.a, Part VII.A.1.b, and Part VII.A.1 .c, within five (5) years of the EDC, and once every five (5) years, thereafter, the MS4 Operator must: i. Deliver an educational message to each target audience(s) (Part VII.A.1 .b.) for each focus area(s) (Part VII.A.1.a.) based on the defined education and outreach topic(s) (Part VII.A.1.c.); and ii. Document the completion of this requirement in the SWMP Plan. c. Updates to the Public Education and Outreach Progran, Following the completion of Part VII.A.1.a, Part VII.A.1.b, and Part VII.A.1 .c, annually, by April 1 , the MS4 Operator must: i. Review and update the focus areas, target audiences, and/or education and outreach topics; and ii. Document the completion of this requirement in the SWMP Plan. B. MCM 2 - Public Involvement/Participation The MS4 Operator must provide opportunities to involve the public in the development, review, and implementation of the SWMP. This MCM is designed to give the public the opportunity to include their opinions in the implementation of this SPDES general permit. 1. Public Involvement/Participation a. Annually, the MS4 Operator must provide an opportunity for public involvement/participation in the development and implementation of the SWMP. The MS4 Operator must document the public involvement/participation opportunities in the SWMP Plan. The opportunities for public involvement/participation are as follows: 58 Part VI I.B. i. Citizen advisory group on stormwater management; ii. Public hearings or meetings; iii. Citizen volunteers to educate other individuals about the SWMP; iv. Coordination with other pre-existing public involvement/participation opportunities; v. Reporting concerns about activities or behaviors observed; or vi. Stewardship activities. b. Annually, the MS4 Operator must inform the public of the opportunity (Part VII.B.1 .a.) for their involvement/participation in the development and implementation of the SWMP and how they can become involved. The MS4 Operator must document the method for distribution of this information in the SWMP Plan. The methods for distribution are as follows: i. Public notice; ii. Printed materials (e.g., mail inserts, brochures and newsletters); iii. Electronic materials (e.g., websites, email listservs); iv. Mass media (e.g., newspapers, public service announcements on radio or cable); v. Workshops or focus groups; vi. Displays in public areas (e.g., town halls, library, parks); or vii. Social Media (e.g., Facebook, Twitter, blogs). c. Within six (6) months of the EDC, the MS4 Operator must identify a local point of contact to receive and respond to public concerns regarding stormwater management and compliance with permit requirements. The name or title of this individual, with contact information, must be published on public outreach and public participation materials and documented in the SWMP Plan. 2. Public Notice and Input Requirements a. Public Notice and Input Requirements for SWMP Plan Annually, the MS4 Operator must provide an opportunity for the public to review and comment on the publicly available SWMP Plan (Part IV.13.2.b.). The public must have the ability to ask questions and submit comments on the SWMP Plan. The completion of this permit requirement must be documented in the SWMP Plan. This requirement may be satisfied by Part VII.B.1 . 59 Part VI I.B. b. Public Notice and Input Requirements for Draft Annual Report i. Annually, the MS4 Operator must provide an opportunity for the public to review and comment on the draft Annual Report. The completion of this permit requirement must be documented in the SWMP Plan. This requirement may be satisfied by either: a) Presentation of the draft Annual Report at a regular meeting of an existing board (e.g., administrative, planning, zoning) or a separate meeting specifically for stormwater, as designated by the MS4 or if requested by the public. The public must have the ability to ask questions about and make comments on the draft annual report during that presentation; or b) Posting of the draft Annual Report on a public website. The website must provide information on the timeframes and procedures to submit comments and/or request a meeting. However, if a public meeting is requested by two or more persons, the MS4 Operator must hold such a meeting. c. Consideration of Public Input i. Annually, the MS4 Operator must include a summary of comments received on the SWMP Plan and draft Annual Report in the SWMP Plan. ii. Within thirty (30) days of when public input is received, the MS4 Operator must update the SWMP Plan, where appropriate, based on the public input received. C. MCM 3 - Illicit Discharge Detection and Eliminatior The MS4 Operator must develop, implement, and enforce a program which systematically detects, tracks down, and eliminates illicit discharges to the MS4. This MCM is designed to manage the MS4 so it is not conveying pollutants associated with flows other than those directly attributable to stormwater runoff. 1. Illicit Discharge Detection a. Public Reporting of Illicit Discharges i. Within six (6) months of the EDC, the MS4 Operator must establish and document in the SWMP Plan an email or phone number (with message recording capability) for the public to report illicit discharges. ii. Within thirty (30) days of an illicit discharge, the MS4 Operator must document each report of an illicit discharge in the SWMP Plan with the following information: a) Date of the report; b) Location of the illicit discharge; c) Nature of the illicit discharge; 60 Part VII.C. d) Follow up actions taken or needed (including response times); and e) Inspection outcomes and any enforcement taken. b. Monitorina Locations The monitoring locations used to detect illicit discharges are identified as follows.. i. MS4 outfalls, ii. Interconnections,.41 and iii. Municipal facility intra connections.42 c. Monitoring Locations Inventory i. Within three (3) years of the EDC, the MS4 Operator must develop and maintain an inventory of the monitoring locations in the SWMP Plan. The following information must be included in the inventory.43 a) Inventory information for MS4 outfalls i) ID; ii) Prioritization (high or low) (Part VII.C.1.d.); iii) Type of monitoring location (Part VII.C.1.b.); iv) Name of MS4 Operator's municipal facility, if located at a municipal facility;44 v) Receiving waterbody name and class (mapped in accordance with Part IV.D.1 .e.ii.a)); vi) Receiving waterbody WI/PWL Segment ID (mapped in accordance with Part IV.D.1 .e.ii.b)); vii) Land use in drainage area; viii)Type of conveyance (open drainage or closed pipe); ix) Material; x) Shape; xi) Dimensions; xii) Submerged in water; and xiii)Submerged in sediment. b) Inventory information for interconnections i) ID; ii) Prioritization (high or low) (Part VII.C.1.d.); iii) Type of monitoring location (Part VII.C.1.b.); iv) Name of MS4 Operator receiving discharge or private storm system; 40 MS4 outfalls can be found at a municipal facility. 41 Interconnections can be found a municipal facility. 42 Municipal facility intraconnections can be found only at a municipal facility. 43 The information included in the inventory is collected during inspections on the Monitoring Locations Inspection and Sampling Field Sheet (Appendix D) unless otherwise specified by the permit conditions. 44 This information is collected as part of the municipal facility inventory. 61 Part VII.C. v) Name of MS4 Operator's municipal facility, if located at a municipal facility; and vi) Receiving waterbody name and class (mapped in accordance with Part IV.D.1 .e.ii.a)). c) Inventory information for municipal facility intraconnections i) ID; ii) Prioritization (high or low) (Part VII.C.1.d.); iii) Type of monitoring location (Part VII.C.1.b.); iv) Name of MS4 Operator's municipal facility; and v) Receiving waterbody name and class (mapped in accordance with Part IV.D.1 .e.ii.a)). ii. Annually, the MS4 Operator must update the inventory if monitoring locations are created or discovered. d. Monitoring Locations Prioritization i. Within three (3) years of the EDC, the MS4 Operator must prioritize monitoring locations which are included in the monitoring locations inventory (Part VII.C.1 .c.) as follows: a) High priority monitoring locations include monitoring locations: vi) At a high priority municipal facility, as defined in Part VII.F.2.c; vii) Discharging to impaired waters (subject to Part VIII. requirements; mapped in accordance with Part IV.D.1.e.ii.b)); viii)Discharging within a TMDL watershed (subject to Part IX. requirements; mapped in accordance with Part IV.D.1.e.ii.c)); ix) Discharging to waters with Class AA-S, A-S, AA, A, B, SA, or SB (mapped in accordance with Part IV.D.1 .e.ii.a)); and/or x) Confirmed citizen complaints on three or more separate occasions in the last twelve (12) months. b) All other monitoring locations are considered low priority. ii. Within thirty (30) days of when a monitoring location is constructed or the MS4 Operator discovers it, the MS4 Operator must prioritize those monitoring locations; and iii. Annually, after the initial prioritization (Part VII.C.1.d.i.), the MS4 Operator must update the monitoring location prioritization in the inventory (Part VII.C.1.c.) based on information gathered as part of the monitoring location inspection and sampling program (Part VII.C.1 .e.). The completion of this permit requirement must be documented in the SWMP Plan. 62 Part VI I.C. e. Monitoring Locations Inspection and Sampling Program Within two (2) years of the EDC, the MS4 Operator must develop and implement a monitoring locations inspection and sampling program. The monitoring locations inspection and sampling program must be documented in the SWMP Plan specifying: i. The monitoring locations inspection and sampling procedures including: a) During dry weather,45 one (1) inspection of each monitoring location identified in the inventory (Part VII.C.1.c.) every five (5) years following the most recent inspection; b) Documentation of all monitoring location inspections, including any sampling results, using the Monitoring Locations Inspection and Sampling Field Sheet (Appendix D) or an equivalent form containing the same information and include the completed monitoring location inspections and sampling results in the SWMP Plan (e.g., the completed Monitoring Locations Inspection and Sampling Field Sheets); c) Provisions to sample all monitoring locations which had inspections which resulted in a suspect or obvious illicit discharge characterization. The sampling requirement is based on the number and severity of physical indicators present in the flow to better inform track down procedures (Part VII.C.2.). If the source of the illicit discharge is clear and discernable (e.g., sewage), sampling is not necessary; d) Sampling may be done with field test kits or field instrumentation that are sufficiently sensitive to detect the parameter below the sampling action level used41 and are not subject to 40 CFR Part 136 requirements for approved methods and certified laboratories; e) Provisions to initiate, or cause to initiate'47 track down procedures (Part VII.C.2.a.), in accordance with the timeframes specified in Part VII.C.2.a.iii, for monitoring locations with an overall characterization48 as suspect illicit discharge or obvious illicit discharge or that exceed any sampling action level used; f) Provisions to re-inspect the monitoring location within thirty (30) days of initial inspection if there is a physical indicator not related to flow, potentially indicative of intermittent or transitory discharges, utilizing techniques described in Chapter 12.6 of the Center for Watershed 46 MS4 Operators can reference the Center for Watershed Protection Illicit Discharge Detection and Elimination:A Guidance Manual for Program Development and Technical Assistance, October 2004 (CWP 2004)for other factors to consider when determining when to conduct monitoring location inspection and sampling. 46 Refer to Chapter 12 of the CWP 2004 for parameters, sampling action levels, and procedures. 47 If track down is conducted by individuals or entities other than those conducting the monitoring locations inspections. 48 Reference to the Monitoring Locations Inspection and Sampling Field Sheet, adapted from CWP 2004, Section 6: Overall Monitoring Location Characterization based on the Relative Severity Index of physical indicators for flowing monitoring locations only. 63 Part VII.C. Protection Illicit Discharge Detection and Elimination: A Guidance Manual for Program Development and Technical Assistance, October 2004 (CWP 2004) or equivalent. i) If those same physical indicators persist, the MS4 Operator must initiate illicit discharge track down procedures (Part VII.C.2.a.). ii. The training provisions for the MS4 Operator's monitoring locations inspection and sampling procedures (Part VII.C.1.e.i.). a) If new staff are added, training on the MS4 Operator's monitoring locations inspection and sampling procedures (Part VII.C.1.e.i.) must be given prior to conducting monitoring locations inspections and sampling procedures; b) For existing staff, training on the MS4 Operator's monitoring locations inspection and sampling procedures (Part VII.C.1 .e.i.) must be given prior to conducting monitoring locations inspections and sampling and once every five (5) years, thereafter; and c) If the monitoring locations inspection and sampling procedures (Part VII.C.1.e.i.) are updated (Part VII.C.1.e.iv.), training on the updates must be given to all staff prior to conducting monitoring locations inspections and sampling. iii. The names, titles, and contact information for the individuals who have received monitoring locations inspection and sampling procedures training and update annually; and iv. Annually, by April 1 , the MS4 Operator must: a) Review and update the monitoring location inspection and sampling procedures (Part VII.C.1 .e.i.) based on monitoring location inspection results (e.g., trends, patterns, areas with illicit discharges, and common problems); and b) Document the completion of this requirement in the SWMP Plan. 2. Illicit Discharge Track Down Program Within two (2) years of the EDC, the MS4 Operator must develop and implement an illicit discharge track down program to identify the source of illicit discharges and the responsible party. The illicit discharge track down program must be documented in the SWMP Plan specifying: a. The illicit discharge track down procedures including: i. Procedures as described in Chapter 13 of CWP 2004 or equivalent; ii. Steps taken for illicit discharge track down procedures; iii. The following timeframes to initiate illicit discharge track down: 64 Part VI I.C. a) Within twenty-four (24) hours of discovery, the MS4 Operator must initiate track down procedures for flowing MS4 monitoring locations with obvious illicit discharges,49 b) Within two (2) hours of discovery, the MS4 Operator must initiate track down procedures for obvious illicit discharges of sanitary wastewater that would affect bathing areas during bathing season, shell fishing areas or public water intakes and report orally or electronically to the Regional Water Engineer and local health department; and c) Within five (5) days of discovery, the MS4 Operator must initiate track down procedures for suspect illicit discharges. b. The training provisions for the MS4 Operator's illicit discharge track down procedures (Part VII.C.2.a.). i. If new staff are added, training on the MS4 Operator's illicit discharge track down procedures (Part VII.C.2.a.) must be given prior to conducting illicit discharge track downs; ii. For existing staff, training on the MS4 Operator's illicit discharge track down procedures (Part VII.C.2.a.) must be given prior to conducting illicit discharge track downs and once every five (5) years, thereafter; and iii. If the illicit discharge track down procedures (Part VII.C.2.a.) are updated (Part VII.C.2.d.), training on the updates must be given to all staff prior to conducting illicit discharge track downs. c. The names, titles, and contact information for the individuals who have received illicit discharge track down procedures training and update annually; and d. Annually, by April 1, the MS4 Operator must: i. Review and update the illicit discharge track down procedures (Part VII.C.2.a.); and ii. Document the completion of this requirement in the SWMP Plan. 3. Illicit Discharge Elimination Program Within two (2) years of the EDC, the MS4 Operator must develop and implement an illicit discharge elimination program. The illicit discharge elimination program must be documented in the SWMP Plan specifying: a. The illicit discharge elimination procedures including: i. Provisions for escalating enforcement and tracking, both consistent with the ERP required in Part IV.F. of this SPDES general permit; ii. Provisions to confirm the corrective actions have been taken; 49 Reference to the Monitoring Locations Inspection and Sampling Field Sheet, adapted from CWP 2004, Section 6: Overall Monitoring Location Characterization based on the Relative Severity Index of physical indicators for flowing monitoring locations only. 65 Part VI I.C. iii. Steps taken for illicit discharge elimination procedures; and iv. The following timeframes for illicit discharge elimination: a) Within twenty-four (24) hours of identification of an illicit discharge that has a reasonable likelihood of adversely affecting human health or the environment, the MS4 Operator must eliminate the illicit discharge; b) Within five (5) days of identification of an illicit discharge that does not have a reasonable likelihood of adversely affecting human health or the environment, the MS4 Operator must eliminate the illicit discharge,- and c) Where elimination of an illicit discharge within the specified timeframes (Part VII.C.3.a.iv.) is not possible, the MS4 Operator must notify the Regional Water Engineer. b. The training provisions for the MS4 Operator's illicit discharge elimination procedures (Part VII.C.3.a.). i. If new staff are added, training on the MS4 Operator's illicit discharge elimination procedures (Part VII.C.3.a.) must be given prior to conducting illicit discharge eliminations; ii. For existing staff, training on the MS4 Operator's illicit discharge elimination procedures (Part VII.C.3.a.) must be given prior to conducting illicit discharge eliminations and once every five (5) years, thereafter; and iii. If the illicit discharge elimination procedures (Part VII.C.3.a.) are updated (Part VII.C.3.d.), training on the updates must be given to all staff prior to conducting illicit discharge eliminations. c. The names, titles, and contact information for the individuals who have received illicit discharge elimination procedures training and update annually; and d. Annually, by April 1, the MS4 Operator must: i. Review and update the illicit discharge elimination procedures (Part VII.C.3.a.); and ii. Document the completion of this requirement in the SWMP Plan. D. MCM 4 - Construction Site Stormwater Runoff Control The MS4 Operator must develop, implement, and enforce a program to ensure construction sites are effectively controlled. This MCM is designed to prevent pollutants from construction related activities'50 as well as promote the proper planning and installation of post-construction SMPs. so Projects that comply with the terms and conditions of the CGP or an individual SPDES permit for stormwater for which they obtained coverage and local erosion and sediment control requirements are effectively controlled. 66 Part VI I.D. 1. Applicable Construction Activities/Projects/Sites a. The construction site stormwater runoff control program must address stormwater runoff to the MS4 from sites with construction activities permitted, approved, funded, or owned/operated by the MS4 Operator that: i. Result in a total land disturbance of greater than or equal to one acre; or, ii. Disturb less than one acre if part of a larger common plan of development or sale. b. For construction activities where the MS4 Operator is listed as the owner/operator on the Notice of Intent for coverage under the CGP: i. The MS4 Operator must ensure compliance with the CGP; and ii. The additional requirements for construction oversight described in Part VII.D.6 through Part VII.D.9 are not required. 2. Public Reporting of Construction Site Complaints a. Within six (6) months of the EDC, the MS4 Operator must establish and document in the SWMP Plan an email or phone number (with message recording capability) for the public to report complaints related to construction stormwater activity. b. The MS4 Operator must document reports of construction site complaints in the SWMP Plan with the following information: i. Date of the report; ii. Location of the construction site; iii. Nature of complaint; iv. Follow up actions taken or needed; and v. Inspection outcomes and any enforcement taken. 3. Construction Uvers gnt t-logram Within one (1) year of the EDC, the MS4 Operator must develop and implement a construction oversight program. The construction oversight program must be documented in the SWMP Plan specifying: a. The construction oversight procedures including: i. When the construction site stormwater control program applies (Part VII.D.1.); ii. What types of construction activity require a SWPPP; iii. The procedures for submission of SWPPPs; iv. SWPPP review requirements (Part VII.D.6.) v. Pre-construction oversight requirements (Part VII.D.7.) 67 Part VI I.D. vi. Construction site inspection requirements (Part VII.D.8.); vii. Construction site close-out requirements (Part VII.D.9.); viii. Enforcement process/expectations for compliance; and ix. Other procedures associated with the control of stormwater runoff from applicable construction activities. b. The training provisions for the MS4 Operator's construction oversight procedures (Part VII.D.3.a.). i. If new staff are added, training on the MS4 Operator's construction oversight procedures (Part VII.D.3.a.) must be given prior to conducting any construction oversight activities; ii. For existing staff, training on the MS4 Operator's construction oversight procedures (Part VII.D.3.a.) must be given prior to conducting any construction oversight activities and once every five (5) years, thereafter; and iii. If the construction oversight procedures (Part VII.D.3.a.) are updated (Part VII.D.3.a.), training on the updates must be given to all staff prior to conducting construction oversight. c. The names, titles, and contact information for the individuals who have received construction oversight training and update annually; d. Procedures to ensure those involved in the construction activity itself (e.g., contractor, subcontractor, qualified inspector, SWPPP reviewers) have received four (4) hours of Department endorsed training in proper erosion and sediment control principles from a Soil & Water Conservation District, or other Department endorsed entity; and e. Annually, by April 1 , the MS4 Operator must: i. Review and update the construction oversight procedures (Part VII.D.3.a.); and ii. Document the completion of this requirement in the SWMP Plan. 4. Construction Site inventory & inspection "I racking a. Within six (6) months of the EDC, the MS4 Operator must develop and maintain an inventory of all applicable construction sites (Part VII.D.1.a.) in the SWMP Plan. The following information must be included in the inventory: i. Location of the construction site; ii. Owner/operator contact information, if other than the MS4 Operator, iii. Receiving waterbody name and class (mapped in accordance with Part IV.D.1 .e.ii.a)); iv. Receiving waterbody WI/PWL Segment ID (mapped in accordance with Part IV.D.1 .e.ii.b)); 68 Part VI I.D. v. Prioritization (high or low) (Part VII.D.5.); vi. Construction project SPDES identification number; vii. SWPPP approval date; viii. Inspection history, including dates and ratings (satisfactory, marginal, or unsatisfactory, when available); and ix. Current status of the construction site/project (i.e., active, temporarily shut down, complete51) b. Annually, the MS4 Operator must update the inventory if construction projects are approved or completed. 5. Construction Site Prioritization a. Within one (1) year of the EDC, the MS4 Operator must prioritize all construction sites which are included in the construction site inventory (Part VII.D.4.) as follows: i. High priority construction sites include construction sites: a) With a direct conveyance (e.g., channel, ditch, storm sewer) to a surface water of the State that is: i) Listed in Appendix C with silt/sediment, phosphorus, or nitrogen as the POC; ii) Classified as AA-S, AA, or A (mapped in accordance with Part IV.D.1.e.ii.a)); or iii) Classified with a trout (T) or trout spawning (TS) designation (mapped in accordance with Part IV.D.1.e.ii.a)); b) With greater than five (5) acres of disturbed earth at any one time; c) With earth disturbance within one hundred (100) feet of any lake or pond (mapped in accordance with Part IV.D.1 .e.ii.b)); and/or d) Within fifty (50) feet of any rivers or streams (mapped in accordance with Part IV.D.1.e.ii.b)); ii. All other construction sites are considered low priority. b. Within thirty (30) days of when a construction site becomes active, the MS4 Operator must prioritize those construction sites; and c. Annually, after the initial prioritization (Part VII.D.5.a.), the MS4 Operator must update the construction site prioritization in the inventory (Part VII.D.4.a.) based on information gathered as part of the construction oversight program (Part VII.D.3.). The completion of this permit requirement must be documented in the SWMP Plan. 51 Construction projects listed on the inventory must be inspected and tracked as described in Part VII.D.8. until a final site inspection has been completed as specified in Part VII.D.9. and the construction site status changes to complete. 69 Part VI I.D. i. If the prioritization of the construction site changes priority based on information gathered as part of the construction oversight program, the MS4 Operator must comply with the requirements that apply to that prioritization. 6. SWPPP Review The MS4 Operator must: a. Ensure individual(s), responsible for reviewing SWPPPs for acceptance, receive: i. Four (4) hours of Department endorsed training in proper erosion and sediment control principles from a Soil & Water Conservation District, or other Department endorsed entity. This training must be completed within three (3) years of the EDC and every three (3) years thereafter. ii. Document the completion of this requirement in the SWMP Plan. b. Ensure SWPPP reviewers receive this training (Part VII.D.6.a.) prior to conducting SWPPP reviews for acceptance. i. Individuals without these trainings cannot review SWPPPs for acceptance. ii. Individuals who meet the definition of a qualified professional or qualified inspector are exempt from this requirement. c. Ensure individuals responsible for reviewing SWPPPs review all SWPPPs for applicable construction activities (Part VII.D.1 .) and for conformance with the requirements of the CGP, including: i. Erosion and sediment controls must be reviewed for conformance with the NYS E&SC 2016, or equivalent; ii. Individuals responsible for review of post-construction SMPs must be qualified professionals or under the supervision of a qualified professional; and iii. Post-construction SMPs must be reviewed for conformance with the NYS SWMDM 2015 or equivalent, including: a) All post-construction SMPs must meet the sizing criteria contained in the CGP and NYS SWMDM 2015. b) Deviations from the performance criteria of the NYS SWMDM 2015 must demonstrate that they are equivalent. c) The SWPPP must include an O&M plan that includes inspection and maintenance schedules and actions to ensure continuous and effective operation of each post-construction SMP. The SWPPP must identify the entity that will be responsible for the long-term operation and maintenance of each practice. 70 Part VI I.D. d. In the SWMP Plan, document and update annually the names, titles, and contact information for the individuals who have received the trainings listed in Part VII.D.6.a. e. In the SWMP Plan, document the SWPPP review including the information found in Part III.B. of the CGP; f. Prioritize new construction activities (Part VII.D.5.a.); and g. Notify construction site owner/operators that their SWPPP has been accepted using the MS4 SWPPP Acceptance Form52 created by the Department and required by the CGP, signed in accordance with Part X.J. 7. Pre-Construction Meeting Prior to commencement of construction activities, the MS4 Operator must ensure a pre-construction meeting is conducted. The date and content of the pre- construction inspection/meeting must be documented in the SWMP Plan. The owner/operator listed on the CGP NOI (if different from the MS4 Operator), the MS4 Operator, contractor(s) responsible for implementing the SWPPP for the construction activity, and the qualified inspector(if required for the construction activity by Part IV.C. the CGP) must attend the meeting in order to: a. Confirm the approved project has received, or will receive53, coverage under the CGP or an individual SPDES permit; b. Verify contractors and subcontractors selected by the owner/operator of the construction activity have identified at least one individual that has received four (4) hours of Department endorsed training in proper erosion and sediment control principles from a Soil & Water Conservation District or other endorsed entity as required by the CGP and Part VII.D.3.d; and c. Review the construction oversight program (Part VII.D.3.) and expectations for compliance. 8. Construction Site Inspections The MS4 Operator must: a. Ensure individuals(s), responsible for construction site inspections, receive: i. Four (4) hours of Department endorsed training in proper erosion and sediment control principles from a Soil & Water Conservation District, or other Department endorsed entity. This training must be complete, within three (3) years of the EDC and every three (3) years thereafter. ii. Document the completion of this requirement in the SWMP Plan. 52 The MS4 SWPPP Acceptance Form can be found on the Department's website. 53 Preconstruction meetings may occur prior to the issuance of the MS4 SWPP Acceptance Form, however, the MS4 Operator must confirm coverage under the CGP will be applied for by the construction site owner/operator prior to commencement of construction of construction activities. 71 Part VI I.D. b. Ensure all MS4 Construction Site Inspectors receive this training prior to conducting construction site inspections. i. Individuals without these trainings cannot inspect construction sites. ii. Individuals who meet the definition of a qualified professional or qualified inspector are exempt from this requirement. c. Annually inspect all sites with construction activity identified in the inventory (Part VII.DA.) during active construction after the pre-construction meeting (Part VII.D.7.), or sooner if deficiencies are noted that require attention. i. Follow up to construction site inspections must confirm corrective actions are completed within timeframes established by the CGP and the MS4 Operator's ERP (Part IV.F.1.). d. In the SWMP Plan, document and update annually the names, titles, and contact information for the individuals who have received the trainings listed in Part VII.D.8.a. e. Document all inspections using the Construction Site Inspection Report Form (Appendix D) or an equivalent form containing the same information. The MS4 Operator must include the completed Construction Site Inspection Reports in the SWMP Plan. 9. Construction Site Close-out a. The MS4 Operator must ensure a final construction site inspection is conducted and documentation of the final construction site inspection must be maintained in the SWMP Plan. The final construction site inspection must be documented using the Construction Site Inspection Report Form (Appendix D), or an equivalent form containing the same information, or accept the construction site owner/operator's qualified inspector final inspection certification required by the CGP. b. The Notice of Termination (NOT)54 must be signed by the MS4 Operator as required by the CGP for projects determined to be complete. The NOT must be signed in accordance with Part X.J. E. MCM 5 — Post-Construction Stormwater Management The MS4 Operator must develop, implement, and enforce a program to ensure proper operation and maintenance of post-construction SMPs for new or redeveloped sites. This MCM is designed to promote the long-term performance of post-construction SMPs in removing pollutants from stormwater runoff. sa The NOT can be found on the Department's website. 72 Part VI I.E. 1. Applicable Post-Construction SMPs The post-construction SMP program must address stormwater runoff to the MS4 from publicly owned/operated post-construction SMPs that meet the following: a. Post-construction SMPs that have been installed as part of any CGP covered construction site or individual SPDES permit (since March 10, 2003); and b. All new post-construction SMPs constructed as part of the construction site stormwater runoff control program (Part VII.D.). 2. Post-Construction SMP Inventory & Inspection Tracking55 a. The MS4 Operators continuing coverage must: i. Maintain the inventory from previous iterations of this SPDES general permit for post-construction SMPs installed after March 10, 2003; and ii. Develop the inventory for post-construction SMPs installed after March 10, 2003 including post-construction SMPs. a) As they are approved or discovered; or b) After the owner/operator of the construction activity has filed the NOT with the Department (Part VII.D.9.b.). b. The newly designated MS4 Operators must develop and maintain the inventory for post-construction SMPs installed after March 10, 2003 including post-construction SMPs: i. As they are approved or discovered; or ii. After the owner/operator of the construction activity has filed the NOT with the Department (Part VII.D.9.b.). c. Annually, the MS4 Operator must update the inventory of post-construction SMPs to include the post-construction SMPs in Part VII.E.2.a. and Part VII.E.2.b. d. Within five (5) years of the EDC, the following information must be included in the inventory either by using the MS4 Operator maintenance records or by verification of maintenance records provided by the owner of the post- construction SMP: i. Street address or tax parcel; ii. Type;56 iii. Receiving waterbody name and class (mapped in accordance with Part IV.D.1 .e.ii.a)); 55 Post-construction SMPs can be found at a municipal facility. 56 Post-construction SMP types are defined in the New York State Department of Environmental Conservation Maintenance Guidance: Stormwater Management Practices, March 31, 2017 (NYS DEC Maintenance Guidance 2017). 73 Part VI I.E. iv. Receiving waterbody WI/PWL Segment ID (mapped in accordance with Part IV.D.1 .e.ii.b)); v. Date of installation (if available) or discovery; vi. Ownership; vii. Responsible party for maintenance; viii. Contact information for party responsible for maintenance; ix. Location of documentation depicting O&M requirements and legal agreements for post-construction SMP; x. Frequency for inspection of post-construction SMP, as specified in the New York State Department of Environmental Conservation Maintenance Guidance: Stormwater Management Practices, March 31 , 2017 (NYS DEC Maintenance Guidance 2017) or as specified in the O&M plan contained in the approved SWPPP (Part VII.D.6.); xi. Reason for installation (e.g., new development, redevelopment, retrofit, flood control), if known; xii. Date of last inspection; xiii. Inspection results; and xiv. Any corrective actions identified and completed. e. MS4 Operators must document the inventory of post-construction SMPs in the SWMP Plan. 3. SWPPP Review For post-construction SMP SWPPP review requirements, see Part VII.D.6. 4. Post-Construction SMP Inspection & Maintenance Program Within one (1) year of the EDC, the MS4 Operator must develop and implement a post-construction SMP inspection and maintenance program. The post- construction SMP inspection and maintenance program must be documented in the SWMP Plan specifying: a. The post-construction SMP inspection and maintenance procedures including: i. Provisions to ensure that each post-construction SMP identified in the post-construction SMP inventory (Part VII.E.2.) is inspected at the frequency specified in the NYS DEC Maintenance Guidance 2017 or as specified in the O&M plan contained in the approved SWPPP (Part VII.D.6.), if available; 74 Part VI I.E. ii. Documentation of post-construction SMP inspections using the Post- Construction SMP Inspection Checklist57 or an equivalent form containing the same information. The MS4 Operator must include the completed post-construction SMP inspections (i.e., the completed Post-Construction SMP Inspection Checklist) in the SWMP Plan; iii. Provisions to initiate follow-up actions (i.e., maintenance, repair, or higher- level inspection) within thirty (30) days of post-construction SMP inspection; and iv. Provisions to initiate enforcement within sixty (60) days of the inspection if follow-up actions are not complete. b. The training provisions for the MS4 Operator's post-construction SMP inspection and maintenance procedures (Part VII.E.4.a.). i. If new staff are added, training on the MS4 Operator's post-construction SMP inspection and maintenance procedures (Part VII.E.4.a.) and procedures outlined in the Department endorsed program must be given prior to conducting any post-construction SMP inspection and maintenance; ii. For existing staff, training on the MS4 Operator's post-construction SMP inspection and maintenance procedures (Part VII.E.4.a.) and procedures outlined in the Department endorsed program must be given prior to conducting any post-construction SMP inspection and maintenance and once every five (5) years, thereafter; and iii. If the post-construction SMP inspection and maintenance procedures (Part VII.E.4.a.) are updated (Part VII.E.4.d.), training on the updates must be given to all staff prior to conducting post-construction SMP inspection and maintenance. c. The names, titles, and contact information for the individuals who have received post-construction SMP inspection and maintenance procedures training and update annually; and d. Annually, by April 1, the MS4 Operator must: i. Review and update the post-construction SMP inspection and maintenance procedures (Part VII.E.4.a.); and ii. Document the completion of this requirement in the SWMP Plan. F. MCM 6 — Pollution Prevention and Good Housekeeping The MS4 Operator must develop and implement a pollution prevention and good housekeeping program for municipal facilities and municipal operations to minimize 57 The Department developed checklist forms specific to each post-construction SMP designed to assist MS4 Operators in conducting inspections and maintenance activities of standard practices. The Post-Construction SMP Inspection Checklist, March 31, 2017, can be found on the Department's website. 75 Part VII.F. pollutant discharges. This MCM is designed to ensure the MS4 Operator's own activities do not contribute pollutants to surface waters of the State. 1. Best Management Practices (BMPs) for Municipal Facilities & Operations Within three (3) years of the EDC, the MS4 Operator must incorporate best management practices (BMPs) into the municipal facility program and municipal operations program to minimize the discharge of pollutants associated with municipal facilities and municipal operations, respectively. The BMPs to be considered are as follows and must be documented in the SWMP Plan: a. Minimize Exposure i. Exposure of materials to rain, snow, snowmelt, and runoff must be minimized, unless not technologically possible or not economically practicable and achievable in light of best industry practices, including areas used for loading and unloading, storage, disposal, cleaning, maintenance, and fueling operations, with the following BMPs: a) Locate materials and activities inside or protect them with storm resistant coverings; b) Use grading, berming, or curbing to prevent runoff of contaminated flows and divert run-on away from these areas; c) Locate materials, equipment, and activities so leaks and spills are contained in existing containment and diversion systems; d) Clean up spills and leaks promptly using dry methods (e.g., absorbents) to prevent the discharge of pollutants; e) Store leaky vehicles and equipment indoors or, if stored outdoors, use drip pans and absorbents; f) Use spill/overflow protection equipment; g) Perform all vehicle and/or equipment cleaning operations indoors, under cover, or in bermed areas that prevent runoff and run-on and also captures any overspray; h) Drain fluids, indoors or under cover, from equipment and vehicles that will be decommissioned, and, for any equipment and vehicles that will remain unused for extended periods of time, inspect at least monthly for leaks; and/or i) Minimize exposure of chemicals by replacing with a less toxic alternative (e.g., use non-hazardous cleaners). ii. No Exposure Certification for High Priority Municipal Facilities a) Municipal facilities may qualify for No Exposure Certification (Appendix D) when all activities and materials are completely sheltered from exposure to rain, snow, snowmelt and/or runoff. 76 Part VII.F. b) High priority municipal facilities (Part VII.F.2.c.i.a)) with uncovered parking areas for vehicles awaiting maintenance may be considered a low priority municipal facility (Part VII.F.2.c.i.c)) if only routine maintenance is performed inside and all other no exposure criteria are met. c) Municipal facilities accepting or repairing disabled vehicles and/or vehicles that have been involved in accidents are not eligible for the No Exposure Certification. d) Municipal facilities must maintain the No Exposure Certification and document in the SWMP Plan. The No Exposure Certification ceases to apply when activities or materials become exposed. b. Follow a Preventive Maintenance Program i. Implement a preventative maintenance program that includes routine inspection, testing, maintenance, and repair of all fueling areas, vehicles and equipment and systems to prevent leaks, spills and other releases. This includes: a) Performing inspections and preventive maintenance of stormwater drainage, source controls, treatment systems, and plant equipment and systems; b) Maintaining non-structural BMPs (e.g., keep spill response supplies available, personnel appropriately trained, containment measures, covering fuel areas); and c) Ensure vehicle washwater is not discharged to the MS4 or to surface waters of the State. Wash equipment/vehicles in a designated and/or covered area where washwater is collected to be recycled or discharged to the sanitary sewer (Part I.B.2.d.). ii. Routine maintenance must be performed to ensure BMPs are operating properly. iii. When a BMP is not functioning to its designed effectiveness and needs repair or replacement: a) Maintenance must be performed before the next anticipated storm event, or as necessary to maintain the continued effectiveness of stormwater controls. If maintenance prior to the next anticipated storm event is impracticable, maintenance must be scheduled and accomplished as soon as practicable; and b) Interim measures must be taken to prevent or minimize the discharge of pollutants until the final repair or replacement is implemented, including cleaning up any contaminated surfaces so that the material will not be discharged during subsequent storm events. 77 Part VI I.F. c. Spill Prevention and Response Procedures i. Minimize the potential for leaks, spills and other releases that may be exposed to stormwater and develop plans for effective response to such spills if or when they occur. At a minimum, the MS4 Operator must: a) Store materials in appropriate containers; b) Label containers (e.g., "Used Oil," "Spent Solvents," "Fertilizers and Pesticides") that could be susceptible to spillage or leakage to encourage proper handling and facilitate rapid response if spills or leaks occur; c) Implement procedures for material storage and handling, including the use of secondary containment and barriers between material storage and traffic areas, or a similarly effective means designed to prevent the discharge of pollutants from these areas; d) Develop procedures for stopping, containing, and cleaning up leaks, spills, and other releases. As appropriate, execute such procedures as soon as possible; e) Keep spill kits on-site, located near areas where spills may occur or where a rapid response can be made; f) Develop procedures for notification of the appropriate facility personnel, emergency response agencies, and regulatory agencies when a leak, spill, or other release occurs. If possible, one of these individuals should be a member of the stormwater pollution prevention team (Part VII.F.2.d.i.a)). Any spills must be reported in accordance with 6 NYCRR 750-2.7; and g) Following any spill or release, the MS4 Operator must evaluate the adequacy of the BMPs identified in the municipal facility specific SWPPP. If the BMPs are inadequate, the SWPPP must be updated to identify new BMPs that will prevent reoccurrence and improve the emergency response to such releases. ii. Measures for cleaning up spills or leaks must be consistent with applicable petroleum bulk storage, chemical bulk storage, or hazardous waste management regulations at 6 NYCRR Parts 596-599, 613 and 370-373. iii. This SPDES general permit does not relieve the MS4 Operator of any reporting or other requirements related to spills or other releases of petroleum or hazardous substances. Any spill of a hazardous substance must be reported in accordance with 6 NYCRR 597.4. Any spill of petroleum must be reported in accordance with 6 NYCRR 613.6 or 17 NYCRR 32.3. d. Erosion and Sediment CControIS58 i. Stabilize exposed areas and control runoff using structural and/or non- structural controls to minimize onsite erosion and sedimentation. 58 The use of the term"controls" in Part VII.F.1.d. aligns with the use of the term"controls" in the CGP. 78 Part VI I.F. ii. The MS4 Operator must consider: a) Structural and/or non-structural controls found in the NYS E&SC 2016; b) Areas that, due to topography, land disturbance (e.g., construction), or other factors, have potential for significant soil erosion; c) Whether structural, vegetative, and/or stabilization BMPs are needed to limit erosion; d) Whether velocity dissipation devices (or equivalent measures) are needed at discharge locations and along the length of any channel to provide a non-erosive flow velocity from the structure to a water course; and e) Address erosion or areas with poor vegetative cover, especially if the erosion is within fifty (50) feet of a surface water of the State e. Manage Vegetated Areas and Open Space on Municipal Property i. Maintain vegetated areas on MS4 Operator owned/operated property and right of ways: a) Specify proper use, storage, and disposal of pesticides, herbicides, and fertilizers including minimizing the use of these products and using only in accordance manufacturer's instruction; b) Use lawn maintenance and landscaping practices that are protective of water quality. Protective practices include: reduced mowing frequencies; proper disposal of lawn clippings; and use of alternative landscaping materials (e.g., drought resistant planting); c) Place pet waste disposal containers and signage concerning the proper collection and disposal of pet waste at all parks and open space where pets are permitted; and d) Address waterfowl congregation areas where needed to reduce waterfowl droppings from entering the MS4. f. Salt59 Storage Piles or Pile Containing Salt Enclose or cover storage piles of salt, or piles containing salt, used for deicing or maintenance of paved surfaces, except during loading, unloading, and handling. Implement appropriate measures (e.g., good housekeeping, routine sweeping, diversions, containment) to minimize exposure resulting from adding to or removing materials from the pile. g. Waste, Garbage, and Floatable Debris i. Keep all dumpster lids closed when not in use. For dumpsters and roll off boxes that do not have lids and could leak, ensure that discharges have a control (e.g., secondary containment, treatment); and 59 For purposes of this SPDES general permit, salt means any chloride-containing material used to treat paved surfaces for deicing, including sodium chloride, calcium chloride, magnesium chloride, and brine solutions. 79 Part VI I.F. ii. Keep exposed areas free of waste, garbage, and debris or intercept them before they are discharged: a) Manage trash containers at parks and open space (scheduled cleanings; sufficient number); b) Pick up trash and debris on MS4 Operator owned/operated property and rights of way; and c) Clean out catch basins within the appropriate timeframes (Part VII.F.3.c.iii.). h. Alternative Implementation Options When alternative implementation options (Part IV.A.1.) are utilized, require the parties performing municipal operations as contracted services, including but not limited to street sweeping, snow removal, and lawn/grounds care, to meet permit requirements as the requirements apply to the activity performed. 2. Municipal Facilities60 a. Municipal Facility Program Within three (3) years of the EDC, the MS4 Operator must develop and implement a municipal facility program. The municipal facility program must be documented in the SWMP Plan specifying: i. The municipal facility procedures including: a) The BMPs (Part VII.F.1.) incorporated into the municipal facility program; b) The high priority municipal facility requirements (Part VII.F.2.d.) as applied to the specific municipal facility; and c) The low priority municipal facility requirements (Part VII.F.2.e.) as applied to the specific municipal facility. ii. The training provisions for the MS4 Operator's municipal facility procedures (Part VII.F.2.a.i.). a) If new staff are added, training on the MS4 Operator's municipal facility procedures (Part VII.F.2.a.i.) must be given prior to conducting municipal facility procedures; b) For existing staff, training on the MS4 Operator's municipal facility procedures (Part VII.F.2.a.i.) must be given prior to conducting municipal facility procedures and once every five (5) years, thereafter; and 60 Municipal facilities that have coverage under a separate SPDES permit(either individual or MSGP)must comply with the terms and conditions of that permit and the requirements set forth in this Part are not applicable. 80 Part VI I.F. c) If the municipal facility procedures (Part VII.F.2.a.i.) are updated (Part VII.F.2.a.iv.), training on the updates must be given to all staff prior to conducting municipal facility procedures. iii. The names, titles, and contact information for the individuals who have received municipal facility training and update annually; and iv. Annually, by April 1 , the MS4 Operator must: a) Review and update the municipal facility procedures (Part VII.F.2.a.i.); and b) Document the completion of this requirement in the SWMP Plan. b. Municipal Facility Inventory i. Within two (2) years of the EDC, the MS4 Operator must develop and maintain an inventory of all municipal facilities in the SWMP Plan. The following information must be included in the inventory: a) Name of municipal facility; b) Street address; c) Type of municipal facility; d) Prioritization (high or low) (Part VII.F.2.c.); e) Receiving waterbody name and class (mapped in accordance with Part IV.D.1.e.ii.a)); f) Receiving waterbody WI/PWL Segment ID (mapped in accordance with Part IV.D.1.e.ii.b)); g) Contact information; h) Responsible department; i) Location of SWPPP (if high priority; when completed); j) Type of activities present on site; k) Size of facility (acres); 1) Date of last assessment; m) BMPs identified; and n) Projected date of next comprehensive site assessment (Part VII.F.2.d.ii.c) or Part VII.F.2.e.ii.c), depending on the municipal facility prioritization (Part VII.F.2.c.)). ii. Annually, the MS4 Operator must update the inventory if new municipal facilities are added. c. Municipal Facility Prioritization i. Within three (3) years of the EDC, the MS4 Operator must prioritize all known municipal facilities as follows: 81 Part VI I.F. a) High priority municipal facilities include municipal facilities that have one or more of the following on site and exposed to stormwater: i) Storage of chemicals, salt, petroleum, pesticides, fertilizers, anti- freeze, lead-acid batteries, tires, waste/debris; ii) Fueling stations; and/or iii) Vehicle or equipment maintenance/repair. b) Low priority municipal facilities include any municipal facilities that do not meet the criteria for a high priority (Part VII.F.2.c.i.a)) municipal facility. c) High priority municipal facilities (Part IV.F.2.c.i.a)) which qualify for a No Exposure Certification (Part VII.F.1.a.ii.) are low priority municipal facilities. ii. Within thirty (30) days of when a municipal facility is added to the inventory, the MS4 Operator must prioritize those municipal facilities; and iii. Annually, after the initial prioritization (Part VII.F.2.c.i.), the MS4 Operator must update the municipal facility prioritization in the inventory (Part VII.F.2.b.i.) based on information gathered as part of the municipal facility program (Part VII.F.2.a.), including cases where a No Exposure Certification (Part VII.F.1.a.ii.) ceases to apply. The completion of this permit requirement must be documented in the SWMP Plan. d. High Priority Municipal Facility Requirements i. Municipal Facility Specific SWPPP Within five (5) years of the EDC, MS4 Operators must develop and implement a municipal facility specific SWPPP for each high priority municipal facility (Part VII.F.2.c.i.a)) and retain a copy of the municipal facility specific SWPPP on site of the respective municipal facility. The SWPPP must contain: a) Stormwater Pollution Prevention Team The municipal facility specific SWPPP must identify the individuals (by name and/or title) and their role/responsibilities in developing, implementing, maintaining, and revising the municipal facility specific SWPPP. The activities and responsibilities of the team must address all aspects of the municipal facility specific SWPPP. b) General Site Description A written description of the nature of the activities occurring at the municipal facility with a potential to discharge pollutants, type of pollutants expected, and location of key features as detailed in the site map (Part VII.F.2.d.i.e)). c) Summary of potential pollutant sources 82 Part VII.F. The municipal facility specific SWPPP must identify each area at the municipal facility where materials or activities are exposed to stormwater or from which authorized non-stormwater discharges (Part I.A.3.) originate, including any potential pollutant sources for which the municipal facility has reporting requirements under the Emergency Planning and Community Right-To-Know Act (EPCRA), Section 313. i) Materials or activities include: machinery; raw materials; intermediate products; byproducts; final products or waste products; and material handling activities which includes storage, loading and unloading, transportation or conveyance of any raw material, intermediate product, final product or waste product. ii) For each separate area identified, the description must include: (a) Activities - A list of the activities occurring in the area (e.g., material storage, equipment fueling and cleaning); (b) Pollutants - A list of the associated pollutant(s) for each activity. The pollutant(s) list must include all materials that are exposed to stormwater; and (c) Potential for presence in stormwater- For each area of the municipal facility that generates stormwater discharges, a prediction of the direction of flow, and the likelihood of the activity to contaminate the stormwater discharge. Factors to consider include the toxicity of chemicals, quantity of chemicals used, produced or discharged, the likelihood of contact with stormwater, and history of leaks or spills of toxic or hazardous pollutants. d) Spills and Releases For areas that are exposed to precipitation or that otherwise drain to a stormwater conveyance to be covered under this SPDES general permit, the municipal facility specific SWPPP must include a list of spills or releases61 of petroleum and hazardous substances or other pollutants, including unauthorized non-stormwater discharges, that may adversely affect water quality that occurred during the last three-year period. The list must be updated when spills or releases occur. e) Site Map The municipal facility specific SWPPP must include a site map identifying the following, as applicable: i) Property boundaries and size in acres; 61 This may also include releases of petroleum or hazardous substances that are not in excess of reporting quantities but which may still cause or contribute to significant water quality impairment. 83 Part VI I.F. ii) Location and extent of significant structures (including materials shelters), and impervious surfaces; iii) Monitoring locations (mapped in accordance with Part IV.D.2.a.i.) with its approximate sewershed. Each monitoring location must be labeled with the monitoring location identification; iv) Location of all post-construction SMPs (mapped in accordance with Part IV.D.2.a.iv.) and MS4 infrastructure (mapped in accordance with Part IV.D.2.b.i.); v) Locations of discharges authorized under other SPDES permits; vi) Locations where potential spills or releases can contribute to pollutants in stormwater discharges and their accompanying drainage points; vii) Locations of haul and access roads; viii)Rail cars and tracks; ix) Arrows showing direction of stormwater flow; x) Location of all receiving waters in the immediate vicinity of the municipal facility, indicating if any of the waters are impaired and, if so, whether the waters have TMDLs established for them (mapped in accordance with Part IV.D.1.e.ii.); xi) Locations where stormwater flows have significant potential to cause erosion; xii) Location and source of run-on from adjacent property containing significant quantities of pollutants and/or volume of concern to the municipal facility; and xiii) Locations of the following areas where such areas are exposed to precipitation or stormwater. (a) Fueling stations; (b) Vehicle and equipment maintenance and/or cleaning areas; (c) Loading/unloading areas; (d) Locations used for the treatment, storage or disposal of wastes; (e) Liquid storage tanks; (f) Processing and storage areas; (g) Locations where significant materials, fuel or chemicals are stored and transferred; (h) Locations where vehicles and/or machinery are stored when not in use (i) Transfer areas for substances in bulk; (j) Location and description of non-stormwater discharges (Part I.A.3.); 84 Part VI I.F. (k) Locations where spills62 or leaks have occurred; and (1) Locations of all existing structural BMPs. f) Stormwater Best Management Practices (BMPs) The municipal facility specific SWPPP must document the location and type of BMPs implemented at the municipal facility (Part VII.F.1). The municipal facility specific SWPPP must describe how each BMP is being implemented for all the potential pollutant sources. g) Municipal facility assessments The municipal facility specific SWPPP must include a schedule for completing and recording results of routine and comprehensive site assessments (Part VII.F.2.d.ii.c)). ii. Municipal Facility Assessments a) Wet Weather Visual Monitoring i) Once every five (5) years, the MS4 Operator must conduct wet weather visual monitoring of the monitoring locations (Part VII.C.1 .b.) and other sites of stormwater leaving the site that are discharging stormwaterfrom fueling areas, storage areas, vehicle and equipment maintenance/fueling areas, material handling areas and similar potential pollutant generating areas (Part VI I.F.2.d.i.e)xiii)). (a) All samples must be collected from discharges resulting from a qualifying storm event. The storm event must be documented using the Storm Event Data Form (Appendix D) and kept with the municipal facility specific SWPPP. The sample must be taken during the first thirty (30) minutes (or as soon as practical, but not to exceed one hour) of the discharge at the monitoring location. (b) No analytical tests are required to be performed on the samples for the purpose of meeting the visual monitoring requirements. (c) The visual examination must document observations of color, odor, clarity, floating solids, settled solids, suspended solids, foam, oil sheen, and any other obvious indicators of stormwater pollution. (d) The visual examination of the sample must be conducted in a well-lit area. (e) Where practicable, the same individual should carry out the collection and examination of discharges for the entire permit term for consistency. 62 A spill includes: any spill of a hazardous substance that must be reported in accordance with 6 NYCRR 597.4 and any spill of petroleum that must be reported in accordance with 6 NYCRR 613.6 or 17 NYCRR 32.3. 85 Part VI I.F. (f) The MS4 Operator must document the visual examination using the Visual Monitoring Form (Appendix D) and keep it with the municipal facility specific SWPPP to record: (i) Monitoring location ID; (ii) Examination date and time; (iii) Personnel conducting the examination; (iv) Nature of the discharge (runoff or snowmelt); (v) Visual quality of the stormwater discharge including observations of color, odor, clarity, floating solids, settled solids, suspended solids, foam, oil sheen, and other obvious indicators of stormwater pollution; and (vi) Probable sources of any observed stormwater contamination. (vii) Corrective and follow up actions — If the visual examination indicates the presence of color, odor, floating solids, settled solids, suspended solids, foam, oil sheen, or other indicators of stormwater pollution, the MS4 Operator must, at minimum, complete and document the following actions: (1) Evaluate the facility for potential sources; (2) Remedy the problems identified; (3) Revise the municipal facility specific SWPPP; and (4) Perform an additional visual inspection during the first qualifying storm event following implementation of the corrective action. If the first qualifying storm event does not occur until the next visual monitoring period, this follow up action may be used as the next visual inspection. b) The monitoring locations inspection and sampling program must be implemented at the municipal facility (Part VII.C.1.e.). c) Comprehensive Site Assessments i) Once every five (5) years following the most recent assessment, the MS4 Operator must complete a comprehensive site assessment for each high priority municipal facility as identified in the inventory (Part VII.F.2.b.) using the Municipal Facility Assessment Form (Appendix D) or an equivalent form containing the same information, and document in the municipal facility specific SWPPP and SWMP Plan that: 86 Part VII.F. (a) The municipal facility is in compliance with the terms and conditions of this SPDES general permit; (b) Deficiencies were identified and all reasonable steps will be taken to minimize any discharge in violation of the permit, which has a reasonable likelihood of adversely affecting human health or the environment; (i) Within twenty-four (24) hours, the MS4 Operator must prepare a schedule that includes corrective actions and specific interim milestones to be implemented until the corrective action is implemented; or (c) Deficiencies were identified and all reasonable steps will be taken to minimize any discharge in violation of the permit, which does not have a reasonable likelihood of adversely affecting human health or the environment; (i) Within seven (7) days, the MS4 Operatormust prepare a schedule that includes corrective actions and specific interim milestones to be implemented until the corrective action is implemented. e. Low Priority Municipal Facility Requirements i. The MS4 Operator must identify procedures outlining BMPs for the types of activities that occur at the low priority municipal facilities as described in Part VII.F.1. A municipal facility specific SWPPP is not required. ii. Municipal Facility Assessments a) Low priority municipal facilities are not required to conduct wet weather visual monitoring. b) The monitoring locations inspection and sampling program must be implemented at the municipal facility (Part VII.C.1.e.). c) Comprehensive Site Assessments i) Once every five (5) years following the most recent assessment, the MS4 Operator must complete a comprehensive site assessment for each low priority municipal facility as identified in the inventory (Part VII.F.2.b.) using the Municipal Facility Assessment Form (Appendix D) or an equivalent form containing the same information, and document in the SWMP Plan that: (a) The municipal facility is in compliance with the terms and conditions of this SPDES general permit; (b) Deficiencies were identified and all reasonable steps will be taken to minimize any discharge in violation of the permit, which has a reasonable likelihood of adversely affecting human health or the environment; 87 Part VII.F. (i) Within twenty-four (24) hours, the MS4 Operatormust prepare a schedule that includes corrective actions and specific interim milestones to be implemented until the corrective action is implemented; or (c) Deficiencies were identified and all reasonable steps will be to minimize any discharge in violation of the permit, which does not have a reasonable likelihood of adversely affecting human health or the environment; (i) Within seven (7) days, the MS4 Operator must prepare a schedule that includes corrective actions and specific interim milestones to be implemented until the corrective action is implemented. 3. Municipal Operations & Maintenance a. Municipal Operations Program Municipal operations are: street and bridge maintenance; winter road maintenance; MS4 maintenance; open space maintenance; solid waste management; new construction and land disturbances; right-of-way maintenance; marine operations; or hydrologic habitat modification. Within three (3) years of the EDC, the MS4 Operator must develop and implement a municipal operations program. The municipal operations program must be documented in the SWMP Plan specifying: i. The municipal operations procedures including: a) The BMPs (Part VII.F.1.) incorporated into the municipal operations program; b) The municipal operations corrective actions requirements (Part VII.F.3.b.); c) Catch basin inspection and maintenance requirements (Part VII.F.3.c.); d) Roads, bridges, parking lots, and right of way maintenance requirements (Part VII.F.3.d.); and e) All other municipal operations maintenance requirements. ii. The training provisions for the MS4 Operator's municipal operations procedures (Part VII.F.3.a.i.). a) If new staff are added, training on the MS4 Operator's municipal operations procedures (Part VII.F.3.a.i.) must be given prior to conducting municipal operations procedures; b) For existing staff, training on the MS4 Operator's municipal operations procedures (Part VII.F.3.a.i.) must be given prior to conducting 88 Part VII.F. municipal operations procedures and once every five (5) years, thereafter; and c) If the municipal operations procedures (Part VII.F.3.a.i.) are updated (Part VII.F.3.a.iv.), training on the updates must be given to all staff prior to conducting municipal operations procedures. iii. The names, titles, and contact information for the individuals who have received municipal operations training and update annually; and iv. Annually, by April 1 , the MS4 Operator must: a) Review and update the municipal operations procedures (Part VII.F.3.a.i.); and b) Document the completion of this requirement in the SWMP Plan. b. Municipal Operations Corrective Actions i. For municipal operations, MS4 Operators must either: a) Ensure compliance with the terms and conditions of this SPDES general permit; or b) Implement corrective actions according to the following schedule and, after implementation, ensure the operations are in compliance with the terms and conditions of this SPDES general permit: i) Within twenty-four (24) hours of discovery for situations that have a reasonable likelihood of adversely affecting human health or the environment; ii) Initiated within seven (7) days of inspection and completed within thirty (30) days of inspection for situations that do not have a reasonable likelihood of adversely affecting human health or the environment; and iii) For corrective actions that require special funding or construction that will take longer than thirty (30) days to complete, a schedule must be prepared that specifies interim milestones that will ensure compliance in the shortest reasonable time. c. Catch Basin Inspection and Maintenance Within three (3) years of the EDC, the MS4 Operator must: i. Identify when catch basin inspection is needed with consideration for: a) Areas with construction activities (mapped in accordance with Part IV.D.2.a.iii.); b) Residential, commercial, and industrial areas (mapped in accordance with Part IV.D.1.d.iii.); c) Recurring or history of issues; or 89 Part VII.F. d) Confirmed citizen complaints on three or more separate occasions in the last twelve (12) months. ii. Inventory catch basin inspection information including: a) Date of inspection; b) Approximate level of trash, sediment, and/or debris captured at time of clean-out (no trash, sediment, and/or debris, <50% of the depth of the sump, >50% of the depth of the sump); c) Depth of structure; d) Depth of sump; and e) Date of clean out, if applicable (Part VII.F.3.c.iii.). iii. Based on inspection results, clean out catch basins within the following timeframes: a) Within six (6) months after the catch basin inspection, catch basins which had trash, sediment, and/or debris exceeding 50% of the depth of the sump as a result of a catch basin inspection must be cleaned out; b) Within one (1) year after the catch basin inspection, catch basins which had trash, sediment, and/or debris at less than 50% of the depth of the sump as a result of a catch basin inspection must be cleaned out; and c) MS4 Operators are not required to clean out catch basins if the catch basins are operating properly and: i. There is no trash, sediment, and/or debris in the catch basin; or ii. The sump depth of the catch basin is less than or equal to two (2) feet. iv. Properly manage (handling and disposal) materials removed from catch basins during clean out so that: a) Water removed during the catch basin cleaning process will not reenter the MS4 or surface waters of the State; b) Material removed from catch basins is disposed of in accordance with any applicable environmental laws and regulations; and c) Material removed during the catch basin cleaning process will not reenter the MS4 or surface waters of the State. v. Determine if there are signs/evidence of illicit discharges and procedures for referral/follow-up if illicit discharges are encountered. 90 Part VII.F. d. Roads, Bridges, Parking Lots, & Right of Way Maintenance i. Sweeping Within six (6) months of the EDC, the MS4 Operator must develop and implement procedures for sweeping and/or cleaning municipal streets, bridges, parking lots, and right of ways owned/operated by the MS4 Operator. The procedures and completion of permit requirements must be documented in the SWMP Plan specifying: a) All roads, bridges, parking lots, and right of ways must be swept and/or cleaned once every five (5) years in the spring (following winter activities such as sanding). This requirement is not applicable to: i) Uncurbed roads with no catch basins; ii) High-speed limited access highways; or iii) Roads defined as interstates, freeways and expressways, or arterials by the United States Department of Transportation, Federal Highway Administration, Highway Functional Classification Concepts, Criteria and Procedures, 2013. b) Annually, from April 1 through October 31 , roads in business and commercial areas must be swept. This requirement is not applicable to: i) Uncurbed roads with no catch basins; ii) High-speed limited access highways; or iii) Roads defined as interstates, freeways and expressways, or arterials by the USDOT 2013. ii. Maintenance Within five (5) years of the EDC, in addition to the BMPs (Part VII.F.1.), the MS4 Operator must implement the following provisions: a) Pave, mark, and seal in dry conditions; b) Stage road operations and maintenance activity (e.g., patching, potholes) to reduce the potential discharge of pollutants to the MS4 or surface waters of the State; c) Restrict the use of herbicides/pesticide application to roadside vegetation; and d) Contain pollutants associated with bridge maintenance activities (e.g., paint chips, dust, cleaning products, other debris). iii. Winter Road Maintenance Within five (5) years of the EDC, in addition to the BMPs (Part VII.F.1.), the MS4 Operator must implement the following provisions: a) Routinely calibrate equipment to control salt/sand application rates; and 91 Part VI I.F. b) Ensure that routine snow disposal activities comply with the Division of Water Technical and Operation Guidance Series 5.1.11, Snow Disposal.63 63 The Division of Water Technical and Operation Guidance Series 5.1.11, Snow Disposal can be found on the Department's website. 92 Part VIII Part VIII. Enhanced Requirements for Impaired Waters Part VIII. requirements must be implemented in addition to the applicable requirements of the six (6) MCMs in Part VI. or Part VII, depending on the MS4 Operatortype. Part VIII. requirements apply in the sewersheds which discharge to waters impaired for phosphorus, silt/sediment, pathogens, nitrogen, or floatables (Appendix C). MS4 outfalls are in the automatically designated area. ADA MS4 outfalls are in the additionally designated area subject to Criterion 3 of the Additional Designation Criteria (Appendix B). MS4 Operator's subject to Part VIII. that implement pollutant specific BMPs after the EDC but prior to MS4 infrastructure and sewershed mapping can use those BMPs to satisfy the permit requirements in this section. The Part VIII. requirements, applicable to the POC, must be incorporated in the MS4 Operator's SWMP and SWMP Plan. H. Pollutant Specific BMPs for Phosphorus Part VIII.A. must be implemented for all phosphorus impaired waters listed in Appendix C. 1. Mapping In accordance with the timeframes listed below, the MS4 Operatormust update, in geographic information system (GIS) format with a scale of 1-24,000 or finer, the comprehensive system mapping (Part IV.D.) to include: a. Within three (3) years of the EDC, MS4 infrastructure mapping requirements (Part IV.D.2.b.i.) and sewersheds for each: i. MS4 outfall; and ii. ADA MS4 outfall. b. Within three (3) years of the EDC, the following information for each MS4 outfall: i. Retail and wholesale plant nurseries (including big box stores); ii. Commercial lawn care facilities; and iii. Golf courses. c. Within three (3) years of the EDC, ADA MS4 outfalls. 2. Public Education and Outreach a. Within six (6) months of the EDC, the MS4 Operator must make available information on how the impairment is being addressed by implementation of the MS4 Operator's local law or legal mechanism with content equivalent to the model local law (Part IV.E.1 and Part IV.E.2.). MS4 Operators must document the completion of this requirement in the SWMP Plan. 93 Part VI II.A. b. Following the completion of Part VIII.A.1, twice a year, once from March to August and once from September to February, the MS4 Operator must provide educational messages with information specific to phosphorus to the applicable target audiences within the sewersheds for impaired waters listed in Appendix C focus area, identified in Part VI.A.1 .b. or Part VII.A.1 .b, depending on the MS4 Operator type. The SWMP Plan must be updated with changes made to public education and outreach program (Part VI.A or Part VILA, depending on the MS4 Operatortype). MS4 Operators must document the completion of this requirement in the SWMP Plan. 3. Public Involvement/Participation No additional requirements. 4. Illicit Discharge Detection and Elimination Following the completion of Part VIII.A.1, within five (5) years of the EDC, the MS4 Operator must include on the MS4 outfall inventory (Part VI.C.1.c. or Part VII.C.1.c, depending on the MS4 Operator type) the number of each item identified in Part VIII.A.1.b. for each associated MS4 outfall. 5. Construction Site Stormwater Runoff Control For Following the completion of Part VIII.A.1 , high priority construction sites must be inspected during active construction after the pre-construction meeting (Part VI.D.7. or Part VII.D.7, depending on the MS4 Operatortype). a. If the MS4 Operator is completing the inspection, the construction site must be inspected every ninety (90) days; or b. If the MS4 Operator utilizes the qualified inspector's weekly inspection reports, as required by the CGP, to satisfy this requirement, the MS4 Operator must inspect the construction site once every six (6) months, or sooner if any deficiencies are noted that require attention. MS4 Operators must document the construction site inspections in the SWMP Plan. 6. Post-Construction Stormwater Management No additional requirements. 7. Pollution Prevention and Good Housekeeping Following the completion of Part VIII.A.1: a. Annually, from April 1 through October 31, all streets located in sewersheds discharging to phosphorus impaired segments must be swept. MS4 Operators must document the completion of this requirement in the SWMP Plan. This requirement is not applicable to: i. Uncurbed roads with no catch basins; 94 Part VI II.A. ii. High-speed limited access highways; or iii. Roads defined as interstates, freeways and expressways, or arterials by the United States Department of Transportation, Federal Highway Administration, Highway Functional Classification Concepts, Criteria and Procedures, 2013. b. Within six (6) months of MS4 outfall inspection, the MS4 Operator must initiate actions to repair all MS4 outfall protection and/or bank stability problems identified during the inspection. Repairs must be completed in accordance with the NYS E&SC 2016. MS4 Operators must document the completion of this requirement in the SWMP Plan. 8. Planned Upgrades to Municipal Facilities in Sewersheds to Impaired Waters Incorporate, where feasible'64 cost-effective runoff reduction techniques65 during planned municipal upgrades including municipal right of ways (e.g., bioswales, green streets, porous pavement, replacement of closed drainage with grass swales, replacement of the existing islands in the parking lots with bioretention or curb cuts to route the flow through below-grade infiltration areas or other low-cost improvements that provide runoff treatment or reduction). B. Pollutant Specific BMPs for Silt/Sediment Part VIII.B. must be implemented for all silt/sediment impaired waters listed in Appendix C. Mapping In accordance with the timeframes listed below, the MS4 Operatormust update, in geographic information system (GIS) format with a scale of 1-24,000 or finer, the comprehensive system mapping (Part IV.D.) to include: a. Within three (3) years of the EDC, MS4 infrastructure mapping requirements (Part IV.D.2.b.i.) and sewersheds for each: i. MS4 outfall; and ii. ADA MS4 outfall. b. Within three (3) years of the EDC, facilities with SPDES permit coverage under the MSGP with stormwater discharges applicable under Sector C, E, L, or J with facility contact. c. Within three (3) years of the EDC, ADA MS4 outfalls. 64 Consideration of feasibility should include type of land use or municipal operation,suitability of soils, presence of utilities, potential for exacerbating existing contamination problems,safety issues, maintenance requirements, and expected Iifespans of available technologies. ss Runoff reduction techniques can be found in Chapters 4 and 5 of the NYS SWMDM 2015. 95 Part V1ILB. 2. Public Education ana Uutreacn a. Within six (6) months of the EDC, the MS4 Operator must make available information on how the impairment is being addressed by implementation of the MS4 Operator's local law or legal mechanism with content equivalent to the model local law (Part IV.E.1 and Part IV.E.2.). MS4 Operators must document the completion of this requirement in the SWMP Plan. b. Following the completion of Part VIII.B.1, each year of active construction, the MS4 Operator must educate individuals involved in construction activity (e.g., contractor, subcontractor, qualified inspector, SWPPP reviewers) within the sewershed boundary on the use of post-construction SMPs that are intended to collect and separate silt and sediment debris from stormwater before discharging to waters of the State (e.g., sediment forebays) as detailed in the NYS SWMDM 2015. MS4 Operators must document the completion of this requirement in the SWMP Plan. 3. Public Involvement/Participation No additional requirements. 4. Illicit Discharge Detection and Elimination Following the completion of Part VIII.B.1 , within five (5) years of the EDC, the MS4 Operator must include on the MS4 outfal/ inventory (Part VI.C.1.c. or Part VII.C.1.c, depending on the MS4 Operator type) the number of each item identified in Part VIII.B.1.b. for each associated MS4 outfall. 5. Construction Site Stormwater Runoff Control Following the completion of Part VIII.B.1, high priority construction sites must be inspected during active construction after the pre-construction meeting (Part VI.D.7. or Part VII.D.7, depending on the MS4 Operatortype). a. If the MS4 Operator is completing the inspection, the construction site must be inspected every ninety (90) days; or b. If the MS4 Operator utilizes the qualified inspector's weekly inspection reports, as required by the CGP, to satisfy this requirement, the MS4 Operator must inspect the construction site once every six (6) months, or sooner if any deficiencies are noted that require attention. MS4 Operators must document the construction site inspections in the SWMP Plan. 6. Post-Construction Stormwater Management No additional requirements. 7. Pollution Prevention and Good Housekeeping Following the completion of Part VIII.B.1: 96 Part VIII.B. a. Annually, from April 1 through October 31 , all streets located in sewersheds discharging to silt/sediment impaired segments must be swept. MS4 Operators must document the completion of this requirement in the SWMP Plan. This requirement is not applicable to: i. Uncurbed roads with no catch basins; ii. High-speed limited access highways; or iii. Roads defined as interstates, freeways and expressways, or arterials by the United States Department of Transportation, Federal Highway Administration, Highway Functional Classification Concepts, Criteria and Procedures, 2013. b. For areas within the sewershed that are compacted, poorly drained, contain areas of exposed soil, or nutrient deficient, the MS4 Operator must: i. Refer to Section 4 of the NYS E&SC 2016 for Soil Stabilization practices, and follow BMP procedures; and ii. Develop and implement procedures for watering and maintenance of implemented BMPs appropriate to establish root and vegetative cover, utilizing products which provide critical support to vegetation and soil stabilization. MS4 Operators must document the completion of this requirement in the SWMP Plan. c. Within six (6) months of MS4 outfall inspection, the MS4 Operator must initiate actions to repair all MS4 outfall protection and/or bank stability problems identified during the inspection. Repairs must be completed in accordance with the NYS E&SC 2016. MS4 Operators must document the completion of this requirement in the SWMP Plan. 8. Planned Upgrades to Municipal Facilities in Sewersheds to Impaired Waters Incorporate, where feasible,66 cost-effective runoff reduction techniques67 during planned municipal upgrades including municipal right of ways (e.g., bioswales, green streets, porous pavement, replacement of closed drainage with grass swales, replacement of the existing islands in the parking lots with bioretention or curb cuts to route the flow through below-grade infiltration areas or other low-cost improvements that provide runoff treatment or reduction). 66 Consideration of feasibility should include type of land use or municipal operation,suitability of soils, presence of utilities, potential for exacerbating existing contamination problems, safety issues, maintenance requirements, and expected lifespans of available technologies. 67 Runoff reduction techniques can be found in Chapters 4 and 5 of the NYS SWMDM 2015. 97 Part VI II.C. C. Pollutant Specific BMPs for Pathogens Part VIII.C. must be implemented for all pathogen impaired waters listed in Appendix C. 1. Mapping In accordance with the timeframes listed below, the MS4 Operatormust update, in geographic information system (GIS) format with a scale of 1-24,000 or finer, the comprehensive system mapping (Part IV.D.) to include: a. Within three (3) years of the EDC, MS4 infrastructure mapping requirements (Part IV.D.2.b.i.) and sewersheds for each: i. MS4 outfall; and ii. ADA MS4 outfall. b. Within three (3) years of the EDC, the following information for each MS4 outfall: i. Areas with a history of sanitary sewer overflows; ii. Waterfowl congregation areas on municipal property or right of way; iii. Areas where pets/domestic animals may frequent (i.e., public trails, dog parks, and zoos); and iv. Waste disposal areas (e.g., active landfills, transfer stations). c. Within three (3) years of the EDC, ADA MS4 outfal/s. 2. Public Education and Outreach a. Within six (6) months of the EDC, the MS4 Operator must make available information on any how the impairment is being addressed by implementation of the MS4 Operator's local law or legal mechanism with content equivalent to the model local law (Part IV.E.1 and Part IV.E.2.). MS4 Operators must document the completion of this requirement in the SWMP Plan. b. Following the completion of Part VIII.C.1 , twice a year, once from March to August and once from September to February, the MS4 Operator must provide educational messages with information specific to pathogens to the applicable target audiences within the sewersheds for impaired waters listed in Appendix C focus area, identified in Part VI.A.1 .b. or Part VII.A.1 .b, depending on the MS4 Operator type. The SWMP Plan must be updated with changes made to public education and outreach program (Part VI.A. or Part VII.A, depending on the MS4 Operatortype). MS4 Operators must document the completion of this requirement in the SWMP Plan. 3. Public Involvement/Participation No additional requirements. 98 Part VI II.C. 4. Illicit Discharge Detection and Elimination Following the completion of Part VIII.C.1, within five (5) years of the EDC, the MS4 Operator must include on the MS4 outfall inventory (Part VI.C.1 .c. or Part VII.C.1.c, depending on the MS4 Operator type) the number of each item identified in Part VIII.C.1.b. for each associated MS4 outfall. 5. Construction Site Stormwater Runoff Control No additional requirements. 6. Post-Construction Stormwater Management No additional requirements. 7. Pollution Prevention and Good Housekeeping Following the completion of Part VIII.C.1: a. Infrastructure Maintenance i. Annually, from April 1 through October 31 , all streets located in sewersheds discharging to pathogen impaired segments must be swept. MS4 Operators must document the completion of this requirement in the SWMP Plan. This requirement is not applicable to: a) Uncurbed roads with no catch basins; b) High-speed limited access highways; or c) Roads defined as interstates, freeways and expressways, or arterials by the United States Department of Transportation, Federal Highway Administration, Highway Functional Classification Concepts, Criteria and Procedures, 2013. ii. Within six (6) months of MS4 outfall inspection, the MS4 Operator must initiate actions to repair all MS4 outfall protection and/or bank stability problems identified during the inspection. Repairs must be completed in accordance with the NYS E&SC 2016. MS4 Operators must document the completion of this requirement in the SWMP Plan. b. Wildlife Control i. Within six (6) months of the EDC, the MS4 Operator must identify municipal facilities with nuisance bird populations that have the potential to contribute pathogens (e.g., Canada Geese) and document those municipal facilities in the SWMP Plan. ii. Within six (6) months of the EDC, signage must be available at these municipal facilities, instructing the public not to feed wildlife. MS4 Operators must document the completion of this requirement in the SWMP Plan. iii. Within six (6) months of the EDC, the MS4 Operator must remove accumulated trash and debris from municipal facilities when necessary to 99 Part VI II.C. eliminate potential food sources for wildlife. MS4 Operators must document the completion of this requirement in the SWMP Plan. iv. Within one (1) year of the EDC, MS4 Operators must evaluate the effectiveness of deterrents, population controls, and other measures that may reduce bird related pathogen contributions and document the results of the evaluation in the SWMP Plan. c. Animal Waste Control Within one (1) year of the EDC, the MS4 Operator must make dog waste receptacles available in areas where pets/domestic animals may frequent (e.g., public trails, dog parks). MS4 Operators must document the completion of this requirement in the SWMP Plan. 8. Planned Upgrades to Municipal Facilities in Sewersheds to Impaired Waters Incorporate, where feasible,68 cost-effective runoff reduction techniques69 during planned municipal upgrades including municipal right of ways (e.g., bioswales, green streets, porous pavement, replacement of closed drainage with grass swales, replacement of the existing islands in the parking lots with bioretention or curb cuts to route the flow through below-grade infiltration areas or other low-cost improvements that provide runoff treatment or reduction). D. Pollutant Specific BMPs for Nitrogen Part VIII.D. must be implemented for all nitrogen impaired waters listed in Appendix C. 1. Mapping In accordance with the timeframes listed below, the MS4 Operatormust update, in geographic information system (GIS) format with a scale of 1-24,000 or finer, the comprehensive system mapping (Part IV.D.) to include: a. Within three (3) years of the EDC, MS4 infrastructure mapping requirements (Part IV.D.2.b.i.) and sewersheds for each: i. MS4 outfall; and ii. ADA MS4 outfall. b. Within three (3) years of the EDC, the following information for each MS4 outfall: i. Retail and wholesale plant nurseries (including big box stores); ii. Commercial lawn care facilities; and 68 Consideration of feasibility should include type of land use or municipal operation,suitability of soils, presence of utilities, potential for exacerbating existing contamination problems, safety issues, maintenance requirements, and expected lifespans of available technologies. 69 Runoff reduction techniques can be found in Chapters 4 and 5 of the NYS SWMDM 2015. 100 Part VIII.D iii. Golf courses. c. Within three (3) years of the EDC, ADA MS4 outfalls. 2. Public Education and Uutreach a. Within six (6) months of the EDC, the MS4 Operator must make available information on any how the impairment is being addressed by implementation of the MS4 Operator's local law or legal mechanism with content equivalent to the model local law (Part IV.E.1 and Part IV.E.2.). MS4 Operators must document the completion of this requirement in the SWMP Plan. b. Following the completion of Part VIII.D.1 , twice a year, once from March to August and once from September to February, the MS4 Operator must provide educational messages with information specific to nitrogen to the applicable target audiences within the sewersheds for impaired waters listed in Appendix C focus area, identified in Part VI.A.1 .b. or Part VII.A.1 .b, depending on the MS4 Operator type. The SWMP Plan must be updated with changes made to public education and outreach program (Part VI.A or Part VILA, depending on the MS4 Operatortype). MS4 Operators must document the completion of this requirement in the SWMP Plan. 3. Public involvement/Participation No additional requirements. 4. Illicit Discnarge Detection and Elimination Following the completion of Part VIII.D.1 , within five (5) years of the EDC, the MS4 Operator must include on the MS4 outfa/l inventory (Part VI.C.1.c. or Part VII.C.1.c, depending on the MS4 Operator type) the number of each item identified in Part VIII.D.1.b for each associated MS4 outfall. 5. Construction Site Stormwater Runoff Control Following the completion of Part VIII.D.1, high priority construction sites must be inspected during active construction after the pre-construction meeting (Part VI.D.7. or Part VII.D.7, depending on the MS4 Operatortype). a. If the MS4 Operator is completing the inspection, the construction site must be inspected every ninety (90) days; or b. If the MS4 Operator utilizes the qualified inspector's weekly inspection reports, as required by the CGP, to satisfy this requirement, the MS4 Operator must inspect the construction site once every six (6) months, or sooner if any deficiencies are noted that require attention. MS4 Operators must document the construction site inspections in the SWMP Plan. 6. Post-Construction Stormwater Management No additional requirements. 101 Part VIII.D 7. Pollution Prevention and Good Housekeeping Following the completion of Part VIII.D.1: a. Annually, from April 1 through October 31 , all streets located in sewersheds discharging to nitrogen impaired segments must be swept. MS4 Operators must document the completion of this requirement in the SWMP Plan. This requirement is not applicable to: i. Uncurbed roads with no catch basins; ii. High-speed limited access highways; or iii. Roads defined as interstates, freeways and expressways, or arterials by the United States Department of Transportation, Federal Highway Administration, Highway Functional Classification Concepts, Criteria and Procedures, 2013. b. Within six (6) months of MS4 outfall inspection, the MS4 Operator must initiate actions to repair all MS4 outfall protection and/or bank stability problems identified during the inspection. Repairs must be completed in accordance with the NYS E&SC 2016. MS4 Operators must document the completion of this requirement in the SWMP Plan. 8. Planned Upgrades to Municipal Facilities in Sewersheds to Impaired Waters Incorporate, where feasible,70 cost-effective runoff reduction techniques71 during planned municipal upgrades including municipal right of ways (e.g., bioswales, green streets, porous pavement, replacement of closed drainage with grass swales, replacement of the existing islands in the parking lots with bioretention or curb cuts to route the flow through below-grade infiltration areas or other low-cost improvements that provide runoff treatment or reduction). E. Pollutant Specific BMPs for Floatables Part VIII.E. must be implemented for all floatable impaired waters listed in Appendix C. 1. Mapping In accordance with the timeframes listed below, the MS4 Operatormust update, in geographic information system (GIS) format with a scale of 1-24,000 or finer, the comprehensive system mapping (Part IV.D.) to include: a. Within three (3) years of the EDC, MS4 infrastructure mapping requirements (Part IV.D.2.b.i.) and sewersheds for each: 70 Consideration of feasibility should include type of land use or municipal operation,suitability of soils, presence of utilities, potential for exacerbating existing contamination problems, safety issues, maintenance requirements, and expected Iifespans of available technologies. 79 Runoff reduction techniques can be found in Chapters 4 and 5 of the NYS SWMDM 2015. 102 Part VIII.E. i. MS4 outfall; and ii. ADA MS4 outfall. b. Within three (3) years of the EDC, ADA MS4 outfalls. 2. Public Education and Outreach a. Within six (6) months of the EDC, the MS4 Operator must make available information on any how the impairment is being addressed by implementation of the MS4 Operator's local law or legal mechanism with content equivalent to the model local law (Part IV.E.1 and Part IV.E.2.). MS4 Operators must document the completion of this requirement in the SWMP Plan. b. Following the completion of Part VIII.E.1, twice a year, once from March to August and once from September to February, the MS4 Operator must provide educational messages with information specific to floatables to the applicable target audiences within the sewersheds for impaired waters listed in Appendix C focus area, identified in Part VI.A.1 .b. or Part VII.A.1 .b, depending on the MS4 Operator type. The SWMP Plan must be updated with changes made to public education and outreach program (Part VI.A or Part VILA, depending on the MS4 Operatortype). MS4 Operators must document the completion of this requirement in the SWMP Plan. 3. Public Involvement/Participation No additional requirements. 4. Illicit Discharge Detection and Elimination No additional requirements. 5. Construction Site Stormwater Runoff Control No additional requirements. 6. Post-Construction Stormwater Management No additional requirements. 7. Pollution Prevention and Good Housekeeping Following completion of Part VIII.E.1: a. Annually, from April 1 through October 31 , all streets located in sewersheds discharging to floatables impaired segments must be swept. MS4 Operators must document the completion of this requirement in the SWMP Plan. This requirement is not applicable to: i. Uncurbed roads with no catch basins; ii. High-speed limited access highways; or 103 Part VIII.E. iii. Roads defined as interstates, freeways and expressways, or arterials by the United States Department of Transportation, Federal Highway Administration, Highway Functional Classification Concepts, Criteria and Procedures, 2013. b. Within six (6) months of MS4 outfall inspection, the MS4 Operator must initiate actions to repair all MS4 outfall protection and/or bank stability problems identified during the inspection. Repairs must be completed in accordance with the NYS E&SC 2016. MS4 Operators must document the completion of this requirement in the SWMP Plan. 8. Planned Upgrades to Municipal Facilities in Sewersheds to Impaired Waters Incorporate, where feasible,72 cost-effective runoff reduction techniques73 during planned municipal upgrades including municipal right of ways (e.g., bioswales, green streets, porous pavement, replacement of closed drainage with grass swales, replacement of the existing islands in the parking lots with bioretention or curb cuts to route the flow through below-grade infiltration areas or other low-cost improvements that provide runoff treatment or reduction). 72 Consideration of feasibility should include type of land use or municipal operation,suitability of soils, presence of utilities, potential for exacerbating existing contamination problems, safety issues, maintenance requirements, and expected lifespans of available technologies. 7s Runoff reduction techniques can be found in Chapters 4 and 5 of the NYS SWMDM 2015. 104 Part IX Part IX. Watershed Improvement Strategy Requirements for TMDL Implementation Part IX. requirements must be implemented in addition to the applicable requirements of the six (6) MCMs in Part VI. or Part VII, depending on the MS4 Operatortype. Part IX. requirements apply in the watersheds where the Department developed implementation plans for which USEPA has approved a TMDL (Table 3). Finalized TMDL implementation plans referenced in this Part are incorporated into and enforceable under this SPDES general permit. MS4 Operator's subject to Part IX. that implement TMDL specific BMPs after the EDC but prior to MS4 infrastructure and sewershed mapping can use those BMPs to satisfy the permit requirements in this section. The Part IX. requirements must be incorporated in the MS4 Operator's SWMP and SWMP Plan. A. NYC East of Hudson Phosphorus Impaired Watershed MS4s Table 4. Phosphorus Impaired Watershed(s) Areas where requirements apply New York City East of Hudson (EOH) Phase 11 Phosphorus Total Maximum Total Maximum TMDLs for Daily Load Daily Load EPA Approved TMDL Reservoirs in the (TMDL) for (TMDL) for NYC Watershed, Phosphorus in Phosphorus in June 2000 Lake Carmel, Palmer Lake,2 October 2016 March 2015 Implementation Plan Croton Watershed Phase II TMDL Implementation Plan (January 2009) POC Phosphorus Area where NYC EOH Watershed requirements Apply Achievement of Continued retrofit implementation to achieve the pollutant Pollutant Load load reduction specified in that Phase II Implementation Reduction Plan MS4 Operators located within the watersheds listed in Table 4 must develop and implement the following phosphorus-specific BMPs in addition to the Croton Watershed Phase II TMDL Implementation Plan (January 2009) and the applicable requirements in Part VI. or Part VII, depending on the MS4 Operatortype. 105 PartIX.A. 1. Mapping In accordance with the timeframes listed below, the MS4 Operator must update, in geographic information system (GIS) format with a scale of 1-24,000 or finer, the comprehensive system mapping (Part IV.D.) to include: a. Within three (3) years of the EDC, areas with potential to contribute phosphorus to the TMDL waterbody, which include: i. Retail and wholesale plant nurseries (including big box stores); ii. Commercial lawn care facilities; iii. Golf courses; iv. Commercial or industrial yard waste storage areas (e.g., yard waste composting and disposal areas); and v. MS4 infrastructure with a history of issues (e.g., clogged infrastructure, infiltration and inflow (I/I)). b. Within three (3) years of the EDC, the following information for all post- construction SMPs as identified in the post-construction SMP inventory (Part VI.E.2. or Part VII.E.2, depending on the MS4 Operatortype): i. Type,.74and ii. Ownership. 2. Public Education and Outreach on Stormwater Impacts a. Within six (6) months of the EDC, the MS4 Operator must make available information on how the impairment is being addressed by implementation of the MS4 Operator's local law or legal mechanism with content equivalent to the model local law (Part IV.E.1 and Part IV.E.2.). MS4 Operators must document the completion of this requirement in the SWMP Plan. b. Following the completion of Part IX.A.1 , twice a year, once from March to August and once from September to February, the MS4 Operator must provide educational messages with information specific to phosphorus to the applicable target audiences within the TMDL watershed focus area, identified in Part VI.A.1 .b. or Part VII.A.1 .b, depending on the MS4 Operator type. The SWMP Plan must be updated with changes made to public education and outreach program (Part VI.A. or Part VILA, depending on the MS4 Operator type). MS4 Operators must document the completion of this requirement in the SWMP Plan. 3. Public Involvement/Participation No additional requirements. 74 Post-construction SMP types are defined in the New York State Department of Environmental Conservation Maintenance Guidance: Stormwater Management Practices, March 31, 2017 (NYS DEC Maintenance Guidance 2017). 106 PartIX.A. 4. Illicit Discharge Detection and Elimination a. Inventory of Potential Phosphorus Sources Following the completion of Part IX.A.1 , within five (5) years of the EDC, the MS4 Operator must include on the MS4 outfall inventory (Part VI.C.1.c. or Part VII.C.1 .c, depending on the MS4 Operator type) the number of each item identified in Part IX.A.1.a. for each associated MS4 outfall. b. On-site wastewater systems The MS4 Operator must develop, implement, and enforce a program that ensures on-site wastewater systems (i.e., septic tanks, cesspools, absorption fields or distribution systems) are properly operated and do not contribute pollutants to the MS4. To ensure this, the MS4 Operator must: i. Once every five (5) years, ensure that residential septic tanks/cesspools are pumped out and system components (i.e., septic tanks, cesspools and installed absorption field) are inspected; ii. Ensure the following information is collected and document the completion of this requirement in the SWMP Plan: a) Individual performing inspection; b) Inspection date; c) Address; d) Location of system on property; and e) Evidence of failed systems. iii. Refer failures to the appropriate agency to ensure corrective actions are taken; and iv. Eliminate illicit discharges from on-site wastewater systems to the MS4 in accordance with the time frames specified in Part VI.C.3. or Part VII.C.3, depending on the MS4 Operatortype. 5. Construction Site Stormwater Runoff Control a. The MS4 Operator must include construction projects that disturb between 5000 square feet (sf) and one (1) acre in the construction site runoff control program as described in Part VI.D. or Part VII.D, depending on the MS4 Operatortype. Construction projects meeting this threshold are low priority construction sites. b. The legal authority used to satisfy Part IV.E.2.b. must include the following language: "Land activity is defined as construction activity including clearing, grading, excavating, soil disturbance or placement of fill that results in land disturbance of equal to or greater than 5000 sf and activities disturbing less 107 PartIX.A. than 5000 sf of total land area that are part of a larger common plan of development or sale and will occur under one plan." c. High priority construction sites must be inspected during active construction after the pre-construction meeting (Part VI.D.7. or Part VII.D.7, depending on the MS4 Operator type). i. If the MS4 Operator is completing the inspection, the construction site must be inspected every ninety (90) days; or ii. If the MS4 Operator utilizes the qualified inspector's weekly inspection reports, as required by the CGP, to satisfy this requirement, the MS4 Operator must inspect the construction site once every six (6) months, or sooner if any deficiencies are noted that require attention. MS4 Operators must document the construction site inspections in the SWMP Plan. 6. Post-Construction Stormwater Management a. The MS4 Operator must require the use of the Enhanced Phosphorus Removal design standards contained in Chapter 10 of the NYS SWMDM 2015 for all new development and redevelopment projects that disturb greater than or equal to one (1) acre and construction projects less than one acre that are part of a larger common plan of development or sale. b. The legal authority used to satisfy Part IV.E. must also meet the following provisions: Land development activities requiring water quantity and quality controls (post-construction stormwater runoff controls) must include: "Single-family home construction located in the NYC East of Hudson watershed" and "Single-family residential subdivisions located in the NYC East of Hudson watershed." c. Requirements for SWPPPs that include post-construction stormwater controls must include: "Post-construction SMPs in the SWPPP must be designed in conformance with Chapter 10 of the NYS SWMDM 2015 for Enhanced Phosphorus Removal Design Standards." d. Performance Standards must include the following enhanced stabilization requirements: "For construction sites located in the NYC East of Hudson watershed, where soil disturbance activity has temporarily or permanently ceased, the application of soil stabilization measures must be initiated by the end of the next business day and completed within seven (7) days from the date the current soil disturbance activity ceased. The soil stabilization measures selected must be in conformance with the NYS E&SC 2016." e. Inspections of land development activities during construction must include requirements for a qualified inspector to conduct two (2) site inspections every seven (7) calendar days for single-family homes, and single-family residential, subdivisions within the NYC East of Hudson watersheds. 108 PartIX.A. f. Retrofit program i. All MS4 Operators identified within the Croton Watershed Phase II TMDL Implementation Plan, January 2009, must continue to implement the retrofit program according to the following schedule: a) Within one (1) year of the EDC, the MS4 Operator must submit to the Department a retrofit plan that identifies the following: i) Project name; ii) Location; iii) Proposed retrofit type; iv) Anticipated date for construction; v) Estimated phosphorus reduction (using the criteria in the Croton Watershed Phase II TMDL Implementation Plan, January 2009); and vi) Estimated total phosphorus reduction for all projects demonstrating they will meet the reduction specified in the Croton Watershed Phase II TMDL Implementation Plan, January 2009. b) Within five (5) years of the EDC, all retrofit projects must be constructed to achieve the five (5) year phosphorus reduction assigned to the MS4 Operator, as required by the Croton Watershed Phase II TMDL Implementation Plan, January 2009. ii. Annually, by December 31 , MS4 Operators (or RSE representing MS4 Operators as described in Part III.B.2.b.) must submit to the Department any changes made to the retrofit plan including the information in Part IX.A.6.e.i. iii. MS4 Operators must document the retrofit program in the SWMP Plan specifying: a) Progress on retrofit projects already commenced; and b) Identification of retrofit projects for the upcoming construction season; and c) Certification that completed retrofit projects have been constructed in accordance with the retrofit plans. 7. Pollution Prevention/Good Housekeeping a. Twice a year, once from March to August and once from September to February, all catch basins located in the TMDL watershed(s) must be inspected (Part VI.F.3.c. or Part VII.F.3.c, depending on the MS4 Operator type). MS4 Operators must document the completion of this requirement in the SWMP Plan. 109 PartIX.A. b. Following the completion of Part IX.A.1 , annually, from April 1 through October 31 , all streets located in the TMDL watershed(s) must be swept. MS4 Operators must document the completion of this requirement in the SWMP Plan. This requirement is not applicable to: i. Uncurbed roads with no catch basins; ii. High-speed limited access highways; iii. Roads defined as interstates, freeways and expressways, or arterials by the United States Department of Transportation, Federal Highway Administration, Highway Functional Classification Concepts, Criteria and Procedures, 2013. c. Within six (6) months of MS4 outfall inspection, the MS4 Operator must initiate actions to repair all MS4 outfall protection and/or bank stability problems identified during the inspection. Repairs must be completed in accordance with the NYS E&SC 2016. MS4 Operators must document the completion of this requirement in the SWMP Plan. Within thirty (30) days of inspection, the MS4 Operator must initiate all necessary maintenance and repair activities discovered for municipally owned or operated post- construction SMPs. MS4 Operators must document the completion of this requirement in the SWMP Plan. 8. Planned Upgrades to Municipal Facilities in Watersheds to Impaired Waters Incorporate, where feasible'75 cost-effective runoff reduction techniques76 during planned municipal upgrades including municipal right of ways (e.g., bioswales, green streets, porous pavement, replacement of closed drainage with grass swales, replacement of the existing islands in the parking lots with bioretention or curb cuts to route the flow through below-grade infiltration areas or other low-cost improvements that provide runoff treatment or reduction). 75 Consideration of feasibility should include type of land use or municipal operation,suitability of soils, presence of utilities, potential for exacerbating existing contamination problems, safety issues, maintenance requirements, and expected Iifespans of available technologies. 7s Runoff reduction techniques can be found in Chapters 4 and 5 of the NYS SWMDM 2015. 110 Part IX.B. B. Other Phosphorus Impaired Watershed MS4s Table 5. Other Phosphorus Impaired Watersheds Area where Onondaga Oscawana Requirements Apply Greenwood Lake Lake Lake Impaired Waters Updated Total Maximum Restoration Plan for Phosphorus Daily Load Greenwood Lake— Total Maximum (TMDL) for EPA Approved TMDL Total Maximum Daily Daily Load for Phosphorus in Load for Total Onondaga Phosphorus, Sept Lake, June Lake na, 2005 2012 Septememberber 2008 Greenwood Lake Watershed Implementation Plan Phosphorus TMDL None None Implementation Plan, October 2019 POC Phosphorus Achievement of In accordance with In accordance In accordance Pollutant Load Implementation Plan with approved with approved Reduction TMDL TMDL MS4 Operators located in the watersheds listed in Table 5 must develop and implement the following phosphorus-specific BMPs in addition to the applicable Implementation Plan and applicable requirements in Part VI. or Part VII, depending on the MS4 Operator type: 1. Mapping In accordance with the timeframes listed below, the MS4 Operator must update, in geographic information system (GIS) format with a scale of 1-24,000 or finer, the comprehensive system mapping (Part IV.D.) to include: a. Within three (3) years of the EDC, include areas with potential to contribute phosphorus to the TMDL waterbody, which include: i. Retail and wholesale plant nurseries (including big box stores); ii. Commercial lawn care facilities; iii. Golf courses; and iv. Commercial or industrial yard waste storage areas (e.g., yard waste composting and disposal areas). b. Within three (3) years of the EDC, include the following information for all post-construction SMPs as identified in the post-construction SMP inventory (Part VI.E.2. or Part VII.E.2, depending on the MS4 Operatortype): 111 PartIX.B. i. Type77; and ii. Ownership. 2. Public Education and Outreach on Stormwater Impacts a. Within six (6) months of the EDC, the MS4 Operator must make available information on any how the impairment is being addressed by implementation of the MS4 Operator's local law or legal mechanism with content equivalent to the model local law (Part IV.E.1 and Part IV.E.2.). MS4 Operators must document the completion of this requirement in the SWMP Plan. b. Following the completion of Part IX.B.1 , twice a year, once from March to August and once from September to February, the MS4 Operator must provide educational messages with information specific to phosphorus to the applicable target audiences within the TMDL watershed focus area, identified in Part VI.A.1 .b. or Part VII.A.1 .b, depending on the MS4 Operator type. The SWMP Plan must be updated with changes made to public education and outreach program (Part VI.A. or Part VII.A, depending on the MS4 Operator type). MS4 Operators must document the completion of this requirement in the SWMP Plan. c. Twice a permit term, separated by a minimum of one (1) year, the MS4 Operator must educate residential on-site wastewater system users on the on-site wastewater inspection program described in Part IX.B.4.c and proper maintenance practices. The SWMP Plan must be updated with changes made to public education and outreach program (Part VI.A or Part VII.A, depending on the MS4 Operatortype). MS4 Operators must document the completion of this requirement in the SWMP Plan. 3. Public Involvement/Participation No additional requirements. 4. Illicit Discharge Detection and Elimination a. Inventory of Potential Phosphorus Sources Following the completion of Part IX.B.1, within five (5) years of the EDC, the MS4 Operator must include on the MS4 outfall inventory (Part VI.C.1.c. or Part VII.C.1.c, depending on the MS4 Operator type) the number of each item identified in Part VIII.B.1.a. for each associated MS4 outfall. b. On-site wastewater systems The MS4 Operator(with the exclusion of MS4 Operators located in the Onondaga Lake watershed) must develop, implement, and enforce a program that ensures residential on-site wastewater systems (i.e., septic tanks, "Post-construction SMP types are defined in the New York State Department of Environmental Conservation Maintenance Guidance: Stormwater Management Practices, March 31, 2017 (NYS DEC Maintenance Guidance 2017). 112 PartIX.B. cesspools, absorption fields or distribution systems) are properly operated and do not contribute pollutants to the MS4. The MS4 Operator must: i. Once every five (5) years, ensure that residential septic tanks/cesspools are pumped out and system components (i.e., septic tanks, cesspools and installed absorption field) are inspected; ii. Ensure the following information is collected and document the completion of this requirement in the SWMP Plan: a) Individual performing inspection; b) Inspection date; c) Address; d) Location of system on property; e) Inspection rating (pass/fail); f) Evidence of failed systems; iii. Refer failures to the appropriate agency to ensure corrective actions are taken; and iv. Eliminate illicit discharges from on-site wastewater systems to the MS4 in accordance with the time frames specified in Part VI.C.3. or Part VII.C.3, depending on the MS4 Operatortype. 5. Construction Site Stormwater Runoff Control High priority construction sites must be inspected during active construction after the pre-construction meeting (Part VI.D.7. or Part VII.D.7, depending on the MS4 Operator type). a. If the MS4 Operator is completing the inspection, the construction site must be inspected every ninety (90) days; or b. If the MS4 Operator utilizes the qualified inspector's weekly inspection reports, as required by the CGP, to satisfy this requirement, the MS4 Operator must inspect the construction site once every six (6) months, or sooner if any deficiencies are noted that require attention. MS4 Operators must document the construction site inspections in the SWMP Plan. 6. Post Construction Stormwater Management a. The MS4 Operator must require the use of the Enhanced Phosphorus Removal design standards contained in Chapter 10 of the NYS SWMDM 2015 for all new development and redevelopment projects within the listed watersheds. b. The legal authority used to satisfy Part IV.E.2.b. must also include the following language requiring the use of the Enhanced Phosphorus Removal 113 PartIX.B. Design Standards in accordance with the NYS SWMDM 2015 for the applicable watershed: "Land development activities requiring water quantity and quality controls (post-construction stormwater runoff controls) must include: "Single-family home construction located in the <insert watershed name> watershed" and "Single-family residential subdivisions located in the <insert watershed name> watershed." c. Requirements for SWPPPs that include post-construction stormwater controls must include: "Post-construction SMPs in the SWPPP must be designed in conformance with the Enhanced Phosphorus Removal Design Standards in the NYS SWMDM 2015." d. Performance Standards must include the following enhanced stabilization requirements: "Where soil disturbance activity has temporarily or permanently ceased, the construction site is located in the <insert watershed name> watershed, the application of soil stabilization measures must be initiated by the end of the next business day and completed within seven (7) days from the date the current soil disturbance activity ceased. The soil stabilization measures selected must be in conformance with the Erosion Control Manual." e. Inspections of land development activities during construction must include requirements for a qualified inspectorto conduct two (2) site inspections every seven (7) calendar days for single-family homes and subdivisions within the <insert watershed name> watersheds. f. Retrofit program i. All MS4 Operators identified within the Greenwood Lake Watershed Phosphorus TMDL Implementation Plan, October 2019, must continue to implement the retrofit program according to the following schedule: a) Within one (1) year of the EDC, the MS4 Operator must submit to the Department a retrofit plan that identifies the following: i) Project name; ii) Location; iii) Proposed retrofit type; iv) Anticipated date for construction; v) Estimated phosphorus reduction (using the criteria in the Greenwood Lake Watershed Phosphorus TMDL Implementation Plan, October 2019); and vi) Estimated total phosphorus reduction for all projects demonstrating they will meet the reduction specified in the Greenwood Lake Watershed Phosphorus TMDL Implementation Plan, October 2019. b) Within five (5) years of the EDC, all retrofit projects must be constructed to achieve the five (5) year phosphorus reduction assigned 114 PartIX.B. to the MS4 Operator, as required by the Greenwood Lake Watershed Phosphorus TMDL Implementation Plan, October 2019. ii. Annually, by December 31 , MS4 Operators (or RSE representing MS4 Operators as described in Part III.B.2.b.) must submit to the Department any changes made to the retrofit plan including the information in Part IX.A.6.e.i. iii. MS4 Operators must document the retrofit program in the SWMP Plan specifying: a) Progress on retrofit projects already commenced; and b) Identification of retrofit projects for the upcoming construction season; and c) Certification that completed retrofit projects have been constructed in accordance with the retrofit plans. 7. Pollution Prevention/Good Housekeeping Following the completion of Part IX.B.1: a. Annually, from April 1 through October 31 , all streets located in the TMDL watershed(s) must be swept. MS4 Operators must document the completion of this requirement in the SWMP Plan. This requirement is not applicable to: i. Uncurbed roads with no catch basins; ii. High-speed limited access highways; or iii. Roads defined as interstates, freeways and expressways, or arterials by the United States Department of Transportation, Federal Highway Administration, Highway Functional Classification Concepts, Criteria and Procedures, 2013. b. Within six (6) months of MS4 outfall inspection, the MS4 Operator must initiate actions to repair all MS4 outfall protection and/or bank stability problems identified during the inspection. Repairs must be completed in accordance with the NYS E&SC 2016. MS4 Operators must document the completion of this requirement in the SWMP Plan. c. Within thirty (30) days of inspection, the MS4 Operator must initiate all necessary maintenance and repair activities discovered for municipally owned or operated post-construction SMPs. MS4 Operators must document the completion of this requirement in the SWMP Plan. 115 Part IX.B. 8. Planned Upgrades to Municipal Facilities in Watersheds to Impaired Waters Incorporate, where feasible'78 cost-effective runoff reduction techniques79 during planned municipal upgrades including municipal right of ways (e.g., bioswales, green streets, porous pavement, replacement of closed drainage with grass swales, replacement of the existing islands in the parking lots with bioretention or curb cuts to route the flow through below-grade infiltration areas or other low-cost improvements that provide runoff treatment or reduction). C. Pathogen Impaired Watersheds MS4s No Pathogen TMDL requirements. D. Nitrogen Impaired Watershed MS4s Table 6. Nitrogen Impaired Watershed(s) Area where Peconic Requirements Apply TMDL for Nitrogen in the Peconic Estuary Program Study Area, Including Waterbodies Currently Impaired Due to EPA Approved TMDL Low Dissolved Oxygen: the Lower Peconic River and Tidal Tributaries, Western Flanders Bay and Lower Sawmill Creek; and Meetinghouse Creek, Terry Creek and Tributaries (September 2007) TMDL for Nitrogen in the Peconic Estuary Program Study Area, Including Waterbodies Currently Impaired Due to Implementation Plan Low Dissolved Oxygen: the Lower Peconic River and Tidal Tributaries, Western Flanders Bay and Lower Sawmill Creek; and Meetinghouse Creek, Terry Creek and Tributaries (September 2007) POC Nitrogen Pollutant Load In accordance with approved TMDL Reduction Terrys Creek & Tributaries Meetinghouse Creek Waterbodies Western Flanders Bay & Lower Sawmill Creek Lower Peconic River and tidal tributaries 78 Consideration of feasibility should include type of land use or municipal operation,suitability of soils, presence of utilities, potential for exacerbating existing contamination problems, safety issues, maintenance requirements, and expected Iifespans of available technologies. 79 Runoff reduction techniques can be found in Chapters 4 and 5 of the NYS SWMDM 2015. 116 Part IX.D. MS4 Operators located in the watersheds listed in Table 6 must develop and implement the following nitrogen-specific BMPs in addition to the applicable Implementation Plan and applicable requirements in Part VI. or Part VII, depending on the MS4 Operator type: 1. Mapping Within three (3) years of the EDC, the MS4 Operator must update, in geographic information system (GIS) format with a scale of 1 .24000 or finer, the comprehensive system mapping (Part IV.D.) to include: a. Areas with potential to contribute nitrogen to the TMDL waterbody, which include: i. Retail and wholesale plant nurseries (including big box stores); ii. Commercial lawn care facilities; iii. Golf courses; and iv. Commercial or Industrial yard waste storage areas (e.g., yard waste composting and disposal areas). b. Information for all post-construction SMPs as identified in the post- construction SMP inventory (Part VI.E.2. or Part VII.E.2, depending on the MS4 Operator type): i. Type;80 and ii. Ownership of SMP. 2. Public Education ana Outreach on Stormwater Impacts a. Within six (6) months of the EDC, the MS4 Operator must make available information on any how the impairment is being addressed by implementation of the MS4 Operator's local law or legal mechanism with content equivalent to the model local law (Part IV.E.1 and Part IV.E.2.). MS4 Operators must document the completion of this requirement in the SWMP Plan. b. Following the completion of Part IX.D.1 , twice a year, once from March to August and once from September to February, the MS4 Operator must provide educational messages with information specific to nitrogen to the applicable target audiences within the TMDL watershed focus area, identified in Part VI.A.1 .b. or Part VII.A.1 .b, depending on the MS4 Operator type. The SWMP Plan must be updated with changes made to public education and outreach program (Part VI.A. or Part VILA, depending on the MS4 Operator type). MS4 Operators must document the completion of this requirement in the SWMP Plan. 80 Post-construction SMP types are defined in the New York State Department of Environmental Conservation Maintenance Guidance: Stormwater Management Practices, March 31, 2017 (NYS DEC Maintenance Guidance 2017). 117 Part IX.D. 3. Public Involvement/Participation No additional requirements. 4. Illicit Discnarge Detection and Elimination Following the completion of Part IX.D.1, within five (5) years of the EDC, the MS4 Operator must include on the MS4 outfall inventory (Part VI.C.1 .c. or Part VII.C.1.c, depending on the MS4 Operator type) the number of each item identified in Part VIII.D.1.a. for each associated MS4 outfall. 5. Construction Site Stormwater Runoff Control High priority construction sites must be inspected during active construction after the pre-construction meeting (Part VI.D.7. or Part VII.D.7, depending on the MS4 Operator type). a. If the MS4 Operator is completing the inspection, the construction site must be inspected every ninety (90) days; or b. If the MS4 Operator utilizes the qualified inspector's weekly inspection reports, as required by the CGP, to satisfy this requirement, the MS4 Operator must inspect the construction site once every six (6) months, or sooner if any deficiencies are noted that require attention. MS4 Operators must document the construction site inspections in the SWMP Plan. 6. Post-Construction Stormwater Management The MS4 Operatormust ensure on-site retention of the 1-year storm or greater from new development or redevelopment projects using runoff reduction techniques81 selected from the NYS SWMDM 2015. 7. Pollution Prevention/Good Housekeeping Following the completion of Part IX.D.1 : a. Annually, from April 1 through October 31 , all streets located in the TMDL watershed(s) must be swept. MS4 Operators must document the completion of this requirement in the SWMP Plan. This requirement is not applicable to: i. Uncurbed roads with no catch basins; ii. High-speed limited access highways; or iii. Roads defined as interstates, freeways and expressways, or arterials by the United States Department of Transportation, Federal Highway Administration, Highway Functional Classification Concepts, Criteria and Procedures, 2013. $' Runoff reduction techniques can be found in Chapters 4 and 5 of the NYS SWMDM 2015. 118 Part IX.D. b. Within six (6) months of MS4 outfall inspection, the MS4 Operator must initiate actions to repair all MS4 outfall protection and/or bank stability problems identified during the inspection. Repairs must be completed in accordance with the NYS E&SC 2016. MS4 Operators must document the completion of this requirement in the SWMP Plan. c. Within thirty (30) days of inspection, the MS4 Operator must initiate all necessary maintenance and repair activities discovered for municipally owned or operated post-construction SMPs. MS4 Operators must document the completion of this requirement in the SWMP Plan. 8. Planned Upgrades to Municipal Facilities in Watersheds to Impaired Waters Incorporate, where feasible,82 cost-effective runoff reduction techniques68 during planned municipal upgrades including municipal right of ways (e.g., bioswales, green streets, porous pavement, replacement of closed drainage with grass swales, replacement of the existing islands in the parking lots with bioretention or curb cuts to route the flow through below-grade infiltration areas or other low-cost improvements that provide runoff treatment or reduction). 82 Consideration of feasibility should include type of land use or municipal operation,suitability of soils, presence of utilities, potential for exacerbating existing contamination problems, safety issues, maintenance requirements, and expected Iifespans of available technologies. 119 Part X Part X. Standard Permit Conditions For the purposes of this SPDES general permit, examples of contractors and subcontractors include: A. Duty to Comply The owner/operator, and all contractors or subcontractors, must comply with all terms and conditions of this SPDES general permit. Any non-compliance with the terms and conditions of this SPDES general permit constitutes a violation of the New York State Environmental Conservation Law, and its implementing regulations, and is grounds for enforcement action. Filing of a request for transfer or termination of coverage under this SPDES general permit, or a notification of planned changes or anticipated non-compliance, does not limit, diminish or stay compliance with any terms and conditions of this SPDES general permit. B. Need to Halt or Reduce Activity is Not a Defense The necessity to halt or reduce the activity regulated by this SPDES general permit, in order to maintain compliance with the conditions of this SPDES general permit, shall not be a defense in an enforcement action. C. Penalties There are substantial criminal, civil, and administrative penalties associated with violating the terms and conditions of this SPDES general permit. Fines of up to $37,500 per day for each violation and imprisonment for up to fifteen (15) years may be assessed depending upon the nature and degree of the offense. D. False Statements Any person who knowingly makes any false material statement, representation, or certification in any application, record, report or other document filed or required to be maintained under this SPDES general permit, including monitoring reports or reports of compliance or noncompliance shall, upon conviction, be punished in accordance with New York State Environmental Conservation Law §71-1933 and or New York State Penal Law Articles 175 and 210. E. Keopener 0ause Upon issuance of this SPDES general permit, a determination has been made on the basis of a submitted Notice of Intent, plans, or other available information, that compliance with the specified general permit terms and conditions will reasonably protect classified water use and assure compliance with applicable water quality standards. Satisfaction of the conditions of this SPDES general permit notwithstanding, if operation pursuant to this SPDES general permit causes or contributes to a condition in contravention of State water quality standards or guidance values, or if the Department determines that a modification is necessary to prevent impairment of the best use of the waters or to assure maintenance of water 120 Part X.E. quality standards or compliance with other provisions of New York State Environmental Conservation Law Article 17 or the Clean Water Act, or any regulations adopted pursuant thereto, the Department may require such modification and the Commissioner may require abatement action to be taken by the owner/operator and may also prohibit such operation until the modification has been implemented. F. Duty to Mitigate. The owner/operator, and its contractors and subcontractors, shall take all reasonable steps to minimize or prevent any discharge in violation of this SPDES general permit which has a reasonable likelihood of adversely affecting human health or the environment. G. Requiring Another General Permit or Individual SPDES Permit The Department may require any discharger authorized to discharge in accordance with this SPDES general permit to apply for and obtain an individual SPDES permit or apply for authorization to discharge in accordance with another general permit. (1) Cases where an individual SPDES permit or authorization to discharge in accordance with another general permit may be required include, but is not limited to the following: (i) the discharger is not in compliance with the conditions of this SPDES general permit or does not meet the criteria for coverage under this SPDES general permit; (ii) a change has occurred in the availability of demonstrated technology or practices for the control or abatement of pollutants applicable to the point source; (iii) new effluent limitation guidelines or new source performance standards are promulgated that are applicable to point sources authorized to discharge in accordance with this SPDES general permit; (iv) existing effluent limitation guidelines or new source performance standards that are applicable to point sources authorized to discharge in accordance with this SPDES general permit are modified; (v) a water quality management plan containing requirements applicable to such point sources is approved by the Department; (vi) circumstances have changed since the time of the request to be covered so that the discharger is no longer appropriately controlled under this SPDES general permit, or either a temporary or permanent reduction or elimination of the authorized discharge is necessary; (vii) the discharge is in violation of section 17-0501 of the New York State Environmental Conservation Law; (viii) the discharge(s) is a significant contributor of pollutants. In making this determination, the Department may consider the following factors: 121 Part X.G. (a) the location of the discharge(s) with respect to waters of New York State; (b) the size of the discharge(s); (c) the quantity and nature of the pollutants discharged to waters of New York State; and (d) other relevant factors including compliance with other provisions of New York State Environmental Conservation Law Article 17, or the Clean Water Act. (1) When the Department requires any discharger authorized by this SPDES general permit to apply for an individual SPDES permit as provided for in this subdivision, it shall notify the discharger in writing that a permit application is required. This notice shall include a brief statement of the reasons for this decision, an application form, a statement setting a time for the owner/operator to file the application for an individual SPDES permit, and a deadline, not sooner than 180 days from the owner/operator's receipt of the notification letter, whereby the authorization to discharge under this SPDES general permit shall be terminated. The Department may grant additional time upon demonstration, to the satisfaction of the Regional Water Engineer, that additional time to apply for an alternative authorization is necessary or where the Department has not provided a permit determination in accordance with 6 NYCRR Part 621. (2) When an individual SPDES permit is issued to a discharger authorized to discharge under this SPDES general permit for the same discharge(s), this SPDES general permit authorization for outfalls authorized under the individual SPDES permit is automatically terminated on the effective date of the individual SPDES permit unless termination is earlier in accordance with 6 NYCRR Part 750. H. Duty to Provide Information The owner/operator shall furnish to the Department, within five (5) business days, unless otherwise set forth by the Department, any information that the Department may request to determine whether cause exists to determine compliance with this SPDES general permit or to determine whether cause exists for requiring an individual SPDES permit in accordance with 6 NYCRR 750-1 .211 (see G. Requiring Another General Permit or Individual Permit). The owner/operator shall make available to the Department, for inspection and copying, or furnish to the Department within 25 business days of receipt of a Department request for such information, any information retained in accordance with this SPDES general permit. Where the owner/operator becomes aware that it failed to submit any relevant facts on the Notice of Intent, or submitted incorrect information in a Notice of Intent or in any report to the Department, the owner/operator shall promptly submit such facts or corrected information to the Department. i. txtensiion In the event a new SPDES general permit is not issued prior to the expiration of this SPDES general permit, and this SPDES general permit is extended pursuant to the State Administrative Procedure Act and 6 NYCRR Part 621, then the owner/operator 122 Part X.I. with coverage under this SPDES general permit may continue to operate and discharge in accordance with the terms and conditions of this SPDES general permit until a new SPDES general permit is issued. J. Signatories and Certification The Notice of Intent, Notice of Termination and reports required by this SPDES general permit shall be signed as provided in 40 CFR §122.22 (a) All Notices of Intent and Notices of Termination shall be signed as follows: (1) For a corporation. By a responsible corporate officer. For the purpose of this section, a responsible corporate officer means: (i) A president, secretary, treasurer, or vice-president of the corporation in charge of a principal business function, or any other person who performs similar policy- or decision-making functions for the corporation, or (i i) The manager of one or more manufacturing, production, or operating facilities, provided, the manager is authorized to make management decisions which govern the operation of the regulated facility including having the explicit or implicit duty of making major capital investment recommendations, and initiating and directing other comprehensive measures to assure long term environmental compliance with environmental laws and regulations; the manager can ensure that the necessary systems are established or actions taken to gather complete and accurate information for Notice of Intent or Notice of Termination requirements; and where authority to sign documents has been assigned or delegated to the manager in accordance with corporate procedures. Note: The Department does not require specific assignments or delegations of authority to responsible corporate officers identified in 40 CFR §122.22(a)(1)(i). The Department will presume that these responsible corporate officers have the requisite authority to sign the Notice of Intent or Notice of Termination unless the corporation has notified the Department to the contrary. Corporate procedures governing authority to sign a Notice of Intent or Notice of Termination may provide for assignment or delegation to applicable corporate positions under 40 CFR §122.22(a)(1)(ii) rather than to specific individuals. (2) For a partnership or sole proprietorship. By a general partner or the proprietor, respectively; or (3) For a municipality, State, Federal, or other public agency. By either a principal executive officer or ranking elected official. For purposes of this section, a principal executive officer of a Federal agency includes: (i) The chief executive officer of the agency, or (i i) A senior executive officer having responsibility for the overall operations of a principal geographic unit of the agency (e.g., Regional Administrators of EPA). 123 Part X.J. (b) All reports required by this SPDES general permit, and other information requested by the Department shall be signed by a person described in paragraph (a) of this section, or by a duly authorized representative of that person. A person is a duly authorized representative only if: (1) The authorization is made in writing by a person described in (a); (2) The authorization specifies either an individual or a position having responsibility for the overall operation of the regulated facility or activity, position of equivalent responsibility, or an individual or position having overall responsibility for environmental matters for the company (A duly authorized representative may thus be either a named individual or any individual occupying a named position.), and (3) The written authorization is submitted to the Department. (c) Changes to authorization. If an authorization under (b) is no longer accurate because a different individual or position has responsibility for the overall operation of the facility or activity, a new authorization satisfying the requirements of (b) must be submitted to the Department prior to or together with any reports, information, or applications to be signed by an authorized representative. (d) Certification. Any person signing a document under (a) or (b) shall make the following certification: 1 certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. 1 am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations. (e) Electronic reporting. If documents described in (a) or (b) are submitted electronically by or on behalf of the activity with coverage under this SPDES general permit, any person providing the electronic signature for such documents shall meet all relevant requirements of this section, and shall ensure that all of the relevant requirements of 40 CFR Part 3 (including, in all cases, subpart D to Part 3) (Cross-Media Electronic Reporting) and 40 CFR Part 127 (NPDES Electronic Reporting Requirements) are met for that submission. K. Inspection & Entry The owner/operator shall allow the Department, the USEPA Regional Administrator, the applicable county health department, or any authorized representatives of those entities, upon the presentation of credentials and other documents as may be required by law, to: 124 Part X.K. (a) enter upon the owner/operator's premises where a regulated facility or activity is located or conducted, or where records must be kept under the conditions of this SPDES general permit; (b) have access to and copy, at reasonable times, any records that must be kept under the conditions of this SPDES general permit, including records required to be maintained for purposes of operation and maintenance; (c) inspect at reasonable times any facilities, equipment (including monitoring and control equipment), practices, or operations regulated or required under this SPDES general permit; (d) sample or monitor at reasonable times, for the purposes of assuring SPDES general permit compliance or as otherwise authorized by the Clean Water Act or New York State Environmental Conservation Law, any substances or parameters at any location; and (e) enter upon the property of any contributor to the regulated facility or activity under authority of the owner/operator. L. Confidentiality of Information The following shall not be held confidential: this SPDES general permit, the fact sheet for this SPDES general permit, the name and address of any owner/operator, effluent data, the Notice of Intent, and information regarding the need to obtain an individual permit or an alternative general permit. This includes information submitted on forms themselves and any attachments used to supply information required by the forms (except information submitted on usage of substances). Upon the request of the owner/operator, the Department shall make determinations of confidentiality in accordance with 6 NYCRR Part 616, except as set forth in the previous sentence. Any information accorded confidential status shall be disclosed to the Regional Administrator upon his or her written request. Prior to disclosing such information to the Regional Administrator, the Department will notify the Regional Administrator of the confidential status of such information. M. Other Permits May Be Required Nothing in this SPDES general permit relieves the owner/operator from a requirement to obtain any other permits required by law. N. Property Rights Coverage under this SPDES general permit does not convey any property rights in either real or personal property, or any exclusive privileges, nor does it authorize any injury to private property or any invasion of personal rights, nor any infringement of Federal, State or local laws or regulations, nor does it obviate the necessity of obtaining the assent of any other jurisdiction as required by law for the discharge authorized. O. Compliance with Interstate Standards If the activity covered by this SPDES general permit originates within the jurisdiction of an interstate water pollution control agency, then the activity must also comply 125 Part X.O. with any applicable effluent standards or water quality standards promulgated by that interstate agency and as set forth in this SPDES general permit for such activities. P. Oil & Hazardous Substance Liability Coverage under this SPDES general permit does not affect the imposition of responsibilities upon, or the institution of any legal action against, the owner or operator under section 311 of the Clean Water Act, which shall be in conformance with regulations promulgated pursuant to section 311 governing the applicability of section 311 of the Clean Water Act to discharges from facilities with NPDES permits, nor shall such issuance preclude the institution of any legal action or relieve the owner or operator from any responsibilities, liabilities, or penalties to which the owner or operator is or may be subject pursuant to the Comprehensive Environmental Response, Compensation and Liability Act of 1980, 42 U.S.C. section 9601 et seq. (CERCLA). Q. Severability The provisions of this SPDES general permit are severable, and if any provision of the permit, or the application of any provision of the permit to any circumstance, is held invalid, the application of such provision to other circumstances, and the remainder of the permit, shall not be affected thereby. 126 Appendix A Appendix A. Acronyms and Definitions Acronym List BMP — Best Management Practice CFR — Code of Federal Regulations CGP — SPDES General Permit for Stormwater from Construction Activities, GP- 0-20-001 CWA — Clean Water Act ECL — Environmental Conservation Law EDC — Effective Date of Coverage EDP— Effective Date of the Permit eNO1 — Electronic Notice of Intent EPCRA - Emergency Planning and Community Right-To-Know Act ERP — Enforcement Response Plan IDDE — Illicit Discharge Detection and Elimination MCM — Minimum Control Measure MS4 — Municipal Separate Storm Sewer System MS4 GP — SPDES General Permit for Stormwater Discharges from the Municipal Separate Storm Sewer Systems, GP-0-24-001 MSGP — SPDES Multi-Sector General Permit for Stormwater Discharges Associated with Industrial Activity, GP-0-23-001 NOI — Notice of Intent NPDES — National Pollutant Discharge Elimination System NYCRR — New York Codes, Rules and Regulations NYS DEC — New York State Department of Environmental Conservation O&M — Operations and Maintenance ORI — Outfall Reconnaissance Inventory POC — Pollutant of Concern RSE — Regional Stormwater Entity SPDES — State Pollutant Discharge Elimination System SMP — Stormwater Management Practice SWMP — Stormwater Management Program SWMP Plan — Stormwater Management Program Plan 127 Appendix A SWPPP — Stormwater Pollution Prevention Plan TMDL — Total Maximum Daily Load USEPA— United States Environmental Protection Agency 128 Appendix A Definition: All definitions in this section are solely for the purposes of this permit. If a word is not defined below, use it how it is commonly defined. Additionally Designated Areas — those areas that meet the additional designation criteria, Designation Criteria for Identifying Regulated Municipal Separate Storm Sewer Systems (MS4s), January 2010, revised January 2023 and found in Appendix B. Additionally Designated Area MS4 Outfall (ADA MS4 outfall) — any point of stormwater discharge from pipes, ditches, and swales, as well as other points of concentrated flow, to impaired waters listed in Appendix C from an MS4 Operator's MS4. Areas of sheet flow which drain to impaired waters listed in Appendix C are not considered ADA MS4 outfalls. Automatically Designated Areas —those areas served by MS4s that meet the automatic designation criteria, Designation Criteria for Identifying Regulated Municipal Separate Storm Sewer Systems (MS4s), January 2010, revised January 2023 and found in Appendix B. Best Management Practice (BMP) — schedules of activities, practices, and prohibitions of practices, maintenance procedures, and other management practices to prevent or reduce the pollution of waters of the state. BMPs also include treatment requirements, operating procedures, and practices to control runoff, spillage and leaks, sludge or waste disposal, or drainage from areas that could contribute pollutants to stormwater discharges. Catch Basin(s) — a cistern, vault, chamber, or well that is part of the MS4 and designed to capture trash, sediment, and/or debris in its sump. Construction Activity(ies) — any clearing, grading, excavation, demolition or stockpiling activity that results in soil disturbance. Clearing activities can include but are not limited to logging equipment operation, the cutting and skidding of trees, stump removal and/or brush root removal. Construction activity does not include routine maintenance that is performed to maintain the original line and grade, hydraulic capacity, or original purpose of a facility. Department — the New York State Department of Environmental Conservation as well as meaning the Department's designated agent. Develop (Developed) —for MS4 Operators continuing coverage, develop means to continue to implement their current SWMP and update the SWMP to comply with the permit requirement; for newly designated MS4 Operators, develop means to create that permit requirement. Discharge (Discharging) — any addition of any pollutant to surface waters of the State through an outlet or point source (6 NYCRR 750-1 .2(a)(28)). Dry Weather — prolonged dry periods (at least 48 hours after the last runoff event). 129 Appendix A Groundwater— waters in the saturated zone. The saturated zone is a subsurface zone in which all the interstices are filled with water under pressure greater than that of the atmosphere. Although the zone may contain gas-filled interstices or interstices filled with fluids other than water, it is still considered saturated. Illicit Discharge — any discharge into an MS4 that is not entirely composed of stormwater, except those identified in Part I.A.3. Examples of illicit discharges are non-permitted sanitary sewage, garage drain effluent, and waste motor oil. However, an illicit discharge could be any other non-permitted discharge which the MS4 Operator or Department has determined to be a substantial contributor of pollutants to the MS4. Illicit discharges can occur throughout the MS4, including at post-construction SMPs. Industrial Activity — the eleven (11) categories of industrial activities included in the definition of "stormwater discharges associated with industrial activity," as defined in 40 CFR 122.26(b)(14)(i)-(ix) and (xi). Interconnection — any point of stormwater discharge from pipes, ditches, and swales, as well as other points of concentrated flow, where the MS4 Operator's MS4 is discharging to another MS4 or private storm sewer system. Areas of sheet flow which drain to another MS4 or private storm sewer system are not considered interconnections. Intermittent Discharge — a discharge which occurs over a shorter period of time (e.g., a few hours per day or a few days per year) (CWP 2004). Larger Common Plan of Development or Sale — a contiguous area where multiple separate and distinct construction activities are occurring, or will occur, under one plan. The term "plan" in "larger common plan of development or sale" is broadly defined as any announcement or piece of documentation (including a sign, public notice or hearing, sales pitch, advertisement, drawing, permit application, State Environmental Quality Review Act Application, zoning request, computer design, etc.) or physical demarcation (including boundary signs, lot stakes, surveyor markings, etc.) indicating that construction activities may occur on a specific plot. For discrete construction projects that are located within a larger common plan of development or sale that are at least 1/4 mile apart, each project can be treated as a separate plan of development or sale provided any interconnecting road, pipeline or utility project that is part of the same "common plan" is not concurrently being disturbed. MS4 Operator — the person, persons, or legal entity that obtains coverage and is responsible for the MS4. MS4 Outfall — any point of stormwater discharge from pipes, ditches, and swales, as well as other points of concentrated flow, to surface waters of the State from an MS4 Operator's MS4. Areas of sheet flow which drain to surface waters of the State are not considered MS4 outfalls. 130 Appendix A Municipal (Municipally) — a county, town, city, village, district corporation, special improvement district, sewer authority or agency thereof. Examples of other public entities that are included in this program include State University Campuses, federal and State prisons, State and federal hospitals, Dormitory Authorities, public housing authorities, school and other special districts. Municipal Facility — an MS4 Operator owned and/or operated facility with the potential to discharge pollutants to the MS4 and/or surface water of the State of the State. Municipal Facility Intraconnection — any point where stormwater is conveyed from the MS4 Operator's municipal facility to the MS4 Operator's own MS4. This is the most down-drainage end of the MS4 infrastructure located on the municipal facility prior to discharge to the MS4. Municipal Operations (Operations) — activities conducted by the MS4 Operator with the potential to discharge pollutants to the MS4 and/or surface water of the State. Municipal Separate Storm Sewer System (MS4) — a conveyance or system of conveyances (including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, man-made channels, or storm drains): 1. owned or operated by a State, city, town, village, borough, county, parish, district, association, or other public body (created by or pursuant to State law) having jurisdiction over disposal of sewage, industrial wastes, stormwater, or other wastes, including special districts under State law such as a sewer district, flood control district or drainage district, or similar entity, or an Indian tribe or an authorized Indian tribal organization, or a designated and approved management agency under section 208 of the CWA, that discharges to surface waters of the State; 2. designed or used for collecting or conveying stormwater, 3. which is not a combined sewer; and 4. which is not part of a Publicly Owned Treatment Works (POTW) as defined at 40 CFR 122.2. National Pollutant Discharge Elimination System — the national system for the issuance of wastewater and stormwater permits under the Federal Water Pollution Control Act (Clean Water Act). No Exposure — all industrial materials or activities are protected by a storm- resistant shelter to prevent exposure to rain, snow, snowmelt, and/or runoff. Non-traditional MS4 Operators— state, federal, county and other publicly owned properties such as state university campuses, prisons, office complexes, hospitals, military installations public housing authorities, school and other special districts. 131 Appendix A Obvious Illicit Discharge —an illicit discharge from a flowing MS4 outfall that does not require sample collection for confirmation; this references the Monitoring Locations Inspection and Sampling Field Sheet, adapted from CWP 2004, Section 6: Overall Outfall Characterization. Physical Indicator Present in the Flow— a sensory indicator present in the discharge from monitoring location including odor, color, turbidity and floatables; this references the Monitoring Locations Inspection and Sampling Field Sheet, adapted from CWP 2004, Section 4: Physical Indicators for Flowing Monitoring Locations Only. Physical Indicator not Related to Flow— an indicator of past discharges, potentially intermittent or transitory discharge, including monitoring location damage, monitoring location deposits or stains, abnormal vegetation growth, poor pool quality or pipe benthic growth; this references the Monitoring Locations Inspection and Sampling Field Sheet, adapted from CWP 2004, Section 5: Physical Indicators for Both Flowing and Non-Flowing Monitoring Locations. These physical indicators can be present at both flowing and non-flowing monitoring locations. Pollutant — dredged spoil, filter backwash, solid waste, incinerator residue, sewage, garbage, sewage sludge, munitions, chemical wastes, biological materials, radioactive materials, heat, wrecked or discarded equipment, rock, sand and industrial, municipal, agricultural waste and ballast discharged into water; which may cause or might reasonably be expected to cause pollution of the waters of the State in contravention of the standards or guidance values adopted as provided in Parts 700 et seq of this Title. For the purposes of this SPDES general permit, relevant pollutants include, but are not limited to, nitrogen, phosphorus, chloride, silt and sediment, pathogens, herbicides/pesticides, floatables, petroleum hydrocarbons, heavy metals, and polycyclic aromatic hydrocarbons (PAHs). Pollutant of Concern (POC) — a pollutant causing the impairment of an impaired water segment with an approved TMDL and/or listed in Appendix C, including phosphorus, silt/sediment, pathogens, nitrogen, and floatables. Privately Owned/Operated — not owned/operated by the MS4 Operator or another MS4 Operator. Publicly Owned/Operated — owned/operated by the MS4 Operator. Qualified Inspector— a person who is knowledgeable in the principles and practices of erosion and sediment control, such as a licensed Professional Engineer, Certified Professional in Erosion and Sediment Control (CPESC), Registered Landscape Architect, or other Department endorsed individual(s). It can also mean someone working under the direct supervision of, and at the same company as, the licensed Professional Engineer or Registered Landscape Architect, provided that person has training in the principles and practices of erosion and sediment control. Training in the principles and practices of erosion and sediment control means that the individual working under the direct 132 Appendix A supervision of the licensed Professional Engineer or Registered Landscape Architect has received four (4) hours of Department endorsed training in proper erosion and sediment control principles from a Soil and Water Conservation District, or other Department endorsed entity. After receiving the initial training, the individual working under the direct supervision of the licensed Professional Engineer or Registered Landscape Architect must receive four (4) hours of training every three (3) years. It can also mean a person that meets the qualified professional qualifications in addition to the qualified inspector qualifications. Note: Inspections of any post-construction SMPs that include structural components, such as a dam for an impoundment, must be performed by a licensed Professional Engineer. Qualified Professional — a person who is knowledgeable in the principles and practices of stormwater management and treatment, such as a licensed Professional Engineer, Registered Landscape Architect, or other Department endorsed individual(s). Individuals preparing SWPPPs that require the post- construction SMP component must have an understanding of the principles of hydrology, water quality management practice design, water quantity control design, and, in many cases, the principles of hydraulics in order to prepare a SWPPP that conforms to the Department's technical standard. All components of the SWPPP that involve the practice of engineering, as defined by the NYS Education Law (see Article 145), must be prepared by, or under the direct supervision of, a professional engineer licensed to practice in the State of New York. Qualifying Storm Event— a storm event with at least 0.1 inch of precipitation, providing the interval from the preceding measurable storm is at least 72 hours. The 72-hour storm interval is waived if the preceding measurable storm did not result in a stormwater discharge (e.g., a storm events in excess of 0.1 inches may not result in a stormwater discharge at some facilities), or if the MS4 Operator is able to document that less than a 72-hour interval is representative for local storm events during the sampling period. Regional Stormwater Entity (RSE) — an organization made up of multiple cooperating regulated and/or nonregulated entities located in the same geographical region of the State who share resources to improve overall stormwater management in their area. Retrofit— to modify or add to existing stormwater infrastructure for the purpose of reducing pollutant loadings. Sheet Flow— stormwater runoff flowing in a thin layer over the ground surface. Sizing Criteria — the criteria included in the CGP that are used to size post- construction stormwater management control practices. The criteria include; Water Quality Volume (WQv), Runoff Reduction Volume (RRv), Channel Protection Volume (Cpv), Overbank Flood (Qp), and Extreme Flood (Qf). 133 Appendix A State Pollutant Discharge Elimination System (SPDES)— the system established pursuant to Article 17 of the ECL and 6 NYCRR Part 750 for issuance of permits authorizing discharges to the waters of the State. Stormwater— that portion of precipitation that, once having fallen to the ground, is in excess of the evaporative or infiltrative capacity of soils, or the retentive capacity of surface features, which flows or will flow off the land by surface runoff to waters of the State. Stormwater Hotspots - a land use or activity that generates higher concentrations of hydrocarbons, trace metals or toxicants than are found in typical stormwater runoff, based on monitoring studies. For further detail, see Section 4.11 of the NYS SWMDM 2015. Stormwater Management Practices (SMPs) — measures, either structural or nonstructural, that are constructed as part of new development or redevelopment projects and are intended to capture, treat, reduce and/or retain stormwater runoff. Stormwater Management Program (SWMP) — the program developed and implemented by the MS4 Operator which provides a comprehensive integrated planning approach involving public participation and, where necessary, intergovernmental coordination, to reduce the discharge of POCs and specified pollutants to the MEP, using management practices, control techniques and systems, design and engineering methods, and other appropriate provisions. MS4 Operators are required at a minimum to develop, implement, and enforce a SWMP designed to address POCs and reduce the discharge of pollutants from the MS4 to the MEP, to protect water quality, and to satisfy the appropriate water quality requirements of the ECL and the Clean Water Act. The SWMP must address all permit requirements in this SPDES general permit. Stormwater Management Program Plan (SWMP Plan) — is used by the MS4 Operator to document and detail the activities and measures that will be implemented to meet the terms and conditions of this SPDES general permit. The SWMP Plan must be updated during the permit term as the MS4 Operator's activities are modified to meet permit conditions. The SWMP Plan can be hardcopy or digital. Storm-sewershed (sewershed) — the catchment that drains to a waterbody based on the MS4 and surface topography. Adjacent catchment areas that drain to the same waterbody are not separate storm-sewersheds. Sump — the part of the catch basin between the bottom interior of the catch basin and the invert of the deepest outlet of the catch basin. Surface Water(s) of the State — must be construed to include lakes, bays, sounds, ponds, impounding reservoirs, springs, rivers, streams, creeks, estuaries, marshes, inlets, canals, the Atlantic ocean within the territorial seas of the state of New York and all other bodies of surface water, natural or artificial, inland or coastal, fresh or salt, public or private (except those private waters that 134 Appendix A do not combine or effect a junction with natural surface or underground waters), which are wholly or partially within or bordering the state or within its jurisdiction. Waters of the state are further defined in 6 NYCRR Parts 800 to 941 . Storm sewers are not waters of the state unless they are classified in 6 NYCRR Parts 800 to 941. Nonetheless, a discharge to a storm sewer must be regulated as a discharge at the point where the storm sewer discharges to waters of the state. Suspect Illicit Discharge — an illicit discharge from flowing monitoring locations with high severity (score of 3) on one or more physical indicators based on the relative severity index of physical indicators for flowing MS4 outfalls only; this references the Monitoring Locations Inspection and Sampling Field Sheet, adapted from CWP 2004, Section 6: Overall Outfall Characterization. Total Maximum Daily Load (TMDL) — the sum of the allowable loads of a single pollutant from all contributing point and nonpoint sources. It is a calculation of the maximum amount of a pollutant that a waterbody can receive and still meet water quality standards, and an allocation of that amount to the pollutant's sources. A TMDL stipulates Waste Load Allocations (WLA) for point source discharges, Load Allocations (LA) for nonpoint sources, and a margin of safety (MOS). Traditional Land Use Control MS4 Operators — a city, town, or village with land use control authority. Traditional Non-land Use Control MS4 Operators — any county agency without land use control. Transitory Discharge — a discharge which occurs rarely, usually in response to a singular event such as an industrial spill, ruptured tank, sewer break, transport accident or illegal dumping episode (CWP 2004). Water Quality Standard — such measures of purity or quality for any waters in relation to their reasonable and necessary use as promulgated in 6 NYCRR Part 700 et seq. 135 Appendix B Appendix B. Designation Criteria for Identifying Regulated Municipal Separate Storm Sewer Systems (MS4s), January 2010, revised January 2023 The universe of small municipal separate storm sewer systems (MS4s) is quite large. However, only a sub-set of small MS4s, referred to as "regulated" small MS4s, are covered by the Federal stormwater regulations. A small MS4 can be designated as a regulated MS4 through automatic designation by the USEPA or by meeting designation criteria developed by the NPDES permitting authority, the New York State Department of Environmental Conservation (Department) in New York State. Automatic Designation Criteria Required by USEPA The USEPA's automatic designation criteria are based strictly on population and density. An area is automatically designated if the population is at least 50,000 and has an overall population density of at least 1,000 people per square mile based on the 2000 and 2010 censuses. Additional Designation Criteria The USEPA requires the Department to develop a set of criteria for additionally designated areas. The following criteria, using a combination of population and environmental factors, have been adopted to designate additional MS4s in NYS. Criterion 1: MS4s discharging to waters for which an USEPA-approved Total Maximum Daily Load (TMDL) requires reduction of a pollutant of concern beyond what can be achieved with existing programs (and the area is not already covered under automatic designation). Criterion 2: MS4s, contiguous to automatically designated areas (municipal lines), that discharge to sensitive waters classified as AA-Special (fresh surface waters), AA (fresh surface waters) with filtration avoidance determination or SA (saline surface waters). Criterion I Automatically designated areas are extended to town, village, or city boundaries, but only for town, village or city implementation of minimum control measure 4 construction site stormwater runoff control and minimum control measure 5 post-construction stormwater management in development and redevelopment. This additional designation may be waived, by written request to the Department, where the automatically designated area is a small portion of the total area of the town, village or city (less than 15 %) and where there is little or no construction activity in the area outside of the automatically designated area (less than 5 disturbed acres per year). 136 Appendix C Appendix C. List of impaired Waters NOTES FOR THE TABLE BELOW: 1 . MS4 Operators must implement Part VIII.A. Pollutant Specific BMPs for Phosphorus for waterbodies with the pollutant listed as "phosphorus." 2. MS4 Operators must implement Part VIII.B. Pollutant Specific BMPs for Silt/Sediment for waterbodies with the pollutant listed as "silt/sediment." 3. MS4 Operators must implement Part VIII.C. Pollutant Specific BMPs for Pathogens for waterbodies with the pollutant listed as "pathogens" or "fecal coliform." 4. MS4 Operators must implement Part VIII.D. Pollutant Specific BMPs for Nitrogen for waterbodies with the pollutant listed as "nitrogen" or "ammonia." 5. MS4 Operators must implement Part VIII.E. Pollutant Specific BMPs for Floatables for waterbodies with the pollutant listed as "garbage & refuse," "oil/grease," or "oil & floating substances." County Waterbody Inventory/Priority Waterbody List Pollutant Name (WI/PWL Number) Albany Ann Lee (Shakers) Pond, Stump Pond (1201-0096) Phosphorus Bronx Bronx River, Lower (1702-0006) 18 Fecal Coliform Bronx Bronx River, Lower (1702-0006) 18 Garbage & Refuse Bronx Bronx River, Middle, and tribs (1702-0106) 18 Fecal Coliform Bronx Bronx River, Middle, and tribs (1702-0106) 18 Garbage & Refuse Bronx Hutchinson River, Lower, and tribs (1702 0003) 18 Garbage & Refuse Bronx Long Island Sound, Western Portion (1702-0027) Nitrogen Bronx Van Cortlandt Lake (1702-0008) Phosphorus Bronx Westchester Creek (1702-0012) 18 Garbage & Refuse Broome Minor Tribs to Lower Susquehanna (0603-0044) Phosphorus Chautauqua Chadakoin River and tribs (0202-0018) Phosphorus Chautauqua Lake Erie (Main Lake, South) (0105-0033) Fecal Coliform Chautauqua Lake Erie, Dunkirk Harbor (0105-0009) Fecal Coliform Dutchess Fallkill Creek (1301-0087) Phosphorus Dutchess Wappingers Lake (1305-0001) Phosphorus Dutchess Wappingers Lake (1305-0001) Silt/Sediment Erie Delaware Park Pond (0101-0026) Phosphorus Erie Ellicott Creek, Lower, and tribs (0102-0018) Phosphorus Erie Ellicott Creek, Lower, and tribs (0102-0018) Silt/Sediment 137 Appendix C Erie Green Lake (0101-0038) Phosphorus Erie Lake Erie (Main Lake, North) (0104-0037) Fecal Coliform Erie Lake Erie (Northeast Shoreline) (0104-0036) Fecal Coliform Erie Rush Creek and tribs (0104-0018) Fecal Coliform Erie Rush Creek and tribs (0104-0018) Phosphorus Erie Scajaquada Creek, Lower, and tribs (0101-0023) Fecal Coliform Oils & Floating Erie Scajaquada Creek, Lower, and tribs (0101-0023) Sub. Erie Scajaquada Creek, Lower, and tribs (0101-0023) Phosphorus Erie Scajaquada Creek, Middle, and tribs (0101-0033) Fecal Coliform Oils & Floating Erie Scajaquada Creek, Middle, and tribs (0101-0033) Sub. Erie Scajaquada Creek, Middle, and tribs (0101-0033) Phosphorus Erie Scajaquada Creek, Upper, and tribs (0101-0034) Fecal Coliform Erie Scajaquada Creek, Upper, and tribs (0101-0034) Phosphorus South Branch Smoke Cr, Lower, and tribs Erie (0101-0036) Phosphorus South Branch Smoke Cr, Lower, and tribs Erie (0101-0036) Silt/Sediment Genesee Tonawanda Cr, Middle, Main Stem (0102-0002) Phosphorus Genesee Tonawanda Cr, Middle, Main Stem (0102-0006) Fecal Coliform Herkimer Mohawk River, Main Stem (1201-0093) Fecal Coliform Oils & Floating Herkimer Mohawk River, Main Stem (1201-0093) Sub. Kings Coney Island Creek (1701-0008) 18 Fecal Coliform Kings Coney Island Creek (1701-0008) 18 Garbage & Refuse Kings Gowanus Canal (1701 0011) 18 Garbage & Refuse Kings Hendrix Creek (1701-0006) 18 Fecal Coliform Kings Hendrix Creek (1701-0006) 18 Garbage & Refuse Kings Hendrix Creek (1701-0006) 18 Nitrogen Kings Mill Basin and tidal tribs (1701 0178) 18 Garbage & Refuse Kings Paerdegat Basin (1701-0363) 18 Garbage & Refuse Kings Prospect Park Lake (1701-0196) Phosphorus Monroe Buck Pond (0301-0017) Phosphorus Monroe Cranberry Pond (0301-0016) Phosphorus 138 Appendix C Monroe Long Pond (0301-0015) Phosphorus Monroe Minor Tribs to Irondequoit Bay (0302-0038) Fecal Coliform Monroe Minor Tribs to Irondequoit Bay (0302-0038) Phosphorus Monroe Rochester E—bayment - East (0302-0002) Fecal Coliform Monroe Rochester E—bayment - West (0301-0068) Fecal Coliform Monroe Thomas Creek/White Brook and tribs (0302-0023) Phosphorus Nassau Beaver Lake (1702-0152) Phosphorus Nassau Camaans Pond (1701-0052) Phosphorus Nassau Cold Spring Harbor, and tidal tribs (1702-0018) Pathogens Nassau Dosoris Pond (1702-0024) Fecal Coliform Nassau East Bay (1701-0202) Fecal Coliform Nassau East Meadow Brook, Upper, and tribs (1701-0211) Silt/Sediment Nassau East Rockaway Inlet (1701-0217) Fecal Coliform Nassau Glen Cove Creek, Lower, and tribs (1702-0146) Fecal Coliform Nassau Glen Cove Creek, Lower, and tribs (1702-0146) Silt/Sediment Nassau Grant Park Pond (1701-0054) Phosphorus Nassau Hempstead Bay (1701-0032) Fecal Coliform Nassau Hempstead Harbor, north, and tidal tribs (1702-0022) Pathogens Nassau Hempstead Harbor, south, & tidal tribs (1702-0263) Fecal Coliform Nassau Hempstead Lake (1701-0015) Phosphorus Long Island Sound, Nassau County Waters Nassau (1702-0028) Fecal Coliform Long Island Sound, Nassau County Waters Nassau (1702-0028) Nitrogen Nassau Manhasset Bay, and tidal tribs (1702-0021) Fecal Coliform Nassau Manhasset Bay, and tidal tribs (1702-0141) Fecal Coliform Nassau Massapequa Creek, Upper, and tribs (1701-0174) Fecal Coliform Nassau Massapequa Creek, Upper, and tribs (1701-0174) Phosphorus Nassau Middle Bay (1701-0208) Fecal Coliform Milburn/Parsonage Creeks, Upp, and tribs (1701- Nassau 0212) Phosphorus Nassau Mill Neck Creek and tidal tribs (1702-0151) Pathogens Nassau Oyster Bay Harbor (1702-0016) Pathogens Nassau Reynolds Channel, east (1701-0215) Fecal Coliform 139 Appendix C Seafords/Seamans Creeks, Upper, and tribs (1701- Nassau 0201) Fecal Coliform Nassau Shell Creek and Barn ums Channel (1701-0213386) Fecal Coliform Nassau South Oyster Bay (1701-0041) Fecal Coliform Nassau Tidal Tribs to Hempstead Bay (1701-0218) Fecal Coliform Nassau Tidal Tribs to Hempstead Bay (1701-0218) Nitrogen Nassau Tidal Tribs to South Oyster Bay (1701-0200) Fecal Coliform Nassau Tribs (fresh) to East Bay (1701-0204) Fecal Coliform Nassau Tribs (fresh) to East Bay (1701-0204) Phosphorus Nassau Tribs (fresh) to East Bay (1701-0204) Silt/Sediment Nassau Tribs to Smith Pond/Halls Pond (1701-0221) Phosphorus Nassau Woodmere Channel (1701-0219) Fecal Coliform Nassau Woodmere Channel (1701-0219) Nitrogen New York East River, Lower (1702-0011) 18 Garbage & Refuse New York Harlem River (1702-0004) 18 Garbage & Refuse New York Harlem Meer (1702-0103) Phosphorus New York The Lake in Central Park (1702-0105) Phosphorus Niagara Bergholtz Creek and tribs (0101-0004) Fecal Coliform Niagara Bergholtz Creek and tribs (0101-0004) Phosphorus Niagara Hyde Park Lake (0101-0030) Phosphorus Oneida Ballou, Nail Creeks (1201-0203) Phosphorus Oneida Mohawk River, Main Stem (1201-0010) Fecal Coliform Oneida Mohawk River, Main Stem (1201-0094) Fecal Coliform Oneida Utica Harbor (1201-0228) Fecal Coliform Onondaga Bloody Brook and tribs (0702 0006) 10 Fecal Coliform Onondaga Ley Creek and tribs (0702 0001) 10 Fecal Coliform Onondaga Ley Creek and tribs (0702-0001) 10 Ammonia (NH3) Onondaga Ley Creek and tribs (0702-0001) 10 Phosphorus Nitrogen (NH3, Onondaga Minor Tribs to Onondaga Lake (0702-0022) 10 NO2) Onondaga Minor Tribs to Onondaga Lake (0702-0022) 10 Phosphorus Onondaga Minor Tribs to Onondaga Lake (0702-0022) 10 Fecal Coliform Onondaga Onondaga Creek, Lower (0702-0023) 10 Ammonia (NH3) Onondaga Onondaga Creek, Lower (0702-0023) 10 Fecal Coliform 140 Appendix C Onondaga Onondaga Creek, Lower (0702-0023) 10 Phosphorus Onondaga Onondaga Creek, Middle, and tribs (0702-0004) 10 Fecal Coliform Onondaga Onondaga Lake, Southern End (0702-0021) [10] Fecal Coliform Ontario Great Brook and minor tribs (0704-0034) Phosphorus 2 Ontario Great Brook and minor tribs (0704-0034) Silt/Sediment Orange Greenwood Lake (1501-0001) Phosphorus Orange Monhagen Brook and tribs (1306-0074) Phosphorus Orange Orange Lake (1301-0008) [16] Phosphorus Oswego Lake Neatahwanta (0701-0018) Phosphorus Putnam Bog Brook Reservoir (1302-0041) Phosphorus Putnam Boyd Corners Reservoir (1302-0045) Phosphorus Putnam Croton Falls Reservoir (1302-0026) Phosphorus Putnam Diverting Reservoir (1302-0046) Phosphorus Putnam East Branch Reservoir (1302-0040) Phosphorus Putnam Middle Branch Reservoir (1302-0009) Phosphorus Putnam Oscawana Lake (1301-0035) Phosphorus Putnam Palmer Lake (1302-0103) Phosphorus Putnam West Branch Reservoir (1302-0022) Phosphorus Queens Alley Creek/Little Neck Bay Trib (1702-0009) 18 Fecal Coliform Queens Atlantic Ocean Coastline (1701-0014) Fecal Coliform Queens Bergen Basin (1701-0009) 18 Fecal Coliform Queens Bergen Basin (1701-0009) 18 Garbage & Refuse Queens Bergen Basin (1701-0009) 18 Nitrogen Queens East River, Upper (1702-0010) 18 Garbage & Refuse Queens East River, Upper (1702-0032) 18 Garbage & Refuse Queens Flushing Creek/Bay (1702 0005) 18 Garbage & Refuse Queens Flushing Creek/Bay (1702-0005) Nitrogen Queens Flushing Creek/Bay (1702-0005) 18 Fecal Coliform Jamaica Bay, Eastern, and tribs, Queens (1701-0005) Queens 18 Fecal Coliform Jamaica Bay, Eastern, and tribs, Queens (1701-0005) Queens 18 Garbage & Refuse Jamaica Bay, Eastern, and tribs, Queens (1701-0005) Queens 18 Nitrogen 141 Appendix C Queens Kissena Lake (1702-0258) Phosphorus Queens Little Neck Bay (1702-0029) Fecal Coliform Queens Meadow Lake (1702-0030) Phosphorus Queens Newtown Creek and tidal tribs (1702 0002) 18 Garbage & Refuse Queens Newtown Creek and tidal tribs (1702-0002) 18 Fecal Coliform Queens Shellbank Basin (1701-0001) 18 Nitrogen Queens Spring Creek and tribs (1701-0361) 18 Garbage & Refuse Queens Thurston Basin (1701-0152) 18 Fecal Coliform Queens Thurston Basin (1701-0152) 18 Garbage & Refuse Queens Willow Lake (1702-0031) Phosphorus Rensselaer Nassau Lake (1310-0001) Phosphorus Richmond Arthur Kill, Class I, and minor tribs (1701 0010) 18 Garbage & Refuse Richmond Arthur Kill, Class SD, and minor tribs (1701-0182) 18 Garbage & Refuse Richmond Grassmere Lake/Bradys Pond (1701-0357) Phosphorus Richmond Kill Van Kull (1701 0184) 18 Garbage & Refuse Richmond Newark Bay (1701 0183) 18 Garbage & Refuse Richmond Raritan Bay, Class SA (1701-0002) Fecal Coliform Rockland Congers Lake, Swartout Lake (1501-0019) Phosphorus Rockland Rockland Lake (1501-0021) Phosphorus Rockland Sparkill Creek, Lower (1301-0088) Fecal Coliform Saratoga Ballston Lake (1101-0036) Phosphorus Saratoga Dwaas Kill and tribs (1101-0007) Phosphorus Saratoga Dwaas Kill and tribs (1101-0007) Silt/Sediment Saratoga Lake Lonely (1101-0034) Phosphorus Saratoga Tribs to Lake Lonely (1101-0001) Fecal Coliform Saratoga Tribs to Lake Lonely (1101-0001) Phosphorus Schenectady Collins Lake (1201-0077) Phosphorus Schenectady Duane Lake (1311-0006) Phosphorus Schenectady Mariaville Lake (1201-0113) Phosphorus Suffolk Acabonack Harbor (1701-0047) Pathogens Suffolk Agawam Lake (1701-0117) Phosphorus Suffolk Beaverdam Creek and tribs (1701-0104) Ammonia Suffolk Bellport Bay (1701-0320) Pathogens 142 Appendix C Suffolk Big/Little Fresh Ponds (1701-0125) Phosphorus Suffolk Canaan Lake (1701-0018) Phosphorus Suffolk Canaan Lake (1701-0018) Silt/Sediment Suffolk Centerport Harbor (1702-0229) Pathogens Suffolk Conscience Bay and tidal tribs (1702-0091) Pathogens Suffolk Flanders Bay, East/Center, and tribs (1701-0030) Pathogens Flanders Bay, West/Lower Sawmill Creek Suffolk (1701-0254) Nitrogen Flanders Bay, West/Lower Sawmill Creek Suffolk (1701-0254) Pathogens Suffolk Flax Pond (1702-0240) Fecal Coliform Suffolk Forge River, Lower and Cove (1701-0316) Fecal Coliform Suffolk Fresh Pond (1701-0241) Phosphorus Suffolk Goldsmith Inlet (1702-0026) Pathogens Suffolk Goose Creek (1701-0236) Pathogens Suffolk Great Cove (1701-0376) Fecal Coliform Suffolk Great South Bay, East (1701-0039) Nitrogen Suffolk Great South Bay, Middle (1701-0040) Nitrogen Suffolk Great South Bay, West (1701-0173) Nitrogen Suffolk Hashamomuck Pond (1701-0162) Pathogens Suffolk Heady and Taylor Creeks and tribs (1701-0294) Pathogens Suffolk Huntington Harbor (1702-0228) Pathogens Suffolk Lake Montauk (1701-0031) Pathogens Suffolk Lake Ronkonkoma (1701-0020) Fecal Coliform Suffolk Lake Ronkonkoma (1701-0020) Phosphorus Suffolk Little Sebonac Creek (1701-0253) Pathogens Suffolk Long Island Sound, Suffolk Co, Central (1702-0265) Fecal Coliform Suffolk Mattituck Inlet/Cr, Low, and tidal tribs (1702-0020) Pathogens Suffolk Meetinghouse/Terrys Creeks and tribs (1701-0256) Pathogens Suffolk Mill and Seven Ponds (1701-0113) Phosphorus Suffolk Millers Pond (1702-0013) Phosphorus Suffolk Moriches Bay, East (1701-0305) Nitrogen Suffolk Moriches Bay, West (1701-0038) Nitrogen Suffolk Mt Sinai Harbor and tidal tribs (1702-0019) Pathogens 143 Appendix C Suffolk Mud Creek, Upper, and tribs (1701-0101) Fecal Coliform Suffolk Narrow Bay (1701-0318) Pathogens Suffolk Nicoll Bay (1701-0375) Fecal Coliform Suffolk North Sea Harbor and tribs (1701-0037) Pathogens Suffolk Northport Harbor (1702-0230) Pathogens Suffolk Northwest Creek and tidal tribs (1701-0046) Pathogens Suffolk Noyack Creek and tidal tribs (1701-0237) Pathogens Suffolk Ogden Pond (1701-0302) Pathogens Suffolk Patchogue Bay (1701-0326) Pathogens Suffolk Peconic River, Lower, and tidal tribs (1701-0259) Nitrogen Suffolk Peconic River, Lower, and tidal tribs (1701-0259) Pathogens Suffolk Penniman Creek and tidal tribs (1701-0300) Pathogens Suffolk Penny Pond, Wells and Smith Creeks (1701-0298) Pathogens Suffolk Phillips Creek, Lower, and tidal tribs (1701-0299) Fecal Coliform Suffolk Port Jefferson Harbor, North, and tribs (1702-0015) Pathogens Suffolk Quantuck Bay (1701-0042) Pathogens Suffolk Quantuck Bay (1701-0042) Nitrogen Suffolk Quantuck Canal/Moneybogue Bay (1701-0371) Pathogens Suffolk Quogue Canal (1701-0301) Fecal Coliform Suffolk Reeves Bay and tidal tribs (1701-0272) Pathogens Suffolk Richmond Creek and tidal tribs (1701-0245) Pathogens Suffolk Sag Harbor and Sag Harbor Cove (1701-0035) Pathogens Suffolk Sebonac Cr/Bullhead Bay and tidal tribs (1701-0051) Pathogens Suffolk Setauket Harbor (1702-0242) Pathogens Suffolk Shinnecock Bay and Inlet (1701 0033) Nitrogen Suffolk Stirling Creek and Basin (1701-0049) Pathogens Stony Brook Harbor and West Meadow Creek Suffolk (1702-0047) Pathogens Suffolk Tidal Tribs to Gr Peconic Bay, Northshr (1701-0247) Pathogens Suffolk Tidal Tribs to West Moriches Bay (1701-0312) Fecal Coliform Suffolk Tidal Tribs to West Moriches Bay (1701-0312) Nitrogen Suffolk Town/Jockey Creeks and tidal tribs (1701-0235) Pathogens Suffolk Tuthill, Harts, Seatuck Coves (1701-0309) Pathogens Suffolk Weesuck Creek and tidal tribs (1701-0111) Pathogens 144 Appendix C Suffolk West Creek and tidal tribs (1701-0246) Fecal Coliform Suffolk Wooley Pond (1701-0048) Pathogens Tompkins Cayuga Lake, Southern End (0705-0040) Phosphorus Tompkins Cayuga Lake, Southern End (0705-0040) Silt/Sediment Warren Hague Brook and tribs (1006-0006) Silt/Sediment Warren Huddle/Finkle Brooks and tribs (1006-0003) Silt/Sediment Warren Indian Brook and tribs (1006-0002) Silt/Sediment Warren Lake George (1006-0016) and tribs Silt/Sediment Warren Tribs to Lake George, East Shore (1006-0020) Silt/Sediment Warren Tribs to Lake George, Lk.George Village (1006-0008) Silt/Sediment Wayne Lake Ontario Shoreline, Central (0302-0044) Fecal Coliform Westchester Amawalk Reservoir (1302-0044) Phosphorus Westchester Bronx River, Upper, and tribs (1702-0107) Fecal Coliform Westchester Cross River Reservoir (1302-0005) Phosphorus Westchester Hutchinson River, Middle, and tribs (1702-0074) Fecal Coliform Westchester Hutchinson River, Middle, and tribs (1702-0074) Oil/Grease Westchester Lake Katonah (1302-0136) Phosphorus Westchester Lake Lincolndale (1302-0089) Phosphorus Westchester Lake Meahagh (1301-0053) Phosphorus Westchester Lake Mohegan (1301-0149) Phosphorus Westchester Lake Shenorock (1302-0083) Phosphorus Westchester Larchmont Harbor (1702-0116) Fecal Coliform Long Island Sound, Westchester Co Waters Westchester (1702-0001) Fecal Coliform Long Island Sound, Westchester Co Waters Westchester (1702-0001) Nitrogen Westchester Mamaroneck Harbor (1702-0125) Fecal Coliform Westchester Mamaroneck River, Lower (1702-0071) Silt/Sediment Westchester Mamaroneck River, Upp, & minor tribs (1702-0123) Silt/Sediment Westchester Milton Harbor/Lower Blind Brook (1702-0063) Fecal Coliform Westchester Muscoot/Upper New Croton Reservoir (1302-0042) Phosphorus Westchester New Croton Reservoir (1302-0010) Phosphorus Westchester New Rochelle Harbor (1702-0259) Fecal Coliform Westchester Port Chester Harbor/Lower Byram River (1702-0260) Fecal Coliform 145 Appendix C Westchester Reservoir No.1/Lake Isle (1702-0075) Phosphorus Westchester Saw Mill River (1301-0007) Fecal Coliform Westchester Saw Mill River (1301-0007) Phosphorus Westchester Saw Mill River, Middle, and tribs (1301-0100) Fecal Coliform Westchester Saw Mill River, Middle, and tribs (1301-0100) Phosphorus Westchester Sheldrake River (1702-0069) Phosphorus Westchester Sheldrake River (1702-0069) Silt/Sediment Westchester Silver Lake (1702-0040) Phosphorus Westchester Teatown Lake (1302-0150) Phosphorus Westchester Titicus Reservoir (1302-0035) Phosphorus Westchester Truesdale Lake (1302-0054) Phosphorus Westchester Wallace Pond (1301-0140) Phosphorus 146 Appendix D Appendix D. Forms Included in this section are the following documents, in order: • Monitoring Locations Inspection and Sampling Field Sheet • Construction Site Inspection Report Form • No Exposure Certification • Municipal Facility Assessment Form • Storm Event Data Form • Visual Monitoring Form 147 Monitoring Locations Inspection and Sampling Field Sheet Section 1: Background Data Subwatershed: Monitoring Location ID: Today's date: Time(Military): Investigators: Form completed by: Temperature(°F): Rainfall(in.): Last 24 hours: Last 48 hours: Latitude: Longitude: GPS Unit: GPS LMK#: Camera: Photo#s: Land Use in Drainage Area(Check all that apply): ❑ Industrial ❑ Open Space ❑ Ultra-Urban Residential ❑ Institutional ❑ Suburban Residential Other: ❑ Commercial Known Industries: Notes(e.g.,origin,if known): Section 2: Monitoring Location Description LOCATION MATERIAL SHAPE DIMENSIONS(IN.) SUBMERGED ❑ RCP ❑ CMP ❑ Circular ❑ Single Diameter/Dimensions: In Water: ❑ No ❑ PVC ❑ HDPE ❑ Elliptical ❑ Double ❑ Partially ❑ Fully ❑ Closed Pipe ❑ Steel ❑ Box ❑Triple With Sediment: ❑ No ❑ Other: ❑ Other: ❑ Other: ❑ Partially ❑ Fully ❑ Concrete ❑Trapezoid Depth: ❑ Earthen Parabolic Top Width: ❑ Open drainage ❑ ��� f`�����/1 ❑ Rip-Rap ❑ Other: Bottom Width: Zf/f/lMl ❑ Other: -i%ili%O%011 ❑ In-Stream (applicable when collecting samples) Flow Present? ❑Yes ❑ No If No,Skip to Section 5 Flow Description (If present) ❑ Trickle ❑ Moderate ❑ Substantial Section 3: Quantitative Characterization FIELD DATA FOR FLOWING MONITORING LOCATIONS PARAMETER RESULT UNIT EQUIPMENT Volume Liter Bottle ❑ Flow#1 Time to fill Sec Flow depth In Tape measure Flow width Ft, In Tape measure ❑ Flow#2 Measured length Ft, In Tape measure Time of travel S Stopwatch Temperature °F Thermometer pH pH Units Test strip/Probe Ammonia mg/L Test strip 148 Monitoring Locations Inspection and Sampling Field Sheet Section 4: Physical Indicators for Flowing Monitoring Locations Only Are Any Physical Indicators Present in the flow? ❑ Yes ❑ No (If No, Skip to Section 5) INDICATOR CHECK if DESCRIPTION RELATIVE SEVERITY INDEX(1-3) Present ❑ Sewage ❑ Rancid/sour ❑ Petroleum/gas 3—Noticeable from a Odor ❑ ❑ 1 -Faint ❑ 2—Easily detected El ❑ Sulfide ❑ Other: distance ❑ Clear ❑ Brown ❑ Gray ❑ Yellow 1 —Faint colors in 2—Clearly visible in Color ❑ ❑ sample bottle ❑ sample bottle ❑ 3—Clearly visible inflow ❑ Green ❑ Orange ❑ Red ❑ Other: p p Turbidity ❑ See severity ❑ 1—Slight cloudiness ❑ 2-Cloudy ❑ 3—Opaque Floatables ❑ Sewage(Toilet Paper,etc.)❑Suds 2-Some;indications of 3-Some;origin clear (e.g., 1—Few/slight;origin origin e. possible obvious oil sheen,suds, or Does Not Include ❑ ❑ not obvious ❑ ( g., p ❑ ii ❑ Petroleum(oil sheen) ❑Other: suds or oil sheen) floating sanitary materials) Trash.. Section 5: Physical Indicators for Both Flowing and Non-Flowing Monitoring Locations Are physical indicators that are not related to flow present? ❑ Yes ❑ No (If No, Skip to Section 6) INDICATOR CHECK if Present DESCRIPTION COMMENTS Monitoring Location El ❑ Spalling,Cracking or Chipping ❑ Peeling Paint Damage ❑ Corrosion Deposits/Stains ❑ ❑ Oily ❑ Flow Line ❑ Paint ❑ Other: Abnormal Vegetation ❑ ❑ Excessive ❑ Inhibited ❑ Odors ❑ Colors ❑ Floatables ❑ Oil Sheen Poor pool quality ❑ ❑ Suds ❑ Excessive Algae ❑ Other: Pipe benthic growth ❑ ❑ Brown ❑ Orange ❑ Green ❑ Other: Section 6: Overall Monitoring Location Characterization ❑ Unlikely ❑ Potential (presence of two or more indicators) ❑ Suspect(one or more indicators with a severity of 3) ❑ Obvious Section 7: Data Collection 1. Sample for the lab? ❑ Yes ❑ No 2. If yes,collected from: ❑ Flow ❑ Pool 3. Intermittent flow trap set? ❑ Yes ❑ No If Yes,type: ❑ OBM ❑ Caulk dam Section 8: Any Non-Illicit Discharge Concerns (e.g.,trash or needed infrastructure repairs)? 149 ip b NEW YORK STATE v DEPARTMENT OF ENVIRONMENTAL CONSERVATION DIVISION OF WATER vokK Department of STATE Environmental Conservation New York State Department of Environmental Conservation Construction Site Inspection Report for SPDES MS4 General Permit GP-0-24-001 Project Name: Date: Project Location: Weather: Permit#(if any): NYR Contacted: ❑Yes ❑No Entry Time: Exit Time. Name of SPDES Permittee: Inspection Type: ❑NOT ❑Complaint Phone Number(s): ❑Compliance ❑ Referral On-site Representative(s)and Company(s): MS4 Operator Name: MS4 Permit ID: NYR20A SPDES Authority Yes No N/A Citation 1. ❑ ❑ ❑ Does the project have permit coverage? GP-0-20-001: LA&II. B 2. ❑ ❑ ❑ Is a copy of the NOI and Acknowledgment Letter available on site and accessible for viewing? GP-0-20-001: II.D.2 3. ❑ ❑ ❑ Is a copy of the MS4 SWPPP Acceptance Form available on site and accessible for viewing? GP-0-20-001: II.D.2 4. ❑ ❑ ❑ Is an up-to-date copy of the signed SWPPP retained at the construction site? GP-0-20-001: II.D.2. &III.A.4 5. ❑ ❑ ❑ Is a copy of the SPDES General Permit retained at the construction site? GP-0-20-001: II.D.2 6. ❑ ❑ ❑ Does the NOI accurately report the number of acres to be disturbed? GP-0-20-001: II.B.4 SWPPP Content Yes No N/A Citation 7. ❑ ❑ ❑ Does the SWPPP describe and identify the erosion and sediment control measures to be employed? GP-0-20-001: III.B.1.e 8. ❑ ❑ ❑ Does the SWPPP provide an inspection schedule and maintenance requirements for the E&SC measures? GP-0-20-001: III.B.1.i 9. ❑ ❑ ❑ Does the SWPPP describe and identify the stormwater management practices to be employed? GP-0-20-001: III.B.2 10. ❑ ❑ ❑ Does the SWPPP identify the contractor(s)and subcontractor(s)responsible for each measure? GP-0-20-001: III.A.6 11. ❑ ❑ ❑ Does the SWPPP identify at least one trained individual from each contractor(s)and subcontractor(s)companies? GP-0-20-001: III.A.6 12. ❑ ❑ ❑ Does the SWPPP include all the necessary Contractor Certification Statements and signatures? GP-0-20-001: III.A.6 13. ❑ ❑ ❑ Is the SWPPP signed by the permittee? GP-0-20-001:VII.H.2 14. ❑ ❑ ❑ Is the SWPPP prepared by a qualified professional(if post-construction stormwater management required)? GP-0-20-001: III.A.3 15. ❑ ❑ ❑ Do the SMPs conform to the Enhanced Phosphorus Removal Standards(projects in TMDL watersheds)? GP-0-20-001: III.B.3 Recordkeeping Yes No N/A Citation 16. ❑ ❑ ❑ Are self-inspections performed as required by the permit(weekly,or twice weekly for>5 acres disturbed)? GP-0-20-001:IV.C.2.a.&b 17. ❑ ❑ ❑ Are the self-inspections performed and signed by a qualified inspector and retained on site? GP-0-20-001:II.C.2.,IV.C.6&VII.H.3 18. ❑ ❑ ❑ Do the qualified inspector's reports include the minimum reporting requirements? GP-0-20-001: IV.C.4 19. ❑ ❑ ❑ Do inspection reports identify corrective measures that have not been implemented or are recurring? GP-0-20-001: IV.C.5 150 ip b NEW YORK STATE v DEPARTMENT OF ENVIRONMENTAL CONSERVATION z, x - DIVISION OF WATER UN OF WP Visual Observations Yes No N/A Citation 20. ❑ ❑ ❑ Are all erosion and sediment control measures installed properly? GP-0-20-001:VILL 21. ❑ ❑ ❑ Are all erosion and sediment control measures being maintained properly? GP-0-20-001: IV.A.1 22. ❑ ❑ ❑ Was written authorization issued for any disturbance greater than 5 acres? GP-0-20-001: II.D.3 23. ❑ ❑ ❑ Have stabilization measures been implemented in inactive areas per Permit(>5acres)or ESC Standard? GP-0-20-001: II.D.3.b&III.B.1.f 24. ❑ ❑ ❑ Are post-construction stormwater management practices constructed/installed correctly? GP-0-20-001: III.B.2 25. ❑ ❑ ❑ Has final site stabilization been achieved and temporary E&SC measures removed prior to NOT submittal? GP-0-20-001:V.A.2 26. ❑ ❑ ❑ Was there a discharge from the site on the day of inspection? 27. ❑ ❑ ❑ Is there evidence that a discharge caused or contributed to a violation of water quality standards? ECL 17-0501,6 NYCRR 703.2& G P-0-20-001: I.D Water Quality Observations Describe the discharge(s):location,source(s),impact on receiving water(s),etc. Describe the quality of the receiving water(s)both upstream and downstream of the discharge: Describe any other water quality standards or permit violations: 151 ip b NEW YORK STATE v DEPARTMENT OF ENVIRONMENTAL CONSERVATION z, x - DIVISION OF WATER UN OF WP Additional Comments: ❑ Photographs attached Overall Inspection Rating: ❑ Satisfactory ❑ Marginal ❑ Unsatisfactory Name/Agency of Lead Inspector: Signature of Lead Inspector: Names/Agencies of Other Inspectors: 152 NO EXPOSURE CERTIFICATION �c For High Priority Municipal Facilities Yv� Department of �SVATE Environmental in SPDES MS4 General Permit, GP-0-24-001 Conservation The completed No Exposure Certification must be documented in the SWMP Plan. Please do not submit this form to the Department unless requested. I. Owner/Facility Information Owner/Operator Name: Mailing Address: City/State/Zip: -7 Contact Name: Phone No.: Facility Name: Street Address: City/State/Zip: County: Latitude: Longitude: II. Exposure Checklist Are any of the following materials or activities exposed to precipitation,now or in the foreseeable future? (Please check either"Yes"or "No"in the appropriate box.) If you answer"Yes"to any of these questions(1)through(11),you are not eligible for no exposure. YES NO 1 Using,storing or cleaning machinery or equipment,and areas where residuals from using,storing or cleaning machinery or equipment remain and are exposed to stormwater 2 Materials or residuals on the ground or in stormwater inlets from spills/leaks 4 Material handling equipment(except adequately maintained vehicles) 5 Materials or products during loading/unloading or transporting activities 6 Materials or products stored outdoors(except final products intended for outside use[e.g.,new cars]where exposure to stormwater does not result in the discharge of pollutants) 7 Materials contained in open,deteriorated or leaking storage drums,barrels,tanks,and similar containers 8 Materials or products handled/stored on roads or railways owned or maintained by the discharger 9 Waste material(except waste in covered,non-leaking containers[e.g.,dumpster]) III. Certification I certify under penalty of law that I have read and understand the eligibility requirements for claiming a condition of"no exposure"and obtaining an exclusion from SPDES stormwater permitting. I certify under penalty of law that there are no discharges of storm water contaminated by exposure to industrial activities or materialsfrom the industrial facility or site identified in this document(except as allowed under 40 CFR 122.26(g)(2)). I understand that I am obligated to submit a no exposure certification form upon request to the NPDES permitting authority orto the operator of the local municipal separate storm sewer system(MS4)into which the facility discharges(where applicable). I understand that I must allow the SPDES permitting authority,or MS4 Operator where the discharge is into the local MS4,to perform inspections to confirm the condition of no exposure and to make such inspection reports publicly available upon request. Printed Name: Title/Position: Signature: Date: 153 NEiN Municipal Facility Assessment Form YORK Department of STATE Environmental For SPDES MS4 General Permit, Conservation GP-0-24-001 Assessments must be conducted by a person with the knowledge and skills to assess conditions and activities that could impact stormwater quality at the facility and evaluate the effectiveness of best management practices required by the SPDES MS4 General Permit(GP-0-24-001). MS4 Permit ID: MS4 Operator Name: Facility Name: Facility Type: Date: Weather Conditions: Is stormwater runoff present during this assessment? ❑Yes ❑No Comments: General Yes No 1 Is this a high priority municipal facility? ❑ ❑ 2 If this is a high priority municipal facility,does the facility qualify for a No Exposure Certification? ❑ ❑ 3 If this is a high priority municipal facility, is there a completed SWPPP available? ❑ ❑ 4 Does the facility have any MS4 outfalls? ❑ ❑ 5 Does the facility have any interconnections? ❑ ❑ -r- 6 Does the facility have any municipal facility intraconnections? ❑ ❑ Comments: Good Housekeeping Yes No 7 Are paved surfaces free of trash,sediment,and/or debris? ❑ ❑ 8 Date the paved area was last swept or vacuumed. ❑ ❑ 9 Do outdoor waste receptacles have covers? ❑ ❑ 10 Are the waste receptacles emptied on a regular basis? ❑ ❑ 11 Are there signs of leaks,contaminants or overfilling at the waste receptacle area? ❑ ❑ 12 Are the following facility areas free of accumulated trash,sediment,debris,contaminants,and spills: ❑ ❑ Salt storage areas ❑ ❑ Container storage areas ❑ ❑ Maintenance areas 1-0 ❑ 154 Staging areas ❑ ❑ Material stockpile areas ❑ ❑ Comments: Vehicle and Equipment Areas ❑ N/A Yes No 13 Are vehicle/equipment parked indoors or under a roof? ❑ ❑ 14 Are vehicles/equipment washed in only designated areas? ❑ ❑ 15 Are vehicles washed regularly to remove contamination and prevent them from polluting stormwater? ❑ ❑ 16 Is all wash water treated in an oil water separator prior to discharge? ❑ ❑ 17 Is all wash water managed so it does not enter the MS4? ❑ ❑ Comments Vehicle/Equipment Maintenance ❑N/A Yes No 18 Is equipment stored under shelter or elevated and covered? ❑ ❑ 19 Are fluids drained over a drip pan or pad? ❑ ❑ 20 Are funnels or pumps used when transferring fluids? ❑ ❑ 21 Are waste rags and used absorbent pads disposed of properly? ❑ ❑ 22 Are any vehicles and/or equipment leaking fluids? ❑ ❑ 23 Are drip pans immediately placed under leaks? ❑ ❑ 24 Are materials,equipment,and activities located so that leaks are contained in existing containment and diversion systems ❑ ❑ (confine the storage of leaky or leak-prone vehicles and equipment awaiting maintenance to protected areas)? 25 Are vehicles inspected daily for leaks? Comments: Fueling areas ❑ N/A Yes No 26 Is fueling performed under a canopy or roof? ❑ ❑ 27 Are spill cleanup materials available at the fueling area? ❑ ❑ 28 Are breakaway valves used on fueling hoses? ❑ ❑ 29 Is the fueling handle lock disconnected so the operator must attend the fueling? ❑ ❑ 30 Is stormwater runoff from fueling area treated in an oil/water separator? ❑ ❑ 31 Is the fueling automatic stop inspected regularly to ensure it is working properly? ❑ ❑ 32 Are all fuel deliveries monitored? ❑ ❑ Comments: 155 Salt Storage Piles or Pile Containing Salt ❑ N/A Yes No 33 Is salt stored in a salt storage building or under a roof? ❑ ❑ 34 Are controls in place to minimize spills while adding or removing material from the pile? ❑ ❑ 35 Are salt spills cleaned up promptly? ❑ ❑ 36 Is overflow and tracked salt removed promptly from loading areas? ❑ ❑ 37 Is stormwater draining away from the salt pile directed to a vegetated filter area ❑ ❑ Comments: Fluids Management ❑ N/A Yes No 38 Are all drums and containers of fluids stored with proper cover and containment? ❑ ❑ 39 Are fluids stored in appropriate containers and/or storage cabinets? ❑ ❑ 40 Are all fluids kept in original containers or labeled in a manner that describes the contents adequately? ❑ ❑ 41 Are Material Safety Data Sheets(MSDS/SDS)readily available? ❑ ❑ 42 Are all containers that are stored free of leaks or deposits? ❑ ❑ 43 Are containers of product inspected regularly? ❑ ❑ 44 Is used oil and antifreeze stored indoors and/or on spill containment pallets? ❑ ❑ 45 Is used oil and antifreeze properly disposed of or recycled? ❑ ❑ Comments: Lead Acid Batteries ❑ N/A Yes No 46 Are lead-acid batteries stored indoors on spill containment pallets or in bins? ❑ ❑ 47 Are intact batteries stored on an acid-resistant rack or tub? ❑ ❑ 48 Are cracked or leaking batteries stored in labeled,closed,leak-proof containers? ❑ ❑ 49 Is the date each battery was placed in storage recorded? ❑ ❑ 50 Are batteries stacked more than 5 high? ❑ ❑ 51 Are batteries inspected regularly for leaks? ❑ ❑ Comments: Spill Prevention and Response Procedures ❑ N/A Yes No 52 Are vehicles inspected daily for leaks? ❑ ❑ 156 53 Is spill control equipment and absorbents readily available? ❑ ❑ 54 Are emergency phone numbers posted in conspicuous areas? ❑ ❑ 55 Are spills contained and cleaned up immediately? ❑ ❑ Comments: General Material Storage Areas ❑ NSA Yes No 56 Are leaking or damaged materials stored inside a building or another type of storm resistance shelter? ❑ ❑ 57 Are all material stockpiles within containment structures(e.g.,concrete barriers, earthen berms)or stored in a manner that ❑ ❑ does not allow discharge of impacted stormwater? 58 Are used fuel tanks and other scrap metal and parts drained of fluids and stored under cover? ❑ ❑ 59 Are outdoor containers covered? ❑ ❑ 60 Are piles of spoils,asphalt,debris,etc.stored under a roof or cover? ❑ ❑ 61 Are spills of material or debris cleaned up promptly? ❑ ❑ 62 Are used tire storage piles placed away from storm drains or conveyances? ❑ ❑ 63 Are tires recycled frequently to keep the number of stored tires manageable? ❑ ❑ Comments: Stormwater Management Yes No 64 Are employees trained on the municipal facility procedures? ❑ ❑ 66 Are BMPs and treatment structures working as designed? ❑ ❑ 67 Are BMPs and treatment structures free from debris buildup or overgrown vegetation that may impair function? ❑ ❑ 68 Catch basins should be cleaned in accordance with the timeframes listed in Part VI.F.3.c.iii./Part VII.F.3.c.iii,depending on ❑ ❑ the MS4 Operator type.Based on this,do any catch basins need to be cleaned? 69 Are berms,curbing or other methods used to divert and direct discharges adequate and in good condition? ❑ ❑ 70 Are rooftop drains directed to areas away from pavement? ❑ ❑ Comments: Erosion and Sediment Controls Yes No 71 Are soil stabilization measures(e.g.,seed and mulch,rolled erosion control products) considered in areas that have the ❑ ❑ potential for significant soil erosion? 72 Are natural buffers maintained around surface waters? ❑ ❑ 73 Are flow velocity dissipation devices in place at monitoring locations and channel outlets (rock riprap,stone check dams, ❑ ❑ concrete baffles)? 74 Do controls conform to the NYS Standards and Specifications for Erosion and Sediment Control(2016),or equivalent? ❑ ❑ 157 Comments: Corrective Actions and Comment Describe Inspection findings and if necessary,the corrective actions taken Inspector Signature Date: 158 NEW Storm Event Data Form YORK for SPDES MS4 General Permit, STATE Environmental Conservation G P-0-24-001 Do not submit this form to the Department;keep this form with the municipal facility's SWPPP and in the MS4 Operator's SWMP Plan. Permit Number: N I Y I R 1 2 0 A Facility Name: Contact First Name: Contact Last Name: Contact Phone: Contact Email: Storm Event Date: Storm Duration(in hours): Rainfall Measurement from Storm Event(in inches): Date of Last Measurable Storm Event: Duration Between Storm Event Sampled and End of Previous Measurable Storm(in hours): Certification I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons who manage the system,or those persons directly responsible for gathering the information,the information submitted is,to the best of my knowledge and belief,true,accurate,and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations. Facility Operator First Name(please print or type) Facility Operator Last Name(please print or type) Date Signature ME►NYORK Department of Visual OF O POAT'RTUNITY Environmental Monitoring Form Conservation MS4 GP-0-24-001 All high priority municipal facilities covered under the MS4 GP-0-24-001 must perform Visual Monitoring twice a permit term, separated by a minimum of one(1)year.Please see the permit Part VI.FIVII.F for additional requirements.This form is part of the facilities records and should be retained onsite with the facility's Stormwater Pollution Prevention Plan.Please do not submit this form to the Department MS4 Operator Permit ID Facili Name Ll OutfallNumber Examiner's Name Examiner's Title Reporting Year RainfallAmount Qualifying Storm? Runoff Source? ()Yes 'ONo ORainfall OSnowmelt Date,Time Collected Date/Time Examined mf mI m m`m®/ 71171 / 71 m'mAM/ PM 1.Does the stormwater appear to be colored?............................................................................................................... Oyes (:)NNO If yes,describe 2_Is the stormwater clear or transparent?...................................................................................................................... Oyes ONO If yes,which of the following best describes the clarity of the stormwater:......................... OC1ear Milky Opaque 3.Can you see a rainbow sheen effect on the water surface?.........................................................................................Oyes ONO If yes,which best describes the sheen?......................................................................... ORainbow Sheen QFloating Oil Globules 4.Does the sample have an odor?................................................................................................................................. ()Yes ONO 160 If yes,describe 5.Is there something floating on the surface of the sample?......................................................................................... OYes ONO If yes,describe 6.Is there something suspended in the water column of the sample?........................................................................... Yes ()No If yes, describe 7.Is there something settled on the bottom of the sample?........................................................................................... 0Yes (7)No If yes, describe S.Is there foam or material forming on the top of the sample surface?......................................................................... OYes ONO If yes, describe Detail any concerns,corrective actions taken and any other indicators of pollution present in the sample: 161 Works Cited Works Cited Center for Watershed Protection, Illicit Discharge Detection and Elimination: A Guidance Manual for Program Development and Technical Assistance, October 2004 (CWP 2004) New York State Department of Environmental Conservation, Maintenance Guidance: Stormwater Management Practices, March 31 , 2017 (NYS DEC Maintenance Guidance 2017) New York State Department of Environmental Conservation, Model Local Law to Prohibit Illicit Discharges, Activities and Connections to Separate Storm Sewer Systems, April 2006 (NYS DEC Model IDDE Local Law 2006) New York State Department of Environmental Conservation, Sample Local Law for Stormwater Management and Erosion & Sediment Control, March 2006 (NYS DEC Sample SM and E&SC Local Law 2006) New York State, Standards and Specifications for Erosion & Sediment Control, November 2016 (NYS E&SC 2016) New York State, Stormwater Management Design Manual, January 2015 (NYS SWMDM 2015) SPDES Multi-Sector General Permit for Stormwater Discharges Associated with Industrial Activity, GP-0-23-001 (MSGP) SPDES General Permit for Stormwater from Construction Activities, GP-0-20-001 (CGP) SPDES General Permit for Stormwater Discharges from the Municipal Separate Storm Sewer Systems, GP-0-24-001 (MS4 GP) United States Department of Transportation Federal Highway Administration, Highway Functional Classification Concepts, Criteria and Procedures, 2013 (USDOT 2013) 162 APPENDIX B Staffing Plan • Town Supervisor—As the ranking Town elected official, the Supervisor is responsible for signing all required MS4 certification forms. • Town Engineer—The Town Engineer is the designated Stormwater Program Coordinator for the Town. The Town Engineer is directly responsible for ensuring compliance with the MS4 SPDES General Permit including the preparation and upkeep of the Stormwater Management Program Plan, preparation of compliance reports and direct implementation of Minimum Control Measures 1 —5. The Town Engineer works with the GIS coordinator to maintain the online comprehensive system map, works with the Town Attorney to resolve violations of Chapter 234 &235 of the Southold Town Code in accordance with the Enforcement Response Plan and coordinates with the Town Highway Superintendent to ensure that highway municipal operations and maintenance protocols comply with the requirements of Minimum Control Measure 6. • GIS Coordinator— Responsible for creating and maintaining the online comprehensive system map in conjunction with the Town Engineer. • Town Attorney— Responsible for resolving violations of Chapter 234 &235 of the Southold Town Code forwarded by the Town Engineer. Assigns an Ordinance Inspector to resolve each violation in accordance with the Enforcement Response Plan. o Ordinance Inspector— Responsible for field verification of violations assigned by the Town Attorney and resolution of each violation in accordance with the Enforcement Response Plan. • Town Highway Superintendent— Responsible for establishing municipal operations and maintenance protocols to comply with Minimum Control Measure 6. Assigns personnel in conjunction with the Deputy Highway Superintendent to complete all compliance activities required by Minimum Control Measure 6. o Deputy Highway Superintendent—Assigns personnel in conjunction with the Highway Superintendent to complete all compliance activities required by Minimum Control Measure 6. ■ Crew Leader—Oversees a crew to complete asphalt patching, street sweeping, drainage installation, drainage maintenance and snow & ice removal operations. • Automotive Equipment Operator—Works as part of a crew to complete asphalt patching, drainage installation, drainage maintenance and snow & ice removal operations. • Heavy Equipment Operator—Works as part of a crew to complete asphalt patching, street sweeping, drainage installation, drainage maintenance and snow & ice removal operations. • Maintenance Mechanic—Works as part of a crew to complete asphalt patching, street sweeping, drainage installation, drainage maintenance and snow & ice removal operations. APPENDIX C STATE OF NEW YORK DEPARTMENT OF STATE ONE COMWERCE PLAZA KATHY HOCHUL 99 WA5HIHGTON AVENUE GOVERNOR AMNY,NY 12231=0001 WALTER T. MOS EY H'TTPS:IJDOS.NY.GQV SECRETARY OF STATE RECEIVED July 1, 2024 JUL - 5 Denis Noncarrow Town Hall, 53095 Main Road Southold Town Clerk PO Box 1179 Southold, NY 11971 RE: Town of Southold, Local Law 9, 10, 11, 12 & 13 2024, filed on 6/26/2024 Dear Sir/Madam: The above referenced material was filed by this office as indicated. Additional local law filing forms can be obtained from our website, www.dos.ny.aov. Sincerely, State Records and Law Bureau (518) 473-2492 K Department STATE of State NEW YORK STATE DEPARTMENT OF STATE Division of Corporations;State Records and Unilbrm Commercial Code One Commerce Plaza,99 Washington Avenue Albany,NY 12231-0001 Local Law .Film (Use this form to file a local law with the Secretary of State.) Text of law should be given as amended. Do not include matter being eliminated and do not use italics or underlining to indicate new matter. ❑ County ❑ City 0 Town of SOUTHOLD ❑ Village Local Law No. 9 of the year 2024 . A Local Law entitled,A Local Law in relation to SPDES Stormwater Management and Erosion & Sediment Control Be it enacted the Town Board of the: ❑ County ❑ City 0 Town of SOUTHOLD ❑ Village I. A new Chapter 234 of the Code of the Town of Southold is hereby adopted as follows: A Local Law entitled, "A Local Law in relation to SPDES Storinwater Management and Erosion& Sediment Control". II. §234-1 Legislative Intent A. Findings. The State of New York, pursuant to the Clean Water Act(33 U.S.C. §1251 et seq.) is authorized to adopt and implement a State Pollutant Discharge Elimination System (SPDES)permit program regulating the discharge of pollutants from new or existing outlets or point sources into the waters of the State. The State enacted Article 17, Title 8, of the Environmental Conservation Law requiring a State Pollution Discharge Elimination System (SPDES) permit prior to the discharge of any pollutants. Under the Federal National Pollutant Discharge Elimination System (NPDES) regulations, as administrated by New York State, municipalities are required to obtain a permit for the discharge of stormwater. The SPDES permit requires that the Town enact a local law that complies with federal and New York State guidelines for stormwater control, which addresses the following findings of fact as determined by the State and accepted by the Town of Southold: 1. Land development activities and associated increases in site impervious cover often alter the hydrologic response of local watersheds and increase stormwater runoff rates and volumes, flooding, stream channel erosion, or sediment transport and deposition; (If additional space is needed, attach pages the salve size as this sheet, and number each.) DOS-2394-I(Rev.0/14) 1 i 2. This stormwater runoff contributes to increased quantities of water-borne pollutants, including siltation of aquatic habitat for fish and other desirable species; 3. Clearing and grading during construction tends to increase soil erosion and add to the loss of native vegetation necessary for terrestrial and aquatic habitat; 4. Improper design and construction of stormwater management practices can increase the velocity of stormwater runoff thereby increasing stream bank erosion and sedimentation; 5. Impervious surfaces allow less water to percolate into the soil,thereby decreasing groundwater recharge and stream baseflow; 6. Substantial economic losses can result from these adverse impacts on the waters of the municipality; 7. Stormwater runoff, soil erosion and nonpoint source pollution can be controlled and minimized through the regulation of stormwater runoff from land development activities; 8. The regulation of stormwater runoff discharges from land development activities in order to control and minimize increases in stormwater runoff rates and volumes, soil erosion, stream channel erosion, and nonpoint source pollution associated with stormwater runoff is in the public interest and will minimize threats to public health and safety. 9. Regulation of land development activities by means of performance standards governing stormwater management and site design will produce development compatible with the natural functions of a particular site or an entire watershed and thereby mitigate the adverse effects of erosion and sedimentation from development. B. Purpose. The purpose of this local law is to establish minimum stormwater management requirements and controls to protect and safeguard the general health, safety, and welfare of the public residing within this jurisdiction and to address the findings of fact in Section 1 hereof. This local law seeks to meet those purposes by achieving the following objectives: 1. Meet the requirements of minimum measures 4 and 5 of the SPDES General Permit for Stormwater Discharges from Municipal Separate Stormwater Sewer Systems(MS4s), Permit No. GP-0-24-001 or as amended or revised; 2. Require land development activities to conform to the substantive requirements of the NYS Department of Environmental Conservation State Pollutant Discharge Elimination System (SPDES)General Permit for Construction Activities GP-0-20-001 or as amended or revised; 3. Minimize increases in stormwater runoff from land development activities in order to reduce flooding, siltation, increases in stream temperature, and streambank erosion and maintain the integrity of stream channels; 4. Minimize increases in pollution caused by stormwater runoff from land development activities which would otherwise degrade local water quality; 5. Minimize the total annual volume of stormwater runoff which flows from any specific site during and following development to the maximum extent practicable; and 6. Reduce stormwater runoff rates and volumes, soil erosion and nonpoint source pollution, wherever possible,through stormwater management practices and to ensure that these management practices are properly maintained and eliminate threats to public safety. C. Statutory Authority. In accordance with Article 10 of the Municipal Home Rule Law of the State of New York,the Town of Southold has the authority to enact local laws and amend local laws and for the purpose of promoting the health, safety or general welfare of the Town of Southold and for the protection and enhancement of its physical environment_The Town of Southold may include in any such local law provisions for the appointment of any municipal officer, employees, or independent contractor to effectuate, administer and enforce such local taw. D. Applicability. This local law shall be applicable to all land development activities as defined in this local law. 1. The municipality shall designate a Stormwater Management Officer who shall accept and review all stormwater pollution prevention plans and forward such plans to the applicable municipal 2 board. The Stormwater Management Officer may (1)review the plans, (2)upon approval by the Town Board of the Town of Southold, engage the services of a registered professional engineer to review the plans, specifications and related documents at a cost not to exceed a fee schedule established by said governing board, or (3) accept the certification of a licensed professional that the plans conform to the requirements of this law. 2. All land development activities subject to review and approval by any duly authorized Board of the Town shall be reviewed subject to the standards contained in this local law 3. All land development activities not subject to review as stated herein at subsection (D)(2) of this paragraph shall be required to submit a Stormwater Pollution Prevention Plan (SWPPP) to the Stormwater Management Officer who shall approve the SWPPP if it complies with the requirements of this law. E. Exemptions. The following activities may be exempt from review under this law. 1. Agricultural activity as defined in this local law. 2. Silvicultural activity except that landing areas and log haul roads are subject to this law. 3. Routine maintenance activities that disturb less than five acres and are performed to maintain the original line and grade, hydraulic capacity or original purpose of a facility. 4. Repairs to any stormwater management practice or facility deemed necessary by the Stormwater Management Officer. 5. Any part of a subdivision if a plat for the subdivision has been approved by the Town of Southold on or before the effective date of this law. 6. Land development activities for which a building permit has been approved on or before the effective date of this law. 7. Cemetery graves. 8.. Installation of fence, sign, telephone, and electric poles and other kinds of posts or poles. 9. Emergency activity immediately necessary to protect life,property or natural resources. 10. Activities of an individual engaging in home gardening by growing flowers, vegetable and other plants primarily for use by that person and his or her family. 11. Landscaping and horticultural activities in connection with an existing structure. §234-2 Definitions The terms used in this local law or in documents prepared or reviewed under this local law shall have the meaning as set forth in this section. Agricultural Activity-the activity of an active farm including grazing and watering livestock, irrigating crops, harvesting crops,using land for growing agricultural products, and cutting timber for sale, but shall not include the operation of a dude ranch or similar operation, or the construction of new structures associated with agricultural activities. Applicant - a property owner or agent of a property owner who has filed an application for a land development activity. Building - any structure, either temporary or permanent, having walls and a roof, designed for the shelter of any person, animal, or property, and occupying more than 100 square feet of area. Channel - a natural or artificial watercourse with a definite bed and banks that conducts continuously or periodically flowing water. Clearing - any activity that removes the vegetative surface cover. Dedication-the deliberate appropriation of property by its owner for general public use. 3 4 � Department- the New York State Department of Environmental Conservation Design Manual-the New York State Stormwater Management Design Manual,most recent version including applicable updates, that serves as the official guide for stormwater management principles, methods and practices. Developer-a person who undertakes land development activities. Erosion Control Manual - the most recent version of the "New York Standards and Specifications for Erosion and Sediment Control"manual, commonly known as the`Blue Book" Grading- excavation or fill of material, including the resulting conditions thereof. Impervious Cover-those surfaces, improvements and structures that cannot effectively infiltrate rainfall, snow melt and water(e.g., building rooftops, pavement, sidewalks,driveways, etc). Industrial Stormwater Permit- a State Pollutant Discharge Elimination System permit issued to a commercial industry or group of industries which regulates the pollutant levels associated with industrial stormwater discharges or specifies on-site pollution control strategies. Infiltration-the process of-percolating stormwater into the subsoil. Jurisdictional Wetland- an area that is inundated or saturated by surface water or groundwater at a frequency and duration sufficient to support a prevalence of vegetation typically adapted for life in saturated soil conditions,commonly known as hydrophytic vegetation. Land Development Activity -construction activity including clearing, grading, excavating, soil disturbance or placement of fill that results in land disturbance of equal to or greater than one acre,or activities disturbing less than one acre of total land area that is part of a larger common plan of development or sale, even though multiple separate and distinct land development activities may take place at different times on different schedules. Landowner-the legal or beneficial owner of land, including those holding the right to purchase or lease the land,or any other person holding proprietary rights in the land. Maintenance Agreement - a legally recorded document that acts as a property deed restriction, and which provides for long-term maintenance of stormwater management practices. Nonpoint Source Pollution-pollution from any source other than from any discernible, confined, and discrete conveyances, and shall include, but not be limited to, pollutants from agricultural, silvicultural, mining, construction, subsurface disposal and urban runoff sources. Phasing -clearing a parcel of land in distinct pieces or parts,with the stabilization of each piece completed before the clearing of the next. Pollutant of Concern - sediment or a water quality measurement that addresses sediment(such as total suspended solids, turbidity or siltation) and any other pollutant that has been identified as a cause of impairment of any water body that will receive a discharge from the land development activity. Project -land development activity 4 Recharge -the replenishment of underground water reserves. Sediment Control -measures that prevent eroded sediment from leaving the site. Sensitive Areas- cold water fisheries, shellfish beds, swimming beaches, groundwater recharge areas,water supply reservoirs, habitats for threatened, endangered or special concern species. SPDES General Permit for Construction Activities GP-0-20-001 -A permit under the New York State Pollutant Discharge Elimination System (SPDES) issued to developers of construction activities to regulate disturbance of one or more acres of land. SPDES General Permit for Stormwater Discharges from Municipal Separate Stormwater Sewer Systems GP-0- 24-001 -A permit under the New York State Pollutant Discharge Elimination System (SPDES)issued to municipalities to regulate discharges from municipal separate storm sewers for compliance with EPA established water quality standards and/or to specify stormwater control standards Stabilization-the use of practices that prevent exposed soil from eroding. Stop Work Order-an order issued which requires that all construction activity on a site be stopped. Stormwater-rainwater, surface runoff, snowmelt and drainage Stormwater Hotspot- a land use or activity that generates higher concentrations of hydrocarbons,trace metals or toxicants than are found in typical stormwater runoff, based on monitoring studies. Stormwater Management-the use of structural or non-structural practices that are designed to reduce stormwater runoff and mitigate its adverse impacts on property,natural resources and the environment. Stormwater Management Facility -one or a series of stormwater management practices installed, stabilized and operating for the purpose of controlling stormwater runoff. Stormwater Management Officer- an employee or officer designated by the municipality to accept and review stormwater pollution prevention plans, forward the plans to the applicable municipal board and inspect stormwater management practices Stormwater Management Practices (SMPs) - measures, either structural or nonstructural,that are determined to be the most effective, practical means of preventing flood damage and preventing or reducing point source or nonpoint source pollution inputs to stormwater runoff and water bodies. Stormwater Pollution.Prevention Plan (SWPPP) - a plan for controlling stormwater runoff and pollutants from a site during and after construction activities. Stormwater Runoff- flow on the surface of the ground,resulting from precipitation Surface Waters of the State of New York- lakes,bays, sounds,ponds, impounding reservoirs, springs, wells, rivers, streams, creeks, estuaries,marshes, inlets, canals, the Atlantic ocean within the territorial seas of the state of New York and all other bodies of surface water, natural or artificial, inland or coastal,fresh or salt,public or private(except those private waters that do not combine or effect a junction with natural surface or underground waters), which are wholly or partially within or bordering the state or within its jurisdiction. Storm sewers and waste treatment systems, including treatment ponds or lagoons which also meet the criteria of this definition are not waters of the state. This exclusion applies only to manmade bodies of water which 5 neither were originally created in waters of the state (such as a disposal area in wetlands)nor resulted from impoundment of waters of the state. Watercourse - a permanent or intermittent stream or other body of water, either natural or man-made, which gathers or carries surface water. Waterway -a channel that directs surface runoff to a watercourse or to the public storm drain. §234-3 Stormwater Pollution Prevention Plans A. Stormwater Pollution Prevention Plan Requirement No application for approval of a land development activity shall be reviewed until the appropriate board has received a Stormwater Pollution Prevention Plan (SWPPP)prepared in accordance with the specifications in this local law. Each application for approval of a land development activity shall be accompanied by a filing fee. B. Contents of Stormwater Pollution Prevention Plans All SWPPPs shall provide the following background information and erosion and sediment controls: 1. Background information about the scope of the project, including location, type and size of project. 2. Site map/construction drawing(s) for the project, including a general location map. At a minimum, the site map should show the total site area; all improvements;areas of disturbance; areas that will not be disturbed; existing vegetation; on-site and adjacent offsite surface water(s); wetlands and drainage patterns that could be affected by the construction activity; existing and final slopes; locations of off-site material,waste,borrow or equipment storage areas; and location(s) of the stormwater discharges(s); 3. Description of the soil(s) present at the site, 4. Construction phasing plan describing the intended sequence of construction activities, including clearing and grubbing, excavation and grading,utility and infrastructure installation and any other activity at the site that results in soil disturbance. Consistent with the New York Standards and Specifications for Erosion.and Sediment Control (Erosion Control Manual),not more than five(5) acres shall be disturbed at any one time unless pursuant to an approved SWPPP. 5. Description of the pollution prevention measures that will be used to control litter, construction chemicals and construction debris from becoming a pollutant source in stormwater runoff, 6. Description of construction and waste materials expected to be stored on-site with updates as appropriate, and a description of controls to reduce pollutants from these materials including storage practices to minimize exposure of the materials to stormwater, and spill prevention and response; 7. Temporary and permanent structural and vegetative measures to be used for soil stabilization, runoff control and sediment control for each stage of the project from initial land clearing and grubbing to project close-out; 8. A site map/construction drawing(s) specifying the location(s), size(s) and length(s) of each erosion and sediment control practice; 9. Dimensions, material specifications and installation details for all erosion and sediment control practices, including the siting and sizing of any temporary sediment basins; 10. Temporary practices that will be converted to permanent control measures; 11. Implementation schedule for staging temporary erosion and sediment control practices, including the timing of initial placement and duration that each practice should remain in place; 12. Maintenance schedule to ensure continuous and effective operation of the erosion and sediment control practice; 13. Name(s) of the receiving water(s); 14. Delineation of SWPPP implementation responsibilities for each part of the site; 6 ` 15. Description of structural practices designed to divert flows from exposed soils, store flows, or otherwise limit runoff and the discharge of pollutants from exposed areas of the site to the degree attainable; and 16. Any existing data that describes the stormwater runoff at the site. C. Land development activities as defined in §234(1) herein and meeting Condition"1",4`2"or"3"below shall also include water quantity and water quality controls (post-construction stormwater runoff controls) as set forth in subsection"D" below as applicable: Condition 1 - Stormwater runoff from land development activities discharging a pollutant of concern to either an impaired water identified on the Department's 303(d) list of impaired waters or a Total Maximum Daily Load (TMDL)designated watershed for which pollutants in stormwater have been identified as a source of the impairment. Condition 2 - Stormwater runoff from land development activities disturbing five (5) or more acres. Condition 3 - Stormwater runoff from land development activity disturbing between one(1)and five (5) acres of land during the course of the project, exclusive of the construction of single-family residences and construction activities at agricultural properties. D. SWPPP Requirements for Conditions 1, 2 and 3: 1. All information in §234-3(B) of this local law 2. Description of each post-construction stormwater management practice; 3. Site map/construction drawing(s)showing the specific location(s) and size(s) of each post- construction stormwater management practice; 4. Hydrologic and hydraulic analysis for all structural components of the stormwater management system for the applicable design storms 5. Comparison of post-development stormwater runoff conditions with pre-development conditions 6. Dimensions, material specifications and installation details for each post-construction stormwater management practice; 7. Maintenance schedule to ensure continuous and effective operation of each postconstruction stormwater management practice. 8. Maintenance easements to ensure access to all stormwater management practices at the site for the purpose of inspection and repair. Easements shall be recorded on the plan and shall remain in effect with transfer of title to the property. 9. Inspection and maintenance agreement binding on all subsequent landowners served by the on- site stormwater management measures in accordance with §234-7 of this local law. 10. For Condition A,the SWPPP shall be prepared by a landscape architect,certified professional or professional engineer and must be signed by the professional preparing the plan,who shall certify that the design of all stormwater management practices meet the requirements in this local law. §234-4 Other Environmental Permits The applicant shall assure that all other applicable environmental permits have been or will be acquired for the land development activity prior to approval cf the final stormwater design plan. §234-5 Contractor Certification 1. Each contractor and subcontractor identified in the SWPPP who will be involved in soil disturbance and/or stormwater management practice installation shall sign and date a copy of the following certification statement before undertaking any land development activity : "I certify under penalty of law that I understand and agree to comply with the terms and conditions of the Stormwater Pollution Prevention Plan. I also understand that it is unlawful for any person to cause or contribute to a violation of water quality standards." 2. The certification must include the name and title of the person providing the signature, address and telephone number of the contracting firm;the address (or other identifying description) of the site; and the date the certification is made. 7 The ceitification statement(s)shall become part of the SWPPP for the land development activity. 4. A copy of the SWPPP shall be retained at the site of the land development activity during construction from the date of initiation of construction activities to the date of final stabilization. §234-6 Performance and Design Criteria for Stormwater Management and Erosion and Sediment Control All land development activities shall be subject to the following performance and design criteria: A. Technical Standards For the purpose of this local law, the following documents shall serve as the official guides and specifications for stormwater management. Stormwater management practices that are designed and constructed in accordance with these technical documents shall be presumed to meet the standards imposed by this law: 1. The New York State Stormwater Management Design Manual (New York State Department of Environmental Conservation, most current version or its successor,hereafter referred to as the Design Manual) 2. New York Standards and Specifications for Erosion and Sediment Control, (Empire State Chapter of the Soil and Water Conservation Society, 2004,most current version or its successor, hereafter referred to as the Erosion Control Manual). B. Equivalence to Technical Standards Where stormwater management practices are not in accordance with technical standards,the applicant or developer must demonstrate equivalence to the technical standards set forth herein at subsection(A) above and the SWPPP shall be prepared by a licensed professional. C. Water Quality Standards Any land development activity shall not cause an increase in turbidity that will result in substantial visible contrast to natural conditions in surface waters of the state of New York. §234-7 Maintenance, Inspection and Repair of Stormwater Facilities A. Maintenance and Inspection During Construction 1. The applicant or developer of the land development activity or their representative shall at all times properly operate and maintain all facilities and systems of treatment and control (and related appurtenances) which are installed or used by the applicant or developer to achieve compliance with the conditions of this local law. Sediment shall be removed from sediment traps or sediment ponds whenever their design capacity has been reduced by fifty (50)percent. 2. For land development activities as defined herein and meeting Condition 1,2 or 3 in 234(3)(C), the applicant shall have a qualified professional conduct site inspections and document the effectiveness of all erosion and sediment control practices every 7 days and within 24 hours of any storm event producing 0.5 inches of precipitation or more. Inspection reports shall be maintained in a site log book. B. Maintenance Easement(s) Prior to the issuance of any approval that has a stormwater management facility as one of the requirements,the applicant or developer must execute a maintenance easement agreement that shall be binding on all subsequent landowners served by the stormwater management facility. The easement shall provide for access to the facility at reasonable times for periodic inspection by the Town of Southold to ensure that the facility is maintained in proper working condition to meet design standards and any other provisions established by this local law. The easement shall be recorded by the grantor in the office of the County Clerk after approval by the counsel for the Town of Southold. C. Maintenance after Construction The owner or operator df permanent stormwater management practices installed in accordance with this law shall ensure they are operated and maintained to achieve the goals of this law. Proper operation and 8 ` maintenance also includes,as a minimum, the following: 1. A preventive/corrective maintenance program for all critical facilities and systems of treatment and control (or related appurtenances) which are installed or used by the owner or operator to achieve the goals of this law. 2. Written procedures for operation and maintenance and training new maintenance personnel. 3. Discharges from the SMPs shall not exceed design criteria or cause or contribute to water quality standard violations in accordance with §234-6(C). D. Maintenance Agreements The Town of Southold shall approve a formal maintenance agreement for stormwater management facilities binding on all subsequent landowners and recorded in the office of the Suffolk County Clerk as a deed restriction on the property prior to final plan approval. The maintenance agreement shall be consistent with the terms and conditions of Schedule B of this local law entitled Sample Stormwater Control Facility Maintenance Agreement. The Town of Southold,in lieu of a maintenance agreement, at its sole discretion may accept dedication of any existing or future stormwater management facility,provided such facility meets all the requirements of this local law and includes adequate and perpetual access and sufficient area, by easement or otherwise, for inspection and regular maintenance. §234-8 Administration and Enforcement Section 1 -Inspections A. Erosion and Sediment Control Inspection The Town of Southold Stormwater Management Officer shall require such inspections as necessary to determine compliance with this law and may either approve that portion of the work completed or notify the applicant wherein the work fails to comply with the requirements of this law and the stormwater pollution prevention plan(SWPPP) as approved. To obtain inspections, the applicant shall notify the Town of Southold enforcement official at least 48 hours before any of the following as required by the Stormwater Management Officer: 1. Start of construction 2. Installation of sediment and erosion control measures 3. Completion of site clearing 4. Completion of rough grading 5. Completion of final grading 6. Close of the construction season 7. Completion of final landscaping 8. Successful establishment of landscaping in public areas. If any violations are found,the applicant and developer shall be notified in writing of the nature of the violation and the required corrective actions. No further work shall be conducted except for site stabilization until any violations are corrected and all work previously completed has received approval by the Stormwater Management Officer. B. Stormwater Management Practice Inspections The Town of Southold Stormwater Management Officer, is responsible for conducting inspections of stormwater management practices (SMPs). All applicants are required to submit"as built"plans for any stormwater management practices located on-site after final construction is completed. The plan must show the final design specifications for all stormwater management facilities and must be certified by a professional engineer. C. Inspection of Stormwater Facilities After Project Completion Inspection programs shall be established on any reasonable basis, including but not limited to: routine inspections; random inspections; inspections based upon complaints or other notice of possible violations; inspection of drainage basins or areas identified as higher than typical sources of sediment or other contaminants or pollutants; inspections of businesses or industries of a type associated with higher than usual discharges of contaminants or pollutants or with discharges of a type which are more likely than the typical 9 discharge to cause violations of state or federal water or sediment quality standards or the SPDES stormwater permit; and joint inspections with other agencies inspecting under environmental or safety laws. Inspections may include,but are not limited to: reviewing maintenance and repair records; sampling discharges, surface water, groundwater, and material or water in drainage control facilities; and evaluating the condition of drainage control facilities and other stormwater management practices. D. Submission of Reports The Town of Southold Stormwater Management Officer shall require monitoring and reporting from entities subject to this law as are necessary to determine compliance with this law, E. Right-of-Entry for Inspection When any new stormwater management facility is installed on private property or when any new connection is made between private property and the public storm water system,the landowner shall grant to the Town of Southold the right to enter the property at reasonable times and in a reasonable manner for the purpose of inspection as specified in this Section at paragraph"C". Section 2. Performance Guarantee A. Construction Completion Guarantee In order to ensure the full and faithful completion of all land development activities related to compliance with all conditions set forth by the Town of Southold in its approval of the Stormwater Pollution Prevention Plan, the Town of Southold shall require the applicant or developer to provide, prior to construction, a performance bond, cash escrow,or irrevocable letter of credit from an appropriate financial or surety institution which guarantees satisfactory completion of the project and names the Town of Southold as the beneficiary. The security shall be in an amount to be determined by the Town of Southold based on submission of final design plans,with reference to actual construction and landscaping costs. The performance guarantee shall remain in force until the surety is released from liability by the Town of Southold,provided that such period shall not be less than one year from the date of final acceptance or such other certification that the facility(ies) have been constructed in accordance with the approved plans and specifications and that a one (1) year inspection has been conducted and the facilities have been found to be acceptable to the Town of Southold. Per annum interest on cash escrow deposits shall be reinvested in the account until the surety is released from liability. B. Maintenance Guarantee Where stormwater management and erosion and sediment control facilities are to be operated and maintained by the developer or by a corporation that owns or manages a commercial or industrial facility,the developer, prior to construction, shall be required to provide the Town of Southold with an irrevocable letter of credit from an approved financial institution or surety to ensure proper operation and maintenance of all stormwater management and erosion control facilities both during and after construction, and until the facilities are removed from operation. If the developer or landowner fails to properly operate and maintain stormwater management and erosion and sediment control facilities,the Town of Southold may draw upon the account to cover the costs of proper operation and maintenance, including engineering and inspection costs. C. Recordkeeping All entities subject to this law shall maintain records demonstrating compliance with this law. Section 3. Enforcement and Penalties A. Notice of Violation. When the Town of Southold determines that a land development activity is not being carried out in accordance with the requirements of this local law,it may issue a written notice of violation to the landowner.The notice of violation shall contain: I. the name and address of the landowner, developer or applicant; 2. the address when available or a description of the building, structure or land upon which the violation is occurring; 3. a statement specifying the nature of the violation; 4. a description of the remedial measures necessary to bring the land development activity into compliance with this local law and a time schedule for the completion of such remedial action; 10 5. a statement of.the penalty or penalties that shall or may be assessed against the person to.whom the notice of violation is directed; 6. a statement that the determination of violation may be appealed to the municipality by filing a written notice of appeal within fifteen (15) days of service of notice of violation- B. Stop Work Orders The Town of Southold may issue a stop work order for violations of this law. Persons receiving a stop work order shall be required to halt all land development activities,except those activities that address the violations leading to the stop work order. The stop work order shall be in effect until the Town of Southold confirms that the land development activity is in compliance and the violation has been satisfactorily addressed. Failure to address a stop work order in a timely manner may result in civil, criminal, or monetary penalties in accordance with the enforcement measures authorized in this local law. C. Violations Any land development activity that is commenced or is conducted contrary to this local Iaw, may be restrained by injunction or otherwise abated in a manner provided by law. D. Penalties In addition to or as an alternative to any penalty provided herein or by law, any person who violates the provisions of this local law shall be guilty of a violation punishable by a fine not exceeding two thousand five hundred dollars($2,500) or imprisonment for a period not to exceed six months, or both for conviction of a first offense; for conviction of a second offense both of which were committed within a period of five years, punishable by a fine not less than Seven Thousand Five Hundred($7,500) dollars nor more than Ten Thousand dollars ($10,000)or imprisonment for a period not to exceed six months, or both; and upon conviction for a third or subsequent offense all of which were committed within a period of five years,punishable by a fine not less than Fifteen Thousand ($15,000) dollars nor more than Twenty Thousand ($20,000) dollars or imprisonment for a period not to exceed six months, or both.However, for the purposes of conferring jurisdiction upon courts and judicial officers generally,violations of this local law shall be deemed misdemeanors and for such purpose only all provisions of law relating to misdemeanors shall apply to such violations. Each week's continued violation shall constitute a separate additional violation. E. Withholding of Certificate of Occupancy If any building or land development activity is installed or conducted in violation of this local law the Stormwater Management Officer may prevent the occupancy of said building or land. F. Restoration of lands Any violator may be required to restore land to its undisturbed condition. In the event that restoration is not undertaken within a reasonable time after notice, the Town of Southold may take necessary corrective action, the cost of which shall become a lien upon the property until paid. §234-9 Fees for Services The Town of Southold may require any person undertaking land development activities regulated by this law to pay a fee for review of SWPPPs, inspections, and SMP maintenance performed by the Town of Southold or performed by a third party for the Town of Southold,at a rate to be determined by Town Board resolution. §234-10 Severability and Effective Date III. Severabi lity If the provisions of any article, section, subsection,paragraph, subdivision or clause of this local law shall be judged invalid by a court of competent jurisdiction, such order of judgment shall not affect or invalidate the remainder of any article, section, subsection,paragraph, subdivision or clause of this local law. IV. Effective Date This local law shall be in full force and effect immediately upon its final adoption and filing with the Secretary of State. All prior laws and parts of law in conflict with this law are hereby repealed. 11 Schedule A Stormwater Management Practices Acceptable for Water Quality (From: New York State Stormwater Management Design Manual, Table 5.1) Group Practice Description Micropool Extended Pond that treats the majority of the water quality volume Pond Detention Pond (P-1) through extended detention, and incorporates a micropool at the outlet of the pond to prevent sediment resuspension. Wet Pond (P-2) Pond that provides storage for the entire water quality volume in the permanent pool. Wet Extended Detention Pond that treats a portion of the water quality volume by Pond (P-3) detaining storm flows above a permanent pool for a specified minimum detention time. Multiple Pond System(P- A group of ponds that collectively treat the water quality 4) volume. Pocket Pond (P-5) A stormwater wetland design adapted for the treatment of runoff from small drainage areas that has little or no baseflow available to maintain water elevations and relies on groundwater to maintain a permanent pool. Shallow Wetland (W-1) A wetland that provides water quality treatment entirely in a shallow marsh. Extended Detention A wetland system that provides some fraction of the water Wetland (W-2) quality volume by detaining storm flows above the marsh surface. Pond/Wetland System A wetland system that provides a portion of the water quality (W-3) volume in Wetland the permanent pool of a wet pond that precedes the marsh for a specified minimum detention time. Pocket Wetland (W-4) A shallow wetland design adapted for the treatment of runoff from small drainage areas that has variable water levels and relies on groundwater for its permanent pool. Infiltration Trench (I-1) An infiltration practice that stores the water quality volume in the void spaces of a gravel trench before it is infiltrated into the ground. Infiltration Basin (I-2) An infiltration practice that stores the water quality volume in a shallow Infiltration depression before it is infiltrated into the ground. Dry Well (I-3) An infiltration practice similar in design to the infiltration trench,and best suited for treatment of rooftop runoff. Surface Sand Filter(F-1) A filtering practice that treats stormwater by settling out larger Filtering particles in a sediment chamber, and then filtering stormwater Practices through a sand matrix. Underground Sand Filter A filtering practice that treats stormwater as it flows through (F--2) underground settling and filtering chambers. 12 Perimeter Sand Filter(F- A filter that incorporates a sediment chamber and filter bed as 3) parallel vaults adjacent to a parking lot. Organic Filter(F-4) A filtering practice that uses an organic medium such as compost in the filter in place of sand. Bioretention (F-5) A shallow depression that treats stormwater as it flows through a soil matrix, and is returned to the storm drain system. Dry Swale (0-1) An open drainage channel or depression explicitly designed to detain and Open promote the filtration of stormwater runoff into the soil media. Channels Wet Swale(0-2) An open drainage channel or depression designed to retain water or intercept groundwater for water quality treatment. Schedule B SAMPLE STORMWATER CONTROL FACILITY MAINTENANCE AGREEMENT Whereas,the Town of Southold (Town)and the ("facility owner")want to enter into an agreement to provide for the long-term maintenance and continuation of stormwater control measures approved by the Town for the below named project, and Whereas, the Town and the facility owner desire that the stormwater control measures be built in accordance with the approved project plans and thereafter be maintained, cleaned,repaired,replaced and continued in perpetuity in order to ensure optimum performance of the components. Therefore,the Town and the facility owner agree as follows: 1. This agreement binds the Town and the facility owner,its successors and assigns,to the maintenance provisions depicted in the approved project plans which are attached as Schedule A of this agreement. 2. The facility owner shall maintain, clean, repair,replace and continue the stormwater control measures depicted in Schedule A as necessary to ensure optimum performance of the measures to design specifications.The stormwater control measures shall include, but shall not be limited to,the following: drainage ditches, swales, dry wells, infiltrators, drop inlets,pipes,culverts, soil absorption devices and retention ponds. 3. The facility owner shall be responsible for all expenses related to the maintenance of the stormwater control measures and shall establish a means for the collection and distribution of expenses among parties for any commonly owned facilities. 4. The facility owner shall provide for the periodic inspection of the stormwater control measures,not less than once in every five(5)year period, to determine the condition and integrity of the measures. Such inspection shall be performed by a Professional Engineer licensed by the State of New York. The inspecting engineer shall prepare and submit to the Town within 30 days of the inspection, a written report of the findings including recommendations for those actions necessary for the continuation of the stormwater control measures. 5. The facility owner shall not authorize, undertake or permit alteration, abandonment, modification or discontinuation of the stormwater control measures except in accordance with written approval of the Town. b. The facility owner shall undertake necessary repairs and replacement of the stormwater control measures at the direction of the Town or in accordance with the recommendations of the inspecting engineer. 7. The facility owner shall provide to the Town within 30 days of the date of this agreement, a security for 13 the maintenance and continuation of the stormwater control measures in the form of(a-Bond, letter of credit or escrow account). 8. This agreement shall be recorded in the Office of the County Clerk, County of Suffolk together with the deed for the common property and shall be included in the offering plan and/or prospectus approved pursuant to 9. If ever the Town determines that the facility owner has failed to construct or maintain the stormwater control measures in accordance with the project plan or has failed to undertake corrective action specified by the Town or by the inspecting engineer, the Town is authorized to undertake such steps as reasonably necessary for the preservation,continuation or maintenance of the stormwater control measures and to affix the expenses thereof as a lien against the property. 10. This agreement is effective 14 h NEW YORK STATE DEPARTMENT OF STATE Division of Corporations.State Records and Uniform Commercial Code One Commerce Plaza,99 Washington Avenue Albany,NY 12231.0001 Local Law Filing (Use this Form to file a local law with the Secretary of State.) Text of law should be given as amended. Do not include matter being eliminated and do not use italics or underlining to indicate new matter. ❑ County ❑ City 0 Town of SOUTHOLD ❑ Village Local Law No, 10 of the year 2024 . A Local Law entitled, A Local Law in relation to Storm Sewer Systems; Illicit Discharges,Activities and Connections Be it enacted the Town Board of the: ❑ County 0 City 0 Town of SOUI'HOLD ❑ Village I. A new Chapter 235 of the Code of the Town of Southold is hereby adopted as follows: A Local Law entitled,"A Local Law in relation to Storm Sewer Systems,Illicit Discharges,Activities and Connections 235-1. PURPOSE/INTENT. The purpose of this law is to provide for the health, safety, and general welfare of the citizens of the Town of Southold through the regulation of non.-stormwater discharges to the municipal separate storm sewer system (MS4)to the maximum extent practicable as required by federal and state law, This law establishes methods for controlling the introduction of pollutants into the MS4 in order to comply with requirements of the SPDES General Permit for Municipal Separate Storm Sewer Systems. The objectives of this law are: 1. To meet therequirements of the SPDES General Permit for Stormwater Discharges from MS4s,Permit no. GP-0-24-001 or as amended or revised; 2. To regulate the contribution of pollutants to the MS4 since such systems are not designed to accept, process or discharge non-stormwater wastes; 3. To prohibit Illicit Connections, Activities and Discharges to the MS4; 4. To establish legal authority to carry out all inspection, surveillance and monitoring procedures necessary to ensure compliance with this law; and (Ifadditioiial space is needed, attach pages the same size as this sheet, and mirnber each.) DOS-239-f<1(Rev.04/14) t A 5 To promote public awareness of the hazards involved in the improper discharge of trash, yard waste, lawn chemicals,pet waste, wastewater, grease, oil, petroleum products, cleaning products, paint products, hazardous waste, sediment and other pollutants into the MS4. 235-2. DEFINITIONS. Whenever used in this law, unless a different meaning is stated in a definition applicable to only a portion of this law, the following terms will have meanings set forth below: Best Management Practices (BMPs) - Schedules of activities,prohibitions of practices, general good house- keeping practices, pollution prevention and educational practices,maintenance procedures, and other management practices to prevent or reduce the discharge of pollutants directly or indirectly to stormwater, receiving waters, or stormwater conveyance systems. BMPs also include treatment practices, operating procedures, and practices to control site runoff, spillage or leaks, sludge or water disposal, or drainage from raw materials storage. Clean Water Act-The Federal Water Pollution Control Act (33 U.S.C. § 1251 et seq.), and any subsequent amendments thereto. Construction Activity - Activities requiring authorization under the SPDES permit for stormwater discharges from construction activity, GP-0-20-001, as amended or revised. These activities include construction projects resulting in land disturbance of one or more acres. Such activities include but are not limited to clearing and grubbing, grading, excavating, and demolition. Department-The New York State Department of Environmental Conservation. Hazardous Materials -Any material, including any substance, waste, or combination thereof,which because of its quantity, concentration, or physical, chemical, or infectious characteristics may cause, or significantly contribute to,a substantial present or potential hazard to human health, safety,property, or the environment when improperly treated, stored, transported,disposed of, or otherwise managed. Illicit Connections -Any drain or conveyance,whether on the surface or subsurface, which allows an illegal discharge to enter the MS4, including but not limited to: 1. Any conveyances which allow any non-stormwater discharge including treated or untreated sewage, process wastewater,and wash water to enter the MS4 and any connections to the storm drain system from indoor drains and sinks, regardless of whether said drain or connection had been previously allowed,permitted, or approved by an authorized enforcement agency; or 2. Any drain or conveyance connected from a commercial or industrial land use to the MS4 which has not been documented in plans, maps, or equivalent records and approved by an authorized enforcement agency. Illicit Discharge -Any direct or indirect non-stormwater discharge to the MS4, except as exempted in 235-5A of this law. Industrial Activity -Activities requiring the SPDES permit for discharges from industrial activities except construction, GP-0-23-001, as amended or revised. MS4 -Municipal Separate Storm Sewer System. Municipal Separate Storm Sewer System -A conveyance or system of conveyances (including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches,man-made channels, or storm drains): 2 ` 1. Owned or operated by the Town of Southold; 2. Designed or used for collecting or conveying stormwater; 3. Which is not a combined sewer; and 4. Which is not part of a Publicly Owned Treatment Works (POTW) as defined at 40CFR 122.2 Municipality-The Town of Southold Non-Stormwater Discharge-Any discharge to the,MS4 that is not composed entirely of stormwater. Person-Any individual,association, organization,partnership, firm, corporation or other entity recognized by law and acting as either the owner or as the owner's agent. Pollutant-Dredged spoil, filter backwash, solid waste, incinerator residue,treated or untreated sewage, garbage, sewage sludge,munitions, chemical wastes, biological materials,radioactive materials,heat,wrecked or discarded equipment,rock, sand and industrial, municipal, agricultural waste and ballast discharged into water; which may cause or might reasonably be expected to cause pollution of the waters of the state in contravention of the standards. Premises-Any building, lot,parcel of land, or portion of land whether improved or unimproved including adjacent sidewalks and parking strips. Special Conditions 1. Discharge Compliance with Water Quality Standards -The condition that applies where a municipality has been notified that the discharge of stormwater authorized under their MS4 permit may have caused or has the reasonable potential to cause or contribute to the violation of an applicable water quality standard. Under this condition the municipality must take all necessary actions to ensure future discharges do not cause or contribute to a violation of water quality standards. 2. 303(d)Listed Waters - The condition in the municipality's MS4 permit that applies where the MS4 discharges to a 303(d) listed water. Under this condition the stormwater management program must ensure no increase of the listed pollutant of concern to the 303(d)listed water. 3. Total Maximum Daily Load (TMDL) Strategy - The condition in the municipality's MS4 permit where a TMDL including requirements for control of stormwater discharges has been approved by EPA for a waterbody or watershed into which the MS4 discharges. if the discharge from the MS4 did not meet the TMDL stormwater allocations prior to September 10,2003,. the municipality was required to modify its stormwater management program to ensure that reduction of the pollutant of concern specified in the TMDL is achieved. 4. The-condition in the municipality's MS4 permit that applies if a TMDL is approved in the future by EPA for any waterbody or watershed into which an M94 discharges. Under this condition the municipality must review the applicable TMDL to see if it includes requirements for control of stormwater discharges. if an MS4 is not meeting the TMDL stormwater allocations,the municipality must, within six (6) months of the TMDL's approval, modify its stormwater management program to ensure that reduction of the pollutant of concern specified in the TMDL is achieved. State Pollutant Discharge Elimination System (SPDES) Stormwater Discharge Permit-A permit issued by the Department that authorizes the discharge of pollutants to waters of the state. Stormwater-Rainwater, surface runoff, snowmelt and drainage. Stormwater Management Officer(SMO'1 - An employee, the municipal engineer or other public official(s) designated by the Town of Southold to enforce this local law. The SMO may also be designated by the municipality to accept and review stormwater pollution prevention plans, forward the plans to the applicable 3 municipal board and inspect stormwater management practices. 303(d)List-A list of all surface waters in the state for which beneficial uses of the water(drinking, recreation, aquatic habitat, and industrial use) are impaired by pollutants,prepared periodically by the Department as required by 235-• 303(d) of the Clean Water Act. 303(d) listed waters are estuaries, lakes and streams that fall short of state surface water quality standards and are not expected to improve within the next two years. TMDL -Total Maximum Daily Load. Total Maximum Daily Load -The maximum amount of a pollutant to be allowed to be released into a waterbody so as not to impair uses of the water, allocated among the sources of that pollutant. Wastewater- Water that is not stormwater, is contaminated with pollutants and is or will be discarded. 235-3. APPLICABILITY. This law shall apply to all water entering the MS4 generated on any developed and undeveloped lands unless explicitly exempted by an authorized enforcement agency. 235-4. RESPONSIBILITY FOR ADMINISTRATION. The Stormwater Management Officer(s) (SMO(s)) shall administer, implement, and enforce the provisions of this law. Such powers granted or duties imposed upon the authorized enforcement official may be delegated in writing by the SMO as may be authorized by the municipality. 235-5. DISCHARGE PROHIBITIONS. A. Prohibition of Illegal Discharges. No person shall discharge or cause to be discharged into the MS4 any materials other than stormwater except as provided in 235-5A. The commencement,conduct or continuance of any illegal discharge to the MS4 is prohibited except as described as follows: 1. The following discharges are exempt from discharge prohibitions established by this local law, unless the Department or the municipality has determined them to be substantial contributors of pollutants: water line flushing or other potable water sources, landscape irrigation or lawn watering,existing diverted stream flows,rising ground water, uncontaminated ground water infiltration to storm drains,uncontaminated pumped ground water,foundation or footing drains, air conditioning condensate, irrigation water, springs,water from individual residential car washing,natural riparian habitat or wetland flows,residential street wash water and water from firefighting activities. Such exempt discharges shall be made in accordance with an appropriate plan for reducing pollutants. 2. Discharges approved in writing by the SMO to protect Iife or property from imminent harm or damage,provided that, such approval shall not be construed to constitute compliance with other applicable laws and requirements,and further provided that such discharges may be permitted for a specified time period and under such conditions as the SMO may deem appropriate to protect such life and property while reasonably maintaining the purpose and intent of this local law. 3. Dye testing in compliance with applicable state and local laws is an allowable discharge, but requires a verbal notification to the SMO prior to the time of the test. 4. The prohibition shall not apply to any discharge permitted under an SPDES permit,waiver, or waste discharge order issued to the discharger and administered under the authority of the Department,provided that the discharger is in full compliance with all requirements of the permit, waiver, or order and other applicable laws and regulations, and provided that written approval has been granted for any discharge to the MS4. B. Prohibition of Illicit Connections. 4 " 1. .. The construction, use, maintenance or continued existence of illicit connections to the MS4 is prohibited. 2. This prohibition expressly includes, without limitation, illicit connections made in the past, regardless of whether the connection was permissible under law or practices applicable or prevailing at the time of connection. 3. A person is considered to be in violation of this local law if the person connects a line conveying sewage to the municipality's MS4,or allows such a connection to continue. 235-6. PROHIBITION AGAINST ACTIVITIES CONTAMINATING STORMWATER A. Activities that are subject to the requirements of this section are those types of activities that: 1. Cause or contribute to a violation of the municipality's MS4 SPDES permit. 2. Cause or contribute to the municipality being subject to the Special Conditions as defined in §235-2 (Definitions) of this local law. B. Upon notification to a person that he or she is engaged in activities that cause or contribute to violations of the municipality's MS4 SPDES permit authorization,that person shall take all reasonable actions to correct such activities such that he or she no longer causes or contributes to violations of the municipality's MS4 SPDES permit authorization. 235-7. REQUIREMENT TO PREVENT, CONTROL, AND REDUCE STORMWATER POLLUTANTS BY THE USE OF BEST MANAGEMENT PRACTICES. A. Best Management Practices Where the SMO has identified illicit discharges as defined in §235-2 or activities contaminating stormwater as defined in §235-6 the municipality may require implementation of Best Management Practices(BMPs)to control those illicit discharges and activities. 1. The owner or operator of a commercial or industrial establishment shall provide, at their own expense,reasonable protection from accidental discharge of prohibited materials or other wastes into the MS4 through the use of structural and non-structural BMPs. 2. Any person responsible for a property or premise,which is, or may be,the source of an illicit discharge as defined in §235-2 or an activity contaminating stormwater as defined in §235-6, may be required to implement,at said person's expense, additional structural and non-structural BMPs to reduce or eliminate the source of pollutant(s) to the MS4. 3. Compliance with all terms and conditions of a valid SPDES permit authorizing the discharge of stormwater associated with industrial activity,to the extent practicable, shall be deemed compliance with the provisions of this section. 235-8. SUSPENSION OF ACCESS TO MS4. Illicit Discharges in Emergency Situations. A. The SMO may,without prior notice, suspend MS4 discharge access to a person when such suspension is necessary to stop an actual or threatened discharge which presents or may present imminent and substantial danger to the environment,to the health or welfare of persons, or to the MS4. The SMO shall notify the person of such suspension within a reasonable time thereafter in writing of the reasons for the suspension. If the violator fails to comply with a suspension order issued in an emergency, the SMO may take such steps as deemed necessary to prevent or minimize damage to the MS4 or to minimize danger to persons. B. Suspension due to the detection of illicit discharge. Any person discharging to the municipality's MS4 in violation of this law may have their MS4 access terminated if such termination would abate or reduce an illicit discharge. The SMO will notify a violator in writing of the proposed termination of its MS4 access and the reasons therefor. The violator may petition the SMO for a reconsideration and hearing. Access may be granted by the SMO if he/she finds that the illicit discharge has ceased and the discharger has taken steps to prevent its recurrence. Access may be denied if the SMO determines in writing that the illicit discharge has not ceased or is likely to recur. A person commits an offense if the person reinstates MS4 access to premises terminated pursuant to this section, without the prior approval of the SMO. 5 235- 9. INDUSTRIAL OR CONSTRUCTION ACTIVITY DISCHARGES. Any person subject to an industrial or construction activity SPDES stormwater discharge permit shall comply with all provisions of such permit. Proof of compliance with said permit may be required in a form acceptable to the municipality prior to the allowing of discharges to the MS4. 235- 10. ACCESS AND MONITORING OF DISCHARGES. A. Applicability. This section applies to all facilities that the-SMO must inspect to enforce any provision of this Law, or whenever the authorized enforcement agency has cause to believe that there exists, or potentially exists, in or upon any premises any condition which constitutes a violation of this Law. B. Access to Facilities. 1. The SMO shall be permitted to enter and inspect facilities subject to regulation under this law as often as may be necessary to determine compliance with this Law. If a discharger has security measures in force which require proper identification and clearance before entry into its premises,the discharger shall make the necessary arrangements to allow access to the SMO. 2. Facility operators shall allow the SMO ready access to all parts of the premises for the purposes of inspection, sampling, examination and copying of records as may be required to implement this law. 3. The municipality shall have the right to set up on any facility subject to this law such devices as are necessary in the opinion of the SMO to conduct monitoring and/or sampling of the facility's stormwater discharge. 4. The municipality has the right to require the facilities subject to this law to install monitoring equipment as is reasonably necessary to determine compliance with this law. The facility's sampling and monitoring equipment shall be maintained at all times in a safe and proper operating condition by the discharger at its own expense. All devices used to measure stormwater flow and quality shall be calibrated to ensure their accuracy. 5. Unreasonable delays in allowing the municipality access to a facility subject to this law is a violation of this law. A person who is the operator of a facility subject to this law commits an offense if the person denies the municipality reasonable access to the facility for the purpose of conducting any activity authorized or required by this law. d. If the SMO has been refused access to any part of the premises from which stormwater is discharged, and he/she is able to demonstrate probable cause to believe that there may be a violation of this law, or that there is a need to inspect and/or sample as part of a routine inspection and sampling program designed to verify compliance with this law or any order issued hereunder,then the SMO may seek issuance of a search warrant from any court of competent jurisdiction. 235- 11. NOTIFICATION OF SPILLS. Notwithstanding other requirements of law, as soon as any person responsible for a facility or operation, or responsible for emergency response for a facility or operation has information of any known or suspected release of materials which are resulting or may result in illegal discharges or pollutants discharging into the MS4, said person shall take all necessary steps to ensure the discovery, containment, and cleanup of such release. In the event of such a release of hazardous materials said person shall immediately notify emergency response agencies of the occurrence via emergency dispatch services. In the event of a release of non-hazardous materials, said person shall notify the municipality in person or by telephone or facsimile no later than the next business day.Notifications in person or by telephone shall be confirmed by written notice addressed and mailed to the municipality within three business days of the telephone notice. If the discharge of prohibited materials emanates from a commercial or industrial establishment, the owner or operator of such establishment shall also retain an on-site written record of the discharge and the actions taken to prevent its recurrence. Such records shall be retained for at least three years. 6 235- 12. ENFORCEMENT. A. Notice of Violation. When the municipality's SMO finds that a person has violated a prohibition or failed to meet a requirement of this law, he/she may order compliance by written notice of violation to the responsible person. Such notice may require without limitation:, 1. The elimination of illicit connections or discharges; 2. That violating discharges, practices, or operations shall cease and desist; 3. The abatement or remediation of stormwater pollution or contamination hazards and the restoration of any affected property; 4. The performance of monitoring, analyses, and reporting; 5. Payment of a fine; and 6. The implementation of source control or treatment BMPs. If abatement of a violation and/or restoration of affected property is required,the notice shall set forth a deadline within which such remediation or restoration must be completed. Said notice shall further advise that, should the violator fail to remediate or restore within the established deadline,the work will be done by a designated governmental agency or a contractor and the expense thereof shall be charged to the violator. B. Penalties In addition to or as an alternative to any penalty provided herein or by law, any person who violates the provisions of this local law shall be guilty of a violation punishable by a fine not exceeding One Thousand dollars ($1,000.00) or imprisonment for a period not to exceed six(6)months, or both for conviction of a first offense; for conviction of a second offense both of which were committed within a period of five (5)years,punishable by a fine not less than Two Thousand Five Hundred dollars ($2,500.00)nor more than Seven Thousand Five Hundred dollars ($7,500.00)or imprisonment for a period not to exceed six (6)months,or both; and upon conviction for a third or subsequent offense all of which were committed within a period of five (5)years,punishable by a fine not less than Ten Thousand dollars ($10,000.00)nor more than Twenty Thousand dollars ($20,000.00)or imprisonment for a period not to exceed six(6)months,or both, However,for the purposes of conferring jurisdiction upon courts and judicial officers generally, violations of this Iocal law shall be deemed misdemeanors and for such purpose only all provisions of law relating to misdemeanors shall apply to such violations each week's continued violation shall constitute a separate additional violation. 235-13. APPEAL OF NOTICE OF VIOLATIONS. Any person receiving a Notice of Violation may appeal the determination of the SMO to the Town of Southold within fifteen (15)days of its issuance,which shall hear the appeal within thirty (30)days after the filing of the appeal, and within five(5)days of making its decision, file its decision in the office of the municipal clerk and mail a copy of its decision by certified mail to the discharger. 235-14. CORRECTIVE MEASURES AFTER APPEAL. A. If the violation has not been corrected pursuant to the requirements set forth in the Notice of Violation, or, in the event of an appeal,within five(5)business days of the decision of the municipal authority upholding the decision of the SMO,then the SMO shall request the owner's permission for access to the subject private property to take any and all measures reasonably necessary to abate the violation and/or restore the property. B. If refused access to the subject private property, the SMO may seek a warrant in a court of competent jurisdiction to be authorized to enter upon the property to determine whether a violation has occurred. Upon determination that a violation has occurred, the SMO may seek a court order to take any and all measures reasonably necessary to abate the violation and/or restore the property. The cost of implementing and maintaining such measures shall be the sole responsibility of the discharger. 7 r 235 15. INJUNCTIVE RELIEF. It shall be unlawful for any person to violate any provision or fail to comply with any of the requirements of this law. If a person has violated or continues to violate the provisions of this law, the SMO may petition for a preliminary or permanent injunction restraining the person from activities which would create further violations or compelling the person to perform abatement or remediation of the violation. 235-16. ALTERNATIVE REMEDIES. A. Where a person has violated a provision of this Law,he/she may be eligible for alternative remedies in lieu of a civil penalty, upon recommendation of the Municipal Attorney and concurrence of the Municipal Code Enforcement Officer, where: 1 o The violation was unintentional 2. The violator has no history of pervious violations of this Law. 3. Environmental damage was minimal. 4. Violator acted quickly to remedy violation. 5. Violator cooperated in investigation and resolution. B. Alternative remedies may consist of one or more of the following: 1. Attendance at compliance workshops 2. Storm drain stenciling or storm drain marking 3. River, stream or creek cleanup activities 235-17. VIOLATIONS DEEMED A PUBLIC NUISANCE. In addition to the enforcement processes and penalties provided, any condition caused or permitted to exist in violation of any of the provisions of this law is a threat to public health, safety, and welfare, and is declared and deemed a nuisance, and may be summarily abated or restored at the violator's expense, and/or a civil action to abate, enjoin, or otherwise compel the cessation of such nuisance may be taken. 235-1 S. REMEDIES NOT EXCLUSIVE. The remedies listed in this law are not exclusive of any other remedies available under any applicable federal, state or local law and it is within the discretion of the authorized enforcement agency to seek cumulative remedies. III. SEVERABILITY. The provisions of this law are hereby declared to be severable. If any provision, clause, sentence, or paragraph of this law or the application thereof to any person, establishment, or circumstances shall be held invalid, such invalidity shall not affect the other provisions or application of this law. IV. EFFECTIVE DATE This law shall be in full force and effect immediately upon its final adoption and filing with the Secretary of State. All prior laws and parts of law in conflict with this law are hereby repealed. 8 PTUWN ATTORNEY SO r ALBERT J.KRUPSKI,JR. r �� �S' Supervisor pauldQsoutholdtownny.gov +� 1 JAMES A.SQUICCIARINI Town Hall Annex,54375 Route 25 DEPUTY TOWN ATTORNEY P.O.Box 1179 jacks@southoldtownny.gov Southold,New York 11971-0959 JULIE M.McGIVNEY ASSISTANT TOWN ATTORNEY Telephone(631)765-1939 juliem®southoldtownny.gov Facsimile(631)765-6639 13ENJAMIN JOHNSON OFFICE OF ASSISTANT TOWN ATTORNEY THE TOWN ATTORNEY benjaminj®southoldtownny.gov TOWN OF SOUTHOLD NYS DEC SPEDES/STORMWATER DISCHARGE MS4 ATTORNEY CERTIFICATION Paul M DeChance, being duly sworn, deposes and says: 1. I am employed as the Southold Town Attorney. 2. That in the course of my duties, I was caused to draft Town Code Chapter 234 "SPDES Stormwater Management and Erosion& Sediment Control" and Town Code Chapter 235 "Storm Sewer Systems; Illicit Discharges,Activities and Connections". 3. That said Chapters were adopted by the Southold Town Board at its regular meeting of June 18, 2024 by Resolution 2024-560 and 2024-561. 4. 1 have compared these adopted laws to the provisions of the New York State Department of Environmental Conservation SPDES Laws regarding General Permits for Construction Activities and for Stormwater Discharges from MS4s. 5. 1 hereby certify that Southold Town Code Chapter 234 "SPDES Stormwater Management and Erosion& Sediment Control" and Chapter 235 "Storm Sewer Systems; Illicit Discharges, Activities and Connections" are consistent with the New York State Department of Environmental Conservation SPDES General Permits for Construction Activities and for Stormwater Discharges from MS4s. Dated: June 27, 2024 0 S utliold Town Attorney Town of Southold APPENDIX D APPENDIX E Table of Contents Table of Contents 1 MS4 Interim Progress Certification*6 Month Requirements 2 (Submission#: HQ4-TOK1-61 D2R,version 1) 2 Details 2 Form Input 2 MS4 Operator Information 2 Part IN 2 Part II 2 Part IV 3 Part VI&VII 3 Part VIII 4 Part IX 5 Compliance Schedule Review _5 Certification 5 Attachments 6 Status History 6 Processing Steps 6 2/26/2025 12:47:29 PM Page 1 of 6 MS4 Interim Progress CertificationQ6 Month Requirements version 1.0 (Submission#:H04-TOK1-61 D2R,version 1) Details Submitted 8/5/2024(205 days ago)by Michael Collins Alternate Identifier NYR2OA524 Submission ID HQ4-T0K1-61D2R Status Deemed Complete Active Steps Review Form Input MS4 Operator Information Municipality Name or Legal Entity Name Town of Southold Permit ID#: NYR20A524 MS4 Operator Type Traditional land use control Traditional Land Use Control Town Traditional Land Use Control Traditional land use control MS4 Operator requirements are found in Part VI of the MS4 General Permit. Legal Municipal/Entity Mailing address 53095 Main Road Southold,New York 11971 Suffolk Ranking Official Official Title First and Last Name Phone Email Town Supervisor Albert J.Krupski,Jr. 6317651889 al.krupski@town.southold.ny.us Report Preparer Report Preparer Title First and Last Name Phone Email Stormwater Program Coordinator Michael Collins 6317651560 michael.collins@town.southold.ny.us Stormwater Program Coordinator Coordinator Title First and Last Name Phone Email Stormwater Program Coordinator Michael Collins 6317651560 michael.collins@town.southold.ny.us Part IN MS4 General Permit Resources Use the following webpages for more information on the permit and fact sheet: MS4 Permit Webpaae MS4 Toolbox Part II 2/26/2025 12:47:29 PM Page 2 of 6 Obtaining Permit Coverage Has a complete Notice of Intent(NOI)been submitted?(Part II.A.) Yes Part IV Administrative Has a written staffing/organizational chart,which includes job titles and other entities as identified in Part IV.A.1,and the roles and responsibilities for each,corresponding to the required elements of the SWMP been developed?(Part IV.A.2.) Yes SWMP Plan Has the current SWMP Plan,and any documentation associated with the implementation of the SWMP Plan,been made available during normal business hours?(Part IV.B.2.a.) Yes Is a copy of the current SWMP Plan available for public inspection during normal business hours at a location that is accessible to the public, or on a public website?(Part IV.B.2.b.) Yes Mapping Are the required components included in the comprehensive system mapping?(Part IV.D.1.) Yes Legal Authority Has adequate legal authority been maintained?(Part IV.E.) Yes Enforcement Measures&Tracking Has an enforcement response plan(ERP)which clearly describes the action(s)to be taken for violations that the MS4 Operator has enacted for illicit discharge been developed?(Part IV.F.1.) Yes Has an enforcement response plan(ERP)which clearly describes the action(s)to be taken for violations that the MS4 Operator has enacted for construction been developed?(Part IV.F.1.) Yes Has an enforcement response plan(ERP)which clearly describes the action(s)to be taken for violations that the MS4 Operator has enacted for post-construction been developed?(Part IV.F.1.) Yes Please enter any comments related to the questions in this section below: NONE PROVIDED Part M&VII Minimum Control Measure 1 Has information related to the prevention of illicit discharges been made available?(Part VWII.A 1.d.) Yes Minimum Control Measure 2 Has a local point of contact to receive and respond to public concerns regarding stormwater management and compliance with permit requirements been identified?(Part VI/VII.B.1.c.) Yes Minimum Control Measure 3 Has an email or phone number to allow the public to report illicit discharges been established?(Part VI/VII.C.1.a.i.) Yes 2/26/2025 12:47:29 PM Page 3 of 6 Minimum Control Measure 4 Has an email or phone number to allow the public to report complaints related to construction stormwater activity been established?(Part VI/VII.D.2.a.) Yes Has a construction site inventory been developed?(Part VWII.DA.a.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. The Town has no SPDES regulated construction sites that discharge to it's MS4. Minimum Control Measure 5 Has the inventory of post-construction stormwater management practices(SMPs)been maintained from previous iterations of this SPDES general permit?(PartVWII.E.2.a.i.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. The Town has no previous post-construction stormwater management practices that discharge to it's MS4. Has the inventory of post-construction stormwater management practices(SMPs)been developed as they are approved/discovered or after the owner/operator of the construction activity has filed the Notice of Termination?(Part VI/VII.E.2.a.ii.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. The Town has no SPDES regulated construction sites that discharge to it's MS4. Minimum Control Measure 6 Have procedures for sweeping and/or cleaning of municipal streets,bridges,parking lots,and right of ways been developed?(Part VI/VII.F.3.d.i.) Yes Please enter any comments related to the questions in this section below: NONE PROVIDED Part VIII Does the MS4 Operator discharge to an impaired water listed in Appendix C of GP-0-24-001? Yes For which pollutant(s)is the waterbody impaired?Select the pollutants for all the impaired waters listed in Appendix C of GP-0-24-001 to which the MS4 Operator discharges. Pathogens Pathogens Has information on how pathogens are being addressed by implementation of the MS4 Operatonos local law or legal mechanism with content equivalent to the model local law been made available?(Part VIII.C.2.a.) Yes Have municipal facilities with nuisance bird populations that have the potential to contribute pathogens been identified?(Part VIII.C.7.b.i.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. There are no municipal facilities within the Town's regulated SPDES sewersheds Has signage at municipal facilities with nuisance bird populations that have the potential to contribute pathogens,instructing the public not to feed wildlife,been made available?(Part VIII.C.7.b.ii.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. There are no municipal facilities within the Town's regulated SPDES sewersheds Has trash and debris been removed from municipally owned facilities when necessary to eliminate potential food sources for wildlife?(Part VIII.C.7.b.iii.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. There are no municipal facilities within the Town's regulated SPDES sewersheds Please enter any comments related to the questions in this section below: r arvL r-Vovrr::Er:: 2/26/2025 12:47:29 PM Page 4 of 6 Part IX Does the MS4 Operator discharge to a TMDL listed in Table 3 of GP-0-24-001? Yes To which TMDL does the MS4 Operator discharge? Peconic Estuary Nitrogen Watershed Peconic Estuary Nitrogen Watershed Has information on how nitrogen is being addressed by implementation of the MS4 Operatonos local law or legal mechanism with content equivalent to the model local law been made available?(Part DC.D.2.a.) Yes Please enter any comments related to the questions in this section below: NONE PROVIDED Compliance Schedule Review Compliance Schedule Resources Use the following links for more information on the permit and compliance schedule: MS4 Permit Webpaae MS4 Toolbox What is the status for compliance items due within one year of effective date of coverage(EDC),January 2,2025? Citation Compliance Items Compliance Progress Part VI/VII.D.3. Develop and implement a construction oversight program Completed Part VI/VII.D.5.a. Prioritize construction sites Not Applicable Part MILE.. Develop and implement a post-construction stormwater management practice inspection and Not Applicable maintenance program Part VIII.C.7.b.iv. Evaluate the effectiveness of deterrents,population controls,and other measures that may reduce bird Not Applicable related pathogen contributions Part VIII.C.7.c. Make dog waste receptacles available in areas where pets/domestic animals mayfrequent Not Applicable Part IX.A.6.f.i.a.and Submit to the Department a retrofit plan that identifies the required components Not Applicable IX.B.6.f.i.a. Please clarify the reason for selecting"Not Applicable"for one or more of the compliance items above. The Town has no SPDES regulated construction sites that discharge to it's MS4 and no post-construction stormwater management practices that discharge to it's MS4. The Town has no municipal facilities within its SPDES regulated sewersheds,therefore the references to bird and dog related items are Not Applicable. The Peconic Nitrogen TMDL does not specify a retrofit requirement for the Town of Southold. Have you reviewed compliance items due within two years of EDC,January 2,2026? Yes Have you reviewed compliance items due within three years of EDC,January 2,2027? Yes Have you reviewed compliance items due within four years of EDC,January 2,2028? Yes Have you reviewed compliance items due within five years of EDC,January 2,2029? Yes Have you reviewed compliance items which need to be completed routinely(annually,every five(5)years,etc.)? Yes Please enter any comments related to the questions in this section. NONE PROVIDED Certification I am the ranking elected official or Principal Executive Officer for the MS4 Operator and will be signing the form electronically. Yes As the Ranking Elected Official or Principal Executive Officer,please download the certification form using the link below.Complete and sign the certification.Then,upload the certification form to this Interim Progress Certification and/or Annual Report. Certification Form 2/26/2025 12:47:29 PM Page 5 of 6 Attach completed certification form. Southold 6 Month Interim Progress Report Certification Form.pdf-08/05/2024 09:21 AM Comment NONE PROVIDED Attachments Date Attachment Name Context User 8/5/2024 9:21 AM I Southold 6 Month Interim Progress Report Certification Form.pdf Attachment Michael Collins Status History User Processing Status 7/1/2024 3:34:03 PM Michael Collins Draft 8/5/2024 9:26:00 AM Michael Collins Submitting 8/5/2024 9:26:17 AM Michael Collins Submitted 10/21/2024 3:13:30 PM Michelle Nowak Deemed Complete Processing Steps Step Name Assigned To/Completed By Date Completed Form Submitted Michael Collins 8/5/2024 9:26:17 AM Review 2/26/2025 12:47:29 PM Page 6 of 6 NEW YORK STATE DEPARTMENT OF ENVIRONMENTAL CONSERVATION Division of Water,Bureau of Water Permits 625 Broadway,Albany,New York 12233-3505 P:(518)402-8111 1 F:(518)402-9029 www.dec.ny.gov MS4 Operator Certification Form for eReports SPDES General Permit for Stormwater Discharges From Municipal Separate Storm Sewer Systems (GP-0-24-001) Instructions As required by Part V.13.2. and Part V.13.3. of GP-0-24-001, the MS4 Operator must submit the Annual Report and the Interim Progress Certification, respectively. As stated in Part V.13.5. of GP-0-24-001, all reports must be signed in accordance with Part X.J. of GP-0-24-001. MS4 Operator Name: Town of Southold Permit ID: NYR20A 524 eReport Submission Number: HQ4-TOK1 -61 D2R MS4 Operator Certification I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations. Name (please print or type) Title Albert J. Krupski, Jr. Town Supervisor Signature Date r �... B yc RK Department of 4Y Environmental KWpFCIlApu,l Uy1 Conservation Table of Contents Table of Contents 1 MS4 Annual Report/Interim Progress Certification*2025 2 (Submission#: HQ9-006N-FMF76,version 1) 2 Details 2 Form Input 2 MS4 Operator Information 2 Part IV 3 Part V 3 Part VI 4 Part VIII 12 Part IX 13 Interim Progress Status __14 Certification 15 Attachments 15 Status History 15 Processing Steps 15 4/7/2025 10:10:15 AM Page 1 of 15 MS4 Annual Report/interim Progress Certificatiomi6M25 version 1.0 (Submission#: HQ9-006N-FMF76,version 1) Details Submitted 2/26/2025(40 days ago)by Michael Collins Alternate Identifier NYR20A524 Submission ID HQ9-006N-FMF76 Status Deemed Complete Form Input MS4 Operator Information Municipality Name or Legal Entity Name Town of Southold Permit ID#: NYR20A524 MS4 Operator Type Traditional land use control Traditional Land Use Control Town Traditional Land Use Control Traditional land use control MS4 Operator requirements are found in Part VI of the MS4 General Permit. Legal Municipal/Entity Mailing address 53095 Main Road Southold, New York 11971 Suffolk Ranking Official Official Title First and Last Name Phone Email Town Supervisor Albert J. Krupski,Jr. 6317651889 al.krupski@town.southold.ny.us Report Preparer Report Preparer Title First and Last Name Phone Email Stormwater Program Coordinator Michael Collins 6317651560 1 michael.collins@town.southold.ny.us Stormwater Program Coordinator Coordinator Title First and Last Name Phone Email Stormwater Program Coordinator Michael Collins 6317651560 michael.collins@town.southold.ny.us 4/7/2025 10:10:15 AM Page 2 of 15 Part IV Was the information in this section completed as part of a coalition/group? No MS4 General Permit Resources Use the following wmbpagem for more information on the permit and fact sheet: &S4 Toolbox SVVMP Plan Annually: Have the alternative implementation agreements in the SVVMP Plan been updated?(Part OJ��1.e.) N/A Please clarify the reason for selecting"Wo"or"WAV'for this item. All aspects ofSoutho|d'm program are handled by in-house staff Annually: Has the SVVMP been updated?(Part OJ.13.3.) Yes Mapping Annually: Has the comprehensive system mapping been updated?(Part IV.D.) Yes What tools are used to satisfy the comprehensive system mapping requirements?(e.g.paper maps,GIS,web mappers,etc.) Online G|SMap Within three(3)years of the EDC: Has Phase I of the comprehensive mapping been completed?(Part IV.D.2.a.) No Please clarify the reason for selecting"Wo"for this item. Itim not due yet Within five(5)years of the EDC: Has Phase 11 of the comprehensive mapping been completed?(Part IV.D.2.b.) No Please clarify the reason for selecting"Wo"for this item. Itim not due yet Legal Auth Within three(3)years cf the EDC: For newly designated K0S4 Operators,has adequate legal authority been developed and implemented?(Part OJ.E.) Yes Please enter any comments related tn the questions in this section below: mowF PRomoso Part V |n Year 5: Has the SVVMP Plan been evaluated?(Part y.C.) No Please clarify the reason for selecting"Wo"or"WAV'for this item. Itim not due yet Part V1 Which MCMs in this Part were completed as a coalition/group,if any? NONE PrrO`rrraED Minimum Control Measure 1 Within three(3)years of the EDC: Have the focus areas been identified?(Part VI.A.1.a.) No Please clarify the reason for selecting"No"or"N/A"for this item. It is not due yet Within three(3)years of the EDC: Have the target audience(s)and associated pollutant generating activities been identified?(Part VI.A.1.b.) No Please clarify the reason for selecting"No"or"N/A"for this item. It is not due yet Within three(3)years of the EDC: Have the education and outreach topics been identified and how the education and outreach topics will reduce the potential for pollutants explained?(Part VI.A.1.c.) No Please clarify the reason for selecting"No"or"N/A"for this item. It is not due yet In Year 5: Has the method(s)used for distribution of educational messages been identified?(Part VI.A.2.a.) No Please clarify the reason for selecting"No"or"N/A"for this item. It is not due yet In Year 5: Has one educational message been delivered to each target audience(s)for each focus area based on the education and outreach topic(s)?(Part VI.A.2.b.) No Please clarify the reason for selecting"No"or"N/A"for this item. It is not due yet In Year 4 and Year 5: Have target audiences,focus areas,and/or education and outreach topics been updated?(Part VI.A.2.c.) No Please clarify the reason for selecting"No"or"N/A"for this item. It is not due yet Please enter any comments related to the questions in this section below: NONE FIROWDED Minimum Control Measure 2 Annually: Has an opportunity for public involvement/participation in the development and implementation of the SWMP been provided?(Part VI.B.1.a.) Yes What was the opportunity for public involvement/participation in the SWMP? Public hearings or meetings Annually: Has the public been informed about the opportunity for their involvement in the development and implementation of the SWMP and how they can get involved?(Part VI.B.1.b.) Yes 4/7/2025 10:10:15 AM Page 4 of 15 What is the method(s)used for distribution to inform the public of the opportunity for involvement? Electronic materials(e.g.,websites,email listservs) Annually: Has an opportunity to review and comment on the publicly available SWMP Plan been provided?(Part VI. .2.a.) Yes Annually: Has an opportunity to review and comment on the draft annual report been provided?(Part VI.B.2.b.i.) Yes What opportunity for review and comment on the draft annual report has been provided? Presentation of the draft Annual Report Posting of draft Annual Report on a public website Annually: Have the comments received on the SWMP Plan been summarized?(Part VI.B.2.c.i.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. No comments received. Annually: Have the comments received on the draft annual report been summarized?(Part VI.B.2.c.i.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. No comments received Please enter any comments related to the questions in this section below: NONE PROVIDED Minimum Control Measure 3 Within three(3)years of the EDC: Has an inventory of monitoring locations been developed?(Part VI.C.1.c.i.) Yes How many monitoring locations are on the inventory? 22 How many MS4 outfalls are on the inventory? 20 How many interconnections are on the inventory? 2 How many municipal facility inteaconnections are on the inventory? 0 In Year 4 and Year 5: Has the monitoring location inventory been updated?(Part VI.C.1.c.ii.) No Please clarify the reason for selecting"No"or"N/A"for this item. It is not due yet Within three(3)years of the EDC: Have monitoring locations been prioritized?(Part VI.C.1.d.i.) Yes How many high priority monitoring locations are on the inventory? 22 How many high priority MS4 outfalls are on the inventory? 20 How many high priority interconnections are on the inventory? 2 4/7/2025 10:10:15 AM Page 5 of 15 How many high priority municipal facility intraconnections are on the inventory? 0 In Year 4 and Year 5: Has the monitoring location prioritization been updated?(Part VI.C.1.d.iii.) No Please clarify the reason for selecting"No"or"N/A"for this item. It is not due yet Within two(2)years of the EDC: Has a monitoring locations inspection and sampling program been developed and implemented?(Part VI.C.1.e.) Yes In Year 5: Have all the monitoring locations been inspected?(Part VI.C.1.e.i.a)) No Please clarify the reason for selecting"No"or"N/A"for this item. It is not due yet How many monitoring locations have been inspected? 6 In Year 5: Has training on the MS4 Operator's monitoring locations inspection and sampling procedures been provided?(Part VI.C.1.e.ii.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. No training required.All inspections conducted by the Town Engineer who also serves as the Stormwater Program Coordinator. In Year 3,Year 4,and Year 5: Have the names,titles,and contact information for the individuals who have received monitoring locations inspection and sampling training been updated?(Part VI.C.1.e.iii.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. No training required.All inspections conducted by the Town Engineer who also serves as the Stormwater Program Coordinator. In Year 3,Year 4,and Year 5: Have the monitoring locations inspection and sampling procedures been updated? (Part Vl.C.1.e.iv.) No Please clarify the reason for selecting"No"or"N/A"for this item. It is not due yet Within two(2)years of the EDC: Has an illicit discharge track down program been developed and implemented? (Part Vl.C.2.) Yes In Year 5: Has training on the MS4 Operator's illicit discharge track down procedures prior to conducting illicit discharge track down been provided?(Part VI.C.2.b.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. No training required.All inspections conducted by the Town Engineer who also serves as the Stormwater Program Coordinator. In Year 3,Year 4,and Year 5: Have the names,titles,and contact information for the individuals who have received illicit discharge track down procedures training been updated?(Part VI.C.2.c.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. No training required.All inspections conducted by the Town Engineer who also serves as the Stormwater Program Coordinator. In Year 3,Year 4,and Year 5: Have the illicit discharge track down procedures been reviewed and updated?(Part Vl.C.2.d.) No 4/7/2025 10:10:15 AM Page 6 of 15 Please clarify the reason for selecting"No"or"N/A"for this item. It is not due yet Within two(2)years of the EDC: Has an illicit discharge elimination program been developed and implemented? (Part Vl.C.3.) Yes In Year 5: Has training on the MS4 Operator's illicit discharge elimination procedures prior to conducting illicit discharge elimination been provided?(Part VI.C.3.b.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. No training required.All inspections conducted by the Town Engineer who also serves as the Stormwater Program Coordinator. In Year 3,Year 4,and Year 5: Have the names,titles,and contact information for the individuals who have received illicit discharge elimination procedures training been updated?(Part VI.C.3.c.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. No training required.All inspections conducted by the Town Engineer who also serves as the Stormwater Program Coordinator. In Year 3,Year 4,and Year 5: Have the illicit discharge elimination procedures been reviewed and updated?(Part Vl.C.3.d.) No Please clarify the reason for selecting"No"or"N/A"for this item. It is not due yet Please enter any comments related to the questions in this section below: NONE PROVIDED Minimum Control Measure 4 Within one(1)year of the EDC: Has a construction oversight program been developed and implemented?(Part VI.D.3) Yes In Year 5: Has training on the MS4 Operator's construction oversight procedures prior to conducting construction oversight been provided?(Part VI.D.3.b.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. No training required.All inspections conducted by the Town Engineer who also serves as the Stormwater Program Coordinator. In Year 2,Year 3,Year 4,and Year 5: Have the names,titles,and contact information for the individuals who have received construction oversight procedures training been updated?(Part VI.D.3.c.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. No training required.All inspections conducted by the Town Engineer who also serves as the Stormwater Program Coordinator. In Year 2,Year 3,Year 4,and Year 5: Have the construction oversight procedures been reviewed and updated?(Part VI.D.3.e.) No Please clarify the reason for selecting"No"or"N/A"for this item. It is not due yet Annually: Has the inventory of construction sites been updated?(Part VI.D.4.b.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. The Town of Southold has not taken jurisdiction over any SPDES regulated construction sites. 4/7/2025 10:10:15 AM Page 7 of 15 How many construction sites are on the inventory? 0 Within one(1)year of the EDC: Have construction sites been prioritized?(Part VI.D.5.a.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. The Town of Southold has not taken jurisdiction over any SPDES regulated construction sites. In Year 2,Year 3,Year 4,and Year 5: Has the construction site prioritization been updated?(Part VI.D.5.c.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. The Town of Southold has not taken jurisdiction over any SPDES regulated construction sites. Within three(3)years of the EDC: Have the individuals responsible for reviewing SWPPPs for acceptance received four(4)hours of Department endorsed training in proper erosion and sediment control principles from a Soil& Water Conservation District,or other Department endorsed entity prior to conducting SWPPP reviews and/or approvals?(Part VI.D.6.a.i.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. The Town Engineer is responsible for reviewing SWPPPs and is exempt from this requirement as a licensed professional engineer. Annually: Have the names,titles,and contact information for the individuals who have received four(4)hours of Department endorsed training in proper erosion and sediment control principles from a Soil&Water Conservation District,or other Department endorsed entity,for individuals responsible for reviewing SWPPPs been updated? (Part VI.D.6.d.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. The Town Engineer is responsible for reviewing SWPPPs and is exempt from this requirement as a licensed professional engineer. Are pre-construction meetings conducted prior to the commencement of construction activity?(Part VI.D.7.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. The Town of Southold has not taken jurisdiction over any SPDES regulated construction sites. Within three(3)years of the EDC: Have the individuals responsible for construction site inspections received four (4)hours of Department endorsed training in proper erosion and sediment control principles from a Soil&Water Conservation District,or other Department endorsed entity prior to conducting construction site inspections?(Part VI.D.8.a.i.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. The Town Engineer is responsible for construction site inspections and is exempt from this requirement as a licensed professional engineer. Annually: Have all sites with construction activity identified in the inventory been inspected during active construction after the pre-construction meeting,or sooner if deficiencies are noted that require attention?(Part VI.D.8.c.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. The Town of Southold has not taken jurisdiction over any SPDES regulated construction sites. Annually: Have the names,titles,and contact information for the individuals who have received four(4)hours of Department endorsed training in proper erosion and sediment control principles from a Soil&Water Conservation District,or other Department endorsed entity,for individuals responsible for construction site inspections been updated?(Part VI.D.8.d.) N/A 4/7/2025 10:10:15 AM Page 8 of 15 Please clarify the reason for selecting"Wo"or"W/N for this item. The Town Engineer imresponsible for construction site inspections and is exempt from this requirement as a licensed professional engineer. Are final construction site inspections conducted?(Part y|.D.9.) N/A Please clarify the reason for selecting"Wo"or"WAV'for this item. The Town of Southold has not taken jurisdiction over any SPIDES regulated construction sites. Please enter any comments related tn the questions in this section below: mowsnromoco Minimum Control Measure 5 Annually: Has the inventory of post-construction SMPs been updated?(Part VI.E.2.c.) N/A Please clarify the reason for selecting"Wo"or"WAV'for this item. The Town of Southold has not taken jurisdiction over any SPIDES regulated construction sites. How many post-construction SK0Po are on the inventory? O Within five(5)years of the EDC: Have the required components been included in the post-construction SMP inventory?(Part yiE.2.d.) N/A Please clarify the reason for selecting"Wo"or"WAV'for this item. The Town of Southold has no post-construction SlVlPmin its inventory. Within one(1)year of the EDC: Has a post-construction SMP inspection and maintenance program been developed and implemented?(Part yiE.4.) N/A Please clarify the reason for selecting"Wo"or"WAV'for this item. The Town of Southold has no post-construction SlVlPmin its inventory. Has each post-construction SMP identified in the inventory been inspected at the required frequency?(Part yiE.4.a.) N/A Please clarify the reason for selecting"Wo"or"WAV'forthisitem. The Town of Southold has no post-construction SlVlPmin its inventory. In Year 5: Has training on the MS4 Operator's post-construction SMP inspection and maintenance procedures prior to conducting post-construction SMP inspection and maintenance been provided?(Part VI.E.4.b.) N/A Please clarify the reason for selecting"Wo"or"WAV'for this item. The Town of Southold has no post-construction SlVlPmin its inventory. Annually: Have names,titles,and contact information for the individuals who have received post-construction SMP inspection and maintenance procedures training updated?(Part VI.E.4.c.) N/A Please clarify the reason for selecting"Wo"or"WAV'forthisitem. The Town of Southold has no post-construction SlVlPmin its inventory. In Year 2,Year 3,Year 4,and Year 5: Have the post-construction SMP inspection and maintenance procedures been reviewed and updated?(Part y|.E.4.d.) N/A Please clarify the reason for selecting"Wo"or"WAV'for this item. The Town of Southold has no post-construction SlVlPmin its inventory. Please enter any comments related to the questions in this section below: NONE rWOvrDE.-,: Minimum Control Measure 6 Within three(3)years of the EDC: Have best management practices(BMPs)been incorporated into the municipal facility program and municipal operations program?(Part VI.F.1.) No Please clarify the reason for selecting"No"or"N/A"for this item. The Town of Southold has no SPIDES regulated municipal facilities.This report only covers through Year 1.BMPs will be incorporated into the municipal operations program as required by the end of Year 3. Within three(3)years of the EDC: Has a municipal facility program been developed and implemented?(Part VI.F.2.a.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. The Town of Southold has no SPIDES regulated municipal facilities. In Year 5: Has training on the MS4 Operator's municipal facility procedures prior to conducting municipal facility procedures been provided?(Part VI.F.2.a.ii.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. The Town of Southold has no SPIDES regulated municipal facilities. In Year 4 and Year 5: Have the names,titles,and contact information for the individuals who have received municipal facility procedures training been updated?(Part VI.F.2.a.iii.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. The Town of Southold has no SPIDES regulated municipal facilities. In Year 4 and Year 5: Have the municipal facility procedures been updated?(Part VI.F.2.a.iv.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. The Town of Southold has no SPIDES regulated municipal facilities. Within two(2)years of the EDC: Has a municipal facility inventory been developed?(Part VI.F.2.b.i.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. The Town of Southold has no SPIDES regulated municipal facilities. In Year 3,Year 4,and Year 5: Has the municipal facility inventory been updated?(Part VI.F.2.b.ii.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. The Town of Southold has no SPIDES regulated municipal facilities. Within three(3)years of the EDC: Have the municipal facilities been prioritized?(Part VI.F.2.c.i.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. The Town of Southold has no SPIDES regulated municipal facilities. In Year 4 and Year 5: Has the municipal facility prioritization been updated?(Part VI.F.2.c.iii.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. The Town of Southold has no SPIDES regulated municipal facilities. 4/7/2025 10:10:15 AM Page 10 of 15 Within five(5)years of the EDC: Has a municipal facility specific SWPPP for each high priority municipal facility been developed?(Part VI.F.2.d.i.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. The Town of Southold has no SPDES regulated municipal facilities. In Year 5: Has all wet weathervisual monitoring of the monitoring locations at all high priority municipal facilities been conducted?(Part VI.F.2.d.ii.a)) N/A Please clarify the reason for selecting"No"or"N/A"for this item. The Town of Southold has no SPDES regulated municipal facilities. In Year 5: Has a comprehensive site assessment for each high priority municipal facility been completed?(Part VI.F.2.d.ii.c)) N/A Please clarify the reason for selecting"No"or"N/A"for this item. The Town of Southold has no SPDES regulated municipal facilities. In Year 5: Has a comprehensive site assessment for each low priority municipal facility been completed?(Part VI.F.2.e.ii.c)) N/A Please clarify the reason for selecting"No"or"N/A"for this item. The Town of Southold has no SPDES regulated municipal facilities. Within three(3)years of the EDC: Has a municipal operations program been developed?(Part VI.F.3.a.) No Please clarify the reason for selecting"No"or"N/A"for this item. It is not due yet In Year 5: Has training on the MS4 Operator's municipal operations procedures prior to conducting municipal operations been provided?(Part VI.F.3.a.ii.) No Please clarify the reason for selecting"No"or"N/A"for this item. It is not due yet In Year 4 and Year 5: Have the names,titles,and contact information for the individuals who have received municipal operations procedures training been updated?(Part VI.F.3.a.iii.) No Please clarify the reason for selecting"No"or"N/A"for this item. It is not due yet In Year 4 and Year 5: Have the municipal operations procedures been reviewed and updated?(Part VI.F.3.a.iv.) No Please clarify the reason for selecting"No"or"N/A"for this item. It is not due yet Within three(3)years of the EDC: Have catch basins in need of inspection been identified?(Part VI.F.3.c.i.) No Please clarify the reason for selecting"No"or"N/A"for this item. It is not due yet Within three(3)years of the EDC: Has catch basin inspection information been inventoried?(Part VI.F.3.c.ii.) No Please clarify the reason for selecting"No"or"N/A"for this item. It is not due yet 4/7/2025 10:10:15 AM Page 11 of 15 In Year 5: Have all streets,bridges,parking lots,and right of ways been swept?(Part VI.F.3.d.i.a)) Yes Annually: Have all streets in business districts and commercial areas been swept?(Part VI.F.3.d.i.b)) Yes Within five(5)years of the EDC: Have roads,bridges,parking lots,and right of way maintenance specific BMPs been implemented?(Part VI.F.3.d.ii.) No Please clarify the reason for selecting"No"or"N/A"for this item. It is not due yet Within five(5)years of the EDC: Have winter road maintenance specific BMPs been implemented?(Part VI.F.3.d.iii.) No Please clarify the reason for selecting"No"or"N/A"for this item. It is not due yet Please enter any comments related to the questions in this section below: NONE Pd?OI/DE:D Part VIII Does the MS4 Operator discharge to an impaired water listed in Appendix C of GP-0-24-001? Yes For which pollutant(s)is the waterbody impaired?Select the pollutants for all the impaired waters listed in Appendix C of GP-0-24-001 to which the MS4 Operator discharges. Pathogens Which requirements in this Part were completed as a coalition/group,if any? NONE PRC)VIPaED Pathogens Within three(3)years of the EDC: Has the comprehensive system mapping been updated,in a geographic information system(GIS),to include MS4 infrastructure and sewershed information for each MS4 outfall and ADA MS4 outfall discharging to a pathogens impaired water listed in Appendix C?(Part VIII.C.1.a.) Yes Within three(3)years of the EDC: Has the comprehensive system mapping been updated,in a geographic information system(GIS),to include the listed items for each MS4 outfall discharging to a pathogens impaired water listed in Appendix C?(Part VIIl.C.1.b.) No Please clarify the reason for selecting"No"or"N/A"for this item. It is not due yet Within three(3)years of the EDC: Has the comprehensive system mapping been updated,in a geographic information system(GIS),to include ADA MS4 outfalls discharging to a pathogens impaired water listed in Appendix C?(Part VIIl.C.1.c.) No Please clarify the reason for selecting"No"or"N/A"for this item. It is not due yet Minimum Control Measure 1 In Year 4 and Year 5: Have educational messages with information specific to pathogens been provided?(Part VIIl.C.2.b.) No 4/7/2025 10:10:15 AM Page 12 of 15 Please clarify the reason for selecting"No"or"N/A"for this item. It is not due yet Minimum Control Measure 3 Within five(5)years of the EDC: Has the number of each item listed in Part VIII.C.1.b.been included on the MS4 outfall inventory for each associated MS4 outfall?(Part VIII.C.4.) No Please clarify the reason for selecting"No"or"N/A"for this item. It is not due yet Minimum Control Measure 6 In Year 4 and Year 5: Have all streets located in sewersheds discharging to pathogens impaired segments been swept?(Part VIII.C.7.a.i.) Yes Within one(1)year of the EDC: Has the effectiveness of deterrents,population controls,and other measures that may reduce bird related pathogen contributions been evaluated?(Part VIII.C.7.b.iv.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. The Town of Southold has no identified bird related pathogen contributions within its regulated sewersheds. Within one(1)year of the EDC: Have dog waste receptacles been made available in areas where pets/domestic animals may frequent?(Part VIII.C.7.c.) N/A Please clarify the reason for selecting"No"or"N/A"for this item. The Town of Southold has no identified areas within its regulated sewersheds where pets/domestic animals mayfrequent. Please enter any comments related to the questions in this section below: &V(DrVk f'Fr'C'7WD D Part I Does the MS4 Operator discharge to a TMDL listed in Table 3 of P-0-24-001? Yes To which TMDL does the MS4 Operator discharge? Peconic Estuary Nitrogen Watershed Which requirements in this Part were completed as a coalition/group,if any? NONE PROVIDED Peconic Estuary Nitrogen Watershed Within three(3)years of the EDC: Has the comprehensive system mapping been updated,in a geographic information system( IS),to include the areas with potential to contribute nitrogen to the TMDL waterbody?(Part IX.D.1.a.) No Please clarify the reason for selecting"No"or"N/A"for this item. It is not due yet Within three(3)years of the EDC: Has the comprehensive system mapping been updated,in a geographic information system( IS),to include the additional information for post-construction SMPs?(Part IX.D.1.b.) No 4/7/2025 10:10:15 AM Page 13 of 15 Please clarify the reason for selecting"No"or"N/A"for this item. It is not due yet Minimum Control Measure 1 Twice a year,in Year 4 and Year 5: Have educational messages with information specific to nitrogen been made available?(Part IX.D.2.b.) No Please clarify the reason for selecting"No"or"N/A"for this item. It is not due yet Minimum Control Measure 3 Within five(5)years of the EDC: Has the number of each item listed in Part IX.D.1.a.been included on the MS4 outfall inventory for each associated MS4 outfall?(Part IX.D.4.) No Please clarify the reason for selecting"No"or"N/A"for this item. It is not due yet Minimum Control Measure 4 How many high priority construction sites discharge to the TMDL? 0 Minimum Control Measure 6 In Year 4 and Year 5: Have all streets located in the TMDL watershed been swept?(Part IX.D.7.a.) Yes Please enter any comments related to the questions in this section below: Interim Progress Status Interim Progress Resources Use the following webpages for more information on the permit and fact sheet: MS4 Permit Wgboaae MS4 Toolbox Have you reviewed compliance items due within two years of EDC? Yes Have you reviewed compliance items due within three years of EDC? Yes Have you reviewed compliance items due within four years of EDC? Yes Have you reviewed compliance items due within five years of EDC? Yes Have you reviewed compliance items which need to be completed routinely(annually,every five(5)years,etc.)? Yes Please enter any comments related to the questions in this section. NONE f'1=C('ODD 4/7/2025 10:10:15 AM Page 14 of 15 Certification The ranking elected official or Principal Executive Officer for the MS4 Operator will be signing the form. Yes As the Ranking Elected Official or Principal Executive Officer,please download the certification form using the link below.Complete and sign the certification.Then,upload the certification form to this Interim Progress Certification and/or Annual Report. Certification Form Attach completed certification form. MS4 Operator Certification-2025-02-26.pdf-02/26/2025 09:13 AM Comment N01VF PROVII)FI.) Attachments Date Attachment Name Context User 2/26/2025 9:13 AM MS4 Operator Certification-2025-02-26.pdf Attachment Michael Collins Status History User Processing Status 1/3/2025 9:19:45 AM Michael Collins Draft 2/26/2025 9:34:52 AM Michael Collins Submitting 2/26/2025 9:34:58 AM Michael Collins Submitted 4/3/2025 3:57:44 PM I Christina Chiappetta , Deemed Complete Processing Steps Step Name Assigned To/Completed By Date Completed Form Submitted Michael Collins 2/26/2025 9:34:58 AM Review Christina Chiappetta 4/3/2025 3:57:40 PM 4/7/2025 10:10:15 AM Page 15 of 15 NEW YORK STATE DEPARTMENT OF ENVIRONMENTAL CONSERVATION Division of Water,Bureau of Water Permits 625 Broadway,Albany,New York 12233-3505 P:(518)402-8111 1 F:(518)402-9029 www.dec.ny.gov S4 Operator Certification Form for eReports SPDES General Permit for Stormwater Discharges From Municipal Separate Storm Sewer Systems (GP-0-24-001) Instructions As required by Part V.B.2. and Part V.13.3. of GP-0-24-001, the MS4 Operator must submit the Annual Report and the Interim Progress Certification, respectively. As stated in Part V.B.5. of GP-0-24-001, all reports must be signed in accordance with Part X.J. of GP-0-24-001. MS4 Operator Name: Town of Southold Permit ID: NYR20A 524 eReport Submission Number: HQ9-CO6N-FMF76 MS4 Operator Certification I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted, Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations. Name (please print or type) Title Albert J. Krupski, Jr. Town Supervisor Signature Date + to lDepart n c Departrnent of rnrr o rc vir"'01=raawra�"njWi r Conservation Table of Contents Table of Contents 1 MS4 Interim Progress Certification*18 Month Requirements 2 (Submission#: HQD-XCQE-NJW1Z,version 1) 2 Details 2 Form Input 2 MS4 Operator Information 2 Compliance Schedule Review 3 Certification 3 Attachments 3 Status History 3 Processing Steps 3 7/7/2025 2:32:32 PM Page 1 of 4 MS4 Interim Progress Certifi cati onQ18 Month Requirements version 1.0 (Submission#: HQD-XCQE-NJW14 version 1) Details Submitted 7/7/2025(0 days ago)by Michael Collins Alternate Identifier NYR20A524 Submission ID HQD-XCQE-NJW1Z Status Deemed Complete Form Input MS4 Operator Information Municipality Name or Legal Entity Name Town of Southold Permit ID#: NYR20A524 MS4 Operator Type Traditional land use control Traditional Land Use Control Town Traditional Land Use Control Traditional land use control MS4 Operator requirements are found in Part VI of the MS4 General Permit. Legal Municipal/Entity Mailing address 53095 Main Road Southold, New York 11971 Suffolk Ranking Official Official Title First and Last Name Phone Email Town Supervisor Albert J. Krupski,Jr. 6317651889 al.krupski@town.southold.ny.us Report Preparer Report Preparer Title First and Last Name Phone Email Stormwater Program Coordinator Michael Collins, P.E. 6317651560 michael.collins@town.southold.ny.us Stormwater Program Coordinator Coordinator Title First and Last Name Phone Email Stormwater Program Coordinator Michael Collins, P.E. 6317651560 michael.collins@town.southold.ny.us 7/7/2025 2:32:32 PM Page 2 of 4 Compliance Schedule Review Compliance Schedule Resources Use the following links for more information on the permit and compliance schedule: MS4 Permit Webpacie MS4 Toolbox Have you reviewed compliance items due within two years of EDC,January 2,2026? Yes Have you reviewed compliance items due within three years of EDC,January 2,2027? Yes Have you reviewed compliance items due within four years of EDC,January 2,2028? Yes Have you reviewed compliance items due within five years of EDC,January 2,2029? Yes Have you reviewed compliance items which need to be completed routinely(annually,every five(5)years,etc.)? Yes Please enter any comments related to the questions in this section. NONE PROVIDE-D Certification The ranking elected official or Principal Executive Officer for the MS4 Operator will be signing the form. Yes As the Ranking Elected Official or Principal Executive Officer,please download the certification form using the link below.Complete and sign the certification.Then,upload the certification form to this Interim Progress Certification and/or Annual Report. Certification Form Attach completed certification form. Southold 18 Month Interim Progress Report Certification Form.pdf-07/07/2025 02:30 PM Comment NONE PROVIDED Attachments Date Attachment Name Context User 7/7/2025 2:30 PM Southold 18 Month Interim Progress Report Certification Form.pdf Attachment Michael Collins Status History User Processing Status 7/7/2025 10:52:18 AM Michael Collins Draft 7/7/2025 2:30:58 PM Michael Collins Submitting 7/7/2025 2:31:01 PM Michael Collins Submitted 7/7/2025 2:31:02 PM Michael Collins Deemed Complete Processing Steps 7/7/2025 2:32:32 PM Page 3 of 4 Step Name Assigned To/Completed By Date Completed Form Submitted Michael Collins 7/7/2025 2:31:01 PM Accepted Michael Collins 7/7/2025 2:31:01 PM 7/7/2025 2:32:32 PM Page 4 of 4 NEW YORK STATE DEPARTMENT OF ENVIRONMENTAL CONSERVATION Division of Water,Bureau of Water Permits 625 Broadway,Albany,New York 12233-3505 P:(518)402-8111 1 F:(518)402-9029 www.dec.ny.gov S4 Operator Certification Form for eReports SPDES General Permit for Stormwater Discharges From Municipal Separate Storm Sewer Systems (GP-0-24-001) Instructions As required by Part V.13.2. and Part V.13.3. of GP-0-24-001, the MS4 Operator must submit the Annual Report and the Interim Progress Certification, respectively. As stated in Part V.13.5. of GP-0-24-001, all reports must be signed in accordance with Part X.J. of GP-0-24-001. MS4 Operator Name: Town of Southold Permit ID: NYR20A 524 eReport Submission Number: HQD-XCQE-NJW1 Z MS4 Operator Certification I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations. Name (please print or type) Title Albert J. Krupski, Jr. Town Supervisor Signature Date J - r w rORK DeV rtrnent c� a as�u-wsrw n rironMentai Conservation APPENDIX F 2839361 d lynda.rudder@town.southold.ny.us AFFIDAVIT OF PUBLICATION The Suffolk Times State of New York, County of,Suffolk County, The undersigned is the authorized designee of The Suffolk Times,a Weekly Newspaper published in Suffolk County, New York.I certify that the public notice,a printed copy of which is attached hereto,was printed and published in this newspaper on the following dates: 02/13/2025 This newspaper has been designated by the County Clerk of Suffolk County,as a newspaper of record in this county, and as such,is eligible to publish such notices. � t Signature Christina Henke Rea ...... _.._...... � Printed Name Subscribed and sworn to before me, This 18 day of February 2025 Digitally signed 7Public SWREA by douglas w rea Notate of New York Date: 2025.02.18 NO,OiRE6398443 19:32:41 +00:00 Qualified in Albany County My Commission Expires Sep 30,2027 LEGAL NOTICE NOTICE OF PUBLIC EAR N NOTICE IS HEREBY GIVEN that the Town of Southold will hold a public informational meeting at the Southold Town Hall , 53095 Main Rotd, Southold, New York, on the 14 day of February 2025 at 5:00 p.m . to inform the public on the Draft 2025 M,S4 Annual Report/Interim Progress Certification and the Town 's Stormwater Management program Plan. A complete copy of both documents can be found at: https://www.southoldtownny.gov/5 67/Stormwater-Management- rog ram Dated : February 7, 2025 BY ORDER OF THE TOWN BOARD OF THE TOWN OF SOUTHOLD Denis Noncarrow Southold Town Clerk APPENDIX G MONITORING RECEIVING WATERBODY TYPE OF SUBMERGED SUBMERGED OUTFALL ID PRIORITY LOCATION TYPE RECEIVING WATERBODY NAME RECEIVING WATERBODY CLASS WI/PWL SEGMENT ID LAND USE IN DRAINAGE AREA CONVEYANCE MATERIAL SHAPE DIMENSIONS IN WATER IN SEDIMENT Outfa11071 High M540utfa11 Cutchogue Harbor&tidal tribs SA 1701-0045 Ultra-Urban Residential Closed Pipe Corrugated Metal Circular 181Tdiameter No No Outtall072 High M540uttall Cutchogue Harbor&tidal tribs SA 1701-0045 Ultra-Urban Residential,Agriculture Closed Pipe Corrugated Metal Circular 10"diameter No No Outtall 073 High M540uttall Cutchogue Harbor&tidal tribs SA 1701-0045 Ultra-Urban Residential Closed Pipe HDPE Circular 12"diameter No Partially Outtall075 High M540uttall Cutchogue Harbor&tidal trios SA 1701-0045 Ultra-Urban Residential Closed Pipe Corrugated Metal Circular 12"diameter Partially No Outfa11077 High M540utfa11 Little Peconic Bay 5A 1701-0172 Ultra-Urban Residential Closed Pipe HDPE Circular 121Tdiameter Partially No Outfa11082 High M540utfa11 Cutchogue Harbor&tidal tribs SA 1701-0045 Ultra-Urban Residential,Commercial Closed Pipe HDPE Circular 81Tdiameter Partially No Outtall083 High M540uttall Cutchogue Harbor&tidal tribs SA 1701-0045 Ultra-Urban Residential,Commercial Closed Pipe HDPE Circular 12"diameter Partially No Outtall084 High M540uttall Cutchogue Harbor&tidal trios SA 1701-0045 Ultra-Urban Residential,Commercial Closed Pipe HDPE Circular 18"diameter Partially No Outfa11085 High M540utfa11 West Creek and tidal tribs SA 1701-0246 Ultra-Urban Residential Closed Pipe HDPE Circular 121Tdiameter Partially Partially Outfa11086 High M540utfa11 West Creek and tidal tribs SA 1701-0246 Ultra-Urban Residential Closed Pipe HDPE Circular 121Tdiameter Partially Partially Outtall 087 High M540uttall West Creek and tidal tribs SA 1701-0246 Ultra-Urban Residential Closed Pipe HDPE Circular 8"diameter Partially Partially Outta11090 High M540utta11 Cutchogue Harbor&tidal trips SA 1707-0045 Ultra-Urban Residential,Commercial Closed Pipe Corrugated Metal Circular 12"diameter Partially No Outta11091 High M540utta11 Cutchogue Harbor&tidal trios SA 7707-0045 Ultra-Urban Residential,Commercial Closed Pipe HDPE Circular 12"diameter Partially No Outfa11095 High M54 Outfaii Tribs(fresh)to Gr Pewnk Bay,Northsh C 1701-0249 Ultra-Urban Residential,Agrkukure Closed Pipe Concrete Circular 15"diameter Partially No Outtall 104 High M540uttall Tidal Tribs to Gr Peconic Bay,Northshr SA 1701-0247 Ultra-Urban Residential,Agriculture Closed Pipe HDPE Circular 10"diameter Partially No Outtall 110 High M540uttall Mattituck lNet/Creek and tidal trios SA 1702-0020 Ultra-Urban Residential Closed Pipe Concrete Circular 18"diameter Partially No Outla11117 High M540utta11 Tribs to Mattituck Creek C 7702-0245 Ultra-Urban Res idential Closed Pipe Corrugated Metal Circular 18"diameter Partially No Ou If.ii 126 High M54 Outfaii Tribs(fresh)to Gr Pewnk Bay,Northsh C 1701-0249 Ultra-Urban Residential Closed Pipe HDPE Circular 12"diameter Partially No Outtall 150 High M540uttall Cutchogue Harbor&tidal tribs SA 1701-0045 Ultra-Urban Residential,Commercial Closed Pipe Corrugated Metal Circular 12"diameter Partially Partially Outtall 162 High M540uttall Cutchogue Harbor&tidal tribs SA 1701-0045 Ultra-Urban Residential,Agriculture Closed Pipe HDPE Circular 8"diameter No No Monitoring Locations Inspection and Sampling Field Sheet Section 1: Background Data Subwatershed:Wickham Creek Monitoring Location ID:outfall 082 Today's date:9/16/24 Time(Military):13:39 Investigators:M. Collins Form completed by:M. Collins Temperature ff):73' Rainfall(in.): Last 24 hours: 0" Last 48 hours:0" Latitude: Longitude: GPS Unit: GPS LMK#: Camera:Olympus Stylus TG-4 Photo#s:Outfall 082-1 Land Use in Drainage Area(Check all that apply): ❑ Industrial ❑ Open Space Fol Ultra-Urban Residential ❑ Institutional ❑ Suburban Residential Other: n Commercial Known Industries: Notes(e.g.,origin,if known):Catch Basins on West Creek Avenue Section 2: Monitoring Location Description LOCATION MATERIAL SHAPE DIMENSIONS(IN.) SUBMERGED ❑ RCP ❑ CMP X Circular EN] Single Diameter/Dimensions: In Water: X No ❑ PVC © HDPE ❑ Elliptical ❑ Double 8"diameter ❑ Partially ❑ Fully [J Closed Pipe ❑ Steel ❑ Box ❑Triple With Sediment: ❑i No ❑Other: ❑ Other: ❑Other: ❑ Partially ❑ Fully ❑Concrete ❑Trapezoid Depth: X/1 Earthen ❑ Parabolic To Width:Open drainage [I Rip-Rap ❑ Botttom Width:Other: // _ ❑Other: ❑ In-Stream (applicable when collecting samples) Flow Present? ❑Yes No If No,Skip to Section 5 Flow Description ❑(If present) Trickle ❑ Moderate ❑ Substantial Section 3: Quantitative Characterization FIELD DATA FOR FLOWING MONITORING LOCATIONS PARAMETER RESULT UNIT EQUIPMENT Volume Liter Bottle ❑ Flow#1 Time to fill Sec Flow depth I n Tape measure Flow width Ft,In Tape measure ❑ Flow#2 Measured length Ft,In Tape measure Time of travel S Stopwatch Temperature °F Thermometer pH pH Units Test strip/Probe Ammonia mg/L Test strip 148 Monitoring Locations Inspection and Sampling Field Sheet Section 4: Physical Indicators for Flowing Monitoring Locations Only Are Any Physical Indicators Present in the flow? ❑ Yes ❑ No (If No, Skip to Section 5) INDICATOR CHECK if DESCRIPTION RELATIVE SEVERITY INDEX(1-3) Present ❑ Sewage ❑ Rancid/sour ❑ Petroleum/gas 3—Noticeable from a Odor ❑ ❑ 1-Faint ❑ 2—Easily detected F-] ❑ Sulfide ❑ Other: distance ❑ Clear ❑ Brown ❑ Gray ❑ Yellow 1—Faint colors in 2—Clearly visible in Color ❑ le bottle El le bottle ❑ 3—Clearly visible in flow ❑ sample sample Green ❑ Orange Red ❑ Other: P P Turbidity ❑ See severity ❑ 1—Slight cloudiness ❑ 2-Cloudy ❑ 3—Opaque Floatables ❑ Sewage(Toilet Paper,etc.)❑Suds 1—Few/slight;origin 2-Some;indications of 3-Some;origin clear(e.g., -Does Not Include E; El not obvious ❑ origin(e.g., possible ❑ obvious oil sheen,suds,or Trash!! ❑ Petroleum(oil sheen) El Other: suds or oil sheen) floating sanitary materials) Section 5: Physical Indicators for Both Flowing and Non-Flowing Monitoring Locations Are physical indicators that are not related to flow present? ❑ Yes FW No (If No, Skip to Section 6) INDICATOR CHECK if Present DESCRIPTION COMMENTS Monitoring Location ❑ Spalling,Cracking or Chipping ❑ Peeling Paint Damage D ❑ Corrosion Deposits/Stains ❑ ❑ Oily ❑ Flow Line ❑ Paint ❑ Other: Abnormal Vegetation ❑ ❑ Excessive ❑ Inhibited ❑ Odors ❑ Colors ❑ Floatables ❑ Oil Sheen Poor pool quality ❑ ❑ Suds ❑ Excessive Algae ❑ Other: Pipe benthic growth ❑ ❑ Brown ❑ Orange ❑ Green ❑ Other: Section 6: Overall Monitoring Location Characterization as Unlikely ❑ Potential (presence of two or more indicators) ❑ Suspect(one or more indicators with a severity of 3) ❑ Obvious Section 7: Data Collection 1. Sample for the lab? ❑ Yes ] No 2. If yes,collected from: ❑ Flow ❑ Pool 3. Intermittent flow trap set? ❑ Yes C No If Yes,type: ❑ OBM ❑ Caulk dam Section 8:Any Non-Illicit Discharge Concerns (e.g.,trash or needed infrastructure repairs)? None 149 ' I a .,'46 to 11 F. :a f y — st + k" 1] c r E� 2024 0 :/ 7 Monitoring Locations Inspection and Sampling Field Sheet Section 1: Background Data Subwatershed:Wickham Creek Monitoring Location ID:outfall 083 Today's date:9/16/24 Time(Military):13:30 Investigators:M. Collins Form completed by:M.Collins Temperature ff):73° Rainfall(in.): Last 24 hours: 0" Last 48 hours:0" Latitude: Longitude: GPS Unit: GPS LMK#: Camera:Olympus Stylus TG-4 Photo#s:Outfall 083-1 Land Use in Drainage Area(Check all that apply): ❑ Industrial ❑ Open Space Ultra-Urban Residential ❑ Institutional ❑ Suburban Residential Other: Commercial Known Industries: Notes(e.g.,origin,if known):West Creek Avenue Section 2: Monitoring Location Description LOCATION MATERIAL SHAPE DIMENSIONS(IN.) SUBMERGED ❑ RCP ❑ CMP I] Circular M Single Diameter/Dimensions: In Water: ❑i No ❑ PVC © HDPE ❑ Elliptical ❑ Double 12"diameter ❑ Partially ❑ Fully ❑� Closed Pipe ❑Steel ❑ Box ❑Triple With Sediment: ❑ No ❑Other: ❑ Other: ❑ Other: ❑i Partially ❑ Fully ❑Concrete ❑Trapezoid Depth: ❑ Earthen ❑ Parabolic Top Width: ❑ Open drainage ❑ f ❑ Rip-Rap Other: Bottom Width: ❑Other: ❑ In-Stream (applicable when collecting samples) Flow Present? ❑Yes C No If No,Skip to Section 5 Flow Description (If present) ❑Trickle ❑ Moderate ❑ Substantial Section 3: Quantitative Characterization FIELD DATA FOR FLOWING MONITORING LOCATIONS PARAMETER! RESULT UNIT EQUIPMENT Volume Liter Bottle ❑ Flow#1 Time to fill Sec Flow depth In Tape measure Flow width Ft,In Tape measure ❑ Flow#2 , Measured length Ft,In Tape measure Time of travel S Stopwatch Temperature °F Thermometer pH pH Units Test strip/Probe Ammonia mg/L Test strip 148 Monitoring Locations Inspection and Sampling Field Sheet Section 4: Physical Indicators for Flowing Monitoring Locations Only Are Any Physical Indicators Present in the flow? ❑ Yes ❑ No (If No, Skip to Section 5) INDICATOR CHECK if DESCRIPTION RELATIVE SEVERITY INDEX(1-3) Present ❑ Sewage ❑ Rancid/sour ❑ Petroleum/gas 3—Noticeable from a Odor ❑ ❑ 1-Faint ❑ 2—Easily detected ❑ ❑ Sulfide ❑ Other: distance Color ❑ Clear ❑ Brown ❑ Gray ❑ Yellow 1—Faint colors in 2—Clearly visible in ❑ ❑ sample bottle sample bottle ❑ 3—Clearly visible inflow ❑ Green ❑ Orange ❑ Red ❑ Other: P P Turbidity ❑ See severity ❑ 1—Slight cloudiness ❑ 2-Cloudy ❑ 3—Opaque Floatables ❑ Sewage(Toilet Paper,etc.)❑Suds 1—Few/slight;origin 2-Some;indications of 3-Some;origin clear(e.g., -Does Not Include ❑ El not obvious ❑ origin(e.g., possible ❑ obvious oil sheen,suds,of Trash!! ❑ Petroleum(oil sheen) ❑Other: suds or oil sheen) floating sanitary materials) Section 5: Physical Indicators for Both Flowing and Non-Flowing Monitoring Locations Are physical indicators that are not related to flow present? ❑ Yes 0 No (If No, Skip to Section 6) INDICATOR CHECK if Present DESCRIPTION COMMENTS Monitoring Location El Corrosion Spalling,Cracking or Chipping ❑ Peeling Paint Damage ❑ Corrosion Deposits/Stains ❑ ❑ Oily ❑ Flow Line ❑ Paint ❑ Other: Abnormal Vegetation ❑ ❑ Excessive ❑ Inhibited ❑ Odors ❑ Colors ❑ Floatables ❑ Oil Sheen Poor pool quality ❑ ❑ Suds ❑ Excessive Algae ❑ Other: Pipe benthic growth ❑ ❑ Brown ❑ Orange ❑ Green ❑ Other: Section 6: Overall Monitoring Location Characterization 10 Unlikely ❑ Potential (presence of two or more indicators) ❑ Suspect(one or more indicators with a severity of 3) ❑ Obvious Section 7: Data Collection 1. Sample for the lab? ❑ Yes N No 2. If yes,collected from: ❑ Flow ❑ Pool 3. Intermittent flow trap set? ❑ Yes a❑ No If Yes,type: ❑ OBM ❑ Caulk dam Section 8:Any Non-Illicit Discharge Concerns (e.g.,trash or needed infrastructure repairs)? None 149 h. 1 l 1 . a r L Monitoring Locations Inspection and Sampling Field Sheet Section 1: Background Data Subwatershed:Wickham Creek Monitoring Location ID:Outfall 084 Today's date:9/16/24 Time(Military):13:28 Investigators:M. Collins Form completed by:M. Collins Temperature ff):73° Rainfall(in.): Last 24 hours: 0" Last 48 hours:0" Latitude: Longitude: GPS Unit: GPS LMK#: Camera:Olympus Stylus TG-4 Photo#s:0utfall 084-1 Land Use in Drainage Area(Check all that apply) ❑ Industrial ❑ Open Space Q Ultra-Urban Residential ❑ Institutional ❑ Suburban Residential Other: Commercial Known Industries: Notes(e.g.,origin,if known):Catch Basin On West Road Section 2: Monitoring Location Description LOCATION MATERIAL SHAPE DIMENSIONS(IN.) SUBMERGED ❑ RCP ❑ CMP Circular a Single Diameter/Dimensions: In Water: Q No ❑ PVC 0 HDPE ❑ Elliptical ❑ Double 18"diameter ❑ Partially ❑ Fully G Closed Pipe ❑Steel ❑ Box ❑Triple With Sediment: No ❑Other: ❑ Other: ❑ Other: ❑ Partially ❑ Fully El Concrete ❑Trapezoid Depth:„ JJ�J J ❑ Earthen ❑ Parabolic Top Width:_ jf f�/� ❑ Open drainage ❑ Rip-Rap ❑ Other: Bottom Width: f' ❑ Other: ;•JfirifJf%i ❑ In-Stream (applicable when collecting samples) Flow Present? ❑Yes no No If No,Skip to Section 5 Flow Description (If present) ❑Trickle ❑ Moderate ❑ Substantial Section 3: Quantitative Characterization FIELD DATA FOR FLOWING MONITORING LOCATIONS PARAMETER RESULT UNIT EQUIPMENT Volume Liter Bottle ❑ Flow#1 Time to fill Sec Flow depth In Tape measure Flowwidth 1 Ft,In Tape measure ❑ Flow#2 Measured length Ft,In Tape measure Time of travel S Stopwatch Temperature °F Thermometer pH pH Units Test strip/Probe Ammonia mg/L Test strip 148 Monitoring Locations Inspection and Sampling Field Sheet Section 4: Physical Indicators for Flowing Monitoring Locations Only Are Any Physical Indicators Present in the flow? ❑ Yes ❑ No (If No, Skip to Section 5) INDICATOR CHECK If Present DESCRIPTION RELATIVE SEVERITY INDEX(1-3) ❑ Sewage ❑ Rancid/sour ❑ Petroleum/gas 3—Noticeable from a Odor ❑ ❑ 1-Faint ❑ 2—Easily detected ❑ ❑ Sulfide ❑ Other: distance ❑ Clear ❑ Brown ❑ Gray ❑ Yellow 1—Faint colors in 2—Clearly visible in Color ❑ El ❑ sample ❑ 3—Clearly visible inflow ❑ Green ❑ Orange ❑ Red ❑ Other: sample P bottle bottle Turbidity ❑ See severity ❑ 1—Slight cloudiness ❑ 2-Cloudy ❑ 3—Opaque Floatables ❑ Sewage(Toilet Paper,etc.)❑Suds 1—Few/slight;origin 2-Some;indications of 3-Some;origin clear(e.g., -Does Not Include ❑ not obvious ❑ origin(e.g., possible ❑ obvious oil sheen,suds,or Trash!! ❑ Petroleum(oil sheen) ❑Other: suds or oil sheen) floating sanitary materials) Section 5: Physical Indicators for Both Flowing and Non-Flowing Monitoring Locations Are physical indicators that are not related to flow present? ❑ Yes X No (If No, Skip to Section 6) INDICATOR CHECK if Present DESCRIPTION COMMENTS Monitoring Location ❑ Spalling,Cracking or Chipping ❑ Peeling Paint Damage ❑ Corrosion Deposits/Stains ❑ ❑ Oily ❑ Flow Line ❑ Paint ❑ Other: Abnormal Vegetation ❑ ❑ Excessive ❑ Inhibited ❑ Odors ❑ Colors ❑ Floatables ❑ Oil Sheen Poor pool quality ❑ ❑ Suds ❑ Excessive Algae ❑ Other: Pipe benthic growth I❑ Brown ❑ Orange ❑ Green ❑ Other: Section 6: Overall Monitoring Location Characterization ® Unlikely ❑ Potential (presence of two or more indicators) ❑ Suspect(one or more indicators with a severity of 3) ❑ Obvious Section 7: Data Collection 1. Sample for the lab? ❑ Yes 0 No 2. If yes,collected from: ❑ Flow ❑ Pool 3. Intermittent flow trap set? ❑ Yes ❑i No If Yes,type: ❑ OBM ❑ Caulk dam Section 8:Any Non-Illicit Discharge Concerns (e.g.,trash or needed infrastructure repairs)? None 149 1^ , . _ 1'.I �- � .' : ;tiJ`•' ■ � i"�. `� If.. I I III. _ �_• I � - II I I_ I �I � � •• r , I , ,�' }II ■ ' ■ I - /I Al -. II;I'I I,; •_11 lyyy, I I I I � , -� .• - , r I . ■ III I' I � I' 1 ` i I 1_F - - i4 I - -' , ' ' it ■ .i'� - - I I'I "� .�I . I I: ,E- M i ■ II ,;� `II Ir III I �� � ""I I - J�, .� ■ I I r �I ' - i, ' ' I _III i. rl ,.,r., I III ■ �' I I � ` f` •1 I ` Hill IlY'I ■ I I .Y f } JJ Monitoring Locations Inspection and Sampling Field Sheet Section 1: Background Data Subwatershed:Halls Creek Monitoring Location ID:outfall 095 Today's date:9/13/24 Time(Military):15:30 Investigators:M. Collins Form completed by:M. Collins Temperature ff):77° Rainfall(in.): Last 24 hours: 0" Last 48 hours:0" Latitude: Longitude: GPS Unit: GPS LMK#: Camera:Olympus Stylus TG-4 Photo#s:Outfall 095-1 Land Use in Drainage Area(Check all that apply): ❑ Industrial 0 Open Space 0 Ultra-Urban Residential ❑ Institutional ❑ Suburban Residential Other: Agricultural ❑ Commercial Known Industries:_ Notes(e.g.,origin,if known):Catch Basins on New Suffolk Avenue Section 2: Monitoring Location Description LOCATION MATERIAL SHAPE DIMENSIONS(IN.) SUBMERGED M RCP ❑ CMP 0 Circular 0 Single Diameter/Dimensions: In Water: ❑s No ❑ PVC ❑ HDPE ❑ Elliptical ❑ Double 15"diameter ❑ Partially ❑ Fully ■❑ Closed Pipe ❑Steel El Box ❑Triple With Sediment: Q No ❑Other: ❑ Other: ❑ Other: ❑ Partially ❑ Fully ❑Concrete ❑Trapezoid Depth: ❑ Earthen ❑ Parabolic Top Width:_ ' ' ❑ Open drainage ❑ Rip-Rap ❑Other: Bottom Width: ❑ Other: ❑ In-Stream (applicable when collecting samples) Flow Present? ❑Yes Q No If No,Skip to Section 5 Flow Description ❑Trickle ❑ Moderate ❑ Substantial (If present) Section 3: Quantitative Characterization FIELD DATA FOR FLOWING MONITORING LOCATIONS PARAMETER v RESULT UNIT EQUIPMENT Volume Liter Bottle ❑ Flow#1 Time to fill Sec Flow depth In Tape measure Flowwidth Ft,In Tape measure ❑ Flow#2 Measured length Ft, In Tape measure Time of travel S Stopwatch Temperature °F Thermometer pH pH Units Test strip/Probe Ammonia mg/L Test strip 148 Monitoring Locations Inspection and Sampling Field Sheet Section 4: Physical Indicators for Flowing Monitoring Locations Only Are Any Physical Indicators Present in the flow? ❑ Yes ❑ No (If No, Skip to Section 5) INDICATOR CHECK if ` DESCRIPTION RELATIVE SEVERITY INDEX(1-3) Present ❑ Sewage ❑ Rancid/sour ❑ Petroleum/gas 3—Noticeable from a Odor [j ❑ 1 -Faint ❑ 2—Easily detected El distance ❑ Sulfide ❑ Other: ❑ Clear ❑ Brown ❑ Gray ❑ Yellow 1—Faint colors in 2—Clearly visible in Color ❑ El ❑ ❑ 3—Clearly visible in flow ❑ Green ❑ Orange ❑ Red ❑ Other: sample bottle sample bottle Turbidity ❑ See severity I ❑ 1—Slight cloudiness ❑ 2-Cloudy ❑ 3—Opaque Floatables ❑ Sewage(Toilet Paper,etc.)❑Suds 1—Few/slight;origin 2-Some;indications of 3-Some;origin clear(e.g., -Does Not Include ❑ ❑ not obvious ❑ origin(e.g., possible ❑ obvious oil sheen,suds, or Trash!! ❑ Petroleum(oil sheen) ❑Other: suds or oil sheen) floating sanitary materials) Section 5: Physical Indicators for Both Flowing and Non-Flowing Monitoring Locations Are physical indicators that are not related to flow present? ❑ Yes A No (If No, Skip to Section 6) INDICATOR CHECK if Present DESCRIPTION COMMENTS Monitoring Location ❑ Spalling,Cracking or Chipping ❑ Peeling Paint Damage ❑ ❑ Corrosion Deposits/Stains ❑ ❑ Oily ❑ Flow Line ❑ Paint ❑ Other: Abnormal Vegetation ❑ ❑ Excessive ❑ Inhibited ❑ Odors ❑ Colors ❑ Floatables ❑ Oil Sheen Poor pool quality ❑ ❑ Suds ❑ Excessive Algae El Other: Pipe benthic growth ❑ ❑ Brown ❑ Orange ❑ Green ❑ Other: Section 6: Overall Monitoring Location Characterization © Unlikely ❑ Potential (presence of two or more indicators) ❑ Suspect(one or more indicators with a severity of 3) ❑ Obvious Section 7: Data Collection 1. Sample for the lab? ❑ Yes ❑1 No 2. If yes,collected from: ❑ Flow ❑ Pool 3. Intermittent flow trap set? ❑ Yes ❑i No If Yes,type: ❑ OBM ❑ Caulk dam Section 8:Any Non-Illicit Discharge Concerns (e.g.,trash or needed infrastructure repairs)? None 149 �-__ �, �� ' .��� ram. � ;`, ', � cY�,� _\, �• ", >(/�r�'�� `` "!�' >.''�°ii No ",00 64 441t., . r • + d � � i-�•" Jf i r . i ris �::-' [` ;'r.. - _ �:. •. _ ' , - .t, Y � Monitoring Locations Inspection and Sampling Field Sheet Section 1: Background Data Subwatershed:Deep Hole Creek Monitoring Location ID:outfall 104 Today's date:9/13/24 Time(Military):15:23 Investigators:M. Collins Form completed by:M. Collins Temperature ff):77° Rainfall(in.): Last 24 hours: 0" Last 48 hours:0" Latitude: Longitude: GPS Unit: GPS LMK#: Camera:Olympus Stylus TG-4 Photo#s:Outfall 104-1 Land Use in Drainage Area(Check all that apply) ❑ Industrial ❑ Open Space Ultra-Urban Residential ❑ Institutional ❑ Suburban Residential Other: Agriculture ❑ Commercial Known Industries: Notes(e.g.,origin,if known):Catch Basins on Marratooka Lane and New Suffolk Avenue Section 2: Monitoring Location Description LOCATION MATERIAL SHAPE DIMENSIONS(IN.) SUBMERGED ❑ RCP ❑ CMP D Circular Ep] Single Diameter/Dimensions. In Water: [I No ❑ PVC Eul HDPE ❑ Elliptical ❑ Double 10"diameter ❑i Partially ❑ Fully 0 Closed Pipe C]Steel ❑ Box ❑Triple With Sediment: ❑rt No Other: ❑Other: ❑ Other: ❑ Partially ❑ Fully ❑ Concrete ❑Trapezoid Depth: ❑ Earthen ❑Parabolic Top Width:_ % f ❑ Open drainage ❑ Rip-Rap Other: Bottom Width: ❑ 1fY ❑ Other: ❑ In-Stream (applicable when collecting samples) Flow Present? ❑Yes 1103 No If No,Skip to Section 5 Flow Description (If present) ❑Trickle ❑ Moderate ❑ Substantial Section 3: Quantitative Characterization FIELD DATA FOR FLOWING MONITORING LOCATIONS PARAMETER RESULT UNIT EQUIPMENT Volume Liter Bottle ❑ Flow#1 Time to fill Sec Flow depth In Tape measure Flow width Ft,In Tape measure ❑ Flow#2 „ Measured length Ft,In Tape measure Time of travel S Stopwatch Temperature °F Thermometer pH pH Units Test strip/Probe Ammonia mg/L Test strip 148 Monitoring Locations Inspection and Sampling Field Sheet Section 4: Physical Indicators for Flowing Monitoring Locations Only Are Any Physical Indicators Present in the flow? ❑ Yes ❑ No (If No, Skip to Section 5) INDICATOR CHECK if DESCRIPTION RELATIVE SEVERITY INDEX(1-3) Present ❑ Sewage ❑ Rancid/sour ❑ Petroleum/gas 3—Noticeable from a Odor ;] ❑ 1-Faint ❑ 2—Easily detected ❑ ❑ Sulfide ❑ Other: distance El Clear ❑ Brown ❑ Gray ❑ Yellow 1—Faint colors in 2—Clearly visible in Color ❑ El I I le bottle ❑ 3—Clearly visible in flow ❑ Green ❑ Orange ❑ Red ❑ Other: sample P bottle sample Turbidity ❑ See severity ❑ 1—Slight cloudiness ❑ 2-Cloudy ❑ 3—Opaque Floatables ❑ Sewage(Toilet Paper,etc.)❑Suds 1—Few/slight;origin 2-Some;indications of 3-Some;origin clear(e.g., -Does Not Include L C not obvious ❑ origin(e.g., possible ❑ obvious oil sheen,suds,or Trash!! ❑ Petroleum(oil sheen) ❑Other: suds or oil sheen) floating sanitary materials) Section 5: Physical Indicators for Both Flowing and Non-Flowing Monitoring Locations Are physical indicators that are not related to flow present? ❑ Yes It No (If No, Skip to Section 6) INDICATOR CHECK if Present DESCRIPTION COMMENTS Monitoring Location ❑ Spalling,Cracking or Chipping ❑ Peeling Paint Damage ❑ ❑ Corrosion Deposits/Stains ❑ ❑ Oily ❑ Flow Line ❑ Paint ❑ Other: Abnormal Vegetation ❑ ❑ Excessive ❑ Inhibited ❑ Odors ❑ Colors ❑ Floatables ❑ Oil Sheen Poor pool quality ❑ ❑ Suds ❑ Excessive Algae ❑ Other: Pipe benthic growth ❑ ❑ Brown ❑ Orange ❑ Green ❑ Other: Section 6: Overall Monitoring Location Characterization [jmg Unlikely ❑ Potential (presence of two or more indicators) ❑ Suspect(one or more indicators with a severity of 3) ❑ Obvious Section 7: Data Collection 1. Sample for the lab? ❑ Yes ;—K, No 2. If yes,collected from: ❑ Flow ❑ Pool 3. Intermittent flow trap set? ❑ Yes M No If Yes,type: ❑ OBM ❑ Caulk dam Section 8:Any Non-Illicit Discharge Concerns (e.g.,trash or needed infrastructure repairs)? None 149 r - 16 Sol Ow * ' 4 `• 40 40 2024A69 13 Monitoring Locations Inspection and Sampling Field Sheet Section 1: Background Data Subwatershed:James Creek(freshwater tribs) Monitoring Location ID:Outfall 126 Today's date:9/13/24 Time(Military):15:13 Investigators:M.Collins Form completed by:M.Collins Temperature(°F):77' Rainfall(in): Last 24 hours: 0" Last 48 hours:0" Latitude: Longitude: GPS Unit: GPS LMK#: Camera:Olympus Stylus TG-4 Photo#s:Outfall 126-1 Land Use in Drainage Area(Check all that apply): ❑ Industrial ❑ Open Space 0 Ultra-Urban Residential ❑ Institutional ❑ Suburban Residential Other: ❑ Commercial Known Industries: Notes(e.g.,origin,if known):Leaching Catch Basin on Ole Jule Lane Section 2: Monitoring Location Description LOCATION MATERIAL SHAPE DIMENSIONS(IN.) SUBMERGED ❑ RCP ❑ CMP iC Circular X Single Diameter/Dimensions: In Water: ❑i No ❑ PVC Q HDPE ❑ Elliptical ❑ Double 12"diameter ❑ Partially ❑ Fully CJ Closed Pipe ❑ Steel ❑ Box ❑Triple With Sediment: ■❑ No ❑ Other: i]Other:_ ❑ Other: ❑ Partially ❑ Fully ❑ Concrete /Trapezoid Depth:_ r Eli ❑ W'/ Zf Earthen ❑ Parabolic Top Width:_ f % f l. %� ❑ Open drainage ' ❑ Rip-Rap ❑Other: Bottom Width: ❑ Other: ❑ In-Stream (applicable when collecting samples) Flow Present? ❑Yes It No If No,Skip to Section 5 Flow Description (If present) ❑ Trickle ❑ Moderate ❑ Substantial Section 3: Quantitative Characterization FIELD DATA FOR FLOWING MONITORING LOCATIONS PARAMETER RESULT UNIT EQUIPMENT Volume Liter Bottle ❑ Flow#1 Time to fill Sec Flowdepth In Tape measure Flowwidth Ft,In Tape measure ❑ Flow#2 Measured length Ft,In Tape measure Time of travel S Stopwatch Temperature °F Thermometer PH pH Units Test strip/Probe Ammonia mg/L Test strip 148 Monitoring Locations Inspection and Sampling Field Sheet Section 4: Physical Indicators for Flowing Monitoring Locations Only Are Any Physical Indicators Present in the flow? ❑ Yes El No (If No, Skip to Section 5) INDICATOR CHECK if DESCRIPTION RELATIVE SEVERITY INDEX(1-3) Present ❑ Sewage ❑ Rancid/sour ❑ Petroleum/gas 3—Noticeable from a Odor ❑ ❑ 1 -Faint ❑ 2—Easily detected ❑ Sulfide ❑ Other: distance ❑ Clear ❑ Brown ❑ Gray ❑ Yellow 1—Faint colors in 2—Clearly visible in Color ❑ L sample bottle ❑ sample bottle ❑ 3—Clearly visible in flow ❑ Green ❑ Orange ❑ Red ❑ Other: P P Turbidity ❑ See severity ❑ 1—Slight cloudiness ❑ 2-Cloudy ❑ 3—Opaque Floatables ❑ Sewage(Toilet Paper,etc.)❑Suds 1—Few/slight;origin 2-Some;indications of 3-Some;origin clear(e.g., -Does Not Include El not obvious ❑ origin(e.g., possible ❑ obvious oil sheen,suds,or Trash!! ❑ Petroleum(oil sheen) ❑Other: suds or oil sheen) floating sanitary materials) Section 5: Physical Indicators for Both Flowing and Non-Flowing Monitoring Locations Are physical indicators that are not related to flow present? ❑ Yes 'DO No (If No, Skip to Section 6) INDICATOR CHECK If Present DESCRIPTION COMMENTS Monitoring Location ❑ Spalling,Cracking or Chipping ❑ Peeling Paint Damage 0 ❑ Corrosion Deposits/Stains ❑ ❑ Oily ❑ Flow Line ❑ Paint ❑ Other: Abnormal Vegetation ❑ ❑ Excessive ❑ Inhibited ❑ Odors ❑ Colors ❑ Floatables ❑ Oil Sheen Poor pool quality U ❑ Suds ❑ Excessive Algae ❑ Other: Pipe benthic growth ❑ ❑ Brown ❑ Orange ❑ Green ❑ Other: Section 6: Overall Monitoring Location Characterization Unlikely ❑ Potential (presence of two or more indicators) ❑ Suspect(one or more indicators with a severity of 3) ❑ Obvious Section 7: Data Collection 1. Sample for the lab? ❑ Yes ❑re No 2. If yes,collected from ❑ Flow ❑ Pool 3. Intermittent flow trap set? ❑ Yes -Em] No If Yes,type: ❑ OBM ❑ Caulk dam Section 8: Any Non-illicit Discharge Concerns (e.g.,trash or needed infrastructure repairs)? None 149 Ift4 {j • iY�t Vr '�� i .. 7 ,0 0.4 }/� • � ` C. I S� ' ,CA •,�,4 ���� � l �� a�f �1�� � i I+f � ,�1 .F � � 6 k�'� �I r! IyI� 1 '1 , 'fir I1 �1.r,fF� i � r i F� � f - � { { '��5���,E���•, 'Yi r.�l 1 I 1y,# ��y �1k r 4��S ,. h tY• k 1 lffl{ k , E i i I,r ! +• r' 11 i { , b { x � I -; ``# �1 FJL- ti 6.. Illicit Discharge Detection and Elimination A Guidance Manual for Program Development and Technical Assessments by the Center for Watershed • - • and Robert Pitt University of • • • • October 2004 Notice The information in this document has been funded wholly or in part by the United States Environmental Protection Agency under cooperative agreement X-82907801-0.Although it has been subjected to the Agency's peer and administrative review,it does not necessarily reflect the views of the Agency,and no official endorsement should be inferred.Also,the mention of trade names or commercial products does not imply endorsement by the United States government,the Center for Watershed Protection, or the University of Alabama. ILLICIT DISCHARGE DETECTION AND ELIMINATION: A GUIDANCE MANUAL FOR PROGRAM DEVELOPMENT AND TECHNICAL ASSESSMENTS by Edward Brown and Deb Caraco Center for Watershed Protection Ellicott City, Maryland 21043 and Robert Pitt University of Alabama Tuscaloosa, Alabama 35487 EPA Cooperative Agreement X-82907801-0 Project Officer Bryan Rittenhouse Water Permits Division Office of Water and Wastewater U.S. Environmental Protection Agency Washington, D.C. October 2004 Photo Acknowledgments Figure Number Source 3 Regional Water Quality Control Board 4 Fort Worth Department of Environmental Management(DEM) 5 Fort Worth DEM 7 South Florida Water Management District(website) 8 Robert Pitt, University of Alabama 14 Robert Pitt 28 (fire hydrant) Fort Worth DEM 34 (Chromium spill) Fort Worth DEM 34 (highly turbid discharge) Rachel Calabro, Massachussets Department of Environmental Protection 34 (industrial discharge) Robert Pitt 34 (paint) Robert Pitt 34 (Toronto industrial spill) Robert Pitt 34 (blood) Fort Worth DEM 34 (failing septic) Snohomish County, WA 34 (construction site) Don Green, Franklin, TN 34 (discharge of rinse water) Rachel Calabro 35 (natural foam) Snohomish County, WA 35 (high severity suds) Fort Worth DEM 35 (moderate severity oil) R. Frymire 35 (high severity oil) Kelly Dinsmore, City of Newark, DE 38 (bright red bacteria) R. Frymire 38 (Sporalitis filamentous) Robert Ressl, City of Arlington,TX 38 (extreme algal growth) Mark Sommerfield, Montgomery Co., Maryland 38 (brownish algae) R. Frymire 39 (all but`brownish stain') R. Frymire 41 (all) R. Frymire 42 Galveston, TX 48 Fort Worth DEM 49 Dr. Robert Pitt 52-53 Jewell, 2001 58-59 Jewell, 2001 60 Sargent and Castonguay, 1998 63 NEIWPCC, 2003 65-67 www.darrscleaning.com 68 www.usabluebook.com 69 www.superiorsignal.com 70-71 www.darrscleaning.com 72 (a) Anish Jantrania 72 (b) Snohomish County, WA 72 (c) King County, WA 73 www.delmarva-homeinspector.com 74 Mecklenburg, NC Water Quality Program 75 U.S. EPA, 1999 Foreword Foreword A number of past projects have found that storm water entries into storm drainage dry-weather flows discharging from storm systems. It also has application for Phase I drainage systems can contribute significant communities looking to modify existing pollutant loadings to receiving waters. If programs and community groups such as these loadings are ignored(by only watershed organizations that are interested considering wet-weather stormwater runoff, in providing reconnaissance and public for example), little improvement in awareness services to communities as part of receiving water conditions may occur. Illicit watershed restoration activities. dry-weather flows originate from many sources. The most important sources This Manual was submitted in partial typically include sanitary wastewater or fulfillment of cooperative agreement X- industrial and commercial pollutant entries, 82907801-0 under the sponsorship of the failing septic tank systems, and vehicle U.S. Environmental Protection Agency. This maintenance activities. report covers a period from July 2001 to July 2004 and was prepared by the Center Provisions of the Clean Water Act(1987) for Watershed Protection, Ellicott City, MD require National Pollutant Discharge in cooperation with Robert Pitt of the Elimination System (NPDES)permits for University of Alabama. storm water discharges. Section 402 (p)(3)(B)(ii)requires that permits for Some references in the document pertain to municipal separate storm sewers shall work conducted during this project. This include a requirement to effectively prohibit internal support information was developed problematic non-storm water discharges into as work tasks were completed and research storm sewers. Emphasis is placed on the findings were developed. In some cases, elimination of inappropriate connections to memoranda or technical support documents urban storm drains. This requires affected were prepared. Most of these documents are agencies to identify and locate sources of in"draft" form and have not been published. non-storm water discharges into storm As a result, they should be considered drains so they may institute appropriate supplemental and preliminary information actions for their elimination. that is not intended for widespread citation or distribution. In the References section, This Manual is intended to provide support these documents are identified as "IDDE and guidance, primarily to Phase II NPDES project support material" at the end of each MS4 communities, for the establishment of citation. Interested readers can access these Illicit Discharge Detection and Elimination documents through the website link to the (IDDE)programs and the design and project archive and support information. procedures of local investigations of non- Illicit Discharge Detection and Elimination:A Guidance Manual I Foreword ii Illicit Discharge Detection and Elimination:A Guidance Manual Acknowledgments Acknowledgments This Guidance Manual could not have been • Amy Schofield, Boston Water and completed had it not been for the Sewer Commission, MA contributions of many individuals. Much of • John Nardone and James Wilcox, City of the field survey and laboratory analysis Cambridge, MA guidance in this manual reflects an update to • Andrew Swanson,Clackamas County,OR information presented in Pitt et. al. (1993). • Michele Jones, City of Dayton, OH Bob Pitt and his students and researchers • John H. Cox, City of Durham,NC have been instrumental in furthering the • Moe Wadda, City of Falls Church, VA science to develop and identify safe, quick, • Angela Morales, Howard County, MD accurate and cost effective methods to • David Hagerman and Bob Jones, City of collect and analyze dry weather flow Knoxville, TN samples. Team members from the University • Alan Searcy, City of Lakewood, CO of Alabama that contributed to this manual • Meosotis Curtis and David Rotolone, include: Bob Pitt, Soumya Chaturvedula, Montgomery County, MD Sanju Jacob, Veera Karri, Uday • Michael Loffa, City of Phoenix, AZ Khambhammettu, Alex Maestre, Renee • Ali Dirks, City of Portland, OR Morquecho,Yukio Nara, and Sumandeep • Mark Senior, City of Raleigh,NC Shergill. Team members from the Center for • Beth Schmoyer, City of Seattle, WA Watershed Protection include Jessica • Todd Wagner, City of Springfield, MO Brooks, Ted Brown, Karen Cappiella, Deb • Arne Erik Anselm, City of Thousand Caraco, Tom Schueler, Stephanie Sprinkle, Oaks, CA Paul Sturm, Chris Swann, Tiffany Wright, • Dean Tuomari, Wayne County, MI and Jennifer Zielinski. • David Harris, City of Worcester,MA Support from EPA has been constant and Others that provided useful insight into their valuable. We would like to thank Wendy community programs include Michael Hunt, Bell and Jack Faulk of the Office of City of Nashville, TN; Mecklenburg Wastewater, and in particular, project County,NC; and Steve Jadlocki, City of officer, Bryan Rittenhouse. Charlotte,NC. We are grateful to the many communities The communities of Baltimore City, MD; that agreed to fill out our extensive surveys Baltimore County, MD; Boston Water and and questionnaires including: Sewer Commission, MA; Cambridge, MA, Dayton, OH; Fort Worth, TX; Raleigh,NC; • Erica Anderson Maguire, Ada County Tuscaloosa,AL; and Wayne County, MI Highway District, ID were extremely generous in hosting project • Charles Caruso, City of Albuquerque, team members and sharing the details of NM their programs. A special thanks goes to • Bill Hicks, City of Alexandria, VA Baltimore City,MD and Baltimore County, • Jason Papacosma,Arlington County, VA MD for providing access to laboratory and • Roger Glick and Roxanne Jackson, City field equipment, and allowing protocols to of Austin, TX be tested in their subwatersheds. Baltimore • Bill Stack, Baltimore City, MD City staff members we would like to recognize include: Bill Stack, Dr. Freddie Alonzo, Ted Illicit Discharge Detection and Elimination:A Guidance Manual III Acknowledgments Eucare, Shelly Jesatko, Hector Manzano, • Fort Worth Department of Umoja Muleyyar, Van Sturtevant, and Joan Environmental Management White. Baltimore County staff we would • Roger Frymire like to recognize include Steve Stewart and • Dave Graves,New York DOT Steve Adamski. • Don Green, Franklin, TN • Hillsborough County Public Works Many of the outstanding graphics in the Department, Stormwater Management Manual were provided by outside sources. Section While sources are noted on the back of the • Rusty Rozzelle,Mecklenburg County,NC title page,we would like to especially thank • Mark Sommerfield, Montgomery the following: County,MD • Greg Stockton, Stockton Infrared • Rachel Calabro,MA DEP Thermographic Services, Inc. • Kelly Dinsmore, City of Newark, DE • Barry Tonning, Tetra Tech • Donette Dunaway, California RWQCB Region 3 IV Illicit Discharge Detection and Elimination:A Guidance Manual Table of Contents Table of Contents Foreword ...........................................................................................................................................i Acknowledgments...............................................................................................................................................iii Listof Tables ...........................................................................................................................................vill Listof Figures ..........................................................................................................................................ix Introduction 1 Chapter 1: The Basics of Illicit Discharges............................................................................................... 5 1 .1 Important Terminology and Key Concepts................................................................................ 5 1 .2 The Importance of Illicit Discharges in Urban Water Quality ......................................................15 1 .3 Regulatory Background For Illicit Discharges..............................................................................16 1 .4 Experience Gained in Phase I....................................................................................................19 Chapter 2: Components of an Effective IDDE Program .........................................................................23 2.1 Management Tips to Develop an Effective IDDE Program.........................................................25 Chapter 3:Auditing Existing Resources and Programs ...........................................................................29 3.1 Audit Overview...........................................................................................................................30 3.2 Develop Infrastructure Profile ....................................................................................................32 3.3 Establish Legal Authority.............................................................................................................32 3.4 Review Available Mapping........................................................................................................33 3.5 Availability of Field Staff .............................................................................................................33 3.6 Access to Laboratory Analysis....................................................................................................34 3.7 Education and Outreach ..........................................................................................................34 3.8 Discharge Removal Capability and Tracking.............................................................................35 3.9 Program Funding.......................................................................................................................35 3.10 The Initial IDDE Program Plan......................................................................................................38 Chapter 4: Establishing Responsibility and Legal Authority......................................................................39 41 Identify Responsible Department/Agency..................................................................................40 4.2 Develop Local Illicit Discharge Ordinance ................................................................................40 Chapter 5: Desktop Assessment of Illicit Discharge Potential..................................................................45 5.1 Overview of Desktop Assessment of Illicit Discharge Potential....................................................46 Chapter 6: Developing Program Goals and Implementation Strategies................................................57 6.1 Overview of Goals and Strategies Development.......................................................................58 6.2 Develop Initial Program Goals ..................................................................................................58 6.3 Crafting Implementation Strategies...........................................................................................60 Illicit Discharge Detection and Elimination:A Guidance Manual v Table of Contents Chapter 7: Searching for Illicit Discharge Problems In the Field..............................................................63 7.1 Overview of Searching for Illicit Discharge Problems in the Field................................................64 7.2 The Outfall Reconnaissance Inventory(ORI)...............................................................................64 7.3 Interpreting ORI Data.................................................................................................................65 7.4 Design and Implementation of an Indicator Monitoring Strategy..............................................66 7.5 Field and Lab Safety Considerations .........................................................................................68 Chapter 8: Isolating and Fixing Individual Illicit Discharges.....................................................................69 8.1 Overview of Isolating and Fixing Individual Illicit Discharges.......................................................70 8.2 Isolating Illicit Discharges............................................................................................................70 8.3 Fixing Illicit Discharges................................................................................................................73 Chapter 9: Preventing Illicit Discharges...................................................................................................75 9.1 Overview of Preventing Illicit Discharges ....................................................................................76 9.2 Methods to Identify Opportunities for Illicit Discharge Prevention...............................................76 9.3 Preventing Illicit Discharges from Neighborhoods......................................................................76 9.4 Preventing Illicit Discharges from Generating Sites.....................................................................80 9.5 Preventing Illicit Discharges from Municipal Operations.............................................................83 9.6 Budgeting and Scoping Pollution Prevention .............................................................................86 Chapter 10: IDDE Program Tracking and Evaluation ..............................................................................87 10.1 Overview of Program Evaluation................................................................................................88 10.2 Evaluate the Program................................................................................................................88 Chapter 11: The Outfall Reconnaissance Inventory(ORI).......................................................................91 11.1 Getting Started ..........................................................................................................................91 11.2 Desktop Analysis to Support the ORI...........................................................................................94 11.3 Completing the ORI...................................................................................................................96 11.4 ORI Section 1- Background Data...............................................................................................98 11.5 ORI Section 2- Outfall Description..............................................................................................99 11.6 ORI Section 3- Quantitative Characterization for Flowing Outfalls..............................................101 11.7 ORI Section 4- Physical Indicators for Flowing Outfalls Only........................................................103 11.8 ORI Sheet Section 5- Physical Indicators for Both Flowing and Non-Flowing Outfalls..................107 11.9 ORI Section 6-8 Initial Outfall Designation and Actions .............................................................109 11.10 Customizing the ORI for Your Community..................................................................................1 10 1 1.1 1 Interpreting ORI Data.................................................................................................................1 12 11.12 Budgeting and Scoping the ORI................................................................................................1 16 Chapter 12: Indicator Monitoring ...........................................................................................................1 19 12.1 Indicator Parameters to Identify Illicit Discharges.......................................................................121 12.2 Sample Collection Considerations ............................................................................................122 12.3 Methods to Analyze Indicator Samples......................................................................................124 12.4 Techniques to Interpret Indicator Data ......................................................................................130 12.5 The Chemical Library.................................................................................................................136 12.6 Special Monitoring Techniques for Intermittent or Transitory Discharges.....................................138 12.7 Monitoring of Stream Quality During Dry Weather......................................................................141 12.8 The Costs of Indicator Monitoring...............................................................................................144 vi Illicit Discharge Detection and Elimination:A Guidance Manual Table of Contents Chapter 13: Trucking Discharges to A Source........................................................................................147 13.1 Storm Drain Network Investigations ............................................................................................147 13.2 Drainage Area Investigations.....................................................................................................158 13.3 On-site Investigations ................................................................................................................159 13.4 Septic System Investigations......................................................................................................166 13.5 The Cost to Trace Discharge Sources ........................................................................................170 Chapter 14: Techniques to Fix Discharges .............................................................................................173 14.1 Implementation Considerations.....................................................................................................173 References ............................................................................................................................................R-1 Appendix A: Generating Sites, Storm Water Regulatory Status, and Discharge Potential........................A-1 Appendix B: Model Illicit Discharge and Connection Ordinance...........................................................B-1 Appendix C: Six Steps to Establishing a Hotline and Reporting and Tracking System..............................C-1 Appendix D: Outfall Reconnaissance Inventory Field Sheet...................................................................D-1 Appendix E: Flow Type Data from Tuscaloosa and Birmingham.............................................................E-1 Appendix F: Laboratory Analytical Procedures for Outfall Monitoring......................................................F-1 Appendix G: Sampling Protocol Considerations.....................................................................................G-1 Appendix H: Two Alternative Flow Charts ................................................................................................H-1 Appendix I: User's Guide for the Chemical Mass Balance Model (CMBM)Version 1.0 ...........................I-1 Appendix J: Using the Chemical Library to Determine the Utility of Boron as an Indicator of IllicitDischarges ................................................................................................................J-1 Appendix K: Specific Considerations for Industrial Sources of Inappropriate Pollutant Entries to the Storm Drainage System ...........................................................................................K-1 Illicit Discharge Detection and Elimination:A Guidance Manual vii Table of Contents List of fables 1. Comparative"Fingerprint"of Flow Types .............................................................................................8 2. Land Uses, Generating Sites and Activities That Produce Indirect Discharges.....................................12 3. Linking Other Municipal Programs to IDDE Program Needs ................................................................21 4. Key Tasks and Products in IDDE Program Implementation..................................................................24 5. Comparison of IDDE Components.....................................................................................................25 6. Potential Local Agencies and Departments to Contact During an Audit............................................30 7. Potential IDDE Audit Questions............................................................................................................31 8. Codes and Ordinances with Potential Links to IDDE............................................................................33 9. Summary of Annual Phase I IDDE Program Costs ..............................................................................36 10. Average Correction Costs ................................................................................................................36 11. IDDE Program Costs..........................................................................................................................37 12. Summary of IDDE-Related Enforcement Tools..................................................................................44 13. Useful Data for the Desktop Assessment...........................................................................................48 14. Defining Discharge Screening Factors in a Community...................................................................50 15. Prioritizing Subwatershed Using IDP Screening Factors ......................................................................53 16. Community-wide Rating of Illicit Discharge Potential........................................................................54 17. Measurable Goals for an IDDE Program...........................................................................................60 18. Linking Implementation Strategies to Community-wide IDP.............................................................61 19. Customizing Strategies for Unique Subwatershed Screening Factors................................................62 20. Field Screening for an IDDE Program................................................................................................65 21. Field Data Analysis for an IDDE Program...........................................................................................66 22. Indicator Monitoring Considerations.................................................................................................66 23. Benefits and Challenges of a Complaint Hotline..............................................................................70 24. Steps to Creating and Maintaining Successful IDDE Hotline .............................................................71 25. IDDE Complaint Hotline Costs...........................................................................................................71 26. Methods to Fix Illicit Discharges ........................................................................................................74 27. Common Discharges Produced at Generating Sites .......................................................................81 28. Summary of Local Household Hazardous Waste Collection Programs.............................................85 29. Estimated Costs for Public Awareness Program Components..........................................................86 30. Resources Needed to Conduct the ORI...........................................................................................92 31. Climate/Weather Conditions for Starting the ORI .............................................................................92 32. Outfalls to Include in the Screening..................................................................................................96 33. Special Considerations for Open Channels/Submerged Outfalls.....................................................III 34. Outfall Designation System Using ORI Data ......................................................................................1 15 35. An Example of ORI Data Being Used to Compare Across Subwatersheds........................................1 15 36. Using Stream and ORI Data to Categorize IDDE Problems ...............................................................1 15 37. Typical Field Equipment Costs for the ORI ........................................................................................1 16 38. Example ORI Costs...........................................................................................................................1 17 39. Indicator Parameters Used to Detect Illicit Discharges......................................................................122 40. Equipment Needed for Sample Collection......................................................................................123 41. Basic Lab Supplies............................................................................................................................126 42. Analytical Methods Supplies Needed...............................................................................................127 43. Chemical Analysis Costs...................................................................................................................128 44. Typical Per Sample Contract Lab Costs............................................................................................130 45. Benchmark Concentrations to Identify Industrial Discharges............................................................134 46. Usefulness of Various Parameters to Identify Industrial Discharges....................................................135 47. Where and How to Sample for Chemical "Fingerprint" Library..........................................................137 48. Evaluation of the Flow Chart Method Using Data from Birmingham, Alabama................................139 49. Follow-Up Monitoring for Transitory Discharges..................................................................................142 50.Typical"Full Body Contact Recreation"Standards for E. coli.............................................................143 51. Example In-Stream Nutrient Indicators of Discharges .......................................................................143 viii Illicit Discharge Detection and Elimination:A Guidance Manual Table of Contents 52. Indicator Monitoring Costs:Two Scenarios.........................................................................................145 53. Methods to Attack the Storm Drain Network......................................................................................148 54. Basic Field Equipment Checklist.......................................................................................................152 55. Field Procedure for Removal of Manhole Covers............................................................................. 153 56. Techniques to Locate the Discharge................................................................................................160 57. Key Field Equipment for Dye Testing.................................................................................................161 58. Dye Testing Options..........................................................................................................................162 59. Tips for Successful Dye Testing ..........................................................................................................163 60. Septic System Homeowner Survey Questions ...................................................................................167 61. Common Field Equipment Needed for Dye,Video, and SmokeTesting ..........................................170 62. Equipment Costs for Dye Testing ......................................................................................................171 63. Equipment Costs for Video Testing ...................................................................................................171 64. Equipment Costs for Smoke Testing..................................................................................................171 65. Methods to Eliminate Discharges .....................................................................................................175 List of Figures 1 . Sewer Pipe Discharging to the Storm Drain System.............................................................................. 7 2. Direct Discharge from a Straight Pipe.................................................................................................. 8 3.A Common Industrial Cross Connection .............................................................................................9 4.Accident Spills are Significant Sources of Illicit Discharges.................................................................. 9 5. Dumping at a Storm Drain Inlet..........................................................................................................10 6. Routine Outdoor Washing and Rinsing can Cause Illicit Discharges...................................................10 7. Non-Target Landscaping Irrigation Water...........................................................................................10 8. GIS Layers of Outfalls in a Subwatershed............................................................................................49 9. Communities With Minimal (A), Clustered (B),And Severe (C) Illicit Discharge Problems.....................55 10. Measuring an Outfall as Part of the ORI............................................................................................64 11. Some Discharges are Immediately Obvious ....................................................................................64 12. IDDE Monitoring Framework..............................................................................................................67 13. Process for Removing or Correcting an Illicit Discharge....................................................................74 14. Storm Drain Stenciling May Help Reduce Illicit Discharges. ..............................................................77 15. Home Mechanic Changing His Automotive Fluids...........................................................................78 16. Household Hazardous Wastes Should be Properly Contained to Avoid Indirect Discharges.............79 17. Swimming Pools can be a Source of Illicit Discharges......................................................................80 18. Spill Response Often Involves Portable Booms and Pumps...............................................................82 19. Walk all Streams and Constructed Open Channels..........................................................................91 20. Example of a Comprehensive Emergency Contact List for Montgomery County, MD.....................94 21. Survey Reach Delineation.................................................................................................................95 22. Typical Outfall Types Found in the Field............................................................................................97 23. Section 1 of the ORI Field Sheet.......................................................................................................98 24. A Variety of Outfall Naming Conventions Can Be Used....................................................................99 25. Corrugated Plastic Pipe....................................................................................................................99 26. Section 2 of The ORI Field Sheet.......................................................................................................100 27. Measuring Outfall Diameter..............................................................................................................100 28. Characterizing Submersion and Flow...............................................................................................101 29. Section 3 of the ORI Field Sheet.......................................................................................................102 30. Measuring Flow (as volume per time)...............................................................................................102 31. Measuring Flow (as velocity times cross-sectional area)...................................................................103 32. Section 4 of the ORI Field Sheet.......................................................................................................103 33. Using a Sample Bottle to Estimate Color and Turbidity......................................................................104 34. Interpreting Color and Turbidity.........................................................................................................105 Illicit Discharge Detection and Elimination:A Guidance Manual ix Table of Contents 35. Determining the Severity of Floatables .............................................................................................106 36. Synthetic Versus Natural Sheen.........................................................................................................107 37. Section 5 of the ORI Field Sheet.......................................................................................................107 38. Interpreting Benthic and Other Biotic Indicators................................................................................108 39. Typical Findings at Both Flowing and Non-Flowing Outfalls...............................................................109 40. Sections 6-8 of the ORI Field Sheet...................................................................................................1 10 41. Cold Climate Indicators of Illicit Discharges .....................................................................................1 12 42. One Biological Indicator is this Red-Eared Slider Turtle......................................................................1 12 43. Example Screen from ORI Microsoft Access Database....................................................................1 14 44, IDDE Monitoring Framework..............................................................................................................1 19 45. Analyzing Samples in the Back of a Truck.........................................................................................126 46. Office/Lab Set-up .............................................................................................................................126 47. Flow Chart to Identify Illicit Discharges in Residential Watersheds.....................................................131 48. OBM Trap That Can Be Placed At An Ouffall.....................................................................................140 49. Stream Sentinel Station.....................................................................................................................141 50. Example Investigation Following The Source Up The Storm Drain System..........................................148 51. Key Initial Sampling Points Along The Trunk Of The Storm Drain .........................................................150 52. Storm Drain Schematic Identifying "Juncture Manholes"..................................................................151 53. A Process For Following Discharges Down The Pipe .........................................................................151 54. Traffic Cones Divert Traffic From Manhole Inspection Area...............................................................152 55. Manhole Observation and Source Identification..............................................................................153 56. Techniques to Sample from The Storm Drain....................................................................................154 57. Use Of Ammonia as a Trace Parameter To Identify an Illicit Discharge ............................................155 58. Boston Water and Sewer Commission Manhole Inspection Log.......................................................156 59. Example Sandbag Placement ........................................................................................................157 60. Optical Brightener Placement in The Storm Drain.............................................................................158 61. Fertilizer Storage................................................................................................................................159 62. Laundromat Discharge.....................................................................................................................159 63. Dye Testing Plumbing .......................................................................................................................160 64. Dye Testing in a Manhole................................................................................................................161 65. Camera Being Towed ......................................................................................................................164 66. Tractor-Mounted Camera ................................................................................................................164 67. Review Of An Inspection Video.........................................................................................................164 68. Smoke Testing System Schematic....................................................................................................165 69. Smoke Candles................................................................................................................................165 70. Smoke Blower...................................................................................................................................166 71. Smoke Rising From Sewer Vent.........................................................................................................166 72. Surface Indicators.............................................................................................................................168 73. Dye Surfacing in a Septic Field .........................................................................................................168 74. Aerial Thermography Showing Sewage Leak....................................................................................169 75. Dead Vegetation and Surface Effluent are Evidence of a Septic System Surface Failure................169 x Illicit Discharge Detection and Elimination:A Guidance Manual Introduction Introduction An up-to-date and comprehensive manual on public education, storm water management, techniques to detect and correct discharges in stream restoration, and pollution prevention. municipal storm drains has been unavailable until now. This has been a major obstacle for This manual incorporates the experience of both Phase I and Phase II National Pollutant more than 20 Phase I communities that were Discharge Elimination System (NPDES) surveyed about their practices, levels of municipal separate storm sewer system (MS4) program effort, and lessons learned (CWP, communities that must have programs in 2002). These communities took many place that detect, eliminate, and prevent illicit different approaches to solve the IDDE discharges to the storm drain system. Smaller problem, and provided great insights on Phase II communities, in particular, need common obstacles,setting realistic expectations simple but effective program guidance to and getting a hard job done right. Many of the comply with permits issued by the IDDE methods presented in this manual were Environmental Protection Agency (EPA) and first developed and tested in many Phase I states. This manual provides communities communities. Specific techniques applied in a with guidance on establishing and community should be adapted to local implementing an effective Illicit Discharge conditions, such as dominant discharge types, Detection and Elimination (IDDE)program. land use, and generating sites. Studies have shown that dry weather flows Designed with a broad audience in mind, from the storm drain system may contribute a including agency heads, program managers, larger annual discharge mass for some field technicians and water quality analysts,this pollutants than wet weather storm water flows manual is primarily focused on providing the (EPA, 1983 and Duke, 1997). Detecting and thousands of Phase II communities that are eliminating these illicit discharges involves now in the process of developing IDDE complex detective work, which makes it hard programs with guidance for the development to establish a rigid prescription to "hunt down" and implementation of their own programs. and correct all illicit connections. Frequently, The manual has been organized to address the there is no single approach to take, but rather broad range of administrative and technical a variety of ways to get from detection to considerations involved with setting up an elimination. Local knowledge and available effective IDDE program. The first 10 chapters resources can play significant roles in of the Manual focus on"big picture" determining which path to take. At the very considerations needed to successfully get an least, communities need to systematically IDDE program off the ground. The final four understand and characterize their stream, chapters provide detailed technical conveyance, and storm sewer infrastructure information on the methods to screen, systems. When illicit discharges are characterize and remove illicit discharges in identified, they need to be removed. The MS4 communities. These chapters present the process is ongoing and the effectiveness of a state-of-the-practice on specific monitoring program should improve with time. In fact, techniques and protocols. well-coordinated IDDE programs can benefit from and contribute to other community-wide water resources-based programs, such as Illicit Discharge Detection and Elimination:A Guidance Manual 1 Introduction In general,the content of this manual gets Chapter 3. Audit Existing Resources and progressively more complex and technical Programs—This chapter provides guidance toward the end. The basic organization of the on evaluating existing resources, regulations, manual is outlined below. The information is and ongoing activities in your community to provided to help: better address illicit discharges. • Define important terminology and Chapter 4. Establish Responsibility, understand key illicit discharge concepts Authority and Tracking—This chapter presents guidance on how to identify the local • Conduct an audit to understand agency who will be responsible for community needs and capabilities administering the IDDE program, and how to • Establish adequate legal authority establish the legal authority to control illicit • Develop a tracking system to map outfalls discharges by adapting an existing ordinance and document reported illicit discharges or adopting a new one. The chapter also • Conduct desktop analyses to prioritize describes how to set up a program tracking targets for illicit discharge control system needed to document discharges and local actions to respond to them. • Conduct rapid reconnaissance of the stream corridor to find problem outfalls Chapter 5. Desktop Assessment of Illicit • Apply new analytical and field methods to Discharge Potential—The fifth chapter find and fix illicit discharges describes desktop analyses to process • Educate municipal employees and the available mapping data to quickly public to prevent discharges characterize and screen illicit discharge problems at the community and subwatershed • Estimate costs to run a program and scale. Key factors include water quality, land conduct specific investigations use, development age, sewer infrastructure and outfall density. Rapid screening Chapter 1. The Basics of Illicit Discharges - techniques are presented to define where to The many different sources and generating begin searching for illicit discharge problems sites that can produce illicit discharges are in your community. described in Chapter 1. The chapter also outlines key concepts and terminology needed Chapter 6. Developing Program Goals and to understand illicit discharges, why they Implementation Strategies—Communities cause water quality problems and the are required to establish and track measurable regulatory context for managing them. goals for their IDDE program under the NPDES MS4 permit program. This chapter Chapter 2. Components of an Effective recommends a series of potential program Illicit Discharge Program—This chapter goals that can guide local efforts, as well as presents an overall framework to build an guidance on how to measure and track IDDE program, by outlining eight key progress toward their achievement. components of good programs. Each of the following eight chapters is dedicated to a key Chapter 7. Searching for Illicit Discharge program component. The first page of the Problems in the Field—This chapter briefly program component chapters is notated with a summarizes the major monitoring techniques puzzle icon labeled with the applicable to find illicit discharges, and discusses how to program component number. select the right combination of monitoring 2 Illicit Discharge Detection and Elimination:A Guidance Manual Introduction methods to incorporate into your local describing different chemical indicators that program. have been used to identify illicit discharges, and presents guidance on how to collect Chapter 8. Isolating and Fixing Individual samples for analysis. The chapter Illicit Discharges—The methods used to find recommends a flow chart approach that and remove illicit discharges are briefly utilizes four chemical indicators to distinguish described in this chapter and include citizen the flow type. The chapter provides specific hotlines and techniques to trace, locate and information on other analytical methods that remove illicit discharge sources. can be used, as well as proper safety, handling, and disposal procedures. Simple Chapter 9. Preventing Illicit Discharges— and more sophisticated methods for Prevention is a cost effective way to reduce interpreting monitoring data are discussed, pollution from illicit discharge. This chapter along with comparative cost information. highlights a series of carrot and stick strategies to prevent illicit discharges. Chapter 13. Tracking Discharges to Their Source—This chapter describes how to Chapter 10. IDDE Program Evaluation— investigate storm drain systems to narrow and IDDE programs must continually evolve to remove individual illicit discharges. These changing local conditions. This chapter techniques include "trunk" investigations describes how to review and revisit program (e.g., video surveillance, damming, and goals to determine if they are being met and infiltration and inflow studies) and on-site to make any needed adjustments. investigations (e.g., dye tests, smoke tests, and pollution prevention surveys). The pros Chapter 11. The Outfall Reconnaissance and cons of each investigation technique are Inventory (ORI)—The chapter presents discussed, and comparative cost estimates are detailed protocols to conduct rapid field given. screening of problem outfalls. The chapter also outlines the staff and equipment costs Chapter 14. Techniques to Fix Discharges— needed to conduct an ORI, and presents This chapter provides tips on the best methods methods to organize, manage and interpret the to repair or eliminate discharges. Specific data you collect. advice is presented on how to identify responsible parties, develop pre-approved Chapter 12. Chemical Monitoring—This subcontractor lists,and estimate unit costs for chapter presents detailed guidance on the typical repairs. wide range of chemical monitoring options that can be used to identify the composition of Appendices—Eleven technical appendices illicit discharge flows. The chapter begins by are provided at the end of the manual. Illicit Discharge Detection and Elimination:A Guidance Manual 3 Introduction 4 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 1: The Basics of Illicit Discharges Chapter 1 : The Basics of Illicit Discharges An understanding of the nature of illicit 2. Each illicit discharge has a unique discharges in urban watersheds is essential frequency, composition and mode of to find, fix and prevent them. This chapter entry in the storm drain system. begins by defining the terms used to describe illicit discharges, and then reviews the water 3. Illicit discharges are frequently caused quality problems they cause. Next, the when the sewage disposal system chapter presents the regulatory context for interacts with the storm drain system. A controlling illicit discharges, and reviews the variety of monitoring techniques is used experience local communities have gained to locate and eliminate illegal sewage in detecting and eliminating them. connections. These techniques trace sewage flows from the stream or outfall, 1 .1 Important Terminology and and go back up the pipes or conveyances Key Concepts to reach the problem connection. This Manual uses several important terms 4. Illicit discharges of other pollutants are throughout the text that merit upfront produced from specific source areas and explanation. This section defines the operations known as "generating sites." terminology to help program managers Knowledge about these generating sites perform important illicit discharge detective can be helpful to locate and prevent non- work in their communities. Key concepts are sewage illicit discharges. Depending on presented to classify illicit discharges, the regulatory status of specific cc generating sites and control techniques. generating sites, education, enforcement and other pollution Illicit Discharge prevention techniques can be used to manage this class of illicit discharges. The term"illicit discharge"has many meanings in regulations and practice, but we use a Communities need to define illicit four-part definition in this manual. discharges as part of an illicit discharge ordinance. Some non-storm water I. Illicit discharges are defined as a storm discharges to the MS4 may be allowable, drain that has measurable flow during such as discharges resulting from fire dry weather containing pollutants and/or fighting activities and air conditioning pathogens. A storm drain with condensate. Chapter 4 provides more detail measurable flow but containing no on ordinance development. pollutants is simply considered a discharge. �40 CFR 122.26(b)(2)defines an illicit discharge as any discharge to an MS4 that is not composed entirely of storm water,except allowable discharges pursuant to an NPDES permit,including those resulting from fire fighting activities. Illicit Discharge Detection and Elimination:A Guidance Manual 5 Chapter 1: The Basics of Illicit Discharges Storm Drain Continuous discharges occur most or all of A storm drain can be either an enclosed the time, are usually easier to detect, and pipe or an open channel. From a regulatory typically produce the greatest pollutant load. standpoint, major storm drains are defined Intermittent discharges occur over a shorter as enclosed storm drain pipes with a diameter of period of time (e.g., a few hours per day or a 36 inches, or greater or open channels that few days per year).Because they are infrequent, drain more than 50 acres. For industrial land intermittent discharges are hard to detect, uses, major drains are defined as enclosed but can still represent a serious water quality storm drain pipes 12 inches or greater in problem, depending on their flow type. diameter and open channels that drain more Transitory discharges occur rarely, usually than two acres. Minor storm drains are in response to a singular event such as an smaller than these thresholds. Both major industrial spill, ruptured tank, sewer break, and minor storm drains can be a source of transport accident or illegal dumping illicit discharges,and both merit investigation. episode. These discharges are extremely hard to detect with routine monitoring, but Some "pipes" found in urban areas may look under the right conditions, can exert severe like storm drains but actually serve other water quality problems on downstream purposes. Examples include foundation receiving waters. drains, weep holes, culverts, etc. These pipes are generally not considered storm drains Discharge Flow Types from a regulatory or practical standpoint. Small diameter"straight pipes,"however, Dry weather discharges are composed of one are a common source of illicit discharges in or more possible flow types: many communities and should be investigated to determine if they are a • Sewage and septage flows are produced pollutant source. from sewer pipes and septic systems. Not all dry weather storm drain flow contains • Washwater flows are generated from a pollutants or pathogens. Indeed, many wide variety of activities and operations. communities find that storm drains with dry Examples include discharges of gray weather flow are, in fact, relatively clean. water(laundry) from homes, commercial Flow in these drains may be derived from carwash wastewater, fleet washing, springs, groundwater seepage, or leaks from commercial laundry wastewater, and water distribution pipes. Consequently, field floor washing to shop drains. testing and/or water quality sampling are needed to confirm whether pollutants are • Liquid wastes refers to a wide variety of actually present in dry weather flow, in flows, such as oil, paint, and process order to classify them as an illicit discharge. water(radiator flushing water, plating bath wastewater, etc.)that enter the Discharge Frequency storm drain system. The frequency of dry weather discharges in Tap water flows are derived from leaks storm drains is important, and can be and losses that occur during the classified as continuous, intermittent or distribution of drinking water in the transitory. water supply system. Tap water 6 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 1: The Basics of Illicit Discharges discharges in the storm drain system volumes of storm water runoff making it may be more prevalent in communities difficult and frequently impossible to detect with high loss rates (i.e., greater than them during wet weather periods. 15%) in their potable water distribution system. (source of 15% is from National Mode of Entry Drinking Water Clearinghouse http://www.nesc.wvu.edu/ndwc/articles/ Illicit discharges can be further classified OT/FA02/Economics_Water.html) based on how they enter the storm drain system. The mode of entry can either be • Landscape irrigation flows occur when direct or indirect. Direct entry means that excess potable water used for residential the discharge is directly connected to the or commercial irrigation ends up in the storm drain pipe through a sewage pipe, storm drain system. shop drain, or other kind of pipe. Direct entry usually produces discharges that are • Groundwater and spring water flows continuous or intermittent. Direct entry occur when the local water table rises usually occurs when two different kinds of above the bottom elevation of the storm "plumbing" are improperly connected. The drain (known as the invert) and enters three main situations where this occurs are: the storm drain either through cracks and joints, or where open channels or pipes Sewage cross-connections: A sewer pipe associated with the MS4 may intercept that is improperly connected to the storm seeps and springs. drain system produces a continuous discharge of raw sewage to the pipe (Figure 1). Sewage Water quality testing is used to conclusively cross-connections can occur in catchments identify flow types found in storm drains. where combined sewers or septic systems Testing can distinguish illicit flow types are converted to a separate sewer system, (sewage/septage, washwater and liquid and a few es i et"crossed." wastes) from cleaner discharges (tap water, pipes g landscape irrigation and ground water). Straight pipe: This term refers to relatively small diameter pipes that intentionally Each flow type has a distinct chemical bypass the sanitary connection or septic fingerprint. Table 1 compares the pollutant drain fields, producing a direct discharge fingerprint for different flow types in into open channels or streams as shown in Alabama. The chemical fingerprint for each Figure 2. flow type can differ regionally, so it is a good idea to develop your own"fingerprint" library by sampling each local flow type. In practice, many storm drain discharges represent a blend of several flow types, particularly at larger outfalls that drain larger catchments.For example,groundwater flows often dilute sewage thereby masking its presence. Chapter 12 presents several techniques to help isolate illicit discharges that are blended with cleaner discharges. Illicit discharges are also masked by high Figure 1: Sewer Pipe Discharging to the Storm Drain Svstem Illicit Discharge Detection and Elimination:A Guidance Manual 7 Chapter 1: The Basics of Illicit Discharges ComparativeTable 1: Hardness NH3 Potassium Conductivity Fluoride Detergents Flow Type (mg/L as (mg/L) (mg/L) (PS/cm) (mg/L) (mg/L) CaCO3) Sewage 50 (0.26)* 25 (0.53)* 12 (0.21)* 1215 (0.45)* 0.7 (0.1)* 9.7 (0.17)* Septage** 57(0.36) 87 (0.4) 19 (0.42) 502 (0.42) 0.93 (0.39) 3.3 (1.33) Laundry Washwater 45 (0.33) 3.2 (0.89) 6.5 (0.78) 463.5 (0.88) 0.85 (0.4) 758 (0.27) Car Washwater 71 (0.27) 0.9 (1.4) 3.6 (0.67) 274 (0.45) 1.2 (1.56) 140 (0.2) Plating Bath (Liquid 1430 (0.32) 66 (0.66) 1009 (1.24) 10352 (0.45) 5.1 (0.47) 6.8 (0.68) Industrial Waste**) Radiator Flushing (Liquid Industrial 5.6 (1.88) 26 (0.89) 2801 (0.13) 3280 (0.21) 149 (0.16) 15 (0.11) Waste**) Tap Water 52 (0.27) <0.06 1.3 (0.37) 140 (0.07) 0.94 (0.07) O(NA) (0.55) Groundwater 38 (0.19) 0.06 (1.35) 3.1 (0.55) 149 (0.24) 0.13 (0.93) O(NA) Landscape Irrigation 53 (0.13) 1.3 (1.12) 5.6 (0.5) 180 (0.1) 0.61 (0.35) O(NA) *The number in parentheses after each concentration is the Coefficient of Variation,NA = Not Applicable **All values are from Tuscaloosa,AL monitoring except liquid wastes and septage, which are from Birmingham, AL. Sources:Pitt(project support material) and Pitt et al. (1993) Sewage has the greatest potential to produce direct illicit discharges within any urban subwatershed, regardless of the diverse land uses that it comprises. The most commonly reported sewage- related direct discharges are broken sanitary sewer lines (81% of survey respondents), cross-connections (71% of survey respondents), and straight pipe discharges (38% of survey respondents). Figure 2: Direct Discharge from a Straight Pipe (CWP, 2002). Industrial and commercial cross- the joints of the pipe. Generally, indirect connections: These occur when a drain pipe modes of entry produce intermittent or is improperly connected to the storm drain transitory discharges, with the exception of system producing a discharge of wash water, groundwater seepage. The five main modes process water or other inappropriate flows of indirect entry for discharges include: into the storm drain pipe. A floor shop drain that is illicitly connected to the storm drain Groundwater seepage into the storm drain system is illustrated in Figure 3. Older pipe: Seepage frequently occurs in storm industrial areas tend to have a higher drains after long periods of above average potential for illicit cross-connections. rainfall. Seepage discharges can be either continuous or intermittent, depending on the Indirect entry means that flows generated depth of the water table and the season. outside the storm drain system enter through Groundwater seepage usually consists of storm drain inlets or by infiltrating through relatively clean water that is not an illicit 8 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 1: The Basics of Illicit Discharges discharge by itself, but can mask other illicit Outdoor washing activities that create flow discharges. If storm drains are located close to a storm drain inlet: Outdoor washing may to sanitary sewers, groundwater seepage or may not be an illicit discharge, depending may intermingle with diluted sewage. on the nature of the generating site that produces the wash water. For example, Spills that enter the storm drain system at an hosing off individual sidewalks and inlet: These transitory discharges occur driveways may not generate significant when a spill travels across an impervious flows or pollutant loads. On the other hand, surface and enters a storm drain inlet. Spills routine washing of fueling areas, outdoor can occur at many industrial, commercial storage areas, and parking lots (power and transport-related sites. A very common washing), and construction equipment example is an oil or gas spill from an accident cleanouts may result in unacceptable that then travels across the road and into the pollutant loads (Figure 6). storm drain system (Figure 4). Non-targetirrigation from landscaping_or Dumping a liquid into a storm drain inlet: lawns that reaches the storm drain s. ste This type of transitory discharge is created Irrigation can produce intermittent discharges when liquid wastes such as oil, grease, paint, from over-watering or misdirected sprinklers solvents, and various automotive fluids are that send tap water over impervious areas dumped into the storm drain(Figure 5).Liquid (Figure 7). In some instances, non-target dumping occurs intermittently at sites that irrigation can produce unacceptable loads of improperly dispose of rinse water and wash nutrients, organic matter or pesticides. The water during maintenance and cleanup most common example is a discharge from operations. A common example is cleaning commercial landscaping areas adjacent to deep fryers in the parking lot of fast food parking lots connected to the storm drain operations. system. Figure 3: A common industrial cross Figure 4: Accident spills are significant connection is a floor drain that is illicitly sources of illicit discharges to the storm connected to a storm drain drain system Illicit Discharge Detection and Elimination:A Guidance Manual 9 Chapter 1: The Basics of Illicit Discharges 2 � Figure 5: Dumping at a storm drain inlet Figure 6: Routine outdoor washing and rinsing can cause illicit discharges .`•sue , Figure 7: Non-target landscaping irrigation water Land Use and Potential Generating discharges. Consequently,the density of Sites potential generating sites within a subwatershed may be a good indicator of the Land use can predict the potential for severity of local illicit discharge problems. indirect discharges, which are often Some common generating sites within major intermittent or transitory. Many indirect land use categories are listed in Table 2, and discharges can be identified and prevented described below. using the concept of"generating sites," which are sites where common operations Residential Generating ites: Failing septic can generate indirect discharges in a systems were the most common residential community. Both research and program discharge reported in 33% of IDDE experience indicate that a small subset of programs surveyed(CWP,2002).In addition, generating sites within a broader land use indirect residential discharges were also category can produce most of the indirect 10 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 1: The Basics of Illicit Discharges frequently detected in 20% of the IDDE Typical commercial discharge generators programs surveyed, which consisted of oil included operations such as outdoor dumping, irrigation overflows, swimming washing; disposal of food wastes; car pool discharges, and car washing. Many fueling, repair, and washing; parking lot indirect discharges are caused by common power washing; and poor dumpster residential behaviors and may not be classified management.Recreational areas, such as as "illicit" even though they can contribute marinas and campgrounds, were also to water quality problems. With the reported to be a notable source of sewage exception of failing septic systems and oil discharges. It is important to note that not all dumping, most communities have chosen businesses within a generating category education rather than enforcement as the actually produce illicit discharges; generally primary tool to prevent illicit discharges only a relatively small fraction do. from residential areas. Consequently, on-site inspections of individual businesses are needed to confirm Commercial Generating Sites: Illicit whether a property is actually a generating discharges from commercial sites were site. reported as frequent in almost 20% of local IDDE programs surveyed (CWP, 2002). Sewage can also be linked to significant indirect illicit discharges in the form of sanitary sewer overflows (52% of survey respondents), sewage infiltration/inflow (48% of survey respondents), and sewage dumping from recreational vehicles (33% of survey respondents) (CWP, 2002). Illicit Discharge Detection and Elimination:A Guidance Manual 11 Chapter 1: The Basics of Illicit Discharges • • Uses, Generating Sites and Activities That Produce • Discharges Land Use Generating Site Activity that Produces Discharge • Car Washing • Driveway Cleaning • Apartments Dumping/Spills (e.g., leaf litter and Residential 0 Multi-family RV/boat holding tank effluent) • Single Family Detached Equipment Washdowns • Lawn/Landscape Watering • Septic System Maintenance • Swimming Pool Discharges • Campgrounds/RV parks 0 Building Maintenance (power washing) • Car Dealers/Rental Car 0 Dumping/Spills Companies 0 Landscaping/Grounds Care (irrigation) • Car Washes 0 Outdoor Fluid Storage • Commercial Laundry/Dry Cleaning 0 Parking Lot Maintenance (power Commercial 0 Gas Stations/Auto Repair Shops washing) • Marinas 0 Vehicle Fueling • Nurseries and Garden Centers 0 Vehicle Maintenance/Repair • Oil Change Shops 0 Vehicle Washing • Restaurants 0 Washdown of greasy equipment and • Swimming Pools grease traps • Auto recyclers • Beverages and brewing • Construction vehicle washouts • Distribution centers All commercial activities • Food processing Industrial process water or rinse water Industrial 0 Garbage truck washouts Loading and un-loading area washdowns • Marinas, boat building and repair Outdoor material storage (fluids) • Metal plating operations • • Paper and wood products • Petroleum storage and refining • Printing • Building Maintenance (e.g., power • Cemeteries washing) • Churches 0 Dumping/Spills Institutional 0 Corporate Campuses 0 Landscaping/Grounds Care (irrigation) • Hospitals 0 Parking Lot Maintenance (power • Schools and Universities washing) • Vehicle Washing • Building Maintenance (power washing) • Dumping/Spills • Airports 0 Landscaping/Grounds Care (irrigation) • Landfills 0 Outdoor Fluid Storage • Maintenance Depots 0 Parking Lot Maintenance (power Municipal 0 Municipal Fleet Storage Areas washing) • Ports 0 Road Maintenance • Public Works Yards 0 Spill Prevention/Response • Streets and Highways 0 Vehicle Fueling • Vehicle Maintenance/Repair • Vehicle Washing 12 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 1: The Basics of Illicit Discharges Industrial Generating Sites: Industrial sites handle solid waste, water, wastewater, street produce a wide range of flows that can cause and storm drain maintenance, fleet washing, illicit discharges. The most common and yard waste disposal. Transport-related continuous discharges are operations areas such as streets and highways, airports, involving the disposal of rinse water, process rail yards, and ports can also generate water,wash water and contaminated,non- indirect discharges from spills, accidents and contact cooling water. Spills and leaks, dumping. ruptured pipes, and leaking underground storage tanks are also a source of indirect Finding, Fixing, and Preventing Illicit discharges. Illicit discharges from industry Discharges were detected in nearly 25% of the local IDDE programs surveyed (CWP, 2002). The purpose of an IDDE program is to find, fix and prevent illicit discharges, and a Industries are classified according to series of techniques exist to meet these hundreds of different Standard Industrial objectives. The remainder of the manual Classification (SIC) codes. The SIC coding describes the major tools used to build a system also includes commercial, local IDDE program, but they are briefly institutional and municipal operations . introduced below: Many industries are required to have storm water pollution prevention and spill Finding Illicit Discharges response plans under EPA's Industrial Storm Water NPDES Permit Program. A The highest priority in most programs is to complete list of the industries covered by the find any continuous and intermittent sewage Storm Water NPDES Permit Program can be discharges to the storm drain system. A found in Appendix A. The appendix also range of monitoring techniques can be used rates each industrial category based on its to find sewage discharges. In general, potential to produce illicit discharges, based monitoring techniques are used to find on analysis by Pitt(2001). problem areas and then trace the problem back up the stream or pipe to identify the Institutional Generatin•e Sites: Institutions ultimate generating site or connection. such as hospitals, corporate campuses, Monitoring can sometimes pick up other colleges, churches, and cemeteries can be types of illicit discharge that occur on a generating sites if routine maintenance continuous or intermittent basis (e.g., wash practices/operations create discharges from water and liquid wastes). Monitoring parking lots and other areas. Many large techniques are classified into three major institutional sites have their own areas for groups: fleet maintenance, fueling, outdoor storage, and loading/unloading that can produce . Outfall Reconnaissance Inventory indirect discharges. . Indicator Monitoring at Storm Water Municipal Generatin'e Sites: Municipal Outfalls and In-stream generating sites include operations that • Tracking Discharges to their Source 2 More recently,federal agencies including EPA,have adopted the North American Industry Classification System(NAICS, pronounced"Nakes")as the industry classification system.For more information on the NAICS and how it correlates with SIC, visit http://www.census.00v/epcd/www/naics.html. Illicit Discharge Detection and Elimination:A Guidance Manual 13 Chapter 1: The Basics of Illicit Discharges !!! Caution !!! Using land use as an indicator for certain flow types such as sewage is often less reliable than other factors in predicting the potential severity of sewage discharges. More useful assessment factors for illicit sewage discharges include the age of the sewer system, which helps define the physical integrity and capacity of the pipe network, as well as age of development, which reveals the plumbing codes and practices that existed when individual connections were made over time. Two particular critical phases in the sewer history of a subwatershed are when sanitary sewers were extended to replace existing septic systems, or when a combined sewer was separated. The large number of new connections and/or disconnections during these phases increases the probability of bad plumbing. Fixing Illicit Discharges Preventing Illicit Discharges Once sewage discharges or other The old adage "an ounce of prevention is connections are discovered, they can be worth a pound of cure" certainly applies to fixed, repaired or eliminated through several illicit discharges. Transitory discharges from different mechanisms. Communities should generating sites can be minimized through establish targeted education programs along pollution prevention practices and well- with legal authority to promote timely executed spill management and response corrections. A combination of carrots and plans. These plans should be frequently sticks should be available to deal with the practiced by local emergency response diversity of potential dischargers. agencies and/or trained workers at generating sites. Other pollution prevention practices are described in Chapter 9 and explored in greater detail in Manual 8 of the Urban Subwatershed Restoration Manual Series (Schueler et al., 2004). National Urban Runoff Project EPA's National Urban Runoff Project (NURP) studies highlighted the significance of pollutants from illicit entries into urban storm sewerage (EPA, 1983). Such entries may be evidenced by flow from storm sewer outfalls following substantial dry periods. Such flow, frequently referred to as "baseflow" or "dry weather flow", could be the result of direct "illicit connections" as mentioned in the NURP final report (EPA, 1983), or could result from indirect connections (such as leaky sanitary sewer contributions through infiltration). Many of these dry weather flows are continuous and would therefore occur during rain induced runoff periods. Pollutant contributions from dry weather flows in some storm drains have been shown to be high enough to significantly degrade water quality because of their substantial contributions to the annual mass pollutant loadings to receiving waters (project research). 14 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 1: The Basics of Illicit Discharges 1 .2 The Importance of Illicit drain system. Of the 160 businesses tested, Discharges in Urban Water 38% were found to have illicit storm drain Quality connections (Schmidt and Spencer, 1986). An investigation of the separate storm sewer system in Toronto, Ontario revealed 59% of Dry and wet weather flows have been outfalls had dry weather flows, while 14% monitored during several urban runoff of the total outfalls were characterized as studies. These studies have found that "grossly polluted,"based on a battery of discharges observed at outfalls during dry chemical tests (GLA, 1983). An inspection weather were significantly different from of the 90 urban storm water outfalls draining wet weather discharges. Data collected into Grays Harbor in Washington showed during the 1984 Toronto Area Watershed that 32% had dry weather flows (Pelletier Management Strategy Study monitored and and Determan, 1988). An additional 19 characterized both storm water flows and outfalls were considered suspect, based on baseflows (Pitt and McLean, 1986). This visual observation and/or elevated pollutant project involved intensive monitoring in two levels compared to typical urban storm test areas (a mixed residential/commercial water runoff. area and an industrial area) during warm, cold, wet, and dry weather. The annual mass The Huron River Pollution Abatement discharges of many pollutants were found to Program ranks as one of the most thorough be greater in dry weather flows than in wet and systematic early investigations of illicit weather flows. discharges (Washtenaw County, 1988). More than a thousand businesses, homes and A California urban discharge study other buildings located in the watershed identified commercial and residential were dye tested. Illicit connections were discharges of oil and other automobile- found at 60% of the automobile-related related fluids as a common problem based businesses tested, which included service on visual observations (Montoya, 1987). In stations, automobile dealerships, car washes, another study, visual inspection of storm and auto body and repair shops. All plating water pipes discharging to the Rideau River shops inspected were found to have illicit in Ontario found leakage from sanitary storm drain connections. Additionally, 67% sewer joints or broken pipes to be a major of the manufacturers, 20% of the private source of storm drain contamination (Pitt, service agencies and 88% of the 1983). wholesale/retail establishments tested were found to have illicit storm sewer connections. Several urban communities conducted Of the 319 homes dye tested, 19 were found studies to identify and correct illicit to have direct sanitary connections to storm connections to their storm drain systems drains. The direct discharge of rug-cleaning during the mid-1980s. These studies were wastes into storm drains by carpet cleaners usually taken in response to receiving water was also noted as a common problem. quality problems or as part of individual NURP research projects. The studies Eliminating illicit discharges is a critical indicated the magnitude and extent of cross- component to restoring urban watersheds. connection problems in many urban When bodies of water cannot meet watersheds. For example, Washtenaw designated uses for drinking water, fishing, County, Michigan tested businesses to locate or recreation, tourism and waterfront home direct illicit connections to the county storm Illicit Discharge Detection and Elimination:A Guidance Manual 15 Chapter 1: The Basics of Illicit Discharges values may fall; fishing and shellfish rule, known as Phase I to implement section harvesting can be restricted or halted; and 402(p) of the Clean Water Act through the illicit discharges can close beaches, primarily NPDES permit system. The EPA effort as a result of bacteria contamination. In expanded in December 1999, when the addition to the public health and economic Phase II final rule was issued. A summary of impacts associated with illicit discharges, how both rules pertain to MS4s and illicit significant impacts to aquatic life and discharge control is provided below. wildlife are realized. Numerous fish kills and other aquatic life losses have occurred Summary of NPDES Phase 1 in watersheds as a result of illicit or Requirements accidental dumping and spills that have resulted in lethal pollutant concentrations in The NPDES Phase I permit program receiving waters. regulates municipal separate storm sewer systems (MS4s) meeting the following 1 .3 Regulatory Background For criteria: Illicit Discharges • Storm sewer systems located in an The history of illicit discharge regulations is incorporated area with a population of long and convoluted, reflecting an ongoing 100,000 or more debate as to whether they should be 0 Storm sewer systems located in 47 classified as a point or nonpoint source of counties identified by EPA as having pollution. The Clean Water Act amendments populations over 100,000 that were of 1987 contained the first provisions to unincorporated but considered specifically regulate discharges from storm urbanized areas drainage systems. Section 402(p)(3)(B) Other storm sewer systems that are provides that"permits for such discharges: specially designated based on the (i) May be issued on a system or location of storm water discharges with jurisdiction-wide basis respect to waters of the United States, the size of the discharge, the quantity (ii) Shall include a requirement to and nature of the pollutants discharged, effectively prohibit non-storm water and the interrelationship to other discharges into the storm sewers; and regulated storm sewer systems, among (iii) Shall require controls to reduce the other factors discharge of pollutants to the maximum extent practical including An MS4 is defined as any conveyance or management practices, control system of conveyances that is owned or techniques and system design and operated by a state or local government entity engineering methods, and such designed for collecting and conveying storm provisions as the Administrator or water, which is not part of a Publicly Owned the State determines appropriate for Treatment Works. The total number of the control of such pollutants." permitted MS4s in the Phase I program is 1,059. In the last 15 years, NPDES permits have gradually been applied to a greater range of communities. In 1990, EPA issued a final 16 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 1: The Basics of Illicit Discharges PHASE I HIGHLIGHTS Who must meet the requirements? M545 with population krkk >_100,000 How many Phase I communities 1,059 exist nationally? What are the requirements related Develop programs to prevent, detect and to illicit discharges? remove illicit discharges Phase I MS4s were required to submit a means to prevent illicit discharges to two-part application. The first part required the MS4 information regarding existing programs and . Procedures to conduct ongoing field the capacity of the municipality to control screening activities during the life of pollutants. Part 1 also required identification the permit of known "major" outfalls3 discharging to waters of the United States, and a field Procedures to be followed to screening analysis of representative major investigate portions of the separate outfalls to detect illicit connections. Part 2 of storm sewer system that, based on the application required identification of the results of the field screening additional major outfalls, limited required in Part 2 of the application, monitoring, and a proposed storm water indicate a reasonable potential for management plan (EPA, 1996). containing illicit discharges or other sources of non-storm water Phase I communities were required to . Procedures to prevent, contain, and develop programs to detect and remove illicit respond to spills that may discharge discharges, and to control and prevent into the MS4 improper disposal into the MS4 of materials such as used oil or seepage from municipal A program to promote,publicize, sanitary sewers. The illicit discharge and facilitate public reporting of the programs were required to include the presence of illicit discharges or water following elements: quality impacts associated with discharges from the MS4 • Implementation and enforcement of Educational activities, public an ordinance, orders or similar information activities, and other appropriate activities to facilitate the s A"major"outfall is defined as an MS4 outfall that discharges proper management and disposal of from a single pipe with an inside diameter of at least 36 inches, used oil and toxic materials or discharges from a single conveyance other than a circular pipe serving a drainage area of more than 50 acres.An MS4 Controls to limit infiltration of outfall with a contributing industrial land use that discharges from a single pipe with an inside diameter of 12 inches or more or seepage from municipal sanitary discharges from a single conveyance other than a circular pipe sewers to the MS4 serving a drainage area of more than two acres. Illicit Discharge Detection and Elimination:A Guidance Manual 17 Chapter 1: The Basics of Illicit Discharges Summary of NPDES Phase 11 Under the third minimum measure, an illicit Requirements discharge is defined as any discharge to an MS4 that is not composed entirely of storm The Phase II Final Rule, published in the water, except allowable discharges pursuant Federal Register regulates MS4s that meet to an NPDES permit, including those both of the following criteria: resulting from fire fighting activities (40 CFR 122.26(b)(2)). To satisfy this minimum • Storm sewer systems that are not a measure, the regulated small MS4 must medium or large MS4 covered by Phase include the following five components: I of the NPDES Program • Storm sewer systems that are located in Develop a storm sewer system map that an Urbanized Area (UA) as defined by shows the location of all outfalls and the the Bureau of the Census, or storm sewer names and locations of all waters of the systems located outside of a UA that are United States that receive discharges designated by NPDES permitting from those outfalls authorities because of one of the Prohibit, through ordinance or other following reasons: regulatory mechanism, non-storm water discharges into the storm sewer system — The MS4's discharges cause, or and implement appropriate enforcement have the potential to cause, an procedures and actions adverse impact on water quality Develop and implement a plan to detect — The MS4 contributes substantially and address illicit discharges to the MS4 to the pollutant loadings of a Educate public employees, businesses, physically interconnected MS4 and the general public of hazards regulated by the NPDES storm associated with illicit discharges and water program improper disposal of waste • Identify the appropriate best MS4s that meet the above criteria are management practices and measurable referred to as regulated small MS4s. Each goals for this minimum measure regulated small MS4 must satisfy six minimum control measures: 1. Public education and outreach 2. Public participation/involvement 3. Illicit discharge detection and elimination 4. Construction site runoff control 5. Post-construction runoff control 6. Pollution prevention/Good housekeeping 18 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 1: The Basics of Illicit Discharges PHASE II HIGHLIGHTS Who must meet the requirements? Selected small M54s How many Phase I communities EPA estimates are 5,000-6,000 exist nationally? What are the requirements related Develop programs to prevent, detect to illicit discharges? and remove illicit discharges What is the deadline for meeting Permits issued by March 10, 2003. these requirements? Programs must be fully implemented by the end of first permit term (5 years) In the regulation, EPA recommends that the detailed survey included 24 communities plan to detect and address illicit discharges from various geographic and climatic include procedures for: regions in the United States. Some of the Locating priority areas likely to have key findings of the s4urvey are presented • illicit discharges (which may include below (CWP 2002) . visually screening outfalls during dry Lack of staff significantly hindered weather and conducting field tests of implementation of a successful IDDE selected pollutants) program. Phase I communities rely • Tracing the source of an illicit discharge heavily on the expertise of their field • Removing the source of the discharge staff—practical expertise that has been • Program evaluation and assessment acquired over many years as programs gradually developed. Methods or approaches recommended for Phase II 1 .4 Experience Gained in communities should be less dependent Phase I on professional judgment. The Center for Watershed Protection conducted a series of surveys and interviews with Phase I communities to determine the Survey results are based on responses from 24 jurisdictions from 16 states.Surveys were supplemented by current state of the practices utilized in local on-site interviews of staff of eight IDDE programs: Baltimore IDDE programs, and t identify the most City, MD; Baltimore County, MD; Boston Water and Sewer p g O eriy Commission(BWSC), MA;Cambridge, MA; Dayton,OH; practical, low-cost, and effective techniques Raleigh, NC;Wayne County, MI;and Fort Worth,TX. Jurisdictions selected for the survey and interviews to find, fix and prevent discharges. The represent a variety of geographic and climatic regions.The EPA storm water coordinators for each region of the country were contacted for recommendations on jurisdictions to include in the survey.Also, a variety of jurisdiction sizes in terms of population, IDDE program service area,and land use was targeted. Illicit Discharge Detection and Elimination:A Guidance Manual 19 Chapter 1: The Basics of Illicit Discharges • Clear and effective ordinance language When purchasing equipment, Phase II should be adopted by Phase II programs should communicate with communities to ensure that all potential other jurisdictions to consider sharing sources of illicit discharges are field equipment and laboratory costs. prohibited, and that the community has sufficient legal authority to inspect Use of some discharge tracers has private properties and enforce proven challenging and sometimes corrections. fruitless, because of false or ambiguous results and complex or hazardous • Many communities lacked up-to-date analytical methods. Accurate, cost- mapping resources, and found that effective, and safe monitoring methods mapping layers such as storm sewers, are needed to effectively use tracers. open drainage channels, waters of the U.S., outfalls, and land use were Municipal IDDE programs worked best particularly useful to conduct and when they integrated illicit discharge prioritize effective field investigations. control in the wider context of urban watershed restoration. Table 3 provides • Outfall screening required the greatest some examples of how greater staff and equipment resources, and did interagency cooperation can be achieved not always find problem outfalls. by linking restoration program areas. Communities recommended a fast and efficient sampling approach that utilizes In summary, survey communities expressed a limited number of indicator parameters a strong need for relatively simple guidance at each outfall to find problem outfalls. to perform illicit discharge investigations. To address this need, the Manual has been designed to make simple program and technical recommendations for Phase II communities to develop cost-effective IDDE programs. 20 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 1: The Basics of Illicit Discharges Table 3: Linking Other Municipal Programs to IDDE Program Needs Watershed-Related Program How Program Relates to IDDE Program Needs Subwatershed Mapping and • Mapping and aerial photography are critical tools needed pp g for illicit connection detection surveys. GIS tax map Analysis layers are often useful to identify property ownership. • Observations from physical stream assessments are Rapid Assessment of Stream often useful in identifying problem areas, including dry Corridors weather flow outfalls, illegal dumping, and failing infrastructure locations. Watershed Monitoring and Reporting • Compiled water quality and other indicator data can be useful in targeting problem areas. • Stream restoration opportunities can often be Stream Restoration Opportunities coordinated with sewer infrastructure upgrades and maintenance. • Educating the public about unwanted discharges can save programs money by generating volunteer networks Watershed Education to report and locate problem areas. Better awareness by the public can also reduce the likelihood of unintentional cross-connections. Pollution Prevention for Generating Providing incentives to businesses to inspect and correct Sites connections can save programs money. Illicit Discharge Detection and Elimination:A Guidance Manual 21 Chapter 1: The Basics of Illicit Discharges 22 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 2:Components of an Effective IDDE Program Chapter 2: Components of an Effective IDDE Program The prospect of developing and administering through rapid analysis of existing mapping an IDDE program can be daunting, complex and water quality monitoring data. and challenging in many communities. This Chapter organizes and simplifies the basic 4. Develop Program Goals and tasks needed to build a program. In general, Implementation Strategies—This program a community should consider eight basic component integrates information developed program components, as follows: from the first three program components to establish measurable goals for the overall 1. Audit Existing Resources and IDDE program during the first permit cycle. Programs—The first program component Based on these goals, managers develop reviews existing local resources, regulations, specific implementation strategies to and responsibilities that bear on illicit improve water quality and measure program discharge control in the community. A success. systematic audit defines local needs and capabilities, and provides the foundation for 5. Search for Illicit Discharge Problems in developing the initial IDDE program plan the Field—This component involves rapid over the first permit cycle. outfall screening to find problem outfalls within priority subwatersheds. Results of 2. Establish Responsibility,Authority and outfall surveys are then used to design a Tracking—This component finds the right more sophisticated outfall monitoring "home" for the IDDE program within system to identify flow types and trace existing local departments and agencies. It discharge sources.Many different monitoring also establishes the local legal authority to options exist, depending on local needs and regulate illicit discharges, either by discharge conditions. amending an existing ordinance, or crafting a new illicit discharge ordinance. This 6. Isolate and Fix Individual Discharges— program component also involves creation Once illicit discharge problems are found, of a tracking system to report illicit the next step is to trace them back up the discharges, suspect outfalls, and citizen pipe to isolate the specific source or complaints, and to document local improper connection that generates them. management response and enforcement Thus, this program component improves efforts. local capacity to locate specific discharges, make needed corrections, and take any 3. Complete a Desktop Assessment of enforcement actions. Illicit Discharge Potential—Illicit discharges are not uniformly distributed 7. Prevent Illicit Discharges—Many across a community, but tend to be clustered transitory and intermittent discharges are within certain land uses,subwatersheds,and produced by careless practices at the home sewage infrastructure eras. This program or workplace. This important program component helps narrow your search for the component uses a combination of education most severe illicit discharge problems, and enforcement to promote better pollution prevention practices. A series of carrots and Illicit Discharge Detection and Elimination:A Guidance Manual 23 Chapter 2:Components of an Effective IDDE Program sticks is used to reach out to targeted its purpose, methods, desired product or individuals to prevent illegal or unintentional outcome, and budget implications. The illicit discharges. remainder of each chapter provides program managers with detailed guidance to choose 8. Evaluate the Program—The last the best options to implement the program component addresses the ongoing component in their community. management of the IDDE program. The measurable goals set for the IDDE program Scheduling of the eight IDDE program are periodically reviewed and revisited to components is not always sequential and determine if progress is being made, or may overlap in some cases. In general, the implementation strategies need to be first four program components should be adjusted. scheduled for completion within the first year of the permit cycle in order to develop Within each program component, a an effective program for the remaining years community has many options to choose, of the permit. Table 4 summarizes the based on its size, capability and the severity specific tasks and products associated with of its illicit discharge problems. Chapters 3 each IDDE program component. The through 10 address each IDDE program scheduling, costs and expertise needed for component in more detail, and summarize each IDDE program component are compared in Table 5. Table 4: Key Tasks and Products in IDDE Program Implementation Program Key Tasks Products Component • Infrastructure Profile • Existing Legal Authority Agreement on Lead Agency 1. Audit existing • Available Mapping . 5 year Program Development programs Experienced Field Crews Plan • Access to Lab Services First Year Budget and Scope • Education and Outreach Outlets of Work • Discharge Removal Capability • Program Budget and Financing 2. Establish Review Existing Ordinances responsibility and Define "Illicit" • Adopt or Amend Ordinance authority Provisions for Access/Inspections 0 Implement Tracking System • Select Enforcement Tools • Design Tracking System 3. Desktop Delineate Subwatersheds assessment of Compile Mapping Layers/Data illicit discharge Define Discharge Screening Factors 9 Prioritize Subwatersheds for potential Screen Subwatersheds for Illicit Field Screening Discharge Potential • Generate Maps for Field Screening 4. Develop program Community Analysis of Illicit Discharge 0 Measurable Program Goals goals and Public Involvement 0 Implementation Strategies strategies 24 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 2:Components of an Effective IDDE Program Tableand Products in IDDE Program • • Program Key Tasks Products Component 5. Search for illicit Outfall Reconnaissance Inventory (ORI) Initial Storm Drain Outfall discharges Integrate ORI data in Tracking System Map problems in the Follow-up Monitoring at Suspect Outfalls Develop Monitoring Strategy field 6. Isolate and fix Implement Pollution Hotline Maintain Tracking System individual 0 Trunk and On-site Investigations discharges 0 Corrections and Enforcement • Select Key Discharge Behaviors 0 Implement Residential, 7. Prevent illicit 0 Prioritize Outreach Targets Commercial, Industrial or discharges 0 Choose Effective Carrots and Sticks Municipal Pollution • Develop Budget and Delivery System Prevention Programs 8. Program Analyze Tracking System • Annual Reports evaluation • Characterize Illicit Discharges Detected , Permit Renegotiation • Update Goals and Strategies Table 5: Comparison of IDDE Program Components IDDE Program When Startup Annual Expertise Component To Do It Costs Cost Level Type of Expertise 1. Audit Immediately $ -0- ?? Planning/Permitting 2. Authority Year 1 $$ $ ?? Legal 3. Desktop Analysis Year 1 $$ -0- ??? GIS 4. Goals/Strategies Year 1 $ -0- ?? Stakeholder Management 5 Field ??? Monitoring Search/Monitoring Year 2 to 5 $$ $$$$ 6 Isolate and Fix Year 2 to 5 $ $$ ??? Pipe and Site Investigations 7. Prevention Year 2 to 5 $$ $$$ ?? Education 8. Evaluation/Tracking Annually -0- $ ? Data Analysis Key: $ _ <$10,000 ? -Simple $$ _ $10,000 -25,000 �? _ Moderately Difficult $$$ _ $25,000 -50,000 ??? - Complex $$$$ _ > $50,000 2.1 Management Tips To 1. Go after continuous sewage discharges Develop an Effective IDDE first. Effective programs place a premium on Program keeping sewage out of the storm drain system. Continuous sewage discharges pose Every community will develop a unique the greatest threat to water quality and IDDE program that reflects its size, public health, produce large pollutant loads, development history, land use, and and can generally be permanently corrected infrastructure. Still, some common threads when the offending connection is finally found. Intermittent or indirect discharges are run through effective and well-managed harder to detect, and more difficult to fix. local IDDE programs. Below are some tips on building an effective local. Illicit Discharge Detection and Elimination:A Guidance Manual 25 Chapter 2:Components of an Effective IDDE Program 2. Put together an interdisciplinary and have the greatest risk. The ORI allows you interagency IDDE development team. A to rapidly develop an accurate outfall map broad range of local expertise needs to be and quantify the severity of your discharge coordinated to develop the initial IDDE problems. ORI data and field photos are plan, as indicated in Table 5. Effective extremely effective in documenting local programs assemble an interagency program problems. Stream walks and the ORI should development team that possesses the diverse be conducted regularly as part of an IDDE skills and knowledge needed for the program. In many areas, it may require as program, ranging from legal analysis, GIS, many as three stream walks to identify all monitoring, stakeholder management and outfall locations. pipe repairs. 6. Use GPS to create your outfall map. In 3. Educate everybody about illicit most communities, the storm water system discharges. Illicit discharge control is a new and sewer pipe networks are poorly mapped, and somewhat confusing program to the and consist of a confusing blend of pipes public, elected officials, and many local and structures that were constructed in many agencies. Effective programs devote different eras. Effective programs perform a considerable resources to educate all three field reconnaissance to ground truth the groups about the water quality impacts of precise locations of all outfalls using GPS illicit discharges. technologies. Effective programs have learned to quickly evaluate outfalls of all 4. Understand your infrastructure. Finding sizes, and not just major ones (>36 inches illicit discharges is like finding a needle in a in diameter). haystack on a shoestring budget. Many indirect or transitory discharges are 7. Understand your discharges before extremely difficult to catch through outfall developing a monitoring plan. Monitoring is screening. Therefore, effective programs usually the most expensive component of seek to understand the history and condition any local IDDE program, so it is extremely of their storm water and sewer infrastructure important to understand your discharges to find the combinations that create the before committing to a particular monitoring greatest risk for illicit discharge. Effective method or tracer. Compiling a simple programs also screen land uses to locate discharge"fingerprint"library that characterizes generating sites within targeted the chemistry of major flow types in the subwatersheds. For example, knowing the community(e.g., sewage,septage,washwater, proximity of the infrastructure to the groundwater, tap water, or non-target groundwater table or knowing that the sewer irrigation waxer)is recommended. This library collection system has a long transit time can can distinguish flow types and adjust influence the indicator parameters and monitoring benchmarks. associated thresholds that a community chooses to target. 8. Consider establishing an ambient(in-stream) chemical and/or biological monitoring 5. Walk all of your streams in the first program. Prioritizing outfall screening and permit cycle. Perform a rapid Outfall investigation can save time in the field. An Reconnaissance Inventory (ORI) on every ambient chemical or biological monitoring mile of stream or channel in the community, program can provide supplemental information starting with the subwatersheds deemed to 26 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 2:Components of an Effective IDDE Program to help prioritize sites and can be used to 12. Cross-train all local inspectors to document long-term success. recognize discharges and report them for enforcement. Effective programs make sure 9. Utilize a simple outfall tracking system to that fire, building, plumbing, health, safety, organize all your IDDE program data. Illicit erosion control and other local inspectors discharges are hard enough to find if an understand illicit discharges and know organized system to track individual outfalls whom to contact locally for enforcement. is lacking. Effective programs develop a unified geospatial tracking system to locate 13. Target your precious storm water each outfall, and store information on its education dollars. Most programs never address, characteristics, photos, complaints have enough resources to perform the and monitoring data. The tracking system amount of storm water education needed to should be developed early in the permit reduce indirect and transitory discharges in cycle so that program managers can utilize it their community. Consequently, effective as an evaluation and reporting tool. programs target their discharges of concern, and spend their scarce dollars in the 10. Outsource some IDDE functions to local subwatersheds, neighborhoods or business watershed groups. Staffing is the greatest sectors most likely to generate them. single line item expense associated with a local IDDE program, although staffing 14. Stress public health and safety benefits needs are often temporary or seasonal in of sewage free streams. Effective programs nature. Some effective programs have publicize the danger of sewage discharges, addressed this staffing imbalance by contracting and notify the public and elected officials with watershed groups to screen outfalls, about the discharges that need to be monitor stream quality, and handle storm prevented or corrected. water education. This strategy reduces overall program costs, and increases local 15. Calibrate your program resources to the watershed awareness and stewardship. magnitude of the illicit discharge problem. After a few years of analysis and surveys, 11. Utilize a hotline as an education and communities get a good handle on the actual detection tool. Citizen hotlines are a low- severity of their illicit discharge problems. cost strategy to engage the public in illicit In some communities, storm drains will be discharge surveillance, and are probably the relatively clean, whereas others may have only effective way to pick up intermittent persistent problems. Effective programs are and transitory discharges that escape outfall flexible and adaptive, and shift program screening. When advertised properly,hotlines resources to the management measure that are also an effective tool to increase awareness will reduce the greatest amount of pollution. of illicit discharges and dumping. Effective programs typically respond to citizen reports 16. Think of discharge prevention as a tool within 24 hours, acknowledge their help, and of watershed restoration. Discharge send them storm water education materials. prevention is considered one of the seven When citizens play a stronger role in primary practices used to restore urban reporting illicit discharge problems, local watersheds (Schueler, 2004). Effective staff can focus their efforts on tracing the programs integrate illicit discharge control problem to its source and fixing it. as a part of a comprehensive effort to restore local watersheds. Illicit Discharge Detection and Elimination:A Guidance Manual 27 Chapter 2:Components of an Effective IDDE Program 28 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 3:Auditing Existing Resources and Programs Chapter 3: Auditing Existing Cho ° 0 Resources and Programs Purpose: This program component identifies Desired Product or Outcome(s): The desired the most capable local agency to staff and outcome is an initial five-year IDDE administer the IDDE program, analyzes program development plan over the current staffing and resource gaps, and searches for permit cycle. This will usually consist of an all available local resources and expertise internal agreement on the lead agency, an that can be applied to the IDDE program. initial scope of work,the first year budget, Method: The key method used for this and a budget forecast for the entire permit cycle. program component is a local IDDE "audit," which consists of external research, agency Budget and/or Staff Resources Required: interviews, and interagency meetings to The cost to conduct an audit depends on the determine existing resources and program size of the community, the degree of gaps. The audit typically looks at eight interagency cooperation, and the local major factors needed to build an IDDE budget process. Plan for less than one staff program: month for smaller communities, and up to • Profile of existing storm water and sewer three staff months for larger ones. infrastructure, as well as historical Integration with Other Programs: The audit plumbing codes is the best time to integrate the other five • Existing legal authority to regulate illicit minimum management measures required discharges under NPDES Phase II permits, including • Available mapping data and GIS public education and outreach, public resources involvement, construction site runoff • Field staff availability and expertise control, post-construction runoff control, and pollution prevention/good housekeeping • Lab/monitoring equipment and for municipal operations. analytical capability • Education and outreach resources and outlets • Discharge removal capability and emergency response • Program budgeting and financing Illicit Discharge Detection and Elimination:A Guidance Manual 29 Chapter 3:Auditing Existing Resources and Programs 3.1 Audit Overview Existing expertise is likely divided among multiple agencies(see Table 6)that should be A community should conduct a quick audit contacted during the audit. Some of these of existing and needed capacity when agencies can become important partners in developing its IDDE program. The audit the development and implementation of the helps develop realistic program goals, IDDE program,and contribute resources, implementation strategies, schedules, and program efficiencies and overall cost savings. budgets to comply with NPDES permit The first agencies to interview are local requirements and improve water quality. emergency responders that already deal with The audit consists of external research, spills, accidents, hazardous materials and agency interviews and interagency meetings sewage leaks that occur. In addition, it is to determine existing resources and program worth getting to know the local agency gaps. The audit examines the community's responsible for plumbing code inspection current capabilities in eight topic areas: during construction. infrastructure profile, legal authority, available mapping, field staff experience, Table 7 provides representative examples of access to monitoring labs, education and questions that the audit should ask to outreach resources, discharge removal determine the needs and capabilities of a capability, and program budgets and community associated with each program financing. element. Table 6: Potential Local Agencies and Departments to Contact During an Audit Audit Topic Potential Agencies and Departments Infrastructure Profile Water and Sewer Authority • Public Works Public Works • Local Health Department Existing Legal Planning Department • Road Engineering Authority Parks and Recreation Fire, Police or Rescue Environmental Protection (Hazardous material responders) Available Mapping Public Works • Planning and Zoning pp g Local Streets/Utilities • Emergency Responders • Public Works • Watershed Groups Field Staff Environmental Compliance • Fire, Building, Health and • Development Review Code Inspectors • Drinking Water or Access to Lab Public Works Wastewater Treatment Plant Services Local College or University ' Private Contract Monitoring Laboratories • Health Department Education and Parks and Schools • Outreach Community Liaison Office Resources Water and Sewer Utility Civic and Watershed Groups Discharge Removal Fire, Rescue and Police Water and Sewer Utilities Capability Public Works Private Plumbing Contractors Program Budget and Grants Utility Fees Financing Fines Department Operating • Application fees Budget 30 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 3:Auditing Existing Resources and Programs PotentialTable 7: Questions Audit Topics Questions • How many miles of streams and storm drains exist in the MS4? Infrastructure Profile • What is the area served by storm drains, sewers, and septics? • What is the general age and condition of the infrastructure? • Does an illicit discharge ordinance already exist? • Does effective inter-departmental coordination and cooperation Existing Legal Authority currently occur? • Is there an existing reporting and tracking system (e.g., hotline)? • Is the municipality involved with industrial storm water NPDES permit activities or pre-treatment programs? • Does current GIS data exist and does it include coverage of sanitary Available Mapping Data and storm sewer networks? pp g • Is there a centralized location for the data? • Are digital and hardcopy versions of mapping data readily available? • Are municipal staff available to walk stream miles and record information? Field Staff • Do municipal staff have the training and expertise to lead a field team? • Are basic field supplies already owned by the municipality and available for use? • Does the municipality have access to an analytical laboratory? • Is there a local university or institution that might be a willing partner? • If yes, is the existing equipment and instrumentation considered to be Access to Lab Services safe, accurate and reliable? • Are experienced municipal staff available to conduct analytical analyses? • Does the lab and staff have the capability to conduct more sophisticated special studies? • Does the community already have an Internet website to post outreach materials? Education and Outreach • Are there regular community events that can be used to spread the Resources message? • Are good inter-agency communication mechanisms in place? • Do outreach materials on illicit discharges already exist? • Who currently responds to spills, overflows and hazardous material emergencies? • Are municipal staff properly equipped and trained to repair most Discharge Removal common types of illicit connections? Capability . Does the municipality have clear authority identifying responsible parties? • Is there a response time commitment to known and reported problems? • Is there a list of pre-approved contractors to perform corrections? • Is there a dedicated annual budget line item planned for the IDDE program? Program Budget • Are there cost-share arrangements/opportunities available with other and Financing departments? • Have grant awards been awarded to the municipality for special studies associated with watershed restoration in the past? Illicit Discharge Detection and Elimination:A Guidance Manual 31 Chapter 3:Auditing Existing Resources and Programs 3.2 Develop Infrastructure 3.3 Establish Legal Authority Profile This part of the audit examines whether a The first part of the audit profiles current community currently has adequate legal and historic storm water and sewer authority to regulate illicit discharges infrastructure in the community. The basic through the following actions: idea is to get a general sense of the 5 magnitude of the task ahead, by looking at • Evaluate and modify plumbing codes the size, age and condition of the storm • Prohibit illicit discharges drain system (and the sewers within the • Investigate suspected illicit discharges MS4 as well). Some useful planning Require elimination of illicit discharges statistics include: • Carry out enforcement actions • Number of storm drain outfalls • Miles of storm drain pipe The audit of existing legal authority entails a • Total stream and channel miles search and review of all existing ordinances that could conceivably bear on illicit • Total area serviced by storm drains discharge control, and interviews with the • Total area serviced by sewers agencies that administer them. Some • Total area serviced by septic systems common local ordinances that may address illicit discharges are outlined in Table 8. Many communities already have regulations These statistics are extremely helpful in prohibiting specific illicit discharges, such getting a handle on the total effort required as hazardous chemicals, litter or sewage. to assess the overall system. Any data on the Often, public health ordinances may prohibit nature and age of storm drains and sewers certain sewage discharges. Local utilities can be useful (e.g., open vs. enclosed, young may have plumbing codes and staff capability to vs. old). The basic infrastructure statistics track down and remove illicit connections can be generated from a quick analysis of on the system they operate. infrastructure and topographic maps. At this stage, ballpark estimates are fine; more detailed estimates can be developed later in the desktop analysis component. It is also worth examining historic plumbing codes to determine what kinds of connections were allowed in the past. Often, interviews with"old-timers"who remember past building codes and practices can provide insights about historical construction as to where illicit connections may be a problem. 5 In some states such as NC, plumbing codes are established through a state process. In these cases, local governments typically need specific authority to adopt any local modifications,which can be difficult to obtain. In such states, it may be prudent for the storm water program managers of several local governments to organize as a single cooperative group to modify codes at the state level. 32 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 3:Auditing Existing Resources and Programs Table • • • Ordinances with Potentialto IDDE • Fire codes 0 Pollution prevention permitting • Hazardous wastes/spill controls requirements • Health codes 0 Restaurant grease regulations • Industrial storm water compliance 0 Septic system regulations • Litter control regulations 0 Sewer/drain ordinances • Nuisance ordinances 0 Storm water ordinance • Plumbing codes Street/ highway codes To establish legal authority, communities assessment, public works,parks and recreation, will need to either develop a new IDDE emergency response, environmental, ordinance or modify an existing ordinance transportation, utilities, or health. If a that addresses illicit discharges. Language watershed extends beyond the boundaries of from existing ordinances that addresses a community, it may be necessary to acquire illicit discharges should be incorporated or mapping data from adjacent communities. cross-referenced into any new IDDE ordinance to minimize conflicts and Non-local sources of mapping data include confusion. Furthermore, existing code state and federal agencies and commercial ordinances may need to be amended or vendors. EPA and state environmental superceded to be consistent with the new regulatory agencies maintain lists of NPDES IDDE ordinance. dischargers; Comprehensive Environmental Response, Compensation, and Liability Act In some instances, communities may want to (CERCLA) sites; Resource Conservation and consider collaborating with neighboring or Recovery Act (RCRA) sites; and other nearby MS4s to develop ordinance language industrial or hazardous material discharge and legal authority, particularly if they share sites. These sites are readily available as GIS a common receiving water. Non-municipal layers6. Commercial vendors are good permittees such as Departments of sources for low-altitude aerial photos of Transportation and special districts may also your community. These can be expensive look to collaborate with municipal MS4s but are often the best way to get a high- when considering ordinance language and resolution recent `snapshot' of the legal responsibility. jurisdiction. Chapter 5 presents more detail on mapping layers needed for an IDDE 3.4 Review Available Mapping program. The third part of the audit looks at the 3.5 Availability of Field Staff coverage and quality of mapping resources available to support the IDDE program. Field staff play a critical role in any IDDE Specifically, efforts should be made to see if program as they walk streams, assess a Geographic Information System (GIS) outfalls, collect samples, respond to exists, and what digital mapping layers it discharge complaints, and handle contains. If a community does not possess a enforcement. This part of the audit evaluates GIS, a community may choose to establish one (which can be quite expensive), or rely 6 Some readily available GIS layers provided by regulatory agencies can be incomplete and inaccurate(particularly on available hardcopy maps. GIS and with location information).Communities should use their hardcopy maps are frequently available from IDDE program and the associated data collection efforts to the following local agencies: planning, tax update their local information associated with these g g p g, databases. Illicit Discharge Detection and Elimination:A Guidance Manual 33 Chapter 3:Auditing Existing Resources and Programs the availability of local staff to perform basic options exist to get access to these functions, and their training needs. laboratory services, including: Phase I communities report that experienced field staff are a major factor in IDDE 1. Contract services from a private lab program success. 2. Use existing lab facilities at local drinking water or wastewater Experienced staff can be supplemented with treatment plants support staff such as interns and local watershed groups, if they are properly 3. Partner with a local water and sewer trained (CWP, 2002). As part of the audit, district, university or community program managers should investigate college whether existing staff can be used or 4. Develop your own"in-house" whether new hires are anticipated, and monitoring and lab capability explore intern opportunities with local universities and community colleges. Any The last three options may require local staff with experience in water quality purchasing special monitoring analysis sampling or development inspection should equipment, depending on the water quality be identified. Fire, building, health, safety indicators ultimately selected. If a and erosion control inspectors are all community is considering developing "in- potential field crew draftees. house" monitoring capabilities, it will need to address quality control, training needs, An initial estimate of the staff time needed safety, and hazardous waste disposal. At this for Field crews should be made at this time. point, a community simply wants to acquire Phase I IDDE programs allocated a median data on costs, indicator parameters, quality of 1.0 person-year for field investigations, control, and experience for each of the with a range of 0.1 to 10 person-years each options being evaluated. Chapter 12 year(CWP, 2002). Several communities provides more detail on factors to consider utilized interns to assist with field when selecting lab analysis options. monitoring and office work. Since many IDDE surveys are short term and seasonal, 3.7 Education and Outreach several communities hired or transferred employees to serve on field crews on a The next part of the audit looks at existing temporary basis. Many Phase I programs educational and outreach resources in the found it hard to precisely quantify actual community. To begin, look for other groups staff time dedicated to IDDE field work that are already involved in storm water or because staff were assigned from many watershed education, including parks, departments, or performed other unrelated schools, watershed groups, utilities and any tasks(building inspections,erosion and other agencies performing this role. Next, sediment control inspections, etc.). look for the current tools the public can use to report water quality problems, such as 3.6 Access to Laboratory complaint hotlines, websites or community Analysis liaison offices. When these exist, it may be possible to "piggy back" illicit discharge This part of the audit identifies the best reporting at little additional cost. If reporting options for laboratory analysis of water tools do not exist, program managers should quality samples collected in the field. Four look for opportunities to share start-up costs 34 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 3:Auditing Existing Resources and Programs with other agencies that may stand to benefit Illicit discharges often occur due to "bad from improved community interaction (e.g., plumbing" connections. Therefore,the audit erosion and sediment control, sanitary sewer should identify key building inspectors to overflows, abandoned cars, etc.). determine what, if any, procedures are in place to prevent these deficiencies. Lastly, The audit should also look at community- where corrections to plumbing are required, wide events and education outlets to spread communities should maintain a list of"pre- the IDDE message, such as fairs, festivals, approved" plumbing contractors that can earth day events, school presentations, and promptly and professionally repair the homeowner association meetings. For a problem. complete review of how to craft an effective outreach and education plan, consult To ensure coordination, an up-to-date Pollution Source Control Practices (Schueler tracking system should be shared among all et al., 2004). Excellent education and agencies involved. outreach materials have already been developed by Phase I communities that are 3.9 Program Funding available at little or no cost(see Chapter 9). Program managers should consult these The last part of the audit explores how much resources and modify them as needed to the local IDDE program will cost, and how meet their local needs. it will be funded. This section provides some general budgeting guidance on the costs to 3.8 Discharge Removal expect for the eight program components. Capability and Tracking Overall IDDE program costs vary depending on the severity of the illicit discharge This part of the audit evaluates local problem, the size of the community (and capacity to locate specific discharges, make storm drain systems), and the IDDE needed corrections or repairs, and take any program choices you make. enforcement actions. These responsibilities are frequently split among several local Planning level budget estimates can be agencies. For example, spills are often derived for the eight IDDE program handled by the fire department hazmat components in three ways. The first way is response team, whereas dumping may be to look at the cost of IDDE program enforced by public works. Communities compliance for Phase I NPDES communities. should always coordinate their IDDE These costs were assessed in a CWP (2002) program with any experienced hazmat survey, and can be used to budget overall response teams that exist. Similarly, local annual costs for an IDDE program. Table 9 water and sewer utilities or private summarizes median program costs for contractors that are in the business of selected Phase I IDDE program activities. repairing pipes should always be consulted. The second technique is to construct unit Their experience in specialized techniques cost budgets for each program component, such as dye or video testing of pipe interiors based on an assumed level of effort. The is essential for many illicit discharge source third technique relies on EPA's overall investigations. Alternatively, communities average estimate of compliance costs for can opt to contract out many of these Phase II IDDE program of$1.30 per capita services. (with a staggering range $0.04 to $2.61/capita). Illicit Discharge Detection and Elimination:A Guidance Manual 35 Chapter 3:Auditing Existing Resources and Programs Phase I IDDE Program Costs test new methods or the direct costs to fix problem connections. However, five The bulk of the cost for most IDDE communities provided data on typical programs is related to staffing—typically, correction costs,with an average cost of about 75% of the total budget. Equipment $2,500 per correction (Table 10). costs were fairly reasonable, with programs spending a median of$1,000 on office Estimated Phase 11 IDDE Program Unit computers and software, and about $4,000 Cost on field equipment. Many equipment costs can typically be shared across other Cost estimates for the eight IDDE program community programs. Lab costs, for either components are outlined in Table 11; more the purchase of lab equipment or the cost detailed guidance on budgeting for associated with sending samples to labs, individual program components is provided were as high as $87,000 annually, with a in subsequent chapters. Under this median of$8,000. Finally, most programs presentation of cost, data, staff, equipment, had additional budgets for"other"which and supply costs are combined and included items such as education, training, incorporated into a primary program travel, consultants, and contractors. element, such as conducting an outfall reconnaissance inventory. This approach It is worth noting that program costs assumes a hypothetical scenario of presented in Table 9 do not reflect stream/MS4 miles and outfalls to investigate expenditures associated with special (see Table 11 notes). investigations, which may be pursued by communities to isolate specific sources or Tableof DDE Program Costs Program Element Median Annual Cost Staff $85,100 Office Equipment (Computer/Software) $1,000 Field Equipment $4,000 Lab Equipment/Testing $8,000 Other $10,000 Total $121,825 Table1: Average CorrectionCosts Jurisdiction Average Cost Per Correction Cambridge, MA $5,000 Boston, MA $3,570 Knoxville, TN $2,000 Raleigh, NC $1,000 Springfield, MO $1,000 Average $2,500 36 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 3:Auditing Existing Resources and Programs Table •• Costs IDDE Program Component Start Up Cost Annual Cost Low High Low High Component 1: a) Perform Audit $3,000 $9,000 NA NA b) Initial Program Plan $1,000 $3,000 NA NA Component 2: a)Adopt Ordinance $1,000 $17,000 NA NA b)Tracking System $2,000 $15,000 $2,000 $2,000 Component 3: a) Desktop Analysis $1,000 $4,000 NA NA b) Field Mapping $500 $1,000 NA NA Component 4: a) Develop Goals $1,000 $3,000 NA NA b) Field Monitoring Strategy $1,000 $3,000 NA NA a) Outfall Reconnaissance NA NA $5,700 $12,800 Inventory (ORI) Component 5: b) Establish Hotline $1,300 $7,700 $1,500 $11,400 c) Sample Analysis $500 $15,500 $9,000 $21,200 d) Outfall Map NA NA $500 $1,000 Component 6: a) Isolate NA NA $2,000 $5,200 b) Fix NA NA $10,000 $30,000 Component 7: a) Education $1,000 $8,100 $1,300 $13,900 b) Enforcement NA NA $1,000 $14,000 Component 8: a) Program Administration $10,000 $15,000 $10,000 $15,000 TOTAL $23,300 $101,300 $43,000 $126,500 Notes: NA= Not Applicable Component 1 -Audit assumes$25/hr, 120 hours for low and 360 hrs for high. Program plan assumes 40 hrs for low and 120 hrs for high. Component 2-Ordinance low cost from Reese(2000), high cost from CWP(1998)adjusted and rounded for inflation (2002$).Tracking system low cost assumes 40 hrs of development and$1 K of equipment for start up.Annual cost for low assumes 40 hrs per year. High estimates are adapted from Reese(2000)and assume 200 hrs for development and$3k for equipment at start-up. High annual costs assume 100 hrs per year. Component 3-Desktop analysis assumes 1 week for low and 4 weeks for high. Mapping costs assume paper maps (CWP, 1998)under low and GIS under high(40 hrs) Component 4-Goals and strategies take 2 weeks for low and 6 weeks for high.Assume even split in time between two tasks. Component 5- a)ORI costs are from Ch 11 and assume 10 miles with 2-person crew for low and 20 miles with 3-person crew for high. ORI costs assume work completed in one year, but not necessarily every year(permit cycle cost). Low hotline costs are adapted from Reese(2000). High costs are from CWP research. Low annual costs assume an increased volume of calls due to advertisement and assume 50 hours per year dedicated to this plus annual training. Sample analyses are from various sources and are presented in Chapter 12. Estimates based on 80 samples per year for both(shown as annual cost). Low start up costs are based on contract lab arrangements. High start up costs assume flow type library is developed for eight distinct flow types. Low annual costs assume in-house analysis for Flow Chart Method parameters. High annual costs assume contract lab analysis for 11 parameters. Outfall map costs are same as the component 3 mapping task Component 6-Isolate and fix have no assumed start up costs and are both vary depending on the community conditions. Low annual isolation costs assume a one day investigation by a 2-person team per incident($400)and four incidents per year plus$400 in equipment and supplies. High assumes one incident per month. Estimates include on-site inspections. Fix costs are from average costs from Phase I survey and assume same number of incidents as isolate. These costs can often be passed on to responsible parties. Component 7-Education estimate adapted from Reese(2000)and assumed to be 1/3 of total Phase I education budget. Some adjustments were made based on assumptions by CWP. Component 8-Low assumes 1/6 FTE, high assumes 1/4 FTE at an annual salary of$60K. Illicit Discharge Detection and Elimination:A Guidance Manual 37 Chapter 3:Auditing Existing Resources and Programs Financing an IDDE Program • Florida Association of Storm Water Utilities. http://www.fasu.org Once the initial budget has been estimated, the next step is to investigate how to pay for • How to Create a Storm Water Utility it. A full discussion of how to finance local http://www.epa.gov/nps/urban.html storm water management programs is beyond the scope of this manual, but it is • The Storm Water Utility: Will It Work worth consulting APWA (2001). The most in Your Community? common financing mechanisms include: www.forester.net/sw 0011_utility.html • Operating budgets 3.10 The Initial IDDE Program • Debt financing Plan • State grants and revolving loans • Property assessments The local IDDE audit reveals resource gaps, and expertise and staffing needed to build an • Local improvement districts effective IDDE program. The next step is to • Wastewater utility fees organize how you plan to phase in the eight • Storm water utility or district fees program components over the permit cycle. The process results in the development of an • Connection fees initial IDDE program plan that normally • Plan review/inspection fees includes five elements: • Water utility revenues • Overall schedule for plan Of these, storm water utilities or districts are implementation, with milestones generally considered one of the best • Detailed work plan for the first year dedicated financing mechanisms. Some • Budget for the first year useful resources to consult to finance your • Five-year budget forecast local storm water programs include the Process for gaining approval for following: first-year budget • An Internet Guide to Financing Storm Water Management. 2001 Program managers should consult the next http://stormwaterfinance.urbancenter.iup seven chapters for more guidance on ui.edu planning and budgeting individual IDDE program components. • Establishing a Storm Water Utility http://www.florida- stormwater.org/manual.html 38 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 4:Establishing Responsibility and Legal Authority Chapter 4: Establishing Responsibility �© ° ° and Legal Authority Purpose: This program component is where little as a month of staff effort to complete if the legal and administrative authority is no major surprises or unforeseen costs are established to regulate, respond and enforce encountered in the process. However, the illicit discharges in the community. The actual time-frame to adopt an ordinance or component also reviews local plumbing fund a response system, for example, is codes to ensure that inappropriate often much longer, given the crowded connections are prohibited, and develops a schedules of elected officials and timing of tracking system to locate illicit discharges the local budget processes. Adoption of the and track management response. ordinance and the actual budget authorization may require multiple votes over many Method(s): Several methods are used to months or years. Continuous engagement implement this program component, and education of key advisors, agency staff including development of a new or amended and elected officials are needed throughout illicit discharge control ordinance and the the effort. Where hotlines exist (covering a creation of a relational computer database range of municipal functions), significant for internal and external tracking of illicit staff and infrastructure savings should be discharges. realized. The primary hurdle in this instance will be employee training and education. Desired Product or Outcome(s): Integration with Other Programs: Public a) Pass or amend a local ordinance that education to advertise the hotline and defines the lead regulatory agency, municipal training to educate employees defines the range of illicit discharges across departments and agencies are the to be covered, and specifies the primary areas where this program component range of enforcement mechanisms. can be integrated with other community- wide initiatives. The hotline can be used to b) Establish an internal and external report other watershed and water quality reporting and tracking system. The problems (e.g., ESC, dumping, sanitary internal system is structured around sewer overflows). Good coordination should the training/education of municipal occur between tracking repair costs and staff to define and facilitate appropriated determining appropriate fine levels for response and enforcement procedures. enforcement purposes. An external system or hotline links to the internal system and assists in Three critical decisions are needed to response and enforcement by providing implement this program component—what access to the public for reporting. local agency will be responsible for administering the IDDE program, will it Budget and/or Staff Resources Required: have adequate legal authority to do its job, Establishing responsibility, legal authority and how will illicit discharges be tracked. and an effective tracking system can take as Guidance is offered below to help program managers make these decisions. Illicit Discharge Detection and Elimination:A Guidance Manual 39 Chapter 4:Establishing Authority and Legal Responsibility 4.1 Identify Responsible 4.2 Develop Local Illicit Department/Agency Discharge Ordinance For most communities, the IDDE program A community must demonstrate that it has will be established under the same agency or adequate legal authority to successfully department that oversees all other MS4 implement and enforce its IDDE program. NPDES requirements (e.g., Department of In fact, establishing legal authority is one of Environmental Protection, Department of the required components identified in Phase Public Works, Department of Health, etc.). II regulations, and can be identified as a For small communities, IDDE program measurable goal. Guidance is provided administration and implementation may be below on how to develop an IDDE wrapped into the broad duties of just a few ordinance to establish legal authority. staff. For larger communities, or where there are significant known problems associated Reviewing What You Have with illicit discharges, a community may elect to have a dedicated department Communities with illicit discharge division with core staff. In either event, the prohibitions in place have typically invoked agency and individuals responsible for the legal authority using one or more of three program should be well identified along mechanisms: with a clear understanding of program purpose, goals and actions. 1. Storm water ordinance that prohibits illicit discharges to the drainage network Other local departments may already have 2. Plumbing code that prohibits illicit authority over certain aspects of illicit connections to the drainage network discharges. Therefore, close coordination and communication with different 3. Health code that regulates the departments is essential, and consideration discharge of harmful substances to the should be given to consolidating responsibilities drainage network and authority.If consolidation is not pursued, regular inter-departmental briefings, training A few concerns arise with the second and sessions, and data sharing will enhance third mechanisms. One example is plumbing program effectiveness and reduce the likelihood codes that only prohibit illicit connections of significant lag times between discovery of fail to address other common discharges, a discharge and enforcement or correction such as indirect discharges, illegal dumping, due to split responsibilities between or failing infrastructure. Similarly, exclusive departments. reliance on health codes to regulate illicit discharges may not pick up discharges that In some cases, communities may want to are not harmful to human health, such as consider collaborating with adjacent or groundwater or potable water infiltration nearby permittees in order to form a regional and residential irrigation return flows. With approach to addressing illicit discharges. some revision and expansion, one or all of This might be appropriate in situations these existing mechanisms can meet the where municipalities share a common needs of the IDDE program. Alternatively, a receiving water, and program new, stand-alone illicit discharge ordinance implementation is conducted on a watershed can be developed that supercedes all other management basis. related codes. 40 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 4:Establishing Responsibility and Legal Authority CASE STUDY The City of Raleigh is an NPDES Phase I community. The Water Quality Group (WQG) within the Public Works Department oversees the City's illicit discharges program. The WQG was created in the early 1990s to be responsible for surface water quality across the City and to ensure compliance with the City's NPDES permits. Prior to that, various departments within city government handled water quality issues. Raleigh's Illicit Discharge Ordinance was adopted in the second year of their original NPDES Phase I permit. The ordinance clearly defines and prohibits illicit discharges and illicit connections; requires containment and clean-up of spills/discharges to, or having the potential to be transported to, the storm drain system (it is also standard operating procedure that the City fire chief be notified of any spills immediately); allows for guaranteed right of entry for inspection of suspected discharges and connections; and outlines escalating enforcement measures, including civil penalties, injunctive relief, and criminal penalties. Although the WQG runs the IDDE program, some functions are undertaken by the City's Public Utilities Department (e.g., fixing problems in the sanitary line, conducting dye and smoke testing, television inspection of the lines). Raleigh began with a flat annual IDDE budget based on their past experience of what the program costs to run. More recently, the program began receiving additional funds from the City's storm water utility. A portion of the budget is allocated for testing. Cleaning and correction costs are funded through various budgets depending on the illicit discharge source. The WQG also budgets for two specialists: one is responsible for enforcement and dealing with citizen complaints and the other is responsible for monitoring and tracing the source of problems. The cost of television inspection and smoke testing is included in the Public Utilities Department budget. Source: Senior(2002, 2004) The length and complexity of an IDDE • Prohibit illicit discharges ordinance is largely a local community . Investigate suspected illicit discharges decision. Appendix B provides a model Require and enforce elimination of illicit ordinance that may be adapted to meet the specific needs of local communities. discharges • Address unique conditions or Some key components that should be requirements addressed to ensure full authority to prevent and correct illicit discharges include the following: Illicit Discharge Detection and Elimination:A Guidance Manual 41 Chapter 4:Establishing Authority and Legal Responsibility Defining What is Illicit Diverted stream flows •An IDDE ordinance should clearly define Rising ground waters and/or identify illicit discharges and clearly Uncontaminated ground water infiltration state that these discharges are prohibited. 0 Uncontaminated pumped ground water Some communities may prefer to provide a a Discharges from potable water sources short, concise definition of illicit discharges, Foundation and footing drain water while others may wish to list specific • substances or practices that qualify as illicit Air conditioning condensation discharges. However, if a detailed list is a Irrigation water provided in the ordinance, a qualifying a Springs statement should follow in order to include polluting discharges not specifically listed. Water from crawl space pumps • Lawn watering Illicit connections should also be defined in Individual residential car washing the ordinance. These connections include Flows from riparian habitats and pipes, drains, open channels, or other wetlands conveyances that have the potential to allow an illicit discharge to enter the storm drain system. The prohibition of illicit connections some cases, communities will need to should be retroactive to include connections assess unique local discharges of concern made in the past, whether or not the and ensure that they are properly addressed connection was permissible at the time. This within the ordinance. Examples of unique is especially important if historic plumbing conditions or requirements sometimes codes or standards of practice allowed for included in IDDE ordinances are septic connection of laterals and drains (e.g., shop system provisions, plumbing codes,point of floor drains) to the MS4. sale dye testing, and pollution prevention plan requirements for certain generating Lastly, the ordinance should identify sites. categories of non-storm water discharges or other flows to the MS4 that are not considered Provisions for Access and Inspection illicit. For example, the Phase II rule exempts discharges resulting from fire fighting activities. Although many communities report that Other activities that are commonly exempt most property owners cooperate when asked include discharges from dye testing and non- for access for illicit discharge investigations, storm water discharges permitted under an this should never be taken for granted. NPDES permit, provided that the discharger Indeed, the right of access to private is in full compliance with the permit. The property for inspections is an essential following categories of non-storm water provision of any IDDE ordinance. The discharges do not need to be addressed in the ordinance should provide for guaranteed IDDE program unless the operator of the right of entry in case of an emergency or a regulated small MS4 designates them as suspected discharge or at any time for significant contributors of pollutants: routine inspections, such as dye or smoke tests. • Water line flushing Landscape irrigation The ordinance should also clarify that right • of entry applies to all land uses in the 42 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 4:Establishing Responsibility and Legal Authority community, and that proof of discharge is The ordinance should provide for escalating not required to obtain entry. It should also enforcement measures to notify operators of state the responsibility of the property owner violations and to require corrective action. to disarm security systems and remove Voluntary compliance should be used for obstructions to safe and easy access. first-time, minor offenders, while more Enforcement actions should be established serious violations or continued non-compliance for property owners that refuse access, may warrant a more aggressive enforcement including the ability to obtain a search approach. Finally, the ordinance should warrant through the court system. include methods for appeal to provide owners with avenues for compliance. Types of Enforcement Tools Establish a Tracking and Reporting An IDDE ordinance should define a range of System enforcement tools so the responsible agency can effectively handle the wide range of Communities need to develop tracking and illicit discharge violations it is likely to reporting systems to support the entire IDDE encounter. Potential enforcement tools can program, including enforcement. A range from warnings to criminal relational database with geospatial features prosecution. The choice of enforcement provides the greatest flexibility to cover tools should be based on volume and type of multiple program objectives. From a legal discharge, its impact on water quality and standpoint, tracking systems are important whether it was intentional or accidental. In for historical documentation of problems addition, it is helpful to spell out the specific and corrective actions. More details on activities that trigger progressively greater designing and operating a tracking system enforcement. Table 12 summarizes the range are described in subsequent chapters. of enforcement tools that have been used by communities to respond to illicit discharges. Illicit Discharge Detection and Elimination:A Guidance Manual 43 Chapter 4:Establishing Authority and Legal Responsibility Tableof • Enforcement Tools Type of Enforcement Description Action Written Warning with Applies to first time, minor violations (Field staff should have Voluntary Compliance authority to do this) Written Notice of Violation Should clearly state description of remedial measures necessary, Ordering Compliance time schedule, penalties assessed if it doesn't happen, and timeframe for appeal Administrative Penalties Daily financial penalty imposed by a responsible department for each day violation remains unfixed Civil Penalties Daily financial penalty imposed by judicial authority for each day violation remains unfixed Compensatory Action In lieu of enforcement proceedings or penalties, impose alternative compensatory action, e.g., storm drain stenciling, etc. • Applies to intentional and flagrant violations of ordinance Criminal Prosecution Each day discharge continues is typically a separate offense • Can result in fines and imprisonment Cost of Abatement of the Applies when jurisdiction remedies the discharge or conducts Violation / Property Liens cleanup, but may also be used to recoup administrative costs • May constitute a property lien if not paid within certain timeframe • Applies when ordinance continues to be violated Emergency Cease and Requires immediate compliance with ordinance by halting Desist Order operations/terminating discharges • May be a written or verbal order to remove illicit discharge • Applied in emergency situations to immediately discontinue Suspension of Water or discharge to MS4 Sewer Service May be applied as enforcement measure when property owner does not comply/fix the problem within timely manner Stop Work Order Typically applies to discharges associated with construction activity • No further work can be done until compliance is achieved 44 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 5:Desktop Assessment of Illicit Discharge Potential Cho Chapter 5: Desktop Assessment of Illicit Discharge Potential Purpose: This program component uses c) Gaining an overall assessment as to the mapping and other available data to severity of illicit discharge problems determine the potential severity of illicit in the community discharges within a community,and identifies d) Generation of basic mapping for which subwatersheds or generating land subsequent field work uses merit priority investigation. Method(s): A simple desktop assessment Budget and/or Staff Resources Required: method can rapidly determine the severity of The initial desktop assessment of illicit illicit discharge problems in a community. If discharge potential should not be a long or an MS4 has fewer than 20 stream miles, this arduous process, and should generally take component can be skipped and a community less than four staff weeks. The quality and can proceed directly to an ORI. The desktop accuracy of the desktop assessment,however, assessment method has five basic elements: will vary depending on the extent of available mapping information and GIS data.If mapping 1) Delineate subwatersheds or other information is poor, the desktop assessment drainage units within your should be skipped, and program managers community should go directly to the field to inventory 2) Compile available mapping and data outfalls. for each drainage unit (e.g., land use, Integration with Other Programs: If the age, outfalls, infrastructure history) desktop assessment suggests few potential 3) Derive subwatershed discharge illicit discharge problems,program managers screening factors using GIS analysis may want to combine outfall surveys with 4) Screen and rank illicit discharge broader stream corridor assessment tools potential at the subwatershed and such as the Unified Stream Assessment community level (Kitchell and Schueler, 2004). The desktop 5) Generate maps to support field assessment provides insight on how to investigations narrow your illicit discharge search, and is helpful when designing a discharge tracking system to best suit your needs. Finally, the Desired Product or Outcome(s): The desktop assessment can identify subwatersheds, desktop assessment is used to guide initial generating sites, and neighborhoods where field screening, and support initial IDDE storm water education should be targeted to program decisions. Key outcomes include: address illicit discharge problems. a) Screening problem catchments or subwatersheds b) Creation of GIS or other database system to track outfalls Illicit Discharge Detection and Elimination:A Guidance Manual 45 Chapter 5:Desktop Assessment of Illicit Discharge Potential 5.1 Overview of Desktop The recommended scale for desktop Assessment of Illicit Discharge assessments is the subwatershed or Potential sewershed, which typically range from two to 10 square miles in area. These small planning units are easily delineated on maps A community should understand the extent or a GIS system. Next, mapping, monitoring of water quality problems caused by illicit and other data are analyzed to identify discharges. The desktop assessment should subwatersheds with the greatest potential to not be atime-consuming research effort, but contribute illicit discharges. The should draw on existing background data sophistication of the analysis varies and anecdotal information to initially depending on the data available, but can characterize illicit discharge potential at the encompass up to 10 different screening subwatershed level. factors. The desktop assessment consists of Subwatersheds are then screened based on five basic steps: their composite score, and are designated as Limited mapping or data should not hinder a having a low, medium or high risk: desktop assessment. Most communities will have some gaps, but should make the most • Low—no known illicit discharge out of what they have. The desktop problems in the subwatershed assessment is an office exercise to locate the • Medium—problems are confined to a most promising subwatersheds to find illicit few stream reaches, outfalls or discharge; subsequent outfall screening is specific generating sites in the needed to discover the problem outfalls in subwatershed the field. • High—Problems are suspected to be severe throughout the subwatershed. Step 1: Delineate subwatersheds Step 2: Compile mapping layers and The desktop assessment also shapes the subwatershed data overall direction of a local IDDE program. Step 3: Compute discharge screening For example, if the desktop assessment factors indicates that the risk of illicit discharges is low in the community, program managers Step 4: Screen for illicit discharge may want to shift resources to other potential at the subwatershed minimum management measures and and community level integrate them into a broader watershed Step 5: Generate maps to support field assessment and restoration effort. For investigations example, IDDE programs may emphasize storm water education, public involvement Step 1: Delineate Subwatersheds and hotline setup. By contrast, if the desktop assessment reveals significant potential for Since hundreds of outfalls and many stream severe discharges, program managers will miles exist in most communities, the MS4 need to allocate significant program should be divided into smaller, more resources to find and fix the discharge manageable planning units known as problems. subwatersheds. If the community already does watershed planning, these subwatersheds may already be delineated, 46 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 5:Desktop Assessment of Illicit Discharge Potential and should be used for subsequent Step 2: Compile Mapping Layers and characterization and screening. Working at Subwatershed Data the subwatershed scale is usually the most efficient way to conduct both desktop Once subwatersheds (or catchments) are assessments and field surveys. delineated, a community can begin to acquire and compile existing data for each In small,heterogeneous or densely developed drainage area, preferably with a Geographic MS4s, conducting the assessment on a Information System (GIS). A GIS allows the smaller scale may be more effective. In this user to analyze and manipulate spatial data, case, sewersheds or catchments that are less rapidly update data and create new data than one square mile in area and have a layers, associate data tables with each map common outfall or discharge point should be layer, and create paper maps to display delineated. This finer level delineation subwatershed information. A GIS can allows for a refined characterization that can greatly speed up data compilation and pinpoint probable sources of illicit discharges, provides greater accuracy in mapping but can obviously consume a lot of time. It specific locations. The mapping information should be noted that sewersheds do not facilitates the interpretation and always follow topographic delineations and understanding of the discharge screening therefore can provide a more accurate factors (Step 3). picture of the contributing areas to a particular outfall. If a community does not currently have a GIS, developing a system from scratch may If subwatersheds are not yet defined, seem daunting, however, most GIS software hydrologic, infrastructure and topographic can be installed on basic PCs, and free GIS map layers are needed to delineate the data layers are often available online. The boundaries. Guidance on the techniques for basic elements of a GIS program include a accurately delineating subwatershed PC, Global Positioning System (GPS) units, boundaries can be found at a plotter, a digitizer, GIS software, data and www.stormwatercenter.net (click staff training. As with many technologies, "Slideshows,"then scroll down to both low-end and high-end versions are "Delineating Subwatershed Boundaries"). available, as are many add-ons, extensions The use of digital elevation models (DEMs) and tools. While a GIS is not necessary for and GIS can also make subwatershed the IDDE desktop assessment, it does make delineation an easier and faster, automated the process more efficient and accurate, process. which can save money in the long run. Moreover, other agencies within a Some subwatersheds extend beyond the community usually need or use GIS and political boundaries of a community. Where may be willing to share hardware, software, possible, it is recommended that the entire support and development costs'. subwatershed be delineated and assessed in conjunction with neighboring municipalities. Acquiring data for each subwatershed is the This helps to ensure that all potential sources of next step in the desktop assessment process. illicit discharges are identified in the subwatershed, regardless of the community from which they originate. 7 If a community plans to defer using GIS,all databases it develops should have location information suitable for later use with GIS(i.e.,using suitable georeferencing technology such as GPS). Illicit Discharge Detection and Elimination:A Guidance Manual 47 Chapter 5:Desktop Assessment of Illicit Discharge Potential The extent and quality of the data available Most data layers can be obtained from local for mapping directly influence subsequent sources, such as the city planning office, analyses and field investigations. A list of emergency response agency, or public works recommended data layers to acquire for the department. If a subwatershed extends desktop assessment is provided in Table 13. beyond the boundaries of your community, you may need to acquire data from another Some mapping data may exist in GIS local government. Some data layers may be format, whereas others are only available in available from state and federal agencies and digital or hardcopy formats that need to be commercial vendors. EPA and most state converted to GIS. Digital data with a geo- environmental agencies maintain databases spatial reference such as latitude and longitude, of industrial NPDES, CERCLA, RCRA and parcel ID numbers or addresses can be other sites that handle or discharge directly entered into a GIS, if an existing pollutants or hazardous materials. These road or parcel GIS layer can be associated to searchable permit databases are often it. Hardcopy maps can also be digitized to available as GIS layers (see Appendix A). create new GIS data layers. This can be a Commercial vendors are good sources for labor-intensive process, but will only need low-altitude aerial photos of your to be done once and can be easily updated. If community. Aerial photos can be expensive GIS is not an option, hardcopy maps and but are often the best way to get a recent data can be analyzed, with an emphasis on high-resolution `snapshot' of subwatershed tax maps, topographic maps, historic aerial conditions. surveys, and storm drain and outfall maps. TableData for • . Assessment Data Likely Format Aerial photos or orthophotos Digital map Subwatershed or catchment boundaries Digital or hardcopy map Hydrology including piped streams Digital or hardcopy map Land use or zoning Digital or hardcopy map aai NPDES storm water permittees Digital data or map E Outfalls Digital or hardcopy map oSewer system, 1" =200' scale or better Digital or hardcopy map aai Standard Industrial Classification codes for all industries Digital or hardcopy data Storm drain system, 1" = 200' scale or better Digital or hardcopy map Street map or equivalent GIS layers Digital or hardcopy map Topography (5 foot contours or better) Digital or hardcopy map Age of development Narrative data As-builts or construction drawings Hardcopy map Condition of infrastructure Narrative data Field inspection records Hardcopy or digital data Depth to water table and groundwater quality Digital data or maps Historical industrial uses or landfills Narrative data or hardcopy map o Known locations of illicit discharges (current and past) Narrative data or digital map Q Outfall and stream monitoring data Digital data O Parcel boundaries Digital or hardcopy map Pollution complaints Narrative data Pre-development hydrology Narrative data or hardcopy map Sanitary sewer Infiltration and Inflow (I/I)surveys Hardcopy or digital data Septic tank locations or area served by septic systems Hardcopy or digital map Sewers stem evaluation surveys Hardcopy or digital data 48 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 5:Desktop Assessment of Illicit Discharge Potential Alternatively, TerraServer (Figure 8). Make sure all data layers are in (http://terraserver.microsoft.com/default.aspx) is the same coordinate system, and perform a free mapping resource that most any conversions needed. Clip data layers to communities can use to get good quality subwatersheds to enable calculation of aerial and other coverages (Figure 8 is an factors such as land use, area, and outfall example). Higher quality photos may be density. Summary data on subwatershed desirable as more detailed investigations are water quality and statistics on the age and pursued. condition of infrastructure should be entered into a database created for analysis in the As GIS technology has become more next step. affordable and easier to use, Phase II communities should harness their Step 3: Compute Discharge capabilities to develop the storm sewer Screening Factors system maps required by NPDES permits. GIS can become a powerful tool to track and The third step of the desktop assessment manage the entire IDDE program, and defines and computes discharge factors to demonstrate compliance in annual reports. screen subwatersheds based on their illicit In addition to being a powerful tool for discharge potential(IDP). As many as 10 analysis, GIS is also a great tool for different discharge screening factors can be communicating with the public. The images derived during the screening process, but not that can be created with GIS can summarize all may apply to every community. The tables of data in a way that the public potential screening factors are described in appreciates. If the recommended data layers Table 14, along with how they are measured are not available, a community may want to or defined. Keep in mind that these devote program resources to create or obtain screening factors are a guide and not a them. Once data layers have been collected guarantee. Each screening factor is and digitized, they can be entered into the described in detail in the following section. GIS to create a map of each subwatershed Figure 8: GIS Layers of Outfalls in a Subwatershed Markings illustrate Tuscaloosa,AL outfalls and drainage areas surveyed as part of this project. Illicit Discharge Detection and Elimination:A Guidance Manual 49 Chapter 5:Desktop Assessment of Illicit Discharge Potential Table • Discharge Screening Factors in a Community Discharge Screening Defining and Deriving the Factor Factors 1. Past Discharge Frequency of past discharge complaints, hotline reports, and spill responses Complaints and Reports per subwatershed. Any subwatershed with a history of discharge complaints should automatically be designated as having high IDP. 2. Poor Dry Weather Frequency that individual samples of dry weather water quality exceed Water Quality benchmark values for bacteria, nutrients, conductivity or other predetermined indicators. High risk if two or more exceedances are found in any given year. 3. Density of Generating Density of more than 10 generating sites or five industrial NPDES storm water Sites or Industrial sites per square mile indicates high IDP. Density determined by screening NPDES Storm Water business or permit databases (Appendix A). Permits 4. Storm Water Outfall Density of mapped storm water outfalls in the subwatershed, expressed as the Density average number per stream or channel mile. A density of more than 20 outfalls per stream mile indicates high IDP. Defined as the average age of the majority of development in a subwatershed. 5. Age of Subwatershed High IDP is often indicated for developments older than 50 years. Determined Development from tax maps and parcel data, or from other known information about neighborhoods. 6. Sewer Conversion Subwatersheds that had septic systems but have been connected to the sanitary sewer system in the last 30 years have high IDP. 7. Historic Combined Subwatersheds that were once served by combined sewer system but were Sewer Systems subsequently separated have a high IDP. 8. Presence of Older Subwatersheds with more than 5% of its area in industrial sites that are more Industrial Operations than 40 years old are considered to have high IDP. Determined from historic zoning, tax maps, and "old-timers." Defined as the age and condition of the subwatershed sewer network. High 9. Aging or Failing IDP is indicated when the sewer age exceeds design life of its construction Sewer Infrastructure materials (e.g., 50 years)or when clusters of pipe breaks, spills, overflows or I/I are reported by sewer authorities. 10. Density of Aging Subwatersheds with a density of more than 100 older drain fields per square Septic Systems mile are considered to have high IDP. Determined from analysis of lot size outside of sewer service boundaries. 1. Past Discharge Complaints and Reports discharges have historically occurred can be found. Ideally, the number of past discharge Many communities already have some complaints should be expressed on a handle on where illicit discharges have subwatershed basis. Even if there is not occurred in the past, based on past enough data to quantify past discharges, it complaints, reports and interviews with spill may be helpful to get a qualitative opinion responders and public works repair crews. from public works crews. Pollution complaints made to the local environmental or health department are also worth analyzing. Each of these historical sources should be analyzed to determine if any patterns or clusters where illicit 50 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 5:Desktop Assessment of Illicit Discharge Potential 2. Poor Dry Weather Water Quality described in Chapter 1 and Appendix A. From the standpoint of discharge screening, If dry weather water quality monitoring data the key variable to derive is the density of have been collected for local streams, it can potential generating sites (e.g., sites/square be an extremely useful resource to screen mile). As a rule of thumb, more than 10 subwatersheds for IDP. In particular, look potential generating sites per square mile for extreme concentrations of enterococci or would indicate a high IDP, while E. coli, or high ammonia-nitrogen or subwatersheds with three to 10 generating conductivity. Remember to edit out any sites per square mile might suggest a samples that were collected during or shortly medium IDP. after storm events, as they reflect the washoff of pollutants during storm water Alternatively, communities may want to runoff. In general, most communities have develop screening factors based on the more subwatersheds than baseflow density of industrial storm water permits in monitoring stations, so complete coverage is place within the subwatershed. State or usually lacking. The following benchmarks federal regulatory agencies often have are recommended to flag streams with high geospatial databases of industrial NPDES IDP, based on individual samples of dry discharges that can be rapidly screened. weather water quality that exceed: Pretreatment programs are another valuable source of information on industrial and non- • Fecal coliform or E. coli standards (e.g., domestic discharges to the sanitary system. typically 1,000 to 5,000 MPN/100 ml) 4. Storm Water Outfall Density • Ammonia-nitrogen levels of 0.30 mg/l • Total phosphorus of 0.40 mg/1 The density of outfalls in a subwatershed is • Conductivity levels that exceed the 90t' an effective discharge screening factor, and percentile value for the pooled dataset. is expressed in terms of the number of outfalls per stream mile. Outfall density can Subwatersheds can be classified as having a be determined by analyzing storm drain moderate risk if stream water quality values maps, if they exist (although they often miss exceed half the benchmark value. An the smaller diameter outfalls that can also alternative approach is to statistically produce discharges). In general, analyze long-term dry weather water quality subwatersheds that have more than 20 monitoring dataset to define breakpoints mapped outfalls per stream mile may (e.g., 50t', 75t', and 90t'percentiles). indicate a higher risk for IDP. Alternatively, the breakpoints for outfall density can be 3. Density of Generating Sites or Industrial statistically analyzed based on the frequency NPDES Storm Water Permits across all subwatersheds. The density of potential generating sites in a 5. Age of Subwatershed Development subwatershed can be a good screening factor, if land use and business databases are The average age of development in a available. The basic database screening subwatershed may predict the potential for method used to locate commercial, illicit discharge problems. For example, a industrial, institutional, municipal and subwatershed where the average age of development is more than 100 years was transport-related generating sites is Illicit Discharge Detection and Elimination:A Guidance Manual 51 Chapter 5:Desktop Assessment of Illicit Discharge Potential probably constructed before sewer service not have been installed to handle wash was widely available, and many of the pipes water, process water and other discharge and connections may have changed over the flows when the operation was originally years as a result of modernization and constructed. In the past, storm drains were redevelopment. Presumably, the risk of often used to handle non-sewage discharges potential discharges would be higher in at older industrial facilities. In addition, these older subwatersheds. By contrast, a sanitary and storm drain lines built in recently developed subwatershed may have different eras are poorly mapped, which a lower discharge risk due to improved increases the chance that someone gets the construction materials, codes and plumbing wrong during an expansion or inspections. Therefore, high IDP may be change in operations at the facility. As a indicated when subwatershed development result, older industries may inadvertently is more than 50 years old, with medium IDP discharge to floor drains or other storm drain for 20 to 50 year old development, and low connections thinking they are discharging IDP if fewer than 20 years old. You should pretreated water to the sanitary sewer. always check with local building and Finally, older industries that produce large plumbing inspectors to confirm the building volumes of process water may not have eras used in the screening analysis. The enough sanitary sewer capacity to handle the actual age of development can be estimated entire discharge stream, causing them to by checking tax maps and plats, or based on improperly discharge excess water through architecture, or common knowledge of the storm drain system. neighborhoods. For these reasons, subwatersheds where 6. Sewer Conversion older industry is present should be regarded as having a high IDP. For operational Subwatersheds that were once served by purposes, older industry is defined as sites septic systems but were subsequently that predate the Clean Water Act (e.g., 40 connected often have a high IDP. These years old or more). They can be identified subwatersheds are identified by reviewing from historic zoning and land use maps, old past sewer construction projects to parcel records or talking with old-timers. determine when and why sewer service was extended. 9. Aging or Failing Sewer Infrastructure 7. Historic Combined Sewer Systems Aging or failing sewer infrastructure often signals potential illicit discharges, and can Subwatersheds that were once served by be defined by the age and condition of the combined sewer systems but were subwatershed sewer network. High IDP is subsequently separated often have a high indicated when the sewer age exceeds the IDP. They can be identified by reviewing design life of its construction materials (e.g., past municipal separation projects. 50 years) or when clusters of pipe breaks, spills, overflows or infiltration and inflow 8. Presence of Older Industrial Operations (I&I) are reported by sewer authorities. Older and aging sewer infrastructure Older industrial areas tend to have a high experience more leaks, cross-connections potential for illicit cross-connections for and broken pipes that can contribute sewage several reasons. First, sanitary sewers may to the storm drain system. The key factor to determine is the approximate age of the 52 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 5:Desktop Assessment of Illicit Discharge Potential sewer pipes and their construction materials, Step 4: Screen for Illicit Discharge which can be gleaned from sewer maps I&I Potential at the Subwatershed and studies, or interviews with crews that Community Level regularly repair broken or leaking sewer pipes. The process for screening IDP at the subwatershed level is fairly simple. The first 10. Density of Aging Septic Systems step is to select the group of screening factors that apply most to your community, Subwatersheds located outside of the sewer and assign them a relative weight. Next, service area are presumably served by septic points are assigned for each subwatershed systems. Septic systems more than 30 years based on defined scoring criteria for each old are prone to failure, based on many site screening factor. The total subwatershed factors (Swann, 2001). In general, a high score for all of the screening factors is then IDP is indicated if older septic tank density used to designate whether it has a low, exceeds 100 per square mile. Sewer medium or high risk to produce illicit envelope boundaries or sewer network maps discharges. Table 15 provides an example. can be helpful to identify subwatersheds that Based on this comparison, high-risk are served by septic systems. Actual density subwatersheds are targeted for priority field is determined by counting or estimating the screening. It is important for program total number of septic households in the managers to track and understand which subwatershed. Tank density should be screening factors contributed to identifying a expressed as septic system units per square watershed as "high-risk," as this may affect mile (average lot size can also be used as a the type of investigatory strategy that is used surrogate estimator). for a particular watershed. Table 15: Prioritizing Subwatersheds Using IDP Screening Factors Past Poor dry Density of Discharge weather water storm water Average Raw Complaints/ quality outfalls age of IDP Normalized Reports (%of times (#of outfalls development score IDP score** (total number bacteria standards per stream (years) logged) are exceeded) mile) Subwatershed 8 (2)* 30% (2)* 14 (2)* 40 (2)* 8 2 A Subwatershed 3 (1) 15% (1) 10 (2) 10 (1) 5 1.25 B Subwatershed 13 (3) 60% (3) 16 (2) 75 (3) 11 2.75 C Subwatershed 1 (1) 25% (1) 9 (1) 15 (2) 5 1.25 D Subwatershed 5 (1) 15% (1) 21 (3) 20 (1) 6 1.5 E Notes: *The number in parentheses is the IDP"score" (with 3 having a high IDP)earned for that subwatershed and screening factor. Basis for assigning scores(based on benchmarks)to assess IDP is as follows: Past discharge complaints/reports: <5 = 1; 5-10 =2; >10=3 Dry weather water quality: <25%= 1; 25-50%=2; >50% =3 Storm water outfall density: <10= 1; 10-20 =2; >20=3 Average age of development: <25= 1; 25-50=2; >50= 3 ** Normalizing the raw IDP scores (by dividing the raw score by the number of screening factors assessed)will produce scores that fall into the standard scale of 1 to 3 for low to high IDP, respectively. Illicit Discharge Detection and Elimination:A Guidance Manual 53 Chapter 5:Desktop Assessment of Illicit Discharge Potential The example provided in Table 15 uses four Table 16 and Figure 9 present an example screening factors to assess five subwatersheds in system for classifying IDP as minimal, a community. Data for each factor are clustered or severe, based on the proportion compared against assigned benchmarks, as of subwatersheds in each risk category. The shown in the table. Each subwatershed community-wide assessment helps program receives a specific score for each individual managers define their initial IDDE program screening factor. These scores are then goals and implementation strategies, and totalled for each subwatershed, and the one target priority subwatersheds for field with the highest score is given top priority investigations. screening. In this case, the screening priority would be given to Subwatershed C. then A, Step 5: Generate Maps to Support followed by E. Subwatersheds B and D, Field Investigations with the lowest potential for illicit discharges, have the lowest priority. The last step in this program component involves generating the maps that field A similar screening process can be used to crews need to screen outfalls in priority evaluate the IDP for the community as a subwatersheds. More detail on mapping whole. In this case, the entire population of requirements is provided in Chapter 11. The subwatersheds in the community is analyzed basic idea is to create relatively simple maps to collectively determine the frequency of that show streams, channels, streets, the three risk areas: high, medium, and low. landmarks, property boundaries and known Predefined criteria for classifying the outfall locations. The idea is to provide community's IDP should be developed. enough information so crews can find their way in the field without getting lost, but otherwise keep them uncluttered. Low altitude aerial photos are also a handy resource when available. Community-wideTable 16: of Potential Rating Indicators Minimal (no known problems) Majority of subwatersheds have a Low IDP risk, with the remainder having Medium IDP risk Clustered (isolated problems) More than 20% of subwatersheds with a Medium or High IDP risk that are in close proximity to each other Severe (severe problems) More than 50% of subwatersheds with a Medium or High IDP risk or more than 20% of subwatersheds with a High IDP risk 54 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 5:Desktop Assessment of Illicit Discharge Potential a b c Key: Low IDP risk Medium IDP risk High IDP risk Figure 9: Communities with Minimal (a), Clustered (b), and Severe (c) Illicit Discharge Problems Illicit Discharge Detection and Elimination:A Guidance Manual 55 Chapter 5:Desktop Assessment of Illicit Discharge Potential 56 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 6:Developing Program Goals and Implementation Strategies Cho 0 0 Chapter 6: Developing Program Goals and Implementation Strategies Purpose: This program component defines Desired Product or Outcome(s): Agreement the goals and performance milestones to on program goals, measurable indicators and measure progress in IDDE program implementation strategies that address four implementation during the first permit cycle, key areas: and selects the most appropriate and cost- effective strategies to find, fix and prevent • Overall program administration illicit discharges. The goals and strategies . Outfall assessment ensure that scarce local resources are allocated to address the most severe illicit Finding and fixing illicit discharges discharge problems that cause the greatest • Prevention of illicit discharges water quality problems in the community. Budget and/or Staff Resources Required: Method: The basic method is to analyze the Staff effort to draft the goals and strategies, results of the IDDE audit, desktop analysis conduct needed meetings, respond to and local water quality conditions to develop comments and finalize ranges from two to realistic, achievable and measurable goals six weeks. Goals and strategies should be for the program. The public and other revisited and updated annually and at the stakeholders should be involved in the goal end of each permit cycle. Staff and budget setting process. Once goals are selected, costs are not anticipated to be high unless a program managers need to select the fundamental shift in program goals occurs. appropriate implementation strategies and develop a timeline to make them happen. Integration with Other Programs: Goal Both goals and strategies should closely setting is always a good opportunity for align with the type and severity of water public involvement, storm water education quality problems and local watershed and watershed outreach. Effective management priorities. The probable implementation strategies often involve cost contribution of illicit discharges to specific sharing with other departments and even water quality problems should be estimated other communities for monitoring or modeled to determine the degree to which equipment and lab facilities, hotlines, and control efforts can meet local TMDLs, education (e.g., public health/septic system bacteria standards for water contact programs). recreation, or other local water quality concerns. Illicit Discharge Detection and Elimination:A Guidance Manual 57 Chapter 6:Developing Program Goals and Implementation Strategies 6.1 Overview of Goals and With this in mind, a series of representative Strategies Development goals that might be set for an IDDE program are presented in Table 17, along with Communities can define program goals and proposed milestones. Four broad types of implementation strategies once they goals should be developed for every understand the extent of their illicit program: discharge problem and how it influences local water quality. Initial program goals 1. Overall program administration should be realistic and provide specific 2. Outfall assessment completion milestones to measure program 3. Preventing illicit discharges compliance. Measurable goals enable a 4. Finding and fixing illicit discharge community to track and evaluate permit compliance over time, and to reassess and modify the program over time. The most The assumed timeframe is based on a five- basic measure of program effectiveness is to year permit cycle. Some of the program assess whether program goals are being met. goals outlined in Table 17 are considered So, if a program goal is to walk all stream essential while others are optional or miles and inventory all outfalls in the MS4 recommended. Communities should feel within the first permit cycle, this becomes a free to adapt these suggested program goals benchmark that determines program to reflect their unique conditions and effectiveness. If a community finds that they capabilities, or create new ones. The key only managed to walk and inventory 80% of point is that program goals should always stream miles, the program may need to be have a timeframe to serve as a benchmark modified so that a full screening sweep is for whether the goal has been achieved. completed in a permit cycle, or they may need to adjust the goal or benchmark. Implementation strategies are designed to achieve program goals, and vary depending 6.2 Develop Initial Program on the types and severity of illicit discharge problems in the community. These are Goals outlined in more detail in the next section. The NPDES Phase II MS4 permit regulations grant communities considerable flexibility to develop program goals, as long as they are defined in a measurable way to gauge permit compliance and program effectiveness. EPA (2000e) states that goals "should reflect the needs and characteristics of the operator and the area served by its small MS4. Furthermore, they should be chosen using an integrated approach that fully addresses the requirements and intent of the minimum control measure." 58 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 6:Developing Program Goals and Implementation Strategies Table • • . for • • EXAMPLE MEASURABLE GOALS ITIMEFRAME PRIORITY Goals related to overall program administration Audit existing capabilities and identify needs • Designate one program head and identify key • support staff Immediately Develop a complete list of ongoing activities related O to IDDE Coordinate and communicate with other affected • agencies At program start up and continuously Develop a projected 5-year budget and regularly after that • Secure funding to match 5-year goals • Draft and promulgate new or modified ordinance Year 1 • Establish a tracking and reporting system Year 1 • Goals related to outfall assessment Define and characterize drainage areas or sewer Year 1 • sheds Begin in Year 1 and complete first Walk all stream miles screening by end of permit cycle. • Repeat once per permit cycle Develop a digital (e.g., GIS) map of all outfalls, land Year 1 and continuously and • use, and other relevant infrastructure regularly after that Secure analytical laboratory services either Initiate in conjunction with field internally or by arrangement with a private • screening laboratory Sample and trace the source of a percentage of • flowing outfalls each year of permit cycle C Initiate during first permit cycle and Conduct regular in-stream assessments O expand and enhance where Conduct investigations at a percentage of non- problems are observed flowing outfalls with poor in-stream water quality to O look for intermittent flows Integrate all collected stream data and citizen Initiate during first year and expand O complaints into the GIS system and enhance with time Goals related to preventing illicit discharges Distribute educational materials to citizens and Initiate during first year and expand O industries and enhance with time Conduct storm drain stenciling O Hold hazardous waste collection days at least Initiate during first permit cycle and O annually expand and enhance where Conduct upland subwatershed site reconnaissance problems are observed surveys to better characterize generating site O potential Goals related to finding and fixing illicit discharges Develop a spill response plan and coordinate Immediately • emergency response with other agencies Ongoing in conjunction with field Remove all obvious illicit discharges screening and in response to hotline • reports Illicit Discharge Detection and Elimination:A Guidance Manual 59 Chapter 6:Developing Program Goals and Implementation Strategies Table • •. for • • EXAMPLE MEASURABLE GOALS TIMEFRAME PRIORITY Train staff on techniques to find the source of an Initiate during first year and expand • illicit discharge and enhance with time Repair a fraction of the illicit discharges identified Initiate during first permit cycle and through field screening or citizen complaints expand and enhance where • problems are observed Establish a hotline for public to call in and report Initiate during first year and expand incidents (consider establishing performance O and enhance with time standards, such as guaranteed response time) Initiate during first permit cycle and Inspect and dye-test all industrial facilities expand and enhance where O problems are observed Develop a system to track results of on-site Initiate during first year and expand O inspections and enhance with time Initiate during first permit cycle and Establish an Adopt-a-Stream program expand and enhance where O problems are observed Establish pre-approved list of plumbers and Initiate during first year and expand O contractors to make corrections and enhance with time Key: • Essential O Optional but Recommended Ultimately, IDDE program goals should be discussion on designing and conducting a linked to water quality goals. Some common receiving water investigation. examples of water quality goals include: 6.3 Crafting Implementation • Keep raw or poorly-treated sewage out Strategies of streams • Reduce pollutant loads during dry In order to meet program goals, managers weather to help meet the TMDL for a must devise cost-effective implementation water body strategies that are most appropriate for the • Meet bacteria water quality standards types of illicit discharge problems they for contact recreation during dry actually have. The community-wide illicit weather flows discharge potential (IDP) developed during • Reduce toxicant and other pollutant the desktop analysis can be quite helpful in discharges to a stream to restore the choosing implementation strategies. Table abundance and diversity of aquatic 18 presents implementation strategies that insects or fish are geared to the findings of the community- wide IDP. As the community acquires more program experience, they can refine the A well-designed IDDE program may not strategies to better address program goals or guarantee that water quality goals will be unique watershed conditions (Table 19). always be achieved. Indeed, if program managers can document that illicit Perhaps the most important implementation discharges do not contribute to poor water strategy is targeting—screening, education quality, they may want to shift resources to and enforcement efforts should always be other pollution sources or practices that do. focused on subwatersheds, catchments or Burton and Pitt(2002) offer a complete generating sites with the greatest IDP. 60 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 6:Developing Program Goals and Implementation Strategies Adaptability after program startup is also an constantly adjusted to reflect knowledge important strategy. Strategies developed gained from field screening, hotline reports from the desktop analysis should be and other monitoring information. Table 18: Linking Implementation Strategies to Community-wide lDP Type Examples of Implementation Strategy • Conduct field screening of outfalls in the context of broader watershed assessment and restoration initiatives using the Unified Stream Assessment (CWP, 2004)or a comparable physical stream assessment approach that has broader focus and benefits. Minimal IDP • Integrate IDDE program efforts into more comprehensive watershed assessment and restoration efforts where multiple objectives are being pursued (e.g., storm water education). • Target and coordinate with existing small watershed organizations as partners to accomplish inventory and data collection efforts. • Establish hotline to report suspicious discharges. • Conduct limited sampling in the suspect areas. The most cost-effective approach will likely involve using outside laboratory services to avoid capital costs for special equipment(in some cases a municipal laboratory may be available for limited cost). Clustered IDP • Select a small set of indicator parameters using the nature of historic problems and land use as a guide. • Target education program in problem areas. • Look for partnerships with local watershed groups to regularly monitor problem areas. • Establish a hotline to report suspicious discharges. • Establish a hotline to report suspicious discharges. • Conduct and repeat screening in all subwatersheds • Plan for more rigorous sampling approach to make establishment of internal laboratory set up more cost effective(i.e., plan for equipment expenditures for sample collection and analysis). Considerations include: expanding set of parameters to use as indicators, adopting a strategy for targeting intermittent discharges, and establishing in-stream stations to supplement screening effort. Severe IDP • Develop a community-specific chemical "fingerprint'of various flow sources to facilitate differentiation between likely flow sources. • Develop community-wide educational messages aimed at increasing public awareness and targeted education programs tailored to problem areas. • Look for partnerships with local watershed groups to be regular monitors of problem areas through an adopt-a-stream approach. • Emphasize cross-training of municipal employees to develop a broader reach of program efforts and lead by example by ensuring municipal facilities are not contributing to illicit discharge problem. Illicit Discharge Detection and Elimination:A Guidance Manual 61 Chapter 6:Developing Program Goals and Implementation Strategies Table 19: Customizing Strategies for Unique Subwatershed Screening Factors Initial Problem Screening Factor (from Table 14) Example Implementation Strategies Assessment • Complaints of sewage Institute a point of sale inspection and Aging Sewer discharges verification process. Infrastructure Poor dry weather quality Select a small set of indicator parameters and/or High outfall density Converted that focuses on sewage connections. Combined Septic to sewer conversion System Historic combined system Develop cost share program to assist y property owners with connection • Aging sewers correction. Aging Septic Develop targeted education program for Infrastructure septic system maintenance and institute a and/or Aging septic systems point of sale inspection and verification Converted process. Combined Develop cost share capabilities to assist System property owners with upgrade of system. • Link IDDE program to existing industrial NPDES discharge permits, and inspect storm water management pollution Discharges Density of generating sites prevention plans. from Generating Older industry Develop targeted training and technical Sites Past complaints and reports assistance programs tailored to specific generating sites. • Aggressively enforce fines and other measures on chronic violators. • Establish a hotline and develop community-wide educational messages aimed at increasing public awareness. High Spill or Look for partnerships with local watershed Dumping Past complaints and reports groups to regularly monitor or adopt Potential problem sites. • Increase number and frequency of used oil and hazardous waste recycling stations. • Post signs, with hotline reporting number at dumping sites. 62 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 7:Searching for Illicit Discharge Problems in the Field Cho g chapter 7: Searching for Illicit Discharge Problems in the Field Purpose: This program component consists Budget and/or Staff Resources Required: of detective work, and involves rapid field Field screening and indicator monitoring can screening of outfalls in priority consume substantial staff and budget subwatersheds followed by indicator resources. Monitoring costs are closely monitoring at suspect outfalls to characterize related to the number of outfalls screened flow types and trace sources. and the complexity of illicit discharge problems discovered. An MS4 that screens Method(s): The primary field screening tool 10 stream miles and analyzes 80 indicator is the Outfall Reconnaissance Inventory samples each year can expect to spend about (ORI), which is used to find illicit discharge $15,000 to $35,000. Consequently, choosing problems and develop a systematic outfall which indicator(s)to use in a community inventory and map of the MS4. The ORI is (and when and where to use them) ranks as frequently supplemented with more one of the most important budget decisions intensive indicator monitoring methods to for any project manager. test suspect outfalls. A wide range of monitoring methods can be used; this Integration with Other Programs: Program chapter describes a framework for choosing managers should explore two strategies to the safest, most accurate and repeatable integrate field screening and indicator methods for a community. monitoring with other programs to achieve cost savings. The first strategy links outfall Desired Product or Outcome(s): The search screening to broader stream corridor for illicit discharge problems yields several assessments that support local watershed important management products, including: restoration efforts. Often, watershed organizations and "stream waders" can be • An updated map of the locations of enlisted and trained to conduct outfall all outfalls within the MS4 screening. The second strategy is to find a local agency partner to conduct laboratory • Incorporation of ORI data into the analysis (such as a drinking water or outfall inventory/tracking system wastewater treatment plant). • Design and implementation of an indicator monitoring strategy to test suspect outfalls • Creation of a local chemical "fingerprint" library of pollutant concentrations for various discharge flow types • Data reports that evaluate the significance and distribution of illicit discharge problems in the community Illicit Discharge Detection and Elimination:A Guidance Manual 63 Chapter 7:Searching for Illicit Discharge Problems in the Field 7.1 Overview of Searching for The ORI can discover obvious discharges Illicit Discharge Problems in the that are indicated by flowing outfalls with Field very high turbidity, strong odors and colors, or an"off the chart"value on a simple field test strip. When obvious discharges are This chapter provides basic information found, field crews should immediately track about the field and laboratory strategies down and remove the source (see Chapters 8 needed to detect illicit discharges, beginning and 13). In other instances, ORI crews may with a field screening technique designed to encounter a transitory discharge, such as a gather basic information and identify highly liquid or oil spill that should be immediately suspect outfalls or obvious discharges. Next, referred to the appropriate agency for it provides a basic framework for using the cleanup (Figure 11). data from this screening to address obvious discharges, develop a chemical monitoring program, and make future program decisions. Finally, it summarizes the basic options for conducting an ongoing chemical monitoring program. The approaches outlined here are only summarized briefly, and primarily in the context of overall program management. Much more detailed + and "hands-on" information is provided in Chapters 11 and 12 that provide specific methods and technical guidance for field crew and laboratory staff. 7.2 The Outfall Reconnaissance Inventory (ORI) The field screening technique recommended for an IDDE program is the Outfall Figure 10: Measuring an Reconnaissance Inventory or ORI. The ORI outfall as part of the ORI is a stream walk designed to inventory and measure storm drain outfalls, and find and correct continuous and intermittent discharges without in-depth laboratory analysis (Figure 10). The ORI should be completed for every stream mile or open , channel within the community during the t first permit cycle, starting with priority subwatersheds identified in the desktop analysis. Outfall screening requires relatively little expertise, and can be incorporated into other stream assessments such as the Unified Stream Assessment (Kitchell and Schueler, 2004). Figure 11: Some discharges are immediately obvious 64 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 7:Searching for Illicit Discharge Problems in the Field The ORI is not meant to be a"one size fits 7.3 Interpreting ORI Data all" method, and should be adapted to suit the unique needs of each community. Once the first few ORI surveys are Program managers should also modify the conducted, data can be analyzed to confirm ORI over time to reflect field observations, and update the desktop analysis originally crew experience, new or modified used for targeting subwatersheds. The ORI indicators, and any other innovations that data analysis follows four basic steps, which make fieldwork easier or faster. Table 20 are described in Table 21. Ideally, ORI data summarizes the four basic steps to conduct should be stored within a continuously- an ORI, and more detail on ORI protocols is updated geospatial tracking system. provided in Chapter 11. FieldTable 20: Screening for an IDDEProgram Step Strategies • Use basic street maps or detailed maps from initial assessment Step 1. Acquire necessary Minimal field equipment required; use a portable spectrophotometer mapping, equipment and if desired staff Two staff per crew with basic field training required; more specialized staff or training is optional Step 2. Determine when to During dry season and leaf off conditions conduct field screening After a dry period of at least 48 hours • Low groundwater levels Step 3. Identify where to Minimal: integrate field screening with broader watershed or stream conduct field screening assessments (based on desktop Clustered: screen drainage areas ranking High and Medium first for assessment) illicit discharge potential • Severe: screen all outfalls systematically • Mark and photograph all outfalls Step 4. Conduct field Record outfall characteristics • Simple monitoring at flowing outfalls screening Take flow sample at outfalls with likely problems • Deal with major problems immediately Illicit Discharge Detection and Elimination:A Guidance Manual 65 Chapter 7:Searching for Illicit Discharge Problems in the Field Table 21: Field Data Analysis for an IDDE Program Step Considerations • Compile GPS data and photographs of outfall locations Step 1. Compile data from the ORI 0 Enter ORI data into database • Send any samples for lab analysis Step 2. Develop ORI designation for 0 Use ORI data to designate outfalls as having obvious, outfalls suspect, potential, or unlikely discharge potential • Use data from initial assessment Step 3. Characterize the extent of 0 Use outfall designation data illicit discharge problems 0 Update initial assessment of illicit discharge problems as minimal, clustered, severe • At a minimum, sample 10% of flowing outfalls per year Step 4. Develop a monitoring 0 Repeat field screening in second permit cycle strategy 0 Use various monitoring methods depending on outfall designation and subwatershed characteristics 7.4 Design and Implementation unique discharge problems and analytical of an Indicator Monitoring capabilities of individual communities. Strategy Some of the recommended monitoring strategies are discussed below. The preferred The next step is to design an indicator method to test flowing outfalls is the flow monitoring program to test suspect or chart method that uses a small set of problem outfalls to confirm whether they are indicator parameters to determine whether a actually an illicit discharge, and determine discharge is clean or dirty, and predicts its or the type of flow. From a program flow type (Pitt, 2004). The flow chart management standpoint, six core issues need method is particularly suited to distinguish to be considered during the design of the sewage and washwater flow types. Industrial monitoring strategy, as shown in Table 22. sites may require special testing, and the benchmark concentrations method The indicator monitoring strategy should be includes several supplemental indicators to concentrated primarily on continuous and distinguish industrial sources. intermittent discharges, and can be adapted to isolate the specific flow type found in a • discharge. Figure 12 presents an overall Considerations monitoring design framework that organizes 0Use ORI data to prioritize problem outfalls some of the key indicators and monitoring or drainage areas • Select the type of indicators needed for techniques that may be needed. In general, your discharge problems different indicators and monitoring methods 0 Decide whether to use in-house or contract are used depending on whether flow is lab analytical services present at an outfall or not. The details of the 0Consider the techniques to detect discharge monitoring framework are intermittent discharges • Develop a chemical library of described in Chapter 12. The basic concentrations for various flow types framework should be adapted to reflect the Estimate staff time, and costs for equipment and disposable supplies 66 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 7:Searching for Illicit Discharge Problems in the Field Non Transitory Flowing Intermittent Caulk Dam Source Area Off Hours Data In-stream Flowchart Chemical Chemical Mass Monitoring ORI Flowing Industrial � Library PP Balance [optional] Benchmark Model Obvious Find and Fix Immediately ❑Denotes a monitoring method Figure 12: IDDE Monitoring Framework Non-flowing outfalls are more challenging As communities acquire more monitoring to diagnose. Intermittent flows can be data,they should consider creating a diagnosed using specialized monitoring chemical"fingerprint" library, which is a techniques such as: database of the chemical make-up of the many different flow types in the community. • Off hours monitoring Chemical libraries should include sewage, • Caulk dams septage, washwater, and common industrial flows. Default values for the chemical • Optical brightener monitoring traps library can initially be established based on existing research and literature values. Data When intermittent discharges are captured are then updated based on local monitoring by these specialized techniques, samples are to develop more accurate decision points in normally diagnosed using the flow chart the flow chart or benchmark methods. Clean method. water sources such as tap water,groundwater, spring water, and irrigation water are also Transitory discharges are extremely difficult important entries in the chemical library. to detect with routine indicator monitoring, The chemical library should also characterize and are frequently identified from hotline the water quality of known or unknown reports. Transitory discharges are usually transitory discharges sampled in the field. diagnosed by inspection, although water Over time, chemical library data should help quality samples may be collected to support a community better understand the potential enforcement measures. pollutant loads delivered to receiving waters from various generating activities. Illicit Discharge Detection and Elimination:A Guidance Manual 67 Chapter 7:Searching for Illicit Discharge Problems in the Field These library data can be used to support these typically provide an excellent starting more advanced strategies such as the point for IDDE programs. Chapters 11, 12, Chemical Mass Balance Model (CMBM) and 13 along with Appendices F and G method. This method, developed by the provide guidance on specific considerations University of Alabama as part of this project associated with IDDE programs. Of (Karri, 2004), is particularly useful in particular note is that program managers identifying flow types in blended discharges, may want to consider requiring/ where groundwater or tap water is diluted or recommending field crews be vaccinated commingled with sewage and other illicit against Hepatitis B, particularly if the crews discharges. The CMBM requires substantial will be accessing waters known to be upfront work to develop an accurate contaminated with illicit sewage discharges. chemical library for local flow types. Program managers should contact local Specifically, the library requires 10-12 health department officials to explore this samples for each flow type (for industrial issue in more detail prior to making a flow types, samples can be obtained in decision. association with NPDES pre-treatment programs). A user's guide for the CMBM can be found in Appendix I. Section 7.5 Field and Lab Safety Considerations Program managers should take into account and fully plan for all necessary field and laboratory safety precautions. Most communities already have well established standard operating procedures they follow when conducting field and lab work, and 68 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 8:Isolating and Fixing Individual Illicit Discharges Chapter 8: Isolating and Fixing 00 Individual Illicit Discharges Purpose: This program component uses a Budget and/or Staff Resources Required: variety of tools to trace illicit discharge Budget and staff resources needed to find problems back up the pipe to isolate the illicit discharges vary greatly. Some specific source or improper connection that discharge sources will be immediately generates the discharge. This often requires obvious, while others will require extensive improved local capacity to locate specific investigations up the pipe until the source discharges, make needed corrections and can be sufficiently narrowed. Fixing the maintain an enforcement program to ensure problem once it is identified is more repairs. predictable and can often involve qualified contractors. Costs associated with repairs Method(s): Five basic tools exist to isolate can also be fully incurred by the offending and fix individual discharges, including: party or shared, depending on the nature and extent of the illicit discharge. • Pollution reporting hotline • Drainage area investigations Integration with Other Programs: Two important aspects of this program • Trunk investigations component can be integrated with other • On-site discharge investigations NPDES minimum management measures • Correction and enforcement and storm water permitting. First, the pollution hotline can be an important Desired Product or Outcome(s): Finding element of any local storm water education and fixing illicit discharges is the core goal initiative. Second, on-site illicit discharge of any IDDE program. The process of investigations should be closely coordinated finding and fixing discharges has several with industrial NPDES storm water site desirable outcomes, such as: inspections. • Improved water quality • Increased homeowner and business awareness about pollution prevention • Maintenance of a tracking system to document repairs and identify repeat offenders. Illicit Discharge Detection and Elimination:A Guidance Manual 69 Chapter 8:Isolating and Fixing Individual Illicit Discharges 8.1 Overview of Isolating and Pollution Complaint Hotline Fixing Individual Illicit Discharges A complaint hotline is a dedicated phone The ultimate goal of every IDDE program is number or website where citizens can easily to find and fix illicit discharges, and a range report illicit discharge and pollution of tools are available to meet this objective. concerns. The hotline should always be The ensuing chapter discusses each of the supported by prompt investigations of each tools in more detail. The choice of which complaint by trained inspectors, usually tools are used depends on the nature of the within 24 hours. Many Phase I communities local storm drain system, and the type and have utilized hotlines to track down mode of entry of the discharges. intermittent and transitory discharges, and regard them as one of their most effective 8.2 Isolating Illicit Discharges tools to isolate illicit discharges (CWP, 2002). Some of the benefits and challenges Phase I communities have encountered in Outfall screening and monitoring are administering an IDDE complaint hotline in excellent for finding illicit discharge summarized in Table 23. problems, but they often cannot detect most intermittent or transient flows, nor can they Six basic steps are needed to establish and always isolate the exact source,particularly maintain a successful IDDE complaint when the outfall has a large contributing hotline, which are outlined in Table 24. area and an extensive pipe network. This More detailed guidance on establishing a section provides guidance on four tools to hotline is provided in Appendix C, along find individual illicit discharges. The first with a sample illicit discharge incident tool is a pollution complaint hotline, which tracking form. is particularly effective at finding obvious illicit discharges, such as transitory flows It is important to keep in mind that a from generating sites and sewer overflows. successful hotline requires considerable Citizens provide free surveillance around the advertising and outreach to keep the phone clock, and their reports should prompt rapid number fresh in the public's mind. Also, investigations and enforcement. The other program managers should continuously three investigative tools involve drainage monitor response times,inspection outcomes, area, trunk, and on-site investigations. and any enforcement taken. All complaints should be entered into the IDDE tracking system so that complaints can be analyzed. Table 23: Benefits and Challenges of a Complaint Hotline Benefits Challenges • Leads to early detection and correction of illicit discharges • Encourages active public stewardship 0 Time and money to provide • Can "piggyback" on other call response needs 24/7 service • Identifies suspected facilities for further investigation and 0 Marketing the hotline number education 0 Establishing inter- and intra- • Increases facilities' and municipalities' sense of accountability departmental process • Increases likelihood of discovering intermittent discharges 70 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 8:Isolating and Fixing Individual Illicit Discharges Table • • Creating and Maintaining Successful IDDE Hotline Steps Key Elements • Determine if a hotline is needed 1. Define the scope 0 Define the intent of the hotline • Define the extent of the hotline 2. Create a tracking and 0 Design reporting method reporting system 0 Design response method • The basics and importance of IDDE 3. Train personnel The complaint hotline reporting, investigation and tracking process • How to provide good customer service • Expected responsibilities of each department/agency 4. Advertise • Advertise hotline frequently through flyers, magnets, newspapers, displays, etc. • Publicize success stories • Provide friendly, knowledgeable customer service 5. Respond to complaints 0 Send an investigator to respond to complaints in a timely manner • Submit incident reports to the hotline database system • Identify recurring problems and suspected offenders 6. Track incidents 0 Measure program success • Comply with annual report requirements The cost to establish and maintain a hotline require special training and staff expertise, varies, but savings can be realized if it can and may result in legal action. They include: be piggy-backed on an existing community hotline or cost shared with other • Storm drain network investigations communities in the region. Also, hotline • Drainage area investigations costs are related to the volume of calls and the staff effort needed for follow-up On-site investigations investigations. A budgeting framework for • Septic system investigations establish and maintaining a hotline from Each type of investigation handles a scratch is provided in Table 25. different type of discharge problem and has its advantages and disadvantages. More Illicit Discharge Investigations detail on these investigations is provided in Chapter 13. Once an illicit discharge is detected at an outfall or stream, one of four types of illicit Storm drain network investigations discharge investigations is triggered to track down the individual source. These investigations Storm drain or "trunk" investigations narrow are often time consuming and expensive, the source of a discharge problem to a single TableDD • •laint Hotline Costs Steps Initial Cost Annual Costs Define the scope $1,500 $0 Create a tracking and reporting system $2,500 $2,440 Train personnel $2,200 $1,000 Advertise $1,500 $2,920 Respond to complaints Track incidents $0 $5,000 TOTAL $7,700 $11,360 Illicit Discharge Detection and Elimination:A Guidance Manual 71 Chapter 8:Isolating and Fixing Individual Illicit Discharges segment of a storm sewer. The investigation Drainage area investigations starts at the outfall, and the field crew must decide how it will explore the upstream pipe Drainage area investigations are initially network. The three options include: conducted in the office, but quickly move into the field. They involve a parcel by • Work progressively up the trunk parcel analysis of potential generating sites from the outfall and test manholes within the drainage area of a problem along the way outfall. They are most appropriate when the • Split the trunk into equal segments drainage area to the outfall is large or and test manholes at strategic points complex, and when the flow type in the of the storm drain system discharge appears to be specific to a certain • Work progressively down the trunk type of land use or generating site. These (i.e., from the headwaters of the investigations may include the following storm drain network and move techniques: downstream) • Land use investigations The decision to move up, split, or move • SIC code review (see Appendix A) down the trunk depends on the nature of the • Permit review drainage system and the surrounding land • As-built review use. The three options also require different • Aerial photography analysis levels of advance preparation. Moving up the trunk can begin immediately when an Infrared aerial photography analysis illicit discharge is detected at an outfall, and • Property ownership certification only a map of the storm drain system is required. Splitting the trunk requires a little more On-site investi_atq ions preparation to examine the storm drain system and find the most strategic manholes to Once the illicit discharge has been isolated sample. Moving down the trunk requires to a specific section of storm drain, an on- even more advance preparation, since the site investigation can be performed to find most upstream segments of the storm drain the specific source of the discharge. In some network may be poorly understood. situations, such as subwatersheds dominated by industrial land uses or many generating Once crews choose one of these options, sites, on-site investigations may be they need to select the most appropriate immediately pursued. investigative methods to track down the source. Common methods include: On-site investigations are typically performed by dye testing the plumbing • Visual inspection at manholes systems of households and buildings. Where • Sandbagging or damming the trunk septic systems are prevalent, inspections of • Dye testing tanks and drain fields may be needed. • Smoke testing On-site investigations are excellent • Video testing opportunities to combine IDDE efforts with industrial site inspections that target review and verification of proper Storm Water 72 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 8:Isolating and Fixing Individual Illicit Discharges Pollution Prevention Plans. Appendix A Financial responsibility for source removal provides a list of industrial activities that will typically fall on property owners, MS4 typically require industrial NPDES operators, or a combination of the two. discharge permits. Methods for removing illicit discharges usually involve a combination of education Septic system investigations and enforcement. A process for addressing illicit discharges that focuses on identifying Communities with areas of on-site sewage the responsible party and enforcement disposal systems (i.e., septic systems) need procedures is presented in Figure 13, while to consider alternative investigatory methods Table 26 presents various options for to track illicit discharges that enter streams removing illicit discharges from various as indirect discharges, through surface sources. Additional information on common breakouts of septic fields, or through straight removal actions and associated costs can be pipe discharges from bypassed septic found in Chapter 14. systems. Techniques can involve on-site investigations or imagery analysis (e.g., Program managers should use judgment in infrared aerials). exercising the right mix of compliance assistance and enforcement. The authority 8.3 Fixing Illicit Discharges and responsibility for correction and enforcement should be clearly defined in the Once the source of an illicit discharge has local IDDE ordinance developed earlier in been identified, steps should be taken to fix the program. An escalating enforcement or eliminate the discharge. Four questions approach is often warranted and is usually a should be answered for each individual reasonable process to follow. Voluntary illicit discharge to determine how to compliance should be used for first-time, proceed;the answers will usually vary minor offenders. Often, property owners are depending on the source of the discharge. not even aware of a problem, and are willing to fix it when educated. More serious • Who is responsible? violations or continued non-compliance may warrant a more aggressive, enforcement- oriented approach. • How long will the repair take? • How will removal be confirmed? Illicit Discharge Detection and Elimination:A Guidance Manual 73 Chapter 8:Isolating and Fixing Individual Illicit Discharges Flow Chart for Corrective Action Contamination Source Identified -------------------------------------------------------------------------- , Determine Party Responsible for Making Repairs Municipality Private Property Owner Issue Work Order Issue Notice of Violation(NOV) Eliminate ContamLinatLionc. ......................................----; Confirm Elimination of Contamination Source Contamination Source Eliminated Contamination Source Still Present Complete Documentation 2nd Contamination Source Present Issue 2nd NOV ---- Issue 2nd Work Order ----- Enforcement Figure 13: Process for Removing or Correcting an Illicit Discharge Table •• • Fix Illicit Discharges Type of Source Removal Action(s) Discharge Break in right-of-way Repair by municipality Commercial or industrial direct connection Enforcement Sewage Residential direct connection Enforcement; Incentive or aid Infrequent discharge (e.g., RV dumping) Enforcement; Spill response Straight pipes/septic Enforcement; Incentive or aid Commercial or industrial direct connection Enforcement; Incentive or aid Residential direct connection Enforcement; Incentive or aid Wash water Power wash/car wash (commercial) Enforcement Commercial wash down Enforcement Residential car wash or household Education maintenance-related activities Professional oil change/car maintenance Enforcement; Spill response Heating oil/solvent dumping Enforcement; Spill response Liquid wastes Homeowner oil change and other liquid waste Warning; Education; Fines disposal (e.g., paint) Spill (trucking) Spill response Other industrial wastes I Enforcement; Spill response 74 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 9:Preventing Illicit Discharges Chapter 9: Preventing Illicit Discharges Purpose: This program component identifies Neighborhood Discharges. The pollution key behaviors of neighborhoods, generating prevention practices related to discharge sites, and municipal operations that produce prevention in residential neighborhoods intermittent and transitory discharges. These include storm drain stenciling, lawn key "discharge behaviors" are then targeted care, septic system maintenance, vehicle for improved pollution prevention practices fluid changing, car washing, household that can prevent or reduce the risk of discharge. hazardous waste disposal and swimming Communities then apply a wide range of pool draining. education and enforcement tools to promote Generating Sites. This group of pollution the desired pollution prevention practices. prevention practices can reduce spills and transitory discharges generated Method(s): The Unified Subwatershed and during common business operations. Site Reconnaissance (USSR; Wright et al., Practices include business outreach, spill 2004) and the desktop analysis of potential prevention and response plans, employee generating sites (Chapter 5) are two methods training and site inspections. used to identify the major behaviors that g Municipal Housekeeping. This group of generate intermittent and transitory discharges. These methods, used alone or in pollution prevention practices is c performed during municipal operations, combination, are extremely helpful to such as sewer and storm drain identify the specific discharge behaviors and maintenance, plumbing code revision, generating sites that will be targeted for education and enforcement efforts. A Source and provision of household hazardous Waste and used oil collection services. Control Plan is then performed to select the right pollution prevention message, choose the appropriate combination of carrots and Budget and/or Staff Resources Required: sticks to change behaviors, and develop a The budget and staff resources needed for prevention programs can be considerable, budget and delivery system to implement the l. and should be coordinated with other storm prevention program. Refer to Schueler et a ( water education, public involvement and 2004) for information on developing a municipal housekeeping initiatives required Source Control Plan and the many carrots and sticks available to communities. under NPDES Phase II MS4 permits. Special emphasis should be placed on cross- Desired Product or Outcome(s): The desired training staff, partnering with local outcome is a mix of local prevention programs watershed groups, and pooling educational that target the most common intermittent resources with other communities. and transitory discharges in the community. Integration with Other Programs: Illicit Program managers need to develop targeted discharge prevention is linked to three of the pollution prevention programs for three six NPDES Phase II minimum management sectors of the community: measures, and should be closely integrated with local watershed restoration efforts. Illicit Discharge Detection and Elimination:A Guidance Manual 75 Chapter 9:Preventing Illicit Discharges 9.1 Overview of Preventing Illicit restoration projects. For more information Discharges on how to conduct the USSR, consult Wright et al. (2004). The USSR has four Intermittent and transitory discharges are major assessment components, three of difficult to detect through outfall screening which directly relate to illicit discharge or indicator monitoring. Indeed, the best prevention: way to manage these discharges is to promote pollution prevention practices in Neighborhood Source Assessment the community that prevent them from (NSA), which helps discover residential occurring. Effective IDDE programs pollution source areas and potential develop education and outreach materials restoration opportunities within the targeted toward neighborhoods, generating many neighborhoods found in urban sites, and municipal operations. The subwatersheds discharge prevention message is normally Hotspot Site Investigation (HSI), which integrated with other storm water education ranks the potential severity of each programs required under MS4 NPDES commercial, industrial, institutional, Phase II permits such as municipal or transport-related hotspot site found within a subwatershed • Public education and outreach Analysis of Streets and Storm Drains • Public participation/involvement (SSD), which measures the average • Municipal pollution prevention/good pollutant accumulation in the streets, housekeeping curbs, and catch basins of a subwatershed 9.2 Methods to Identify Desktop Analysis of Generating Sites Opportunities for Illicit Discharge Prevention The desktop analysis method screens local business and permit databases to identify The USSR and the desktop analysis of specific commercial, industrial, institutional, potential generating sites both help identify municipal, and transport-related sites that the major behaviors that generate are known to have a higher risk of producing intermittent and transitory discharges. These illicit discharges. Chapter 5 and Appendix A assessment methods are briefly described provide discussions of this analysis. below: 9.3 Preventing Illicit Discharges The Unified Subwatershed and Site from Neighborhoods Reconnaissance (USSR) The USSR is a field survey that rapidly Many common neighborhood behaviors can evaluates potential pollution sources and cause transitory discharges that are seldom restoration potential in urban subwatersheds. defined or regulated as illicit discharges by The survey quickly characterizes upland most communities. Individually, these areas in order to inventory problem sites that behaviors cause relatively small discharges, may contribute pollutants and identifies but collectively, they can produce significant pollution source controls and other pollutant loads. Most communities use outreach and education to promote pollution 76 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 9:Preventing Illicit Discharges prevention practices, and some of the more coordinate storm drain stenciling and be effective practices to influence these responsible for recruiting, training, behaviors are described in this section: managing, and supplying volunteers. • Storm drain stenciling Storm drain stenciling programs are • Septic system maintenance relatively inexpensive. Most communities • Vehicle fluid changing use stencils, although some are now using permanent markers made of tile, clay, or • Car washing metal. Stencils cost about 45 cents per linear • Household hazardous waste storage and inch and can be used for 25 to 500 drains, disposal depending on whether paint is sprayed or • Swimming pool draining applied with a brush or roller. Permanent signs are generally more costly; ceramic tiles cost $5 to $6 each and metal stencils Storm Drain Stenciling can cost $100 or more. More guidance on designing a stenciling program can be found Storm drain stenciling sends a clear message in Schueler et al. (2004). to keep trash and debris, leaf litter, and pollutants out of the storm drain system, and Septic System Maintenance may deter illegal dumping and discharges (Figure 14). Stenciling may increase Failing septic systems can be a major source watershed awareness and neighborhood of bacteria, nitrogen, and phosphorus, stewardship and can be used in any depending on the overall density of systems neighborhood with enclosed storm drains. present in a subwatershed (Swann, 2001). Failure results in illicit surface or subsurface Stenciling is an excellent way to involve the discharges to streams. According to U.S. public, and just a few trained volunteers can EPA (2002), more than half of all existing systematically stencil all the storm drains septic systems are more than 30 years old, within a neighborhood in a short time. which is well past their design life. The Volunteers can be recruited from scouting, same study estimates that about 10% of all community service, and watershed septic systems are not functioning properly organizations, or from high schools and at any given time, with even higher failure neighborhood associations. Program rates in some regions and soil conditions. managers should designate a staff person to Septic systems are a classic case of out of _ sight and out of mind. Many owners take their septic systems for granted, until they P back a or break out on the surface of their r lawn. Subsurface failures, which are the most common, go unnoticed. In addition, LL inspections, pump outs, and repairs can be r�r,ar€ costly, so many homeowners tend to put off the expense until there is a real problem. Lastly, many septic system owners are not Figure 14: Storm drain stenciling may aware of the link between septic systems help reduce illicit discharges. Illicit Discharge Detection and Elimination:A Guidance Manual 77 Chapter 9:Preventing Illicit Discharges CASE STUDY In 1997, Madison County, NC implemented a project to address straight piping problems. In 1999, a survey identified 205 households with black water straight-piping (toilet waste), 243 households with gray water straight-piping (sink, shower, washer waste), and 104 households with failing septic systems. The project facilitated more than 10 community meetings, and issued more than 20 educational articles on straight-piping and water quality in the local papers. In addition, the project leveraged $903,000 from the N.C. Clean Water Management Trust Fund to establish a Revolving Loan and Grant Program for low and moderate income county residents that need assistance installing a septic system or repairing a failing one. (Land of Sky Regional Council website, 2002). and water quality. Communities can employ and other pollutants to streams, which can a range of tools to improve septic system be toxic during dry-weather conditions when maintenance. These include: existing flow cannot dilute these discharges. The major culprit has been the backyard • Media campaigns and conventional mechanic who changes his or her own outreach materials to increase awareness automotive fluids (Figure 15). Communities about septic system maintenance and have a range of tools to prevent illegal water quality (e.g., billboards, radio, dumping of car fluids, including: newspapers, brochures, bill inserts, and newsletters) • Outreach materials distributed at auto • Discount coupons for septic system parts store and service stations maintenance • Community oil recycling centers • Low interest loans for septic system • Directories of used oil collection stations repairs • Free or discounted oil disposal • Mandatory inspections containers • Performance certification upon property • Pollution hotlines transfer • Fines and other enforcement actions • Creation of septic management districts • Certification and training of operation/maintenance professionals • Termination of public services for failing systems Vehicle Fluid Changing Dumping of automotive fluids into storm drains can cause major water quality �• problems, since only a few quarts of oil or a few gallons of antifreeze can severely degrade a small stream. Dumping delivers Figure 15: Home mechanic changing his hydrocarbons, oil and grease, metals, xylene automotive fluids 78 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 9:Preventing Illicit Discharges Car Washing PHI 1 i Car washingis a common neighborhood g behavior that can produce transitory discharges of sediment, nutrients and other pollutants to the curb, and ultimately the storm drain. Communities have utilized many innovative outreach tools to promote environmentally safe car washing, including: • Media campaigns Figure 16: Household hazardous wastes • Brochures promoting nozzles with shut should be properly contained to avoid indirect off valves discharges • Storm drain plug and wet vac provisions collection programs. Participation depends for charity car wash events on the number of days each year collection • Water bill inserts promoting events are held and is inversely related to both the distance homeowners must travel to environmentally safe car washing recycle waste and the restrictions on what is products accepted. Communities have used a variety • Discounted tickets for use at commercial of techniques to promote and expand HHW car washes collection, including: Household Hazardous Waste Storage • Mass media campaigns to educate And Disposal residents about proper outdoor cleaning/rinsing techniques The average garage contains a lot of . Conventional outreach materials products that are classified as hazardous notifying residents about HHW and wastes, including paints, stains, solvents, collection days used motor oil, pesticides and cleaning . More frequent HHW collection days products. While some household hazardous waste (HHW) may be dumped into storm aProviding curbside disposal options for drains, most enters the storm drain system as some HHW a result of outdoor rinsing and cleanup. • Establishing permanent collection Improper disposal of HHW can result in facilities at solid waste facilities acute toxicity to downstream aquatic life. Providing mobile HHW pickup The desired neighborhood behavior is to participate in HHW collection days, and to Waiving disposal fees at landfills use appropriate pollution prevention techniques when conducting rinsing, Swimming Pool Draining cleaning and fueling operations (Figure 16). Routine and end-of-season maintenance Convenience and awareness appear to be the tasks for aboveground or in-ground pools critical factors in getting residents to can cause the discharge of chlorinated water participate in household hazardous waste or filter back flush water into the storm drain Illicit Discharge Detection and Elimination:A Guidance Manual 79 Chapter 9:Preventing Illicit Discharges system or the stream (Figure 17). The ideal 9.4 Preventing Illicit Discharges practice is to discharge chlorinated pool from Generating Sites water into the sanitary sewer system, or hold it until chlorine and temperature levels are Many indirect discharges can be identified acceptable to permit spreading it over a and prevented using the concept of suitable pervious surface. generating sites, which are a small subset of Most pool owners understand that regular commercial, industrial, institutional, maintenance is essential to keep pools safe municipal and transport-related operations and clean, and they may be more receptive that have the greatest risk of generating to changing discharge behaviors with proper indirect discharges. Program managers education. Effective outreach methods should become intimately familiar with the include: types of generating sites found in their community, particularly those regulated by • Conventional outreach techniques on industrial NPDES storm water permits. proper discharge (pamphlets, water bill Some of the more common operations that inserts, posters) generate spills and transitory discharges are Educational kiosks at the retail outlets profiled in Table 27. selling pool chemicals Most communities consider nearly all non- Changes in local plumbing codes to storm water discharges from generating sites require discharge to sanitary sewer to be illicit, and take a more regulatory systems approach. Consequently, pollution • Local ordinances that allow for prevention practices are more prescriptive, fines/enforcement for unsafe pool and are frequently incorporated into a discharges pollution prevention plan for a facility or operation. Like anyone else, businesses respond better to carrots than sticks, but often need both. Communities possess four broad tools to promote effective pollution r prevention practices at generating sites: • Business outreach and education • Spill prevention and response planning A • Employee training Site inspections Figure 17: Swimming pools can be a source of illicit discharges. 80 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 9:Preventing Illicit Discharges Table • • •es Produced at Generating Sites Generating Site Activity Generating the Discharge • Improper disposal of fluids down shop and storm drains Vehicle Operations a Spilled fuel, leaks and drips from wrecked vehicles (Maintenance, Repair, Fueling, a Hosing of outdoor work areas Washing, Storage) a Wash water from cleaning • Spills Outdoor Materials Liquid spills at loading areas (Loading/unloading, Outdoor Hosing/washing of loading areas into shop or storm drains storage) Leaks and spills of liquids stored outside Waste Management Spills and leaks of liquids (Spill prevention and response, Dumping into storm drains Dumpster management) Leaking dumpsters Physical Plant Maintenance Discharges from power washing and steam cleaning (Building Repair, Remodeling and Rinse water and wash water discharges during cleanup maintenance, Parking lot Runoff from degreasing and re-surfacing maintenance) Turf and Landscaping Non-target irrigation (Turf Management Improper rinsing of fertilizer/pesticide applicators Landscaping/Grounds care) Unique Hotspot Operations (Pools, Golf Courses, Marinas, Discharge of chlorinated water from pools Construction, Restaurants, Dumping of sewage and grease Hobby farms) Business Outreach and Education employees to read or hear them, and then take active steps to change their behavior. Targeted distribution of educational materials to specific business sectors in the Communities can also provide direct subwatershed is the most common method technical assistance to develop a customized of promoting pollution prevention. Outreach pollution prevention prescription for materials are designed to educate owners individual generating sites. In this case, local and employees about polluting behaviors, staff work closely with owners and operators recommend appropriate pollution prevention to inspect the site and develop an effective practices, and notify them of any local or pollution prevention plan. In other cases, state regulations. Useful outreach materials pollution prevention workshops or model include brochures, training manuals, posters, plans are offered to businesses and trade directories of pollution prevention vendors, groups that represent specific groups of and signs. Passive business outreach works generating sites. In either case, the locality best when it is specially adapted and acts as a technical partner to provide targeted to a specific business sector(e.g., ongoing consultation to individual vehicle repair, landscaping, restaurants) and businesses to support their pollution is routinely and directly presented to local prevention efforts. business groups and trade associations. Business outreach materials require Illicit Discharge Detection and Elimination:A Guidance Manual 81 Chapter 9:Preventing Illicit Discharges Spill Prevention and Response When spills do occur, a good spill prevention and response plan will clearly: A spill prevention and response plan is useful for any potential generating site, and • Identify potential spill sites and their is mandatory for any operation that uses, drainage points generates, produces, or transports hazardous • Specify material handling procedures materials, petroleum products or fertilizers. • Describe spill response procedures These operations are known as SARA 312 • Ensure that adequate spill clean-up operators and are regulated by state equipment is available environmental agencies. In addition, all industrial sites regulated by individual or Employee Training group NPDES storm water permits must have an updated spill prevention and Effective and repeated employee training is response plan on its premises. Spill essential to maintain pollution prevention containment and response plans should also practices at generating sites. Indeed, be prepared for major highways that cross continuous employee training is an essential streams and other water bodies, since truck component of any pollution prevention plan, and tanker accidents often represent the particularly at generating sites where the greatest potential spill risk in most work force turns over frequently. Many communities (Figure 18). businesses perceive time devoted to pollution prevention training as reducing Spill prevention and response plans describe their bottom line, and may be hesitant to the operational procedures to reduce the develop training materials or allocate time risks of spills and accidental discharge and for training. In some cases, local agencies ensure that proper controls are in place in supply free or low cost videos, posters, shop the event they do occur. Spill prevention signs, or training brochures (often in plans standardize everyday procedures and multilingual formats). In other cases, short rely on employee training to reduce potential training classes are offered for employees or liability, fines and costs associated with supervisors that are scheduled for down clean up. Planning begins with an analysis times of the year (e.g., winter classes for of how pollutants are handled at the site and landscaping companies or construction how they interact with storm water. Spill contractors) or coincide with regular prevention and response plans have five employee safety meetings. major components: 1. A site map and evaluation of past spills and leaks 2. An inventory of materials at the site AN 3. Identification of potential spill areas - f 4. A list of required spill response equipment 5. Employee training Figure 18: Spill response often involves portable booms and pumps 82 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 9:Preventing Illicit Discharges Program managers can refer to Schueler et permit. These operations should be educated al. (2004) for more guidance on developing about the industrial permit program, and effective pollution practices at generating encouraged to apply for permit coverage. sites and storm water hotspots. Employee Non-filers should be referred to the NPDES training should be conducted at least permitting authority for details on how to annually to educate workers on the proper obtain permit coverage. practices to avoid illicit discharges and respond to spills. Training can be reinforced Inspections are an important stick to with signs, and posters. improve compliance at generating sites subject to industrial NPDES permits. Site Inspections Inspectors should frequently observe site operations to ensure that the right mix of Regular inspections of generating sites are a pollution prevention practices is routinely key tool to foster pollution prevention and employed. Communities with MS4 permits reduce the risk of illicit discharges. have the authority to inspect storm water Communities that possess an MS4 permit NPDES sites that discharge to their storm should ensure that they have the authority to drain system, and refer any violations for inspect non-regulated sites that connect to subsequent state or federal enforcement. the municipal storm drain system they operate. These inspections can be used to Voluntary inspections of non-regulated assess the site and educate owners/operators generating sites are a good tool to educate about recommended pollution prevention owners/operators about recommended practices. Site inspections are staff intensive pollution prevention practices. When and therefore are best suited to high-risk generating sites are inspected, existing fire, generating sites. building or health inspectors should be considered since they are already acquainted An industrial NPDES storm water permit is with how to deal with small businesses. an extremely important compliance tool at many generating sites. NPDES permits 9.5 Preventing Illicit Discharges require operators to prepare a pollution from Municipal Operations prevention plan for the site and implement the practices specified in the plan. Significant Many municipal operations and services penalties can be imposed for non-compliance. have the potential to create or reduce illicit To date, compliance with the industrial discharges. Program managers should storm water permit program has been spotty, review all municipal operations and services and a significant fraction of regulated to make sure good housekeeping is industries has failed to file their required practiced. In addition, program managers permits. According to Duke and Shaver should examine: (1999) and Pronold (2000), as many as 50% of industrial sites that are required to have a Routine sewer and storm drain permit do not actually have one. These sites maintenance are termed "non-filers," and are often small 0 Plumbing code revisions businesses or operations that are unaware of 0 HHW collection services the relatively new regulations. It is therefore Used motor oil collection services quite likely that many hotspots in a subwatershed may not have a valid NPDES Illicit Discharge Detection and Elimination:A Guidance Manual 83 Chapter 9:Preventing Illicit Discharges Routine Sewer And Storm Drain 0 A permanent facility that accepts Maintenance HHW year-round and can serve as a central location for HHW exchange Failure to regularly inspect and maintain and recycling local sewer and storm water infrastructure 0 Mobile collection at temporary can cause illicit discharges to receiving facilities. On designated special waters. Within the storm drain system, collection days, mobile units can maintenance should focus on frequent move through communities accepting cleaning to keep trash, debris and illegally HHW and take the form of curbside dumped material from entering the storm pickup or central collection locations drain system. In the sanitary sewer network, Some local businesses may act as drop maintenance should focus on finding damaged • infrastructure that allows sewage discharges off centers for certain products. Some local garages, for example, may accept from the sanitary sewer.In-stream monitoring, used motor oil for recycling historical data reviews of past complaints,or aging sewer infrastructure can often be used to identify likely problem areas.$ Overall, the costs for implementing HHW collection programs can be high. Factors Plumbing Code Revisions such as frequency of the collection, size of community, environmental awareness, level Communities need to establish the legal of staff training, and level of outreach all authority to prohibit illicit connections to the contribute to the overall cost. Participation storm drain system. When the illicit discharge in collection programs usually ranges from ordinance is being prepared, communities 1%to 5% of the population (HGAC, 2001), should thoroughly review all of their plumbing and the cost per participant can vary greatly codes to prevent any misinterpretation that (Table 28). might create cross connections to the storm drain system. Program managers should also Used Motor Oil Collection Services specifically target licensed plumbers to educate them on any code changes. Used motor oil collection has been a common municipal service for many years, Household Hazardous Waste however, program managers may need to Collection Services refine their programs to increase participation. Suggested outreach Households generate a lot of hazardous approaches include: wastes, and communities need to educate residents about proper household hazardous Conventional outreach materials waster(HHW) handling and disposal, and provided at points of sale (e.g., auto provide convenient options for pick up and parts stores, service stations) disposal. Communities have experimented 0 Multilingual outreach materials with several innovative ways to deal with 0 Directories of used oil collection HHW including: stations • Free or discounted oil disposal $Preliminary sewer system investigations are not discussed containers further in this manual. For more detail on how to conduct these investigations consult the EPA handbook,"Sewer System Infrastructure Analysis and Rehabilitation."(U.S. EPA, 1991) 84 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 9:Preventing Illicit Discharges CASE STUDY The City of Denver operates a pilot, door-to-door collection program to assist residents in the proper disposal and recycling of HHW. To be eligible for collection, residents must currently be receiving trash collection service from City Solid Waste Management crews. Residents are permitted one HHW collection annually and are asked to have at least three different materials before calling for a pickup. Residents then receive a collection date and an HHW Kit that holds up to 75 pounds. Residents are instructed on what items can be placed inside the Kit, and can have additional items picked up for a small fee. The program also educates citizens on how to prevent the accumulation of chemicals in the home environment. The key element of this service is convenience for area residents. Customers can make a phone call, put their waste in a container, and schedule a pickup (City of Denver, 2003). HouseholdTable 28: Summary of Local Hazardous Waste Collection Programs Location Budget Households participants Cost per Program Description Served Participant Fort Worth TX Accept 3 days a week at (2002) $937,740 26 cities 15,629 $60 permanent facility, plus approx 24 mobile units Monmouth $900,000 620,000 6,200 $145.16 Permanent facility plus County, NJ (2002) 2-3 remote days Nashville, TN $149,000 180,000 5,800 $26 361 day drop off at (2002) permanent facility Putnam County, $20,279 27,409 349 $58.10 One collection day per NY (1997) year Town of East Hampton, NY $36,495 4,878 452 $80 Three collection days per (1997) year CASE STUDY Municipal cross-training is a proven and effective tool for identifying illicit discharges. Wayne County, Michigan has a very active IDDE program that has included efforts to train all County "field" staff to identify and report suspicious discharges in the course of their duties. The Illicit Discharge Elimination Training Program includes presentations for general field staff that instructs them in the identification and reporting of suspicious discharges. To date, 734 people from various agencies and communities throughout Michigan have attended the training sessions (Tuomari and Thompson, 2002). The information these individuals gained from attending the training session helped identify 82 illicit discharges in the counties of Oakland, Washtenaw, and Wayne. Road division staff trained in recognizing illicit discharges discovered 12 septic systems in Wayne County that were failing or had direct discharges to surface water. Other counties found 70 illicit discharges during their investigations. The elimination of these illicit discharges will prevent an estimated 3.5 million gallons of polluted water from reaching Michigan surface waters each year (associated load reductions are estimated at 7,200 pounds/year of Biological Oxygen Demand and 25, 000 Ibs/yr of Total Suspended Solids). Illicit Discharge Detection and Elimination:A Guidance Manual 85 Chapter 9:Preventing Illicit Discharges 9.6 Budgeting and Sc®ping cooperative extensions or citizen watershed Pollution Prevention groups. Table 29 provides some cost data for storm water education in one community. The cost of preventing illicit discharges is directly related to the scope of the education In reality, program managers have to do a effort. Larger communities often employ lot of homework to scope and budget their education staff on a full-time basis, or at pollution prevention education program. least have one staff member who spends Normally, these education efforts are much of their time doing outreach on issues integrated with other storm water education such as illicit discharges. Smaller programs. One of the best tools to develop communities often spread the education an overall education budget is the Source effort out over several departments, and try Control Plan which is described in Schueler et al. (2004). to use already established programs such as ProgramTable 29: Estimated Costs for Public Awareness .. (Adapted from Wayne County,Mi.2001) Education Component Estimated Cost Assumptions $100/hour for development Information Brochures $0.10-$0.20/pamphlet for black and 160-320 hours white printing $0.30/pamphlet for mailing Technical Manuals $100/hour for development 160-480 hours $100.00/manual for printing $50/hour for business/activity list 40-80 hours for compilation Business Education $100/hour for development 80-160 hours for development. $50/hour for employee presentation 8 hours for presentation, including prep time. Program Planning and $10,000 per year 0.2 Full Time Equivalents (FTE) Administration per year Source: Wayne County, MI. 2001. Planning and Cost Estimating Criteria for Best Management Practices. Rouge River Wet Weather Demonstration Project. TR-NPS25.00 86 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 10:IDDE Program Evaluation and Tracking Cho Chapter ®: I®®E ProgramTracking and Evaluation Purpose: This last program component Desired Product or Outcome(s): Updated addresses the ongoing management of the tracking database and annual report with IDDE program and reviews progress made summary of progress to date, findings, in meeting the measurable program goals recommendations for program revisions, and established earlier in the permit cycle. work plan (including milestones and goals) Adaptive management is critical since most for the upcoming year. communities initially have a poor understanding of the scope and nature of Budget and/or Staff Resources Required: their illicit discharge problem. Frequent Program assessment is an ongoing program review can ensure that the most responsibility of the program manager. The severe illicit discharges are eliminated in the staff effort to prepare an annual report is most cost-effective way during the permit about three to four weeks. In general, the cycle. Program evaluation should also be first annual report will require more effort directly tied to program goals (see Chapter 6 than subsequent ones. on Developing Program Goals and Implementation Strategy) Integration with Other Programs: Program managers should always consider other Method(s): The primary method is frequent programs and regulatory requirements when maintenance and analysis of the IDDE assessing program performance and revising tracking system developed as part of the goals. At a minimum, the annual report program. The integrated tracking system should be shared with other departments and contains geospatial data on ORI results, agencies to head off duplication of efforts indicator monitoring, on-site investigations, and to look for opportunities to pool dumping and spill sites and hotline calls. resources. The tracking system is important from both an enforcement and program evaluation standpoint. Each of the eight program components should be reviewed annually and prior to new permit negotiation, using data collected, compiled, and assessed from the tracking system. Illicit Discharge Detection and Elimination:A Guidance Manual 87 Chapter 10:IDDE Program Evaluation and Tracking 10.1 Establish a Tracking and 10.2 Evaluate the Program Reporting System Since IDDE programs are a first time An accurate and user-friendly system to endeavor for many communities, program track, report and respond to illicit discharge managers need to be extremely adaptable in problems is critical for program managers. how they allocate their resources. Effective Ideally, the tracking system should be IDDE programs are dynamic and flexible to designed and operational within the first respond to an ever-changing set of discharge year of the program. The tracking system problems, program obstacles, and emerging enables managers to measure program technologies. At a minimum, program indicators, and gives field crews a home to managers should maintain and evaluate their store the data they collect. The ideal tracking IDDE tracking system annually, and modify system consists of a relational database that program components as needed. Tracking is linked to a GIS system, which can be used systems should be designed so that progress to store and analyze data and produce maps. toward measurable goals (see Chapter 6) can be easily reported. Communities that The fundamental units to track are develop and maintain a comprehensive individual outfalls, along with any tracking system should realize program supporting information about their efficiencies. The tracking system should contributing drainage area. Some of the key contain the following features at a information to include when tracking minimum: outfalls includes: • Updated mapping to reflect outfalls • Geospatial coordinates of each outfall located during the ORI location a Surveyed stream reaches with • The subwatershed and watershed locations of obvious, suspect, and address potential discharges, and locations of • Any supporting information about the dumping sites contributing land use Indicator sampling results for specific • Diameter and physical characteristics streams, outfalls and storm drains of the outfall Frequency of hotline use and • Outfall Reconnaissance Inventory associated number of"hits" or (ORI) data, as it is collected confirmed illicit discharges • Any accompanying digital photos Costs for each of the eight program components (e.g., office, field, lab, • Any follow-up monitoring at the outfall education, enforcement, etc.) or further up the pipe • Number of discharges corrected • Any hotline complaints logged for the Status and disposition of enforcement outfall, along with the local response • actions • Status and disposition of any enforcement actions Regular analysis of the tracking system • Maintenance and inspection data sheds light on program strengths and deficiencies, and improves targeting of limited program resources. For example, if 88 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 10:IDDE Program Evaluation and Tracking hotline complaints are found to uncover the most severe illicit discharge problems, program managers may want to allocate more resources to increase public awareness about the hotline, and shift resources from outfall screening and indicator monitoring. Illicit Discharge Detection and Elimination:A Guidance Manual 89 Chapter 10:IDDE Program Evaluation and Tracking 90 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 11: The Outfall Reconnaissance Inventory Chapter 11 : The ®utfall Reconnaissance Inventory This chapter describes a simple field community should plan on surveying its assessment known as the Outfall entire drainage network at least once over Reconnaissance Inventory (ORI). The ORI the course of each five-year permit cycle. is designed to fix the geospatial location and Experience suggests that it may take up to record basic characteristics of individual three stream walks to identify all outfalls. storm drain outfalls, evaluate suspect outfalls, and assess the severity of illicit Best Times t® Start discharge problems in a community. Field crews should walk all natural and man-made Timing is important when scheduling ORI streams channels with perennial and field work. In most regions of the country, intermittent flow, even if they do not appear spring and fall are the best seasons to on available maps (Figure 19). The goal is to perform the ORL Other seasons typically complete the ORI on every stream mile in have challenges such as over-grown the MS4 within the first permit cycle, vegetation or high groundwater that mask starting with priority subwatersheds illicit discharges, or make ORI data hard to identified during the desktop analysis. The interpree. results of the ORI are then used to help guide future outfall monitoring and Prolonged dry periods during the non- discharge prevention efforts. growing season with low groundwater levels are optimal conditions for performing an I I .1 Getting Started ORL Table 31 summarizes some of the regional factors to consider when scheduling The ORI requires modest mapping, field ORI surveys in your community. Daily equipment, staffing and training resources. weather patterns also determine whether ORI A complete list of the required and optional field work should proceed. In general, ORI resources needed to perform an ORI is field work should be conducted at least 48 presented in Table 30. The ORI can be hours after the last runoff-producing rain combined with other stream assessment event. tools, and may be supplemented by simple indicator monitoring. Ideally, a Phase II Field Maps Y - The field maps needed for the ORI are normally generated during the desktop assessment phase of the IDDE program described in Chapter 5.This section provides guidance on the basic requirements for good 9 Upon initial program start-up,the ORI should be conducted during periods of low groundwater to more easily identify likely illicit discharges.However,it should be noted that high water tables can increase sewage contamination in storm drain networks due to infiltration and inflow interactions. Therefore,in Figure 19: Walk all streams and certain situations,seasonal ORI surveys may be useful at identifying these types of discharges.Diagnosis of this source of constructed open channels contamination,however,can be challenging. Illicit Discharge Detection and Elimination:A Guidance Manual 91 Chapter 11: The Outfall Reconnaissance Inventory Table 30: Resources Needed to Conduct the ORI Need Area Minimum Needed Optional but Helpful • Known problem areas • Major land uses • Roads Outfalls Mapping Streams 0Specific industries • Storm drain network • SIC-coded buildings • Septics • 5 one-liter sample bottles • Backpack • Camera (preferably digital) Portable Spectrophotometer • Cell phones or hand-held radios and reagents (can be shared • Clip boards and pencils among crews) • Field sheets Insect repellant • First aid kit Machete/clippers Field Flash light or head lamp 0 Sanitary wipes or Equipment GPS unit biodegradable soap • Spray paint (or other marker) Wide-mouth container to • Surgical gloves measure flow • Tape measure Test strips or probes (e.g., pH • Temperature probe and ammonia) • Waders (snake proof where necessary) • Watch with a second hand • Ability to track discharges up the drainage system Staff Basic training on field methodology 0 Knowledge of drainage area, to • Minimum two staff per crew identify probable sources. • Knowledge of basic chemistry and biology Table 31: Preferred Climate/Weather Considerations for Conducting the ORI Preferred Condition Reason Notes/Regional Factors Low groundwater(e.g., very High groundwater can In cold regions, do not conduct the ORI few flowing outfalls) confound results in the early spring, when the ground is saturated from snowmelt. No runoff-producing rainfall Reduces the confounding The specific time frame may vary within 48 hours influence of storm water depending on the drainage system. Applies in regions of the country with a Allows for more days of "wet/dry seasonal pattern." This pattern Dry Season field work is most pronounced in states bordering or slightly interior to the Gulf of Mexico or the Pacific Ocean. Dense vegetation makes Dense vegetation is most problematic in Leaf Off finding outfalls difficult the southeastern United States. This criterion is helpful but not required. 92 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 11: The Outfall Reconnaissance Inventory field maps. First, ORI field maps do not Field Sheets need to be fancy. The scale and level of mapping detail will vary based on preferences ORI field sheets are used to record and navigational skills of field crews. At a descriptive and quantitative information minimum, maps should have labeled streets about each outfall inventoried in the field. and hydrologic features (USGS blue line Data from the field sheets represent the streams, wetlands, and lakes), so field crews building blocks of an outfall tracking system can orient themselves and record their allowing program managers to improve findings spatially. IDDE monitoring and management. A copy of the ORI field sheet is provided in Field maps should delineate the contributing Appendix D, and is also available as a drainage area to major outfalls, but only if Microsoft WordTM document. Program they are readily available. Urban landmarks managers should modify the field sheet to such as land use, property boundaries, and meet the specific needs and unique storm drain infrastructure are also quite conditions in their community. useful in the field. ORI field maps should be used to check the accuracy and quality of Field crews should also carry an pre-existing mapping information, such as authorization letter and a list of emergency the location of outfalls and stream origins. phone numbers to report any emergency leaks, spills, obvious illicit discharges or Basic street maps offer the advantage of other water quality problems to the simplicity, availability, and well-labeled appropriate local authorities directly from road networks and urban landmarks. the field. Local law enforcement agencies Supplemental maps such as a V: 2000' scale may also need to be made aware of the field USGS Quad sheet or finer scale aerial work. Figure 20 shows an example of a photograph are also recommended for the water pollution emergency contact list field.USGS Quad sheets are readily available developed by Montgomery County,MD. and display major transportation networks and landmarks, "blue line" streams, Equipment wetlands, and topography. Quad maps may be adequate for less developed subwatersheds, Basic field equipment needed for the ORI but are not always accurate in more urban includes waders, a measuring tape,watch, subwatersheds. camera, GPS unit, and surgical gloves (see Table 30). GPS units and digital cameras are Recent aerial photographs may provide the usually the most expensive equipment items; best opportunity to navigate the subwatershed however, some local agencies may already and assess existing land cover. Aerial have them for other applications. Adequate photos, however, may lack topography and ranging, water-resistant, downloadable GPS road names, can be costly, and are hard to units can be purchased for less than $150. record field notes on due to their darkness. Digital cameras are preferred and can cost GIS-ready aerial photos and USGS Quad between $200 and $400,however, sheets can be downloaded from the internet conventional or disposable cameras can also or obtained from local planning,parks, or work, as long as they have flashes. Hand- public works agencies. held data recorders and customized software can be used to record text,photos, and GPS coordinates electronically in the field. While Illicit Discharge Detection and Elimination:A Guidance Manual 93 Chapter 11: The Outfall Reconnaissance Inventory these technologies can eliminate field sheets 11 .2 Desktop Analysis to Support and data entry procedures, they can be quite the ORI expensive. Field crews should always carry basic safety items, such as cell phones, Two tasks need to be done in the office surgical gloves, and first aid kits. before heading out to the field. The major Staffing ORI preparation tasks include estimating the total stream and channel mileage in the subwatershed and generating field maps. The ORI requires at least atwo-person crew, The total mileage helps program managers for safety and logistics. Three person crews scope out how long the ORI will take and provide greater safety and flexibility, which how much it will cost. As discussed before, helps divide tasks, allows one person to field maps are an indispensable navigational assess adjacent land uses, and facilitates aid for field crews working in the tracing outfalls to their source. All crew subwatershed. members should be trained on how to complete the ORI and should have a basic Delineating Survey Reaches understanding of illicit discharges and their water quality impact. ORI crews can be ORI field maps should contain a preliminary staffed by trained volunteers,watershed delineation of survey reaches. The stream groups and college interns. Experienced network within your subwatershed should be crews can normally expect to cover two to delineated into discrete segments of three stream miles per day, depending on relatively uniform character. Delineating stream access and outfall density. , WATER POLLUTION PHONE FNU UI HER IN FORMATION CALL WHEN A WATER ERQUQUALITY PROBLEM IS OBSERVED or TO OBTAIN FURTHER INFORHIRTION ABOUT WATER QURLITY ISSUES Spring 2UM °ler COUNTY AGENCIES INTERCOUrM AGENCIES DEP. Uepea—M Or€M6mmeMd Pm[eplon MNCPPC: lA yldr d1Nakm tQepW Park WSW: Wastanglm 8utrdm LtrN4ry REAL: CMrlxen a Errnrnnmemal rtlleyaCuRp�ance d PI%n i con."Sicrr crxnreissien W44D: Wai—hed Maneyernani Divefcv DPS: DHCa DOW&n A a Kw"&C—RWAy OeralaameM LDS: Lard Devm poa n Srvicae SWM: Skrrm '.mwea4r t wa We&d&WW CPwT� DOWmunl a NOW Woft 4 7—pan"" PROBLEMIQUESTION _ AGENCY A TELEPHONE NUMBER ILLEGAL DUMPING HOTLINE DEPM 240.777-7700 Daytime hours 4 3 NoIllme hours 24W777-DUMP(3Wn or 241)-777-77aa Blocked alarm draln.INal or pipe or en>slon Iran public stop,Uran DPWT; 240r,77-ROAD(7623)Highway Mainla�) Discolored pubfi:drinft waw.odor le drnkklg we =1206 4002 Erosion,llooding,drainage problems between private Properties DHCD! 24W777.36DD J0000 F-nfoncentent) Erosion•stream banks on park land MNCPPC: 301MSS-26.95 Flea&rrWa $arvicaa{gmeeygncles:911) (Non ErrergenalasY 24W777-0744 Rocyding Frogranrs/spocial plck up sarviwe DPWT: 2401777-6400 or 6466 Sonllary 5ewsr pr AA— WSSD! 30112pFr4 (Sedinncra(mud)rrom camtruction site entering Sue- LOS: 240r777-6.9BCy1 Septic LeWW Septic Tunics WS: 240 r77-63DD Slomwrater Management,pond safety and mainteMnoe DEPC: 2401777.7744 Starmwater Management and Sedimert Control Plan Review issues SWM: 240rT77-6aW stream Claan-ups WMD: 240 M-7712 Swin or"Pool Discharges DEPC: 240IM-7770 Trash and debris it Parks and shaams MNCPPC: 3011495-2535 W atur main break VISSC: 30112064002 Water pollulion DEM. 240 M-7770 (discharging,dumping,d emlcal apil is ntu sheanrg ar storm dram) LOS: 2_40777.6260 s Water quality monitoring programs for schools(Stream Teems) WMD; '7--7714, Walls and Well inspacuorw WS: �4W77.6.400 askl�E :cam Figure 20: Example of a comprehensive emergency contact list for Montgomery County, MD 94 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 11: The Outfall Reconnaissance Inventory survey reaches provides good stopping and length. Survey reaches in lightly starting points for field crews, which is developed subwatersheds can be longer useful from a data management and logistics than those in more developed standpoint. Each survey reach should have subwatersheds, particularly if uniform its own unique identifying number to stream corridor conditions are expected facilitate ORI data analysis and throughout the survey reach. interpretation. Figure 21 illustrates some tips Access through private or public for delineating survey reaches, and property should be considered when additional guidance is offered below: delineating survey reaches as permission • Survey reaches should be established may be required. above the confluence of streams and between road crossings that serve as a It should be noted that initial field maps are convenient access point. not always accurate, and changes may need • Survey reaches should be defined at the to be made in the field to adjust survey reaches transition between major changes in land to account for conditions such as underground use in the stream corridor(e.g. forested streams, missing streams or long culverts. land to commercial area). Nevertheless,upfront time invested in • Survey reaches should generally be delineating survey reaches makes it easier limited to a quarter mile or less in for field crews to perform the ORI. a b 1 � 1 'R r t • 'r Figure 21:Various physical factors control how survey reaches are delineated. (a)Survey reaches based on the confluence of stream tributaries. (b)A long tributary split into'/4 mile survey reaches. (c) Based on a major road crossing (include the culvert in the downstream reach). (d)Based on significant changes in land use (significant changes in stream features often occur at road crossings, and these crossings often define the breakpoints between survey reaches). Illicit Discharge Detection and Elimination:A Guidance Manual 95 Chapter 11: The Oufall Reconnaissance Inventory 11 .3 Completing the ORI completing each section of the ORI field sheet is presented below. Field crews conduct an ORI by walking all streams and channels to find outfalls,record Ouffalls t0 Survey their location spatially with a GPS unit and physically mark them with spray paint or The ORI applies to all outfalls encountered other permanent marker. Crews also during the stream walk, regardless of photograph each outfall and characterize its diameter, with a few exceptions noted in dimensions, shape, and component material, Table 32. Common outfall conditions seen and record observations on basic sensory in communities are illustrated in Figure 22 and physical indicators. If dry weather flow As a rule, crews should only omit an outfall occurs at the outfall, additional flow and if they can definitively conclude it has no water quality data are collected. Field crews potential to contribute to a transitory illicit may also use field probes or test strips to discharge. While EPA's Phase I guidance measure indicators such as temperature,pH, only targeted major outfalls (diameter of 36 and ammonia at flowing outfalls. inches or greater), documenting all outfalls The ORI field sheet is divided into eight is recommended, since smaller pipes make sections that address both flowing and non- up the majority of all outfalls and frequently flowing outfalls (Appendix D). Guidance on have illicit discharges (Pitt et al., 1993 and Lalor, 1994). A separate ORI field sheet should be completed for each outfall. TableOutfalls to Include in the Screening Outfalls to Record Outfalls to Skip • Both large and small diameter pipes that appear to be part of the storm drain infrastructure Outfalls that appear to be piped headwater Drop inlets from roads in culverts (unless • streams evidence of illegal dumping, dumpster leaks,• Field connections to culverts etc.) Submerged or partially submerged outfalls Cross-drainage culverts in transportation •• Outfalls that are blocked with debris or sediment right-of-way(i.e., can see daylight at other deposits end) Weep holes • Pipes that appear to be outfalls from storm water treatment practices • Flexible HDPE pipes that are known to serve • Small diameter ductile iron pipes as slope drains • Pipes that appear to only drain roof downspouts • Pipes that are clearly connected to roof but that are subsurface, preventing definitive downspouts via above-ground connections confirmation 96 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 11: The Outfall Reconnaissance Inventory ` 1 4 1, Ductile iron round pipe 4-6" HDPE; Check if roof leader Field connection to inside of connection (legal) culvert-,Always mark and record. �AW i ., - ,. � �k�.� A'��'4i ';1� ,�+."-vim �, � •. Small diameter(<2") HDPE; Often Elliptical RCP; Measure both Double RCP round pipes- Mark a sump pump(legal),or may be horizontal and vertical diameters. as separate outfalls unless known used to discharge laundry water to connect immediate) up-pipe illicit . y C,%�� Nb Open channel "chute"from Culvert(can see to other side); p Small diameter PVC pipe- Mark, Don't mark as an outfall. commercial parking lot-, Very and look up-pipe to find the origin. unlikely illicit discharge. Mark, but do not return to sample unless there is an obvious roblem . - s CMP outfall; Crews should also ~ note upstream sewer crossing. Box shaped outfall CMP round pipe with two weep holes at bridge crossing. (Don't mark weep holes Figure 22: Typical Outfall Types Found in the Field Illicit Discharge Detection and Elimination:A Guidance Manual 97 Chapter 11: The Outfall Reconnaissance Inventory Obvious Discharges and past weather conditions (Figure 23). Much of the information in this section is Field crews may occasionally encounter an self-explanatory, and is used to create an obvious illicit discharge of sewage or other accurate record of when, where, and under pollutants, typified by high turbidity, odors, what conditions ORI data were collected. floatables and unusual colors. When obvious Every outfall should be photographed and discharges are encountered, field crews marked by directly writing a unique should STOP the ORI survey, track down identifying number on each outfall that the source of the discharge and immediately serves as its subwatershed"address" (Figure contact the appropriate water pollution 24). Crews can use spray paint or another agency for enforcement. Crews should temporary marker to mark outfalls, but may photo-document the discharge, estimate its decide to replace temporary markings with flow volume and collect a sample for water permanent ones if the ORI is repeated later. quality analysis (if this can be done safely). Markings help crews confirm outfall All three kinds of evidence are extremely locations during future investigations, and helpful to support subsequent enforcement. gives citizens a better way to report the Chapter 13 provides details on techniques to location of spills or discharges when calling track down individual discharges. a water pollution hotline. Crews should mark the spatial location of all outfalls they 11 .4 ORI Section 1 - Background encounter directly on field maps, and record Data the coordinates with a GPS unit that is accurate to within 10 feet. Crews should The first section of the ORI field sheet is take a digital photo of each outfall, and used to record basic data about the survey, record photo numbers in Section 1 of the including time of day, GPS coordinates for field sheet. the outfall, field crew members, and current Section 1:Background Data Subwatcnhcd: Outfall 1D: Today's date: Time(Military): investigators: Form completed by: Temperature(°I'): Rainfall(in.): Last 24 hours: Last 48 hours: Latitutde Longitude: GPS Unit GPS LMK V. C:arrtera: Photo#s: Land Use in Drainage Area(Check all that apply): ❑Industrial Q open Space Q Ultra-Urban Residential ❑Institutional ❑Suburban Rcsidential Other- 0 commercial Known Industries: Notes(e.g_origin of outfal1,if known): Figure 23: Section 1 of the ORI Field Sheet 98 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 11: The Outfall Reconnaissance Inventory large diameter outfalls that drain dozens or even hundreds of acres (unless you have aerial photographs). On the other hand, land use can be easily observed at smaller diameter outfalls, and in some cases, the specific origin can be found (e.g., a roof leader or a parking lot; Figure 25). The _ specific origin should be recorded in the "notes"portion of Section 1 on the field sheet. 11 .5 ORI Section 2 - Outf®II AV Description This part of the ORI field sheet is where basic outfall characteristics are noted (Figure 26). These include material, and presence of flow at the outfall, as well as the pipe's dimensions (Figure 27). These Figure 24: Labeling an Outfall measurements are used to confirm and (a variety of outfall naming supplement existing storm drain maps (if conventions can be used) they are available). Many communities only The land use of the drainage area contributing to map storm drain outfalls that exceed a given the outfall should also be recorded. This pipe diameter, and may not contain data on may not always be easy to characterize at the material and condition of the pipe. K Y r, {ve f � t Figure 25: The origin of this corrugated plastic pipe was determined to be a roof leader from the house up the hill. Illicit Discharge Detection and Elimination:A Guidance Manual 99 Chapter 11: The Outfall Reconnaissance Inventory Section 2 of the field sheet also asks if the submergence, deposition and flow at outfall is submerged in water or obstructed outfalls. If no flow is observed at the outfall, by sediment and the amount of flow, if you can skip the next two sections of the present. Figure 28 provides some photos that ORI field sheet and continue with Section 5. illustrate how to characterize relative Section 2:Outiall Description LOCATION MATERIAL SHAPE DIMENSIONS(IN.) SUBMERGED C]AC I' ❑CMP ❑Cimular ❑Singlc Diamcicrll)inwnsicns; In WatcF ❑No ❑PVC []HDT'F ❑F iptieal ❑Double ❑partially ❑Fully ❑Closed Pipe ❑Stec] ❑6ax ❑Triple W 11h 5edi"WRt: ❑Oder; ❑Other: ❑Othcr; _ ❑Nn ❑Paniaily ❑hLlly ❑concrcic ❑Trapezoid Depth; ❑Earthen ❑Open drainage ❑Parabolic Top Width: ❑rip'raP ❑011wr: Boltom Width: ❑01hec ❑In tirrcam {appli"hlr whrn enllrcrbnR samplrs] Flow Present' ❑ Y'e.. ❑.No 11Iva,SRlp to See in++t Flow Vest riptiurr ❑Trickle ❑Moderate ❑Substantial (If prescnt) Figure 26: Section 2 of the ORI Field Sheet i s 1 4 y f Figure 27: Measuring Outfall Diameter 100 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 11: The Outfall Reconnaissance Inventory VU Submerged: More than Partially submerged: Bottom is below Fully submerged:Can't see outfall below water water Fully submerged from downstream Partially submerged by Outfall fully submerged by debris trees trapping debris leaf debris"back water" Trickle Flow: Very narrow stream of Significant flow water Moderate Flow: Steady stream, but (Source is a fire hydrant discharge) very shallow depth Figure 28: Characterizing Submersion and Flow 11 .6 ®RI Section 3 - Quantitative flow, temperature, pH and ammonia (Figure Characterization for Flowing 29). If desired, additional water quality ®utfalls parameters can be added to this section. Chapter 12 discusses the range of water This section of the ORI records direct quality parameters that can be used measurements of flowing outfalls, such as Illicit Discharge Detection and Elimination:A Guidance Manual 101 Chapter 11: The Outfall Reconnaissance Inventory Section 3:Quantitative Characterization FIELD DATA FOR FLOWING OUTFALLS PARAMETER RESULT UNIT EQUIPMENT Vobp Laer Boude ❑Flow#1 Tnne to fill Sec Flow depth In Tape meastuc Flow width Ft,1n Tape meanne ❑Flow#3 bde—d length Ft,In Tape meannn Time oft-1 S Stop wdQ h Tempff&ze ThennDumtff pH pH Chins Test sb4A)r be __- _9M TesL M,p Figure 29: Section 3 of the ORI Field crews measure the rate of flow using depth and width of flow. Lastly, cross- one of two techniques. The first technique sectional area(in square feet) is multiplied simply records the time it takes to fill a by flow velocity (feet/second)to calculate container of a known volume, such as a one the flow rate (in cubic feet/second). liter sample bottle. In the second technique, the crew measures the velocity of flow, and Crews may also want to measure the quality multiplies it by the estimated cross sectional of the discharge using relatively inexpensive area of the flow. probes and test strips(e.g.,water temperature, pH, and ammonia). The choice of which To use the flow volume technique, it may be indicator parameters to measure is usually necessary to use a"homemade"container to governed by the overall IDDE monitoring capture flow, such as a cut out plastic milk framework developed by the community. container that is marked to show a one liter Some communities have used probes or test volume_ The shape and flexibility of plastic strips to measure additional indicators such containers allows crews to capture relatively as conductivity, chlorine, and hardness. flat and shallow flow (Figure 30). The flow Research by Pitt(for this project) suggests volume is determined as the volume of flow that probes by Horiba for pH and captured in the container per unit time. conductivity are the most reliable and The second technique measures flow rate accurate, and that test strips have limited based on velocity and cross sectional area, value. and is preferred for larger discharges where containers are too small to effectively capture the flow(Figure 31)_The crew measures and marks off a fixed flow length (usually about five feet), crumbles leaves or other light material, and drops them into the discharge (crews can also carry peanuts or ping pong balls to use). The crew then measures the time it takes the marker to travel across the length_ The velocity of flow is computed as the length of the flow path (in feet)divided by the travel time(in seconds). Next,the cross-sectional flow area is Figure 30: Measuring flow as measured by taking multiple readings of the volume per time 102 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 11: The Outfall Reconnaissance Inventory When probes or test strips are used, Step 1: Measure flow depth measurements should be made from a _ sample bottle that contains flow captured from the outfall. The exact measurement recorded by the field probe should be recorded in Section 3 of the field sheet. Some interpolation may be required for test strips, but do not interpolate further than the mid-range between two color points. ip 11 .7 ORI Section 4 - Physical r ' Indicators for Flowing Outfclls e Only Step 2: Measure flow width This section of the ORI field sheet records data about four sensory indicators associated with flowing outfalls -- odor,color,turbidity and floatables (Figure 32). Sensory indicators can be detected by smell or sight, and require no measurement equipment. Sensory indicators do not always reliably predict illicit discharge, since the senses can be fooled,and may result in a"false negative"(i.e., Step 3: Time the travel of a light sensory indicators fail to detect an illicit object(e.g., leaves) along a known discharge when one is actually present). distance to calculate velocity Sensory indicators are important,however,in detecting the most severe or obvious discharges. Section 4 of the field sheet asks whether the ,rt. sensory indicator is present, and if so, what is its severity, on a scale of one to three. e ~� M Figure 31: Measuring flow(as velocity times cross-sectional area) Secition 4:Physical Indicators for Flowing Outfalls Only Arc Ans Yla.Siuul Indicators Present is the flow? Yes ❑kn (T(.Ym Skip ev Scar—it INDICATOR CHECK t DESCRIPTION RELATIVE SEVERITY INDEX((1.3) Prew ❑Sew�e ❑Rancidrsrxv❑Pehaleum+gm lydm ❑ ❑I-Fainl ❑?-3=xsiEpJctt[ELiI ❑'3-Nrai[eahle[men a ❑sulfide ❑odw-- distance ❑ ❑Clew ❑Wown ❑Gray ❑Yellow I-Fain1 colon.in 2-Ck-1 color ❑ ❑ r risible in ❑3-Cloaeiy dsibk in ❑Green ❑Orange ❑Red ❑Other swW]c boplc saertplc bunk oulrall now Tmkddlty ❑ See sererin• ❑I-Sligkt etuudnesa ❑?-Ctaurh,, ❑3-Opaque Floasables ❑Se 4e(Toilel Paper,eic.) ❑Sod ❑2-Some:indications ❑3-Some;origin cicar • ❑I-Fewidighr_arigio of origin{e,g., [e.g..obvious bit Does Not Include T,�ylr ❑ ❑Pennkum(oil sheeny ❑other: nototmous powiblc suds or oat shecn.wds,or floating 5hxw7 swwry maacrialal Figure 32: Section 4 of the ORI Field Sheet Illicit Discharge Detection and Elimination:A Guidance Manual 103 Chapter 11: The Outfall Reconnaissance Inventory Odor Turbidity Section 4 asks for a description of any odors The ORI asks for a visual estimate of the that emanate from the outfall and an turbidity of the discharge, which is a associated severity score. Since noses have measure of the cloudiness of the water. Like different sensitivities,the entire field crew color, turbidity is best observed in a clear should reach consensus about whether an sample bottle, and can be quantitatively odor is present and how severe it is. A measured using field probes. Crews should severity score of one means that the odor is also look for turbidity in the plunge pool faint or the crew cannot agree on its presence below the outfall, and note any downstream or origin. A score of two indicates a moderate turbidity plumes that appear to be related to odor within the pipe. A score of three is the outfall. Field crews can sometimes confuse assigned if the odor is so strong that the turbidity with color, which are related but crew smells it a considerable distance away are not the same. Remember, turbidity is a from the outfall. measure of how easily light can penetrate through the sample bottle,whereas color is TIP defined by the tint or intensity of the color Make sure the origin of the odor is the observed. Figure 34 provides some examples of how to distinguish turbidity from color, outfall. Sometimes shrubs, trash or and how to rank its relative severity. carrion, or even the spray paint used to mark the outfall can confuse the noses of field crews. a. Color The color of the discharge, which can be clear, slightly tinted, or intense is recorded next. Color can be quantitatively analyzed in the lab,but the ORI only asks for a visual assessment of the discharge color and its intensity. The best way to measure color is to collect the discharge in a clear sample bottle and hold it up to the light(Figure 33). Figure 33: Using a sample bottle to Field crews should also look for downstream estimate color and turbidity plumes of color that appear to be associated with the outfall. Figure 34 illustrates the spectrum of colors that may be encountered during an ORI survey, and offers insight on how to rank the relative intensity or strength of discharge color.Color often helps identify industrial discharges; Appendix K provides guidance on colors often associated with specific industrial operations. 104 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 11: The Outfall Reconnaissance Inventory s, 4 " Highly Turbid Discharge Color: Brown; Severity: 2 Chromium Spill Color: Brown; Severity: 3 Turbidity Severity: 2 Color: Green; Severity: 3 Turbidity Severity: 3 Turbidity Severity: None �. V-f Sewage Discharge Paint Industrial Discharge Color: 3 Color:White; Severity: 3 Color: Green; Severity: 3 Turbidity: 3 Turbidity: 3 Turbidity Severity: 3 3 r ae z 74 a Blood Failing Septic System: Turbidity in Downstream Plume Color: Red; Severity: 3 Turbidity Severity: 3 Turbidity Severity: 2 Turbidity Severity: None (also confirm with sample bottle) 2. High Turbidity in Pool Iron Floc Slight Turbidity Turbidity Severity: 2 Color: Reddish Orange; Severity: 3 Turbidity: 1 (Confirm with sample bottle) (Often associated with a natural source) (Difficult to interpret this observation- May be natural or an illicit dischar e Construction Site Discharge of Rinse Discharge from Floor Sanding Turbidity Severity: 3 (Found during wet weather) Turbidity Severity: 3 Figure 34: Interpreting Color and Turbidity Illicit Discharge Detection and Elimination:A Guidance Manual 105 Chapter 11: The Outfall Reconnaissance Inventory FI®atables created by in-stream processes, such as shown in Figure 36. A thick or swirling The last sensory indicator is the presence of sheen associated with a petroleum-like odor any floatable materials in the discharge or may be diagnostic of an oil discharge. the plunge pool below. Sewage, oil sheen, and suds are all examples of floatable Suds are rated based on their foaminess and indicators; trash and debris are generally not staying power. A severity score of three is in the context of the ORI. The presence of designated for thick foam that travels many floatable materials is determined visually, feet before breaking up. Suds that break up and some guidelines for ranking their quickly may simply reflect water turbulence, severity are provided in Figure 35, and and do not necessarily have an illicit origin. described below. Indeed, some streams have naturally occurring foams due to the decay of organic If you think the floatable is sewage, you matter. On the other hand,suds that are should automatically assign it a severity accompanied by a strong organic or sewage- score of three since no other source looks like odor may indicate a sanitary sewer leak quite like it. Surface oil sheens are ranked or connection. If the suds have a fragrant based on their thickness and coverage. In odor,they may indicate the presence of some cases, surface sheens may not be laundry water or similar wash waters. related to oil discharges, but instead are SUDS � Natural Foam Note: Suds only associated with high Low Severity Suds High severity suds flows at the "drop off' Rating: 1 Rating: 3 Do not record. Note: Suds do not appear to travel; very Sewage thin foam layer OIL SHEENS L_��A i y.T Low Severity Oil Sheen Moderate Severity Oil Sheen High Severity Oil Film Rating: 1 Rating: 2 Rating: 3 Figure 35: Determining the Severity of Floatables 106 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 11: The Outfall Reconnaissance Inventory y, a 5y aim ry e fi t ,.� �f• �.it Figure 36: Synthetic versus Natural Sheen (a) Sheen from bacteria such as iron floc forms a sheet-like film that cracks if disturbed (b) Synthetic oil forms a swirling pattern examples of physical indicators are 11 .8 ®ICI Section 5 - Physical portrayed in Figures 38 and 39. Many of Indicators for Both Flowing and these physical conditions can indicate that an intermittent or transitory discharge has Non-Flowing ®utfclls occurred in the past, even if the pipe is not currently flowing. Physical indicators are Section 5 of the ORI field sheet examines not ranked according to their severity, physical indicators found at both flowing because they are often subtle, difficult to and non-flowing outfalls that can reveal the interpret and could be caused by other impact of past discharges (Figure 37). sources. Still,physical indicators can Physical indicators include outfall damage, provide strong clues about the discharge outfall deposits or stains, abnormal history of a storm water outfall,particularly vegetation growth,poor pool quality, and if other discharge indicators accompany benthic growth on pipe surfaces. Common them. Section 5:Physical Indicators for Both Flowing and Non-Flowing Outfalls Are physical indicators that are not related to flow resent? ❑Yes ❑No I No,Skw to Sect2on 6 INDICATOR CHECKiFPresent DESCRIPTION COMMENTS fnefs»Damage ❑ ❑ sp­g'­g--W-,g ❑ Peelmg Paint ❑ C—ion De➢ositslkafrss ❑ ❑Oily ❑Flow Line ❑Pa= ❑Other: Ab—nnUVeeetaticm ❑ ❑no:e i ❑h1kit.,l Poor pool quuity ❑ ❑Odaas ❑Cobs ❑Floatables ❑Oil Sheen ❑Suds El Fkcessi'Algae ❑Other: Pipe hemhi,n—ffi ❑ ❑B_ ❑C¢axtge ❑[Eeeen ❑Other: Figure 37: Section 5 of the ORI Field Sheet Illicit Discharge Detection and Elimination:A Guidance Manual 107 Chapter 11: The Outfall Reconnaissance Inventory Bacterial growth at this outfall This bright red bacterial growth Sporalitis filamentous bacteria, indicates nutrient enrichment and often indicates high manganese also known as"sewage fungus" a likely sewage source. and iron concentrations. can be used to track down Surprisingly, it is not typically sanitary sewer leaks. associated with illicit discharges. .I Algal mats on lakes indicate` ' eutrophication. Several sources Illicit discharges or excessive The drainage to this outfall most can cause this problem. nutrient application can lead to likely has a high nutrient Investigate potential illicit sources. extreme algal growth on stream concentration. The cause may be beds. an illicit discharge, but may be excessive use of lawn chemicals. } s.. This brownish algae indicates an elevated nutrient level. Figure 38: Interpreting Benthic and Other Biotic Indicators 108 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 11: The Outfall Reconnaissance Inventory Reddish staining on the rocks below Toilet paper directly below the this outfall indicate high iron storm drain outlet. Watershed Protection?? concentrations. s'Hise Nam JAL, l Staining at the base of the outfall Excessive vegetation may Trash is not an indicator of illicit may indicate a persistent, indicate enriched flows discharges, but should be noted. intermittent discharge. associated with sewage. "mil,_ ; _ —• � � . � r. Brownish stain of unclear origin. May Cracked rock below the outfall Poor pool quality.Consider be from degradation of the brick may indicate an intermittent sampling from the pool to infrastructure. discharge. determine origin. Figure 39: Typical Findings at both Flowing and Non-Flowing Outfalls 11 .9 ®RI Sections 6-8 - Initial number and severity of discharge indicators ®utfall Designation and Actions checked in preceding sections. The last three sections of the ORI field sheet It is important to understand that the ORI are where the crew designates the illicit designation is only an initial determination discharge severity of the outfall and of discharge potential. A more certain recommends appropriate management and determination as to whether it actually is an monitoring actions (Figure 40). A discharge illicit discharge is made using a more rating is designated as obvious, suspect, sophisticated indicator monitoring method. potential or unlikely, depending on the Nevertheless, the ORI outfall designation gives program managers a better understanding Illicit Discharge Detection and Elimination:A Guidance Manual 109 Chapter 11: The Outfall Reconnaissance Inventory of the distribution and severity of illicit conditions and field experience. Some discharge problems within a subwatershed. indicators can be dropped, added or modified in the ORI form. This section Section 7 of the ORI field sheet records looks at four of the most common whether indicator samples were collected for adaptations to the ORI: laboratory analysis,or whether an intermittent flow trap was installed (e.g., an optical • Open Channels brightener trap or caulk dam described in . Submerged/Tidally Influenced Outfalls Chapter 13). Field crews should record whether the sample was taken from a pool or Cold Climates directly from the outfall, and the type of • Use of Biological Indicators intermittent flow trap used, if any. This section can also be used to recommend In each case, it may be desirable to revise follow-up sampling, if the crew does not the ORI field sheet to collect data reflecting carry sample bottles or traps during the these conditions. survey. Open Channels The last section of the ORI field sheet is used to note any unusual conditions near the Field crews face special challenges in more outfall such as dumping, pipe failure, bank rural communities that have extensive open erosion or maintenance needs. While these channel drainage. The ditches and channels maintenance conditions are not directly serve as the primary storm water conveyance related to illicit discharge detection, they system, and may lack storm drain and sewer often are of interest to other agencies and pipes. The open channel network is often utilities that maintain infrastructure. very long with only a few obvious outfalls that are located far apart. While the network 11 .10 Customizing the ORI for ® can have illicit discharges from septic Community systems, they can typically only be detected in the ORI if a straight pipe is found. Some The ORI method is meant to be adaptable, adaptations for open channel systems are and should be modified to reflect local suggested in Table 33. Section F:Overall Outfall Characterization ❑ Itniikcly ❑ Potential(presence of two or more indicators) ❑ Suspect(one or more indicators with a severity of 3) ❑ Obvious Section 7:Data Collection 1. Sample ror The Lab? ❑Yes ❑No I If Yes,Collected From: ❑Flow ❑Pool 3. Intermittent flow trap set? 0 Yes 0 No if Yes,type: ❑i7BM ©Caulk dwl Section 8:Any Non-Illicit Discharge Concerns(e.g,,trash or needed infrastructure repairs)? Figure 40: Sections 6-8 of the ORI Field Sheet 110 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 11: The Outfall Reconnaissance Inventory Submerged/Tidally Influenced Outfalls frozen or flowing outfall may indicate warm water from sewage or industrial discharge. The ORI can be problematic in coastal Be careful, because groundwater is warm communities where outfalls are located enough to cause some melting at below along the waterfront and may be submerged freezing temperatures. Also,ice acts like an at high tide. The ORI methods need to be intermittent flow trap, and literally freezes significantly changed to address these these discharges. Crews should also look for constraints. Often, outfalls are initially these traps to find any discolored ice within located from offshore using canoes or boats, the pipe or below the outfall. and then traced landward to the first manhole that is not tidally influenced. Field crews A Final winter indicator is "rime ice,"which then access the storm drain pipe at the manhole forms when steam freezes. This beautiful ice and measure whatever indicators they can formation is actually a good indicator of observe in the confined and dimly lit space. sewage or other relatively hot discharge that Table 33 recommends strategies to sample causes steam to form (Figure 41). outfalls in the challenging environment of coastal communities. Biological Indicators Winter and Ice The diversity and pollution tolerance of various species of aquatic life are widely Ice can be used as a discharge indicator in used as an indicator of overall stream health, northern regions when ice forms in streams and has sometimes been used to detect illicit and pipes during the winter months(Figure 41). discharges. One notable example is the presence Because ice lasts for many weeks, and most of the red-eared slider turtle, which is used illicit discharges are warm, astute field in Galveston, Texas to find sewage crews can interpret outfall history from ice discharges, as they have a propensity for the melting patterns along pipes and streams. nutrient rich waters associated with sewage For example, exaggerated melting at a (Figure 42). Table 33: Special Considerations for Open Channels/Submerged Outfalls OPEN CHANNELS Challenge Suggested Modification Too many miles of channel to walk Stop walking at a given channel size or drainage area Difficulty marking them Mark on concrete or adjacent to earth channel Interpreting physical indicators For open channels with mild physical indicators, progress up the system to investigate further. SUBMERGED/TIDALLY INFLUENCED OUTFALLS Challenge Suggested Modification Access for ORI —Tidal Influence Access during low tide Access for ORI —Always submerged Access by boat or by shore walking Interpreting physical indicators For outfalls with mild physical indicators, also inspect from the nearest manhole that is not influenced by tides Sampling (if necessary) I Sample "up pipe" Illicit Discharge Detection and Elimination:A Guidance Manual 111 Chapter 11: The Outfall Reconnaissance Inventory 7 I f; r Figure 42: One biological indicator is this red-eared slider turtle Figure 41: Cold climate indicators of illicit discharges 11 .11 Interpreting ®RI Data The level of detail for each analysis method should be calibrated to local resources,program The ORI generates a wealth of information goals, and the actual discharge problems that can provide managers with valuable discovered in the stream corridor. In general, insights about their illicit discharge problems, if the most common conditions and problems the data are managed and analyzed will shape your initial monitoring strategy, effectively. The ORI can quickly define which prioritizes the subwatersheds or whether problems are clustered in a particular reaches that will be targeted for more area or spread across the community. This intensive investigations. section presents a series of methods to compile, organize and interpret ORI data, Program managers should analyze ORI data including: well before every stream mile is walked in the community, and use initial results to 1. Basic Data Management and Quality modify field methods. For example, if initial Control results reveal widespread potential problems, 2. Outfall Classification program managers may want to add more indicator monitoring to the ORI to track 3. Simple Suspect Outfall Counts down individual discharge sources (see 4. Mapping ORI Data Chapter 12). Alternatively, if the same kind 5. Subwatershed and Reach Screening of discharge problem is repeatedly found, it may be wise to investigate whether there is a 6. Characterizing IDDE Problems at the common source or activity generating it Community Level (e.g., high turbidity observed at many flowing outfalls as a result of equipment washing at active construction sites). 112 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 11: The Outfall Reconnaissance Inventory Basic Data Management and Quality can also be downloaded with Appendix D Control from hM2://www.stonnwatercenter.net. Information stored in this database can The ORI produces an enormous amount of easily be imported into a GIS for mapping raw data to characterize outfall conditions. It purposes. The GIS can generate its own is not uncommon to compile dozens of database table that allows the user to create individual ORI forms in a single subwatershed maps showing outfall subwatershed. The challenge is to devise a characteristics and problem areas. system to organize,process, and translate this data into simpler outputs and formats that Once data entry is complete, be sure to can guide illicit discharge elimination check the quality of the data. This can be efforts. The system starts with effective done quickly by randomly spot-checking quality control procedures in the field. 10% of the entered data. For example, if 50 field sheets were completed, check five of Field sheets should be managed using either the spreadsheet or database entries. When a three-ring binder or a clipboard. A small transferring data into GIS, quality control field binder offers the ability to quickly flip maps that display labeled problem outfalls back and forth among the outfall forms. should be created. Each survey crew is Authorization letters, emergency contact responsible for reviewing the accuracy of lists, and extra forms can also be tucked these maps. inside. Outfall Classification At the end of each day, field crews should regroup at a predetermined location to A simple outfall designation system has compare notes. The crew leader should been developed to summarize the discharge confirm that all survey reaches and outfalls potential for individual ORI field sheets. of interest have been surveyed, discuss Table 34 presents the four outfall initial findings, and deal with any logistical designations that can be made. problems. This is also a good time to check whether field crews are measuring and TableDesignation recording outfall data in the same way, and 0111 Data are consistent in what they are (or are not) Designation Description recording. Crew leaders should also use this Outfalls where there is an time to review field forms for accuracy and 1: Obvious illicit discharge that doesn't thoroughness. Illegible handwriting should Discharge even require sample be neatened and details added to notes and collection for confirmation any sketches. The crew leader should also 2: Suspect Flowing outfalls with high severity on one or more e organize the forms together into a single Discharge physical indicators master binder or folder for future analysis. Flowing or non-flowing 3: Potential outfalls with presence of Once crews return from the field, data Discharge two or more physical should be entered into a spreadsheet or indicators 4: Unlikely Non-flowing outfalls with no database. A Microsoft Access database is y physical indicators of an provided with this Manual as part of Discharge illicit discharge Appendix D (Figure 43), and is supplied on a compact disc with each hard copy. It Illicit Discharge Detection and Elimination:A Guidance Manual 115 Chapter 11: The Oufall Reconnaissance Inventory Simple Suspect Outfall Counts they can visually depict reach quality and the location of problem outfalls. The key The first priority is to count the frequency of point to remember is that maps are tools for each outfall designation in the subwatershed understanding data. Try to map with a or the community as a whole. This simple purpose in mind. A large number of screening analysis counts the number of cluttered maps may only confuse,while a problem outfalls per stream mile (i.e., the smaller number with select data may sum of outfalls designated as having potential, stimulate ideas for the follow-up monitoring suspected or obvious illicit discharge potential). strategy. The density of problem outfalls per stream mile is an important metric to target and Suk?watershed and Survey Reach screen subwatersheds. Screening Based on problem outfall counts, program Problem outfall metrics are particularly managers may discover that a particular valuable to screen or rank priority monitoring strategy may not apply to the subwatersheds or survey reaches. The basic community. For example, if few problem approach is simple: select the outfall metrics outfalls are found, an extensive follow-up that are most important to IDDE program monitoring program may not be needed, so goals, and then see how individual that program resources can be shifted to subwatersheds or reaches rank in the pollution hotlines to report and control process. This screening process can help transitory discharges such as illegal determine which subwatersheds will be dumping. The key point of this method is to priorities for initial follow-up monitoring avoid getting lost in the raw data,but look efforts. When feasible, the screening process instead to find patterns that can shape a cost- should incorporate non-ORI data, such as effective IDDE program. existing dry weather water quality data, citizen complaints,permitted facilities, and Mapping ORI Data habitat or biological stream indicators. Maps are an excellent way to portray outfall data. If a GIS system is linked to the ORI � database, maps that show the spatial distribution of problem outfalls, locations of dumping, and overall reach conditions can illicit Discharge be easily generated. Moreover, GIS provides Detection and Elimination flexibility that allows for rapid updates to maps as new data are collected and - compiled. The sophistication and detail of maps will depend on the initial findings, ti nu.rall xeconnaissans Inamtory Fi.ld 6h ac E—Y Farm program goals, available software, and GIS capability. Subwatershed maps are also an effective and important communication and education tool Figure 43: Sample screen from ORI to engage stakeholders (e.g., public officials, Microsoft Access database businesses and community residents), as 114 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 11: The Outfall Reconnaissance Inventory An example of how outfall metrics can is learned about the nature and distribution screen subwatersheds is provided in Table of illicit discharge problems in the community. 35. In this hypothetical example, four metrics For example, ORI discharge designation were used to screen three subwatersheds within should be compared against illicit discharge a community: number of suspect discharges, potential (IDP)predictions made during the subwatershed population as a percent of the original desktop analysis (Chapter 5) to total community, number of industrial refine discharge screening factors, and discharge permits, and number of outfalls formulate new monitoring strategies. per stream mile. Given these screening criteria, subwatershed C was selected for the In general, community illicit discharge next phase of detailed investigation. problem can be characterized as minimal, clustered, or severe (Table 36). In the Characterizing the IDDE Problem at the minimal scenario, very few and scattered Community Level problems exist; in the clustered scenario, problems are located in isolated ORI data should be used to continuously subwatersheds; and in the severe scenario, revisit and revise the IDDE program as more problems are widespread. Table 35: An Example of ORI Data Being Used to Compare Across Subwatersheds #of suspect Population as% #of industrial #of outfalls per discharges of total discharge permits stream/conveyance community mile Subwatershed A 2 30 4 6 Subwatershed B 1 10 0 3 Subwatershed C 8 60 1 2 12 Table 36: Using Stream and ORI Data to Categorize IDDE Problems Extent ORI Support Data Minimal Less than 10% of total outfalls are flowing • Less than 20% of total outfalls with obvious, suspect or potential designation • Two thirds of the flowing outfalls are located within one third of the Clustered subwatersheds • More than 20% of the communities subwatersheds have greater than 20% of outfalls with obvious, suspect or potential designation • More than 10% of total outfalls are flowing Severe 0 More than 50% of total outfalls with obvious, suspect or potential designation • More than 20% of total outfalls with obvious or suspect designation Illicit Discharge Detection and Elimination:A Guidance Manual 115 Chapter 11: The Outfall Reconnaissance Inventory 11 .12 Budgeting and Sc®ping The majority of the budget for an ORI is for the ORI staffing the desktop analysis, field crews and data analysis. Field crews can consist of two Many different factors come into play when or three members, and cover about two to budgeting and scoping an ORI survey: three miles of stream (or open channel) per equipment needs, crew size and the stream day. Three staff-days should be allocated for miles that must be covered. This section pre- and post-field work for each day spent presents some simple rules of thumb for in the field. ORI budgeting. Table 38 presents example costs for two Equipment costs for the ORI are relatively hypothetical communities that conduct the minor, with basic equipment to outfit one ORI. Community A has 10 miles of open team of three people totaling about$800 channel to investigate, while Community B (Table 37). This cost includes one-time has 20 miles. In addition, Community A has expenses to acquire waders, a digital camera fewer staff resources available and therefore and a GPS unit, as well as disposable uses two-person field crews,while Community supplies. B uses three-person field crews. Total costs are presented as annual costs, assuming that each community is able to conduct the ORI for all miles in one year. Table 37: Typical Field Equipment Costs for the ORI Item Cost 100 Latex Disposable Gloves $ 25 5 Wide Mouth Sample Bottles (1 Liter) $ 20 Large Cooler $ 25 3 Pairs of Waders $ 150 Digital Camera $ 200 20 Cans of Spray Paint $ 50 Test Kits or Probes $ 100-$500 1 GPS Unit $ 150 1 Measuring Tape $ 10 1 First Aid Kit $ 30 Flashlights, Batteries, Labeling tape, Clipboards $ 25 Total $ 785-$1185 116 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 11: The Outfall Reconnaissance Inventory Table • ORI Costs Item Community A Community B Field Equipment' $700 $785 Staff Field Time $2,000 $6,000 Staff Office Time3 $3,000 $6,000 Total $5,700 $12,785 From Table 44 2 Assumes$25/hour salary(2 person teams in Community A and three-person teams in Community 8)and two miles of stream per day. s Assumes three staff days for each day in field. Illicit Discharge Detection and Elimination:A Guidance Manual 117 Chapter 11: The Outfall Reconnaissance Inventory 118 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 12:Indicator Monitoring Chapter 12: Indicator Monitoring Indicator monitoring is used to confirm indicator monitoring program or are looking illicit discharges, and provide clues about for simple, cost-effective, and safe their source or origin. In addition, indicator alternatives to their current program. monitoring can measure improvements in water quality during dry weather flow as a Organization of the Chapter result of the local IDDE program. This chapter reviews the suite of chemical This chapter provides technical support to indicator parameters that can identify illicit implement the basic IDDE monitoring discharges, and provides guidance on how to framework shown in Figure 44, and is collect, analyze and interpret each organized into eight sections as follows: parameter. 1. Review of indicator parameters Program managers have a wide range of 2. Sample collection considerations indicator parameters and analytical methods 3. Methods to analyze samples to choose from when determining the 4. Methods to distinguish flow types presence and source of illicit discharges. 5. Chemical library The exact combination of indicator 6. Special monitoring methods for parameters and methods selected for a intermittent and transitory discharges community is often unique. This chapter 7. In-stream dry weather monitoring recommends some general approaches for 8. Costs for indicator monitoring communities that are just starting an Non- � Transitory Flowing Intermittent Caulk Dam Source Area Off Hours Data In-stream Flowchart Chemical Chemical Mass Monitoring ORI Flawing Industrial Library 110 BMo lance [optional] Benchmark del Obvious Find and Fix Immediately Denotes a monitoring method Figure 44: IDDE Monitoring Framework Illicit Discharge Detection and Elimination:A Guidance Manual 119 Chapter 12:Indicator Monitoring Program managers developing an indicator Flow Chart Method. The use of four monitoring program need a solid background in indicators (surfactants, ammonia,potassium, basic water chemistry, and field and and fluoride) to identify illicit discharges. laboratory methods. This chapter describes the major factors to consider when designing Indicator Parameter: A water quality an indicator monitoring program for illicit measurement that can be used to identify a discharges, and assumes some familiarity specific discharge flow type, or discriminate with water quality sampling and analysis between different flow types. protocols. Monitoring:A strategy of sample collection Indicator monitoring terminology can be and laboratory analysis to detect and confusing, so some of the basic terms are characterize illicit discharges. defined as they specifically relate to illicit discharge control. Some of the common Optical Brightener Monitoring (OBM) terms introduced in this Chapter are defined Traps: Traps that use absorbent pads to below: capture dry weather flows, which can later be observed under a fluorescent light to Chemical Library: A database and statistical determine if detergents using optical summary of the chemical characteristics, or brighteners were present. "fingerprint" of various discharge flow types in a community (e.g., sewage, wash water, Reagent: A chemical added to a sample to shallow groundwater, tap water, irrigation create a reaction that enables the water, and liquid wastes). The library is measurement of a target chemical parameter. assembled by collecting and analyzing representative samples from the source of Sampling: Water sample collection from an each major flow type in the community. outfall, pipe or stream, along with techniques to store and preserve them for Chemical Mass Balance Model(CMBM: A subsequent laboratory analysis. computer model that uses flow characteristics from a chemical library file of flow types to Surfactants: The main component of estimate the most likely source components commercial detergents that detaches dirt that contribute to dry weather flows. from the clothing. The actual concentration of surfactants is much lower than the Detergents: Commercial or retail products concentration of detergent, but analytical used to wash clothing. Presence of methods that measure surfactants are often detergents in flow is usually measured as referred to as "detergents." To avoid surfactants or fluorescence. confusion, this chapter expresses the concentration of surfactants as "detergents False Negative: An indicator sample that as surfactants." identifies a discharge as uncontaminated when it actually is contaminated. False Positive: An indicator sample that identifies a discharge as contaminated when it is not. 120 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 12:Indicator Monitoring 12.1 Indicator Parameters to • Exhibit relatively small variations in Identify Illicit Discharges concentrations within the same flow or discharge type At least fifteen different indicator • Be conservative (i.e., concentration will parameters can confirm the presence or not change over time due to physical, origin of an illicit discharge. These chemical or biological processes) parameters are discussed in detail in • Be easily measured with acceptable Appendix F and include: detection limits, accuracy, safety and repeatability. . Ammonia • Boron No single indicator parameter is perfect, and each community must choose the combination • Chlorine of indicators that works best for their local • Color conditions and discharge types. Table 39 • Conductivity summarizes the parameters that meet most • Detergents of the indicator criteria, compares their • E. coli, enterococi, and total coliform ability to detect different flow types, and • Fluorescence reviews some of the challenges that may be • Fluoride encountered when measuring them. More details on indicator parameters are provided . Hardness in Appendix F. • pH • Potassium Data in Table 39 are based on research by • Surface Tension Pitt(Appendix E) conducted in Alabama, • Surfactants and therefore, the percentages shown to • Turbidity distinguish "hits" for specific flow types should be viewed as representative and may In most cases, however, only a small subset shift for each community. Also,in some of indicator parameters (e.g., three to five)is instances, indicator parameters were required to adequately characterize an illicit downgraded to account for regional discharge. This section summarizes the variation or dilution effects. For example, different indicator parameters that have been both color and turbidity are excellent used. indicators of sewage based on discharge fingerprint data, but both can vary regionally An ideal indicator parameter should reliably depending on the composition of clean distinguish illicit discharges from clean groundwater. water and provide clues about its sources. In addition, they should have the following characteristics: • Have a significantly different concentration for major flow or discharge types Illicit Discharge Detection and Elimination:A Guidance Manual 121 Chapter 12:Indicator Monitoring Table • • • to Detect Illicit Discharges Discharge Types it can Detect Parameter Tap Industrial or Laboratory/Analytical Challenges Sewage Washwater Water Commercial Liquid Wastes Can change into other nitrogen Ammonia • O O O forms as the flow travels to the outfall Boron O O O N/A High chlorine demand in natural Chlorine O O O O waters limits utility to flows with very high chlorine concentrations Color O O O O Conductivity O O O O Ineffective in saline waters Detergents— O O Reagent is a hazardous waste Surfactants E. coli 24-hour wait for results Enterococci O O O O Need to modify standard monitoring Total Coliform protocols to measure high bacteria concentrations Reagent is a hazardous waste Fluoride* O O • O Exception for communities that do not fluoridate their tap water Hardness O O O O pH O O O O May need to use two separate Potassium O O O • analytical techniques, depending on the concentration Turbidity O O O O • Can almost always (>80%of samples)distinguish this discharge from clean flow types (e.g., tap water or natural water). For tap water, can distinguish from natural water. O Can sometimes (>50%of samples)distinguish this discharge from clean flow types depending on regional characteristics, or can be helpful in combination with another parameter O Poor indicator. Cannot reliably detect illicit discharges, or cannot detect tap water N/A: Data are not available to assess the utility of this parameter for this purpose. Data sources: Pitt (this study) *Fluoride is a poor indicator when used as a single parameter, but when combined with additional parameters such as detergents, ammonia and potassium), it can almost always distinguish between sewage and washwater. 12.2 Sample Collection for collecting samples, elements of sampling Considerations protocols, and general tips. Several useful documents are available that detail accepted Sample collection is an important aspect of water quality sampling protocols such as the an IDDE program. Program managers need following: to be well informed about the key facets of sampling such as sample handling, QA/QC, Burton and Pitt(2002) - Stormwater and safety. The guidance in this section is Effects Handbook: A Toolbox for limited to an overview of sample collection Watershed Managers Scientists and considerations including: equipment needed Engineers 122 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 12:Indicator Monitoring • USGS National Field Manual for the 8. Safety considerations Collection of Water-Quality Data hllp://water.usgs.gov/owq/FieldManual/ Appendix G provides more detail on each monitoring element. Some communities • Standard Methods for the Examination already have established sampling protocols of Water and Wastewater that are used for in-stream or wet weather hllp://www.standardmethods.org/ sampling. In most cases these existing sampling protocols are sufficient to conduct • EPA NPDES Stormwater Sampling illicit discharge sampling. Guidance Document http://cfpub.epa. o�v/npdes (Note: while Tips for Collecting Illicit Discharge this document is oriented towards wet Samples weather sampling, there are still many sampling procedures that apply to dry The following tips can improve the quality weather sampling) of your indicator monitoring program. State environmental agencies are also a good 1. Remember to fill out an ORI field form resource to contact for recommended or at every outfall where samples are required sampling protocols. collected. The ORI form documents sample conditions, outfall characteristics Equipment Needed for Field Sampling and greatly aids in interpreting indicator monitoring data. The basic equipment needed to collect samples is presented in Table 40. Most 2. Most state water quality agencies have sampling equipment is easily available for detailed guidance on sampling protocols. purchase from scientific supply companies These resources should be consulted and and various retail stores. the appropriate guidelines followed. Another useful guidance on developing a Developing a Consistent Sample quality assurance plan is the "Volunteer Collection Protocol Monitor's Guide to Quality Assurance Project Plans" (EPA, 1996). Samples should never be collected haphazardly. To get reliable, accurate, and Table 40: Equipment Needed for Sample defensible data, it is important to develop a Collection consistent field sampling protocol to collect • A cooler (to be kept in the vehicle) each indicator sample.A good field sampling 0 Ice or"blue ice" (to be kept in the vehicle) protocol incorporates eight basic elements: • Permanent marker(for labeling the samples) 1. Where to collect samples Labeling tape or pre-printed labels • Several dozen one-liter polyethylene 2. When to collect samples plastic sample bottles 3. Sample bottle preparation 0 A"dipper," a measuring cup at the end of 4. Sample collection technique a long pole, to collect samples from 5. Storage and preservation of samples outfalls that are hard to reach 6. Sample labeling and chain of • Bacteria analysis sample bottles (if custody plan applicable), typically pre-cleaned 120mL y P sample bottles, to ensure against 7. Quality assurance/control samples contamination Illicit Discharge Detection and Elimination:A Guidance Manual 123 Chapter 12:Indicator Monitoring 3. Sample in batches where feasible to cut legally document a violation or down on field and mobilization time. enforcement action. The lab setting is important, since the quality of the data 4. Avoid sampling lagged storm water may be challenged. Precise data are flows by sampling at least 48 to 72 hours also needed for outfalls that have very after runoff producing events. large drainage areas. These discharges are often diluted by groundwater, so 5. It may be necessary to collect multiple lab methods must be sensitive and have samples at a single outfall if low detection limits to isolate illicit preservatives are going to be used. discharges that are masked or blended Preservatives are typically necessary with other flow types. Accurate data when long hold times are required for are also needed for large outfalls since samples before analysis occurs. the cost and effort triggered by a false Appendix G contains guidance on the positive reading to track and isolate required preservation and maximum discharges in a large and complex allowable hold times for various drainage area is much greater. parameters. How quickly are sampling results 12.3 Methods to Analyze needed? Fast results are essential if the Indicator Samples community wants to respond instantly to problem outfalls. In this case, the This section reviews methods to analyze capability to collect and analyze indicator samples, and begins with a indicator samples in-house is desirable discussion of whether they should be to provide quick response. analyzed in-house or sent to an independent contract lab. Next,recommended methods How much staff time and training is for analyzing indicator parameters are needed to support in-house analysis? outlined, along with data on their Local staff that perform lab analysis comparative cost, safety, and accuracy. must be certified in laboratory safety, Lastly, tips are offered to improve an quality control and proper analytical indicator monitoring program. procedures. Communities that do not expect to collect many indicator Analyzing Samples In-house vs. samples may want to utilize a contract Contract Lab lab to reduce staff training costs. Program managers need to decide whether • Does a safe environment exist to to analyze samples in-house, or through an analyze samples and dispose of independent monitoring laboratory. The wastes?A safe environment is needed decision on which route to take is often for lab analysis including storage in a based on the answers to the following fireproof environment, eyewash stations, safety showers, fume hoods questions: and ventilation. Lab workers should have standard safety equipment such as • What level ofprecision or accuracy is gloves, safety glasses and lab coats. needed for the indicator parameter(s)? Lastly, many of the recommended Precise and accurate data are needed analytical methods create small when indicator monitoring is used to 124 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 12:Indicator Monitoring quantities of hazardous wastes that In Field Analysis A few indicator need to be properly disposed. Program parameters can be analyzed in the field with managers should carefully evaluate in- probes and other test equipment(Figure 45). house work space to determine if a safe While most field parameters can identify lab environment can be created. problem outfalls, they generally cannot distinguish the specific type of discharge. • What is the comparative cost for Some of the situations where in-field sample analysis in each option? The analysis10 is best applied are: initial up-front costs to use an independent laboratory are normally When a community elects to use one or lower than those required to establish two indicator parameters, such as an in-house analysis capability. An in- ammonia and potassium, that can be house analysis capability normally measured fairly easily in the field becomes cost-effective when a community expects to analyze more When field crews measure indicator than 100 indicator samples per year. parameters to trace or isolate a Section 12.8 outlines some of the key discharge in a large storm drain pipe budget factors to consider when network, and need quick results to making this decision, but program decide where to go next managers should always get bids from reputable and certified contract labs to Office Analysis Many of the recommended determine analysis costs. indicator parameters can be analyzed in an informal "office"lab with the possible • Are existing monitoring laboratories exception of surfactants and fluoride (Figure available in the community? Cost 46). The office analysis option makes sense savings are often realized if an existing in communities that have available and wastewater treatment or drinking water trained staff, and choose analytical methods lab can handle the sample analysis. that are safe and have few hazardous waste These labs normally possess the disposal issues. Another option is to use the equipment, instruments and trained office lab to conduct most indicator staff to perform the water quality analyses, but send out fluoride and analyses for indicator parameters. surfactant indicator samples to a contract lab. Considerations for In-house Analysis Capability TIP Three basic settings can be used to analyze The methodology for any bacteria indicator parameters in-house: direct field analysis also has a waste disposal issue measurements, small office lab, and a more (e.g., biohazard). Check state guidance formal municipal lab. The choice of which for appropriate disposal procedures. in-house setting to use depends on the indicator parameters selected, the need for fast and accurate results and safety/disposal considerations. 10 Some communities have had success with in-field analysis;however, it can be a challenging environment to conduct rapid and controlled chemical analysis. Therefore,it is generally recommended that the majority of analyses be conducted in a more controlled"lab"setting. Illicit Discharge Detection and Elimination:A Guidance Manual 125 Chapter 12:Indicator Monitoring Formal Laboratory Setting—The ideal detailed in Appendix F and summarized option in many communities is to use an below. existing municipal or university laboratory. Existing labs normally have systems in place Supplies and Equipment to dispose of hazardous material,have room and facilities for storing samples, and are The basic supplies needed to perform lab equipped with worker safety features. Be analysis are described in Table 41, and are careful to craft a schedule that does not available from several scientific equipment interfere with other lab activities. suppliers. In addition, reagents, disposable supplies and some specialized instruments When in-house analysis is used,program may be needed, depending on the specific managers need to understand the basic indicator parameters analyzed. For a partial analytical options, safety considerations, list of suppliers, consult the Volunteer equipment needs and analysis costs for each Stream Monitoring Manual (US EPA, analytical method used to measure indicator 1997), which can be accessed at parameters. This understanding helps www.epa.gov/owow/monitoring/volunteer/st program managers choose what indicator ream/ap]2endb.html. Table 42 summarizes parameters to collect and where they should the equipment needed for each analytical be analyzed. Much of this information is method. y _ Figure 45: Analyzing samples in the Figure 46: Office/lab set up in Fort back of a truck. Worth, TX Table 41: Basic . . Supplies Disposable Supplies Glassware/Tools • Deionized water(start with about 10 0 About two dozen each of 100 and 200 gallons, unless a reverse osmosis mL beakers machine is available) 0 Two or three 100 mL graduated • Nitric acid for acid wash (one or two cylinders gallons to start) 0 Two or three tweezers Safety 0 Pipettes to transfer samples in small Lab or surgical gloves quantities Lab coats Safety glasses 126 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 12:Indicator Monitoring MethodsTable 42: Analytical . . Indicator Specific Equipment Reagents or Kits Unique Suppliers Parameter Glassware Sample Spectrophotometer Hach reagents for Ammonia www.hach.com Cells or Colorimeter method 8155 Boron None Spectrophotometer Hach reagents for www.hach.com or Colorimeter method 10061 Chlorine None Spectrophotometer Hach reagents for www.hach.com or Colorimeter method 8021 Color None None Color Kit www.hach.com Conductivity None Horiba probe Standards www.horiba.com Detergents- None None Chemets www.chemetrics.com Surfactants (MBAS) Detergents Test Sealer Colilert Reagent IDEXX Corporation E. Coli None Black Light Comparator Quanti-Tray Sheets www.idexx.com Fluorescence Cuvettes Fluorometer None Several Fluoride None Spectrophotometer Hach reagents for www.hach.com or Colorimeter method 8029 Erlenmeyer Burette and Stand EDTA Cartridges or Hardness Flask or Reagent www.hach.com Digital Titrator and Buffer Solution pH None Horiba Probe Standards www.horiba.com Potassium None Horiba Probe Standards www.horiba.com Potassium Spectrophotometer Hach Reagents for (Colorimetric) None or Colorimeter method 8012 www.hach.com Cost Enterococci. Reagents typically cost less than $2.00 per sample, and equipment Table 43 compares the per sample cost to purchases seldom exceed $1,000. The analyze indicator parameters. In general,the typical analysis time averages less than 10 per sample cost is fairly similar for most minutes per sample. More information on parameters, with the exception of bacteria budgeting indicator monitoring programs analyses for E. coli, total coliform, or can be found in Section 12.8. Illicit Discharge Detection and Elimination:A Guidance Manual 127 Chapter 12:Indicator Monitoring Table 43: Chemical Analysis Costs Analysis Cost Parameter Per Sample Costs Approximate Disposable Analysis Staff Cost Total Cost Initial Equipment Cost supplies Time (@$25/hr) Per Sample (Item) (min/sample) Ammonia $1.81 253 $10.42 $12.23 $950 (Colorimeter) Boron $0.50 203 $8.33 $8.83 $950 (Colorimeter) Chlorine $0.60 5 $2.08 $2.68 $950 (Colorimeter) Color $0.52 1 $0.42 $0.94 $0 Conductivity $0.652 43 $1.67 $2.32 (Probe) Detergents 1 $3.15 7 $2.92 $6.07 $0 Surfactants Enterococci, 7 $4,000 E. Coli or $6.75 (24 hour $2.92 $9.67 Total Coliform' waiting time) (Sealer and Incubator) Fluoride' $0.68 3 $1.25 $1.93 $950 (Colorimeter) Hardness $1.72 5 $2.08 $3.80 $125 (Digital Titrator) pH $0.652 3.53 $1.46 $2.11 (Probe) Potassium $0.502 5.53 $2.29 $2.79 $250 (High Range) (Probe) Potassium $1.00 5 $2.08 $3.08 $950 Low Range) (Colorimeter) Turbidity $0.502 63 $2.50 $3.00 $850 (Turbiditimeter) Potentially high waste disposal cost for these parameters. 2 The disposable supplies estimates are based on the use of standards to calibrate a probe or meter. 3 Analysts can achieve significant economies of scale by analyzing these parameters in batches. 4 Represents the cost of a colorimeter. The price of a spectrophotometer, which measures a wider range of parameters, is more than $2,500. This one-time cost can be shared among chlorine, fluoride, boron, potassium and ammonia. Additional Tips for In-house Laboratory Program managers may want to use Analysis both in-house analysis and contract labs to measure the full range of The following tips can help program indicator parameters needed in a safe managers with in-house laboratory analysis and cost-effective manner. In this case, decisions: a split sample analysis strategy is used, where some samples are sent to the contract lab, while others are analyzed in house. 128 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 12:Indicator Monitoring • Remember to order enough basic lab 4. Ensure that the maximum hold time for supplies, because they are relatively each indicator parameter exceeds the cheap and having to constantly re- time it takes to ship samples to the lab order supplies and wash glassware can for analysis. be time-consuming. In addition, some scientific supply companies have 5. Carefully review and understand the minimum order amounts, below which shipping and preservation instructions additional shipping and handling is provided by the contract lab. charged. 6. Look for labs that offer electronic • Be careful to craft a sample analysis reporting of sample results, which can schedule that doesn't interfere with greatly increase turn-around time, other lab operations, particularly if it make data analysis easier, and improve is a municipal lab. With appropriate response times. preservation, many samples can be stored for several weeks. 7. Periodically check the lab's QA/QC procedures,which should include lab Considerations for Choosing a Contract spikes, lab blanks, and split samples. Lab The procedures for cleaning equipment and calibrating instruments should also When a community elects to send samples be evaluated. These QA/QC to an independent contract lab for analysis, it procedures are described below. should investigate seven key factors: • Lab spikes—Samples of known I. Make sure that the lab is EPA-certified concentration are prepared in the for the indicator parameters you choose. A laboratory to determine the state-by-state list of EPA certified labs accuracy of instrument readings. for drinking water can be found at: http://www.epa.gov/safewater/privatew Lab blanks—Deionized water ells/labs.html. State environmental samples that have a known zero agencies are also good resources to concentration are used to test contact for pre-approved laboratories. methods, or in some methods to "zero"the instruments. 2. Choose a lab with a short turn-around time. Some Phase I communities had Split samples—Samples are problems administering their programs divided into two separate samples because of long turn-around times from at the laboratory for a comparative local labs (CWP, 2002). As a rule, a analysis. Any difference between lab should be able to produce results the two sample results suggests the within 48 hours. analysis method may not be repeatable. 3. Clearly specify the indicator parameter and analysis method you want, using Equipment cleaning and instrument the guidance in this manual or advice maintenance protocols—Each lab from a water quality expert. should have specific and routine procedures to maintain equipment Illicit Discharge Detection and Elimination:A Guidance Manual 129 Chapter 12:Indicator Monitoring and clean glassware and tubing. All four techniques rely on benchmark These procedures should be clearly concentrations for indicator parameters in labeled on each piece of equipment. order to distinguish among different flow types. Program managers are encouraged to • Instrument calibration— adapt each technique based on local Depending on the method, discharge concentration data, and some instruments may come with a simple statistical methods for doing so are standard calibration curve, or may provided throughout the section. require calibration at each use. Lab analysts should periodically test the The Flow Chart Method default calibration curve. The Flow Chart Method is recommended for Table 44 summarizes estimated costs most Phase II communities, and was associated with sample analyses at a contract originally developed by Pitt et al. (1993) and lab. Lalor(1994) and subsequently updated 12.4 Techniques to Interpret based on new research by Pitt during this project. The Flow Chart Method can Indicator Data distinguish four major discharge types found in residential watersheds,including sewage and Program managers need to decide on the wash water flows that are normally the most best combination of indicator parameters common illicit discharges. Much of the data that will be used to confirm discharges and supporting the method were collected in identify flow types. This section presents Alabama and other regions, and some local guidance on four techniques to interpret adjustment may be needed in some indicator parameter data: communities. The Flow Chart Method is recommended because it is a relatively • Flow Chart Method(recommended) simple technique that analyzes four or five • Single Parameter Screening indicator parameters that are safe, reliable • Industrial Flow Benchmarks and inexpensive to measure. The basic • Chemical Mass Balance Model decision points involved in the Flow Chart (CMBM) Method are shown in Figure 47 and Table ' ' • ' Contract described below: • Costs Parameter Costs Step 1: Separate clean flows from Ammonia $12 - $25 contaminated flows using detergents Boron $16 - $20 Chlorine $6 -$10 The first step evaluates whether the Color $7 -$11 discharge is derived from sewage or Conductivity $2 -$6 washwater sources, based on the presence of Detergents—Surfactants $17-$35 detergents. Boron and/or surfactants are Enterococci, E. Coli or $17 - $35 used as the primary detergent indicator, and Total Coliform values of boron or surfactants that exceed Fluoride $14 - $25 0.35 mg/L and 0.25 mg/L, respectively, Hardness $8 -$16 signal that the discharge is contaminated by pH $2 -$7 sewage or washwater. Potassium $12 - $14 Turbidity $9 -$12 130 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 12:Indicator Monitoring Possible sanitary wastewater contamination Yes Ammonia/ Possible Potassium No washwater ratio>1.0 contamination Yes Likely natural water source No Surfactants No >0.25 mg/L Fluoride Start110. or Boron >0.25 mg/L >0.35 mg/L Yes Likely tap and/or irrigation water source Figure 47: Flow Chart to Identify Illicit Discharges in Residential Watersheds Step 2: Separate washwater from Step 3: Separate tap water from natural wastewater using the Ammonia/Potassium water ratio If the sample is free of detergents, the next If the discharge contains detergents, the next step is to determine if the flow is derived step is to determine whether they are derived from spring/groundwater or comes from tap from sewage or washwater, using the water. The benchmark indicator used in this ammonia to potassium ratios. A ratio greater step is fluoride, with concentrations than one suggests sewage contamination, exceeding 0.60 mg/L indicating that potable whereas ratios less than one indicate water is the source. Fluoride levels between washwater contamination. The benchmark 0.13 and 0.6 may indicate non-target ratio was developed by Pitt et al. (1993) and irrigation water. The purpose of determining Lalor(1994) based on testing in urban the source of a relatively "clean discharge" Alabama watersheds. is that it can point to water line breaks, outdoor washing, non-target irrigation and other uses of municipal water that generate flows with pollutants. Illicit Discharge Detection and Elimination:A Guidance Manual 131 Chapter 12:Indicator Monitoring Adapting the Flow Chart Method discharges. The ratio can be refined over time using indicator monitoring at local The Flow Chart Method is a robust tool for outfalls, or through water quality sampling identifying illicit discharge types, but may of sewage and washwater flow types for the need to be locally adapted, since much of chemical library. the supporting data was collected in one region of the country. Program managers 3) Is fluoride a good indicator of tap should look at four potential modifications water? to the flow chart in their community. Usually. The two exceptions are 1) Is boron or surfactants a superior communities that do not fluoridate their local indicator of detergents? drinking water or have elevated fluoride concentrations in groundwater. In both Surfactants are almost always a more cases, alternative indicator parameters such reliable indicator of detergents, except for as hardness or chlorine may be preferable. rare cases where groundwater has been contaminated by sewage. The disadvantage 4) Can the flow chart be expanded? of surfactants is that the recommended analytical method uses a hazardous chemical The flow chart presented in Figure 47 is as the reagent. Boron uses a safer analytical actually a simplified version of a more method. However, if boron is used as a complex flow chart developed by Pitt for detergent indicator, program managers this project, which is presented in Appendix should sample boron levels in groundwater H. An expanded flow chart can provide and tap water, since they can vary more consistent and detailed identification regionally. Also, not all detergent of flow types, but obviously requires more formulations incorporate boron at high analytical work and data analysis. Section levels, so it may not always be a strong 12.5 provides guidance on statistical indicator. techniques to customize the flow chart method based on your local discharge data. 2) Is the ammonia/potassium ratio of one the best benchmark to distinguish Single Parameter Screening sewage from washwater? Research by Lalor(1994) suggests that The ammonia/potassium ratio is a good way detergents is the best single parameter to to distinguish sewage from washwater, detect the presence or absence of the most although the exact ratio appears to vary in common illicit discharges (sewage and different regions of the country. The washwater). The recommended analytical benchmark value for the ratio was derived method for detergents uses a hazardous from extensive testing in one Alabama city. reagent, so the analysis needs to be In fact, data collected in another Alabama conducted in a controlled laboratory setting city indicated an ammonia/potassium ratio with proper safety equipment. This may of 0.6 distinguished sewage from wash limit the flexibility of a community if it is water. Clearly,program managers should conducting analyses in the field or in a evaluate the ratio in their own community, simple office lab. although the proposed ratio of 1.0 should still capture the majority of sewage 132 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 12:Indicator Monitoring Ammonia is another single parameter Industrial Flow Benchmark indicator that has been used by some communities with widespread or severe If a subwatershed has a high density of sewage contamination. An ammonia industrial generating sites, additional concentration greater than 1 mg/L is indicator parameters may be needed to generally considered to be a positive detect and trace these unique discharges. indicator of sewage contamination. They are often needed because industrial Ammonia can be analyzed in the field using and commercial generating sites produce a portable spectrophotometer, which allows discharges that are often not composed of for fairly rapid results and the ability to either sewage or washwater. Examples immediately track down sources and include industrial process water, or wash improper connections (see Chapter 13 for down water conveyed from a floor drain to details on tracking down illicit discharges)ii. the storm drain system. Since ammonia can be measured in the field, crews can get fast results and immediately This guidance identifies seven indicator proceed to track down the source of the parameters that serve as industrial flow discharge using pipe testing methods (see benchmarks to help identify illicit Chapter 13 for details). discharges originating from industrial and other generating sites. The seven indicators As a single parameter, ammonia has some (ammonia, color, conductivity,hardness, limitations. First, ammonia by itself may not pH,potassium and turbidity) are used to always be capable of identifying sewage identify liquid wastes and other industrial discharges,particularly if they are diluted by discharges that are not always picked up by "clean" flows. Second, while some the Flow Chart Method. Table 45 washwaters and industrial discharges have summarizes typical benchmark relatively high ammonia concentrations, not concentrations that can distinguish between all do,which increases the prospects of false unique industrial or commercial liquid negatives. Lastly, other dry weather wastes. Note that two of the seven indicator discharges, such as non-target irrigation, can parameters, ammonia and potassium, are also have high ammonia concentrations that already incorporated into the flow chart can occasionally exceed 1 mg/L. method. Supplementing ammonia with potassium and looking at the ammonia/potassium ratio Table 46 illustrates how industrial is a simple adjustment to the single benchmark parameters can be used parameter approach that helps to further and independently or as a supplement to the flow more accurately characterize the discharge. chart method, based on data from Alabama Ratios greater than one indicate a sewage (Appendix E). The best industrial source, while ratios less than or equal to one benchmark parameters are identified in pink indicate a washwater source. Potassium is shading and can distinguish industrial easily analyzed using a probe (Horiba sources from residential washwater in 80% CardyTM is the recommended probe). of samples. Supplemental indicator parameters denoted by yellow shading, can distinguish industrial source from residential illn-field analysis may be appropriate when tracking down washwater in 50% of samples, or roughly illicit flows,but it is typically associated with challenging and one in two samples. uncontrollable conditions. Therefore,it is generally recommended that analyses be conducted in a controlled lab setting. Illicit Discharge Detection and Elimination:A Guidance Manual 133 Chapter 12:Indicator Monitoring Most industrial discharges can consistently Adapting Industrial Flow Benchmark be identified by extremely high potassium levels. However, these discharges would be By their very nature, industrial and other misclassified as washwater when just the generating sites can produce a bewildering Flow Chart Method is used. Other diversity of discharges that are hard to benchmark parameters have value in classify. Therefore,program managers will identifying specific industrial types or experience some difficulty in differentiating operations. For example, metal plating bath industrial sources. Over time, the waste discharges are often indicated by composition of industrial discharges can be extremely high conductivity, hardness and refined as chemical libraries for specific potassium concentrations. industrial flow types and sources are developed. This can entail a great deal of sampling, but can reduce the number of false positive or negative readings. Table • • • Identify IndustrialDischarges Indicator Parameter Benchmark Notes Concentration • Existing "Flow Chart" Parameter Ammonia >_50 mg/L 0 Concentrations higher than the benchmark can identify a few industrial discharges. • Supplemental parameter that identifies a Color >_500 Units few specific industrial discharges. Should be refined with local data. • Identifies a few industrial discharges Conductivity >_2,000pS/cm 0 May be useful to distinguish between industrial sources. <10 mg/L as CaCO3 Identifies a few industrial discharges Hardness >2,000 mg/L as CaCO3 May be useful to distinguish between industrial sources. • Only captures a few industrial discharges pH <5 High pH values may also indicate an industrial discharge but residential wash waters can have a high pH as well. • Existing "Flow Chart" Parameter Potassium >_20 mg/L 0 Excellent indicator of a broad range of industrial discharges. • Supplemental parameter that identifies a Turbidity >_1,000 NTU few specific industrial discharges. Should be refined with local data. 134 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 12:Indicator Monitoring Tableof • to Identify IndustrialDischarges Detergents Hardness Best Additional as Ammonia Potassium Initial Color Conductivity Turbidity Indicator Indicator Benchmark CaCO3) Industrial Surfactants (mg/L) (mg/L) "Flow (Units) (pS/cmJ (mg/L as pH (NTU) Parameters Parameters Concentration (mg/L) Chart" to Identify to Identify Class <10 This Flow This Flow -- >_50 >_20 >_500 >_2000 >_ <5 >_1,000 Type Type 2,000 Concentrations in Industrial and Commercial Flow Types Automotive 1 5 0.6 66 Wash 15 220 30 6.7 118 Potassium Manufacturer water Poultry 5 4.2 41 Wash 23 618 31 6.3 ill Potassium Supplier' water Roofing Product 8 102 27 242 32 7 Wash 2 None Potassium Manufacturing' . water >100 .1 229 Color Uniform 1 6 6.1 64 Wash >1002 798 35 10.4 2,631 Potassium Color Manufacturingwater Turbidity Radiator Wash Potassium Flushing 15 (26.3) (2,801) water (3,000) (3,278) (5.6) (7.0) - Conductivity Hardness Color Ammonia Metal Plating 7 (65.7) (1,009) Wash (104) (10,352) (1,429) (4.9) - Potassium pH Bath water Conductivity Hardness Commercial Car 140 0.9; (0.2) 4; (43) Wash >61; 274; (485) 71; (157) 7'7- 156 Potassium Wash water 222 6.7 Turbidity Commercial (27) (0.8) 3 Wash 47 (563) (36) (9.1) - Laundrywater Best Indicators,shaded in pink,distinguish this source from residential wash water in 80%of samples in both Tuscaloosa and Birmingham,AL. Supplemental indicators, shaded in yellow, distinguish this source from residential wash water in 50%of samples, or in only one community. (Data in parentheses are mean values from Birmingham); Data not in parentheses are from Tuscaloosa ' Fewer than 3 samples for these discharges. 2 The color analytical technique used had a maximum value of 100, which was exceeded in all samples. Color may be a good indicator of these industrial discharges and the benchmark concentration may need adjustment downward for this specific community. Illicit Discharge Detection and Elimination:A Guidance Manual 135 135 Chapter 12:Indicator Monitoring Chemical Mass Balance Model Technology, and can be accessed at (CMBM) for Blended Flows http://www.itl.nist.s4ov/div898/handbook/. The Chemical Mass Balance Model 12.5 The Chemical Library (CMBM) is a sophisticated technique to identify flow types at outfalls with blended The chemical library is a summary of the flows (i.e., dry weather discharges chemical composition of the range of originating from multiple sources). The discharge types found in a community. The CMBM, developed by Karri (2004) as part primary purpose of the library is to of this project is best applied in complex characterize distinct flow types that may be sewersheds with large drainage areas, and observed at outfalls, including both clean relies heavily on the local chemical library and contaminated discharges. A good library discussed in the next section. includes data on the composition of tap water, groundwater, sewage, septage, non- The CMBM can quantify the fraction of target irrigation water, industrial process each flow type present in dry weather flow waters, and washwaters (e.g., laundry, car at an outfall (e.g., 20% spring water; 40% wash, etc.). The chemical library helps sewage; 20%wash water). The CMBM program managers customize the flow chart relies on a computer program that generates method and industrial benchmarks, and and solves algebraic mass balance equations, creates the input data needed to drive the based on the statistical distribution of specific CMBM. flow types derived from the chemical library. The CMBM is an excellent analysis To develop the library, samples are collected tool, but requires significant advance directly from the discharge source (e.g., tap preparation and sampling support. More water, wastewater treatment influent, detailed guidance on how to use and shallow wells, septic tanks, etc.). Table 47 interpret CMBM data can be found in provides guidance on how and where to Appendix I. sample each flow type in your community. As a general rule, about 10 samples are The chemical library requires additional typically needed to characterize each flow statistical analysis to support the CMBM. type, although more samples may be needed Specifically, indicator parameter data for if the flow type has a high coefficient of each flow type need to be statistically variation. The measure of error can be analyzed to determine the mean, the statistically defined by evaluating the coefficient of variation, and the coefficient of variation of the sample data distribution type. In its current version, the (variability relative to the mean value), and CMBM accepts two distribution types: the statistical distribution for the data(the normal or lognormal distributions. Various probable spread in the data beyond the statistical methodologies can determine the mean). For more guidance on statistical distribution type of a set of data. Much of techniques for assessing sampling data, this analysis can be conducted using consult Burton and Pitt(2002) and US EPA standard,readily-available statistical (2002), which can be accessed at software, such as the Engineering Statistics http://galton.uchicago.edu/—cises/resources/ Handbook which is available from the EPA-QA-Sampling-2g 003.pdf. National Institute of Standards and 136 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 12:Indicator Monitoring Chemical libraries should also be compared Over time, communities may want to add to databases that summarize indicator other flow types to the chemical library, monitoring of dry weather flows at suspect such as transitory discharges that generate outfalls. Outfall samples may not always be small volume flows such as "dumpster representative of individual flow types juice,"power washing and residential car because of mixing of flows and dilution, but washing. Transitory discharges are hard to they can serve as a valuable check if the detect with outfall monitoring,but may discharge source is actually confirmed. cumulatively contribute significant dry Program managers can also use both the weather loads. Understanding the chemical chemical library and indicator database to makeup of the transitory discharges can help refine flow chart or industrial benchmarks program managers prioritize education and (see Appendix J for an example). pollution prevention efforts. Table 47: Where and How to Sample for Chemical "Fingerprint" Library Flow Type Places to Collect the Data Any Other Potential Sources? From road cuts or stream banks Samples from shallow wells Shallow Groundwater 0 USGS regional groundwater quality data None. Locally distinct. Dry weather in-stream flows at headwaters with no illicit discharges Spring Water 0 Directly from springs None. Locally distinct. Individual taps throughout the community Tap water 0 or analyze local drinking water monitoring None. Locally distinct reports or annual consumer confidence reports Collect irrigation water from several different Irrigation sites. May require a hand operated vacuum None. Locally distinct. pump to collect these shallow flows(see Burton and Pitt, 2002 Reported sewage treatment plant influent data provides a characterization of raw sewage and is usually available from discharge monitoring reports. Because the characteristics of sewage will vary within the collection system depending Sewage upon whether the area is serving residential or Data in Appendix E can provide a commercial uses, climate, residence time in the starting point, but local data are collection system, etc, it is often more accurate preferred. and valuable to collect"fingerprint'samples from within the system, rather than at the treatment plant. Septage 0Outflow of several individual septic tanks or leach fields Direct effluent from the industrial process Data in Appendix E characterize some Most Industrial specific industrial flows. Industrial treatment program in locaall community) Discharges (Obtain samples as part industrial pre- NPDES permit monitoring can also be used. Commercial Car Data in Appendix E can provide a Wash; Sumps at these establishments starting point, but local data are Commercial Laundry preferred. Illicit Discharge Detection and Elimination:A Guidance Manual 137 Chapter 12:Indicator Monitoring Evaluating Interpretive Techniques Using 12.6 Special Monitoring Outfall Indicator Monitoring Data Techniques for Intermittent or Outfall sampling data for confirmed sources Transitory Discharges or flow types can be used to test the accuracy and reliability of all four The hardest discharges to detect and test are interpretive techniques. The sampling record intermittent or transitory discharges to the is used to determine the number of false storm drain system that often have an positives or false negatives associated with a indirect mode of entry. With some interpretive technique. A simple ingenuity, luck, and specialized sampling specific techniques,however, it may be possible to tabulation of false test readings can identify the types and levels of indicator parameters catch these discharges. This section that are most useful. describes some specific monitoring techniques to track down intermittent Table 48 provides an example of how the discharges. Transitory discharges cannot be Flow Chart Method was tested with outfall reliably detected using conventional outfall monitoring data from Birmingham, AL (Pitt monitoring techniques, and are normally et al., 1993). In this case, the Flow Chart found as a result of hotline complaints or Method was applied without adaptation to spill events.Nevertheless,when transitory local conditions, and the number of correctly discharges are encountered, they should be (and incorrectly) identified discharges was sampled if possible. tracked. Tests on 10 Birmingham outfalls Techniques for Monitoring Intermittent were mostly favorable, with the flow chart Discharges method correctly identifying contaminated discharges in all cases (i.e.,washwater or An outfall may be suspected of having sewage waste water). At one outfall, the intermittent discharges based on physical flow chart incorrectly identified sewage as indicators (e.g., staining),poor in-stream dry washwater, based on an ammonia(NH3)/ weather water quality, or the density of potassium (K)ratio of 0.9 that was very generating sites in the contributing close to the breakpoint in the Flow Chart subwatershed. The only sure way to detect Method(ratio of one). Based on such tests, an intermittent discharge is to camp out at program managers may want to slightly the outfall for a long period of time, which is adjust the breakpoints in the Flow Chart obviously not very cost-effective or feasible. Method to minimize the occurrence of As an alternative, five special monitoring errors. techniques can be used to help track these elusive problems: • Odd hours monitoring • Optical brightener monitoring traps • Caulk dams • Pool sampling • Toxicity monitoring 138 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 12:Indicator Monitoring Table 48: Evaluation of the Flow Chart Method Using Data from Birmingham,Alabama (Adapted Outfall Concentrations (mg/L) Detergents- Fluoride Predicted Confirmed Outfall ID Surfactants NH3/K (>0.25 is Flow Type Flow Type Result (>0.25 is NH3 K (>1.0 is tap, if no sanitary or sanitary) detergents) wash water 14 0 0 0.69 0.0 0.04 Natural Spring Water Correct Water Rinse Water 20 0 0.03 1.98 0.0 0.61 Tap Water and(TSp) Correct Water 21 20 0.11 5.08 0.0 2.80 Washwater Washwater Correct (Automotive) 26 0 0.01 0.72 0.0 0.07 Natural Spring Water Correct Water 28 0.25' 2.89 5.96 0.5 0.74 Washwater Washwater Correct (Restaurant) 31 0.95 0.21 3.01 0.1 1.00 Washwater Laundry Correct (Motel) Shallow Identifies 40z 0.25' 0.87 0.94 0.9 0.12 Washwater Groundwater Contaminated and Septage but Incorrect Flow Type 42 0 0 0.81 0.0 0.07 Natural Spring Water Correct Water 48 3.0 5.62 4.40 1.3 0.53 Sanitary Spring Water Correct Wastewater and Sewage Landscaping 60a 0 0.31 2.99 0.1 0.61 Tap Water Irrigation Correct Water These values were increased from reported values of 0.23 mg/L (outfall 28)and 0.2 mg/L (outfall 40z). The analytical technique used in Birmingham was more precise (but more hazardous)than the method used to develop the flow chart in Figure 47. It is assumed that these values would have been interpreted as 0.25 mg/L using the less precise method. Odd Hours Monitoring • Weekday evenings Many intermittent discharges actually occur • Weekend mornings and evenings on a regular schedule, but unfortunately not the same one used by field crews during the Optical Brightener Monitoring Traps raps week. For example, some generating sites Optical brightener monitoring (OBM)traps discharge over the weekend or during the are another tool that crews can use to gain evening hours. If an outfall is deemed insight into the "history" of an outfall suspicious,program managers may want to without being physically present. OBM traps consider scheduling "odd hours" sampling at can be fabricated and installed using a different times of the day or week. Some variety of techniques and materials. All key times to visit suspicious outfalls include: configurations involve an absorbent, unbleached cotton pad or fabric swatch and Both morning and afternoon a holding or anchoring device such as a wire Illicit Discharge Detection and Elimination:A Guidance Manual 139 Chapter 12:Indicator Monitoring mesh trap (Figure 48) or a section of small machine (see Appendix F for results). diameter (e.g., 2-inch)PVC pipe. Traps are Consequently, OBM traps may be best anchored to the inside of outfalls at the suited as a simple indicator of presence or invert using wire or monofilament that is absence of intermittent flow or to detect the secured to the pipe itself or rocks used as most concentrated flows. OBM traps need to temporary weights. be retrieved before runoff occurs from the outfalls,which will contaminate the trap or Field crews retrieve the OBM traps after wash it away. they have been deployed for several days of dry weather, and place them under a Caulk Dams fluorescent light that will indicate if they This technique uses caulk,plumber's putty, have been exposed to detergents. OBM traps or similar substance to make a dam about have been used with some success in two inches high within the bottom of the Massachusetts (Sargent et al., 1998) and storm drain pipe to capture any dry weather northern Virginia (Waye, 2000). Although flow that occurs between field observations. each community used slightly different Any water that has pooled behind the dam is methods, the basic sampling concept is the then sampled using a hand-pump sampler, same. For more detailed guidance on how to and analyzed in the lab for appropriate use OBM traps and interpret the results, indicator parameters. consult the guidance manual found at: http://www.naturecompass.org/8tb/sampling Pool Sampling /index.html and In this technique, field crews collect http://www.novare ig on.org/obm.htin. indicator samples directly from the "plunge pool"below an outfall, if one is present. An Although OBM traps appear useful in upstream sample is also collected to detecting some intermittent discharges, characterize background stream or ditch research during this project has found that water quality that is not influenced by the OBM traps only pick up the most outfall. The pool water and stream sample contaminated discharges, and the detergent are then analyzed for indicator parameters, level needed to produce a"hit"was roughly and compared against each other. Pool similar to pure washwater from a washing sampling results can be constrained by r stream dilution, deposition, storm water - flows, and chemical reactions that occur within the pool. Toxicity Monitoring Another way to detect intermittent discharges is to monitor for toxicity in the pool below the outfall on a daily basis. Burton and Pitt(2002) outline several options to measure toxicity, some of which can be fairly expensive and complex. The Figure 48: OBM Equipment includes Fort Worth Department of Environmental a black light and an OBM Trap that Management has developed a simple low- can be placed at an outfall cost outfall toxicity testing technique known Source:R. Pitt as the Stream Sentinel program. Stream 140 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 12:Indicator Monitoring sentinels place a bottle filled with minnows sample scheduling (City of Fort Worth, in the pool below suspected outfalls and 2003). More information about the Stream measure the survival rate of the minnows as Sentinel program can be found at: an indicator of the toxicity of the outfall 12 www.fortworthgov.org/DEM/stream_sentin (see Figure 49). el.pdf. One advantage of the sentinel program is Due to the cost and difficulty of interpreting that volunteer monitors can easily findings, toxicity testing is generally not participate, by raising and caring for the recommended for communities unless they minnows, placing bottles at outfalls, and have prior experience and expertise with the visiting them everyday to record mortality. method. The long-term nature of sentinel monitoring can help pick up toxicity trends at a given Techniques for Monitoring Transitory outfall. For example, Fort Worth observed a Discharges trend of mass mortality on the second Tuesday of each month at some outfalls, Transitory discharges, such as spills and which helped to pinpoint the industry illegal dumping, are primarily sampled to responsible for the discharges, and improved assign legal responsibility for enforcement actions or to reinforce ongoing pollution prevention education efforts. In most cases, crews attempt to trace transitory discharges back up the pipe or drainage area using visual techniques (see Chapter 13). However, field crews should always collect a sample to document the event. Table 49 summarizes some follow-up monitoring strategies to document transitory discharges. 12.7 Monitoring of Stream Quality During Dry Weather In-stream water quality monitoring can help detect sewage and other discharges in a community or larger watershed. Stream monitoring can identify the subwatersheds with the greatest illicit or sewage discharge potential that is then used to target outfall indicator monitoring. At the smaller reach scale, stream monitoring may sometimes Figure 49: Float and wire system to detect major individual discharges to the suspend a bottle in a stream sentinel station deployed in Fort Worth, TX (a); stream. Minnows in the perforated bottle below the water surface (b). 12 It may be necessary to obtain approval from the appropriate state of federal regulatory agency before conducting toxicity monitoring using vertebrates. Illicit Discharge Detection and Elimination:A Guidance Manual 141 Chapter 12:Indicator Monitoring Table 49: Follow-Up Monitoring for Transitory Discharges Condition Response Oils or solvents Special hydrocarbon analysis to characterize the source of the oil Unknown but toxic material Full suite of metals, pesticides, other toxic materials Monitor for parameters associated with the Flow Chart Technique Probable sewage (detergents, ammonia, potassium, fluoride) for residential drainage areas Stream Monitoring to Identify Problem An important caveat when interpreting Reaches or Subwatersheds stream monitoring data is that a violation of bacteria standards during dry weather flow Stream monitoring data can be used to does not always mean that an illicit locate areas in subwatersheds where illicit discharge or sewage overflow is present. discharges may be present, and where While raw sewage has bacteria concentrations human or aquatic health risks are higher. To that greatly exceed bacteria standards provide this information, stream monitoring (approximately 12,000 MPN/100 mL) other should be conducted regularly during dry bacteria sources, such as urban wildlife, can weather conditions to track water quality (at also cause a stream to violate standards. least monthly) and to document changes in Consequently, stream monitoring data need water quality over a period of time. Stream to be interpreted in the context of other monitoring data are particularly effective information, such as upstream land use,past when combined with ORI data. For complaints, age of infrastructure, and ORI example, a subwatershed with many ORI surveys. physical indicators of illicit discharges (e.g., a high number of flowing outfalls)that also Ideally, stream monitoring stations should has poor stream water quality would be an be strategically located with a minimum of obvious target for intensive outfall one station per subwatershed, and additional monitoring. stations at stream confluences and downstream of reaches with a high outfall density. Stream monitoring parameters should reflect Stations should also be located at beaches, local water quality goals and objectives, and shellfish harvesting and other areas where frequently include bacteria and ammonia. discharges represent a specific threat to Bacteria are useful since sewage discharges public health. See Burton and Pitt(2002) for can contribute to violations of water contact guidance on stream monitoring. standards set for recreation during dry weather conditions. Table 50 summarizes Stream Monitoring to Identify Specific water quality standards for E. coli that EPA Discharges recommends for water contact recreation. It is important to note that individual states Stream monitoring data can help field crews may use different action levels or bacteria locate individual discharges within a specific indicators (e.g., Enterococci or fecal stream reach. Immediate results are needed coliform)to regulate water contact for this kind of monitoring, so indicator recreation. For a review of the impacts parameters should be analyzed using simple bacteria exert on surface waters, consult field test kits or portable analytical CWP (2000). instruments(e.g.,spectrophotometer). Bacteria is not a good indicator parameter to use for 142 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 12:Indicator Monitoring this purpose because lab results cannot be If stream monitoring indicates that a received for at least one day (analytical potential problem level benchmark has been method requires a"hold time" of 24 hours). exceeded, field crews continue stream Table 51 summarizes nutrient indicator sampling to locate the discharge through a parameters along with their"potential process of elimination. Crews walk problem level" benchmarks. It is important upstream taking regular samples above and to note that other factors, such as animal below stream confluences until the operations, can elevate stream nutrient benchmark concentration declines. The concentrations, so data should always be crews then take samples at strategic points interpreted in the context of surrounding to narrow down the location of the land use. Stream monitoring benchmarks discharge, using the in-pipe monitoring should be continuously refined as strategy described in Chapter 13. communities develop a better understanding of what dry weather baseline concentrations to expect. Table 50: Typical "Full Body Contact Recreation" Standards for E. coli (Source:EPA, 1986) Use Criterion Designated beach area 235 MPN/100 mL Moderately-used full body contact recreation area 298 MPN/100 mL Lightly-used full body contact recreation 406 MPN/100 mL Infrequently-used full body contact recreation 576 MPN/100 mL These concentrations represent standards for a single sampling event. In all waters, a geometric mean concentration of 126 MPN/100 mL cannot be exceeded for five samples taken within one month. Table •le In-Stream Nutrient Indicators of • 00 Parameter Potential Problem Possible Cause of Water Quality Problem Level* Total Nitrogen High nutrients in ground water from agriculture, lawn (TN) 3.5 mg/I practices, or sewage contamination from illicit connection, sanitary line break or failing septic system. Total Phosphorus 0.4 mg/I Contamination from lawn practices, agriculture, (TP) sewage or washwater. Ammonia Sewage or washwater contamination from illicit (NH3) 0.3 mg/I connection, sanitary line break or failing septic system. *Nutrient parameters are based on USGS NA WQA data with 85%of flow weighted samples being less than these values in urban watersheds(Note:data from Nevada were not used, due to climatic differences and for some parameters they were an order of magnitude higher). Communities can modify these benchmarks to reflect local data and experience. Illicit Discharge Detection and Elimination:A Guidance Manual 143 Chapter 12:Indicator Monitoring 12.8 The Costs of Indicator create a chemical library, and instead relied Monitoring on default values to identify illicit discharges. The community analyzed the This section provides general guidance on samples in-house at a rate of one sample scoping and budgeting an indicator (includes analysis of all six parameters)per monitoring program. The required budget staff hour. will ultimately be dictated by the monitoring decisions and local conditions within a Community B: Mixed Land Use-Multiple community. The budgeting data presented in Potential Sources, Complex Analysis this section are based on the level of indicator sampling effort in two hypothetical In the second scenario,the community communities, using different numbers of analyzed 11 indicator parameters, including samples, indicator parameters, and analysis a bacteria indicator, and took samples of methods. eight distinct flow types to create a chemical library, for a total of 88 samples. The Budgets for Indicator Monitoring in a community analyzed the samples in-house at Hypothetical Community a rate of one sample per 1.5 staff hours. Communities can develop annual budgets Some general rules of thumb that were used for indicator monitoring if the degree of for this budget planning example include the sampling effort can be scoped. This is following: normally computed based on the expected number of samples to analyze and is a $500 in initial sampling equipment function of stream miles surveyed and (e.g., sample bottles, latex gloves, outfall density. For example, if a community dipper, cooler, etc). collects samples from 10 stream miles with Outfall samples are collected in eight outfalls per mile,it will have 80 batches of 10. Each batch of samples samples to analyze. This number can be can be collected and transported to the used to generate start-up and annual lab in two staff days (two-person crew monitoring cost estimates that represent the required to collect samples for safety expected level of sampling effort. Table 52 summarizes how indicator monitoring purposes). budgets were developed for two Staff rate is $25/hr. hypothetical communities, each with 80 outfalls to sample. Budgets are shown using Overall effort to collect samples for both in-house and contract lab set-ups, and the chemical library and statistically are split between initial start-up costs and annual costs. analyze the data is approximately one staff day per source type. Community A:Primarily Residential Land The staff time needed to prepare for Use, Flow Chart Method field work and interpret lab results is In this scenario, six indicator parameters roughly two times that required for were analyzed, several of which were used conducting the field work(i.e., eight to support the Flow Chart Method. The days of collecting samples requires 16 community took no additional samples to days of pre- and post-preparation). 144 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 12:Indicator Monitoring Costs for Intermittent Discharge As a rule of thumb, assume about four hours Analyses of staff time to deploy, retrieve and analyze samples collected from a single outfall using Equipment costs for most specialized these techniques. intermittent discharge techniques tend to be low (<$500), and are dwarfed by staff effort. Table 52: Indicator Monitoring Costs: Two Scenarios _ Community A: Community A: Community B: FC c_mmunity B: In-House Contract Lab In-House Contract Lab Initial Costs Initial Sampling Supplies and Lab Equipment $1,700 $500 $7,500 $500 Staff Cost: Library DevelopmentDevelopment $0 $0 $4,6003 $2,000 Analysis Costs: Library Development (Reagents $0 $0 $1,400 $13'0004 or Contract Lab Cost) Total Initial Costs $1,700 $500 $13,500 $15,500 Annual Costs in Subsequent Years Staff Field Cosa (Sample Collection) $3,200 $3,200 $3,200 $3,200 Staff Costs: Chemical Analysis $2,000 $200' $3,000 $200 Staff Time to Entter/ Interpret Data $3,200 $3,200 $4,800 $4,800 Analysis Costs: Annual Outfall Sampling $600 $8,4004 $1,400 $13'0004 (Reagents or Contract Lab Cost) TOTAL ANNUAL COST $9,000 $15,000 $12,400 $21,200 Notes: ' $500 in initial sampling equipment. 2 Samples can be shipped to a contract lab using one staff hour. 3 Overall effort to collect samples for the library and statistically analyze the data is approximately one staff day per source type. 4 For contract lab analysis, assume a cost that is an average between the two extremes of the range in Table 43. 5 Outfall samples are collected in batches of 10. Each batch of samples can be collected and transported to the lab in two staff days (two-person crew required to collect samples for safety purposes). 6 Assume that the staff time needed to interpret lab results and prepare for field work is roughly 16 staff days. An additional eight days are required for the flow type pre-and post-preparation for Community 2. Staff rate is $25/hr. Illicit Discharge Detection and Elimination:A Guidance Manual 145 Chapter 12:Indicator Monitoring 146 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 13: Tracking Discharges To a Source Chapter 13: Tracking Discharges To A Source Once an illicit discharge is found,a combination storm water is conveyed in ditches or of methods is used to isolate its specific swales. The major illicit discharges found in source. This chapter describes the four low-density development are failing septic investigation options that are introduced systems and illegal dumping. Homeowner below. surveys, surface inspections and infrared photography have all been effectively used Storm Drain Network Investigation to find failing septic systems in low-density watersheds. Field crews strategically inspect manholes within the storm drain network system to 1 3.1 Storm Drain Network measure chemical or physical indicators that Investigations can isolate discharges to a specific segment of the network. Once the pipe segment has This method involves progressive sampling been identified, on-site investigations are at manholes in the storm drain network to used to find the specific discharge or narrow the discharge to an isolated pipe improper connection. segment between two manholes. Field crews need to make two key decisions when Drainage Area Investigation conducting a storm drain network investigation—where to start sampling in This method relies on an analysis of land use the network and what indicators will be used or other characteristics of the drainage area to determine whether a manhole is that is producing the illicit discharge. The considered clean or dirty. investigation can be as simple as a "windshield" survey of the drainage area or Where to Sample in the Storm Drain a more complex mapping analysis of the Network storm drain network and potential generating sites.Drainage area investigations The field crew should decide how to attack work best when prior indicator monitoring the pipe network that contributes to a reveals strong clues as to the likely problem outfall. Three options can be used: generating site producing the discharge. On-site Investigation • Crews can work progressively up the trunk from the outfall and test manholes along the way. On-site methods are used to trace the source Crews can split the trunk into of an illicit discharge in a pipe segment, and 0 equal segments and test manholes may involve dye,video or smoke testing at strategic junctions in the storm within isolated segments of the storm drain drain system. network • Crews can work progressively down from the upper parts of the Septic System Investigation storm drain network toward the Low-density residential watersheds may problem outfall. require special investigation methods if they are not served by sanitary sewers and/or Illicit Discharge Detection and Elimination:A Guidance Manual 147 Chapter 13: Tracking Discharges To a Source The decision to move up, split, or move can help identify manholes,pipes and down the trunk depends on the nature and junctions, and establish a new map of the land use of the contributing drainage area. storm drain network. Some guidance for making this decision is provided in Table 53. Each option requires Option 1 ; Move up the Trunk different levels of advance preparation. Moving up the trunk of the storm drain Moving up the trunk can begin immediately network is effective for illicit discharge when an illicit discharge is detected at the problems in relatively small drainage areas. outfall, and only requires a map of the storm Field crews start with the manhole closest to drain system. Splitting the trunk and moving the outfall, and progressively move up the down the system require a little more network, inspecting manholes until preparation to analyze the storm drain map indicators reveal that the discharge is no to find the critical branches to strategically longer present(Figure 50). The goal is to sample manholes. Accurate storm drain isolate the discharge between two storm maps are needed for all three options. If drain manholes. good mapping is not available, dye tracing Table • • • Attack the StormNetwork Method Nature of Investigation Drainage System Advance Prep Required Follow the Narrow source of an individual Small diameter outfall (< 36") No discharge up discharge Simple drainage network Large diameter outfall (> 36"), Split into Narrow source of a discharge Complex drainage Yes segments identified at outfall Logistical or traffic issues may make sampling difficult. Move down Multiple types of pollution, many suspected problems— possibly Very large drainage area (>one the storm Yes due to old plumbing practices or square mile). drain number of NPDES permits Source narrowed to this LIL trunk section 3 tl manhole checked—no flow, no obvious indicators 1"and2"manholes checked— illicit discharge present Discharge observed at outfall Figure 50: Example Investigation Following the Source up the Storm Drain System 148 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 13: Tracking Discharges To a Source Option 2: Split the storm drain network 6. If narrowed to a contributing branch, When splitting the storm drain network, move up or split the branch until a field crews select strategic manholes at specific pipe segment is isolated, and junctions in the storm drain network to commence the appropriate on-site isolate discharges. This option is particularly investigation to determine the suited in larger and more complex drainage source. areas since it can limit the total number of manholes to inspect, and it can avoid Option 3: Move down the storm drain locations where access and traffic are network problematic. In this option, crews start by inspecting manholes at the"headwaters" of the storm The method for splitting the trunk is as drain network, and progressively move follows: down pipe. This approach works best in very large drainage areas that have many 1. Review a map of the storm drain potential continuous and/or intermittent network leading to the suspect discharges. The Boston Water and Sewer outfall. Commission has employed the headwater 2. Identify major contributing branches option to investigate intermittent discharges to the trunk. The trunk is defined as in complex drainage areas up to three square the largest diameter pipe in the storm miles (Jewell, 2001). Field crews certify that drain network that leads directly to each upstream branch of the storm drain the outfall. The "branches" are network has no contributing discharges networks of smaller pipes that before moving down pipe to a"junction contribute to the trunk. manhole" (Figure 52). If discharges are 3. Identify manholes to inspect at the found, the crew performs dye testing to farthest downstream node of each pinpoint the discharge. The crew then contributing branch and one confirms that the discharge is removed immediately upstream (Figure 51). before moving farther down the pipe 4 Working up the network, investigate network. Figure 53 presents a detailed flow manholes on each contributing chart that describes this option for analyzing branch and trunk,until the source is the storm drain network. narrowed to a specific section of the trunk or contributing branch. 5. Once the discharge is narrowed to a specific section of trunk, select the appropriate on-site investigation method to trace the exact source. Illicit Discharge Detection and Elimination:A Guidance Manual 149 Chapter 13: Tracking Discharges To a Source Legend: O Manhole Outfall Storm Drain OInitial Sampling Point Figure 51: Key initial sampling points along the trunk of the storm drain 150 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 13: Tracking Discharges To a Source [.agced •ttonlode Juncture mamole —Sionn Drain Dj=bon offlow Figure 52: Storm Drain Schematic Identifying "Juncture Manholes" (Source: Jewell, 2001) DoW onto Sturm Drain Juncture Open Storm Crain Manhde No Cry Weather Flow Cry Weather Flow Centaminetlon NoContmrtinatlan Contownhaton No Contamination Oltaarred Otrsarved Observed Observed SNsct Rich Sandbag Manhole SelmaRaadi Uae Fkdd Kit saw Seatlon Flaw Captured No flow Captured Sheet Secaon Evidence of No Evkena oT Contemin0on Contamination Dye Teat Evidence at No EvidenceW Proceed Dye Test- Select Reach Proceed Contaminadon Conteminetan Need Next Coxnatreem Oownstraam Juncture Juncarro Select Reach ilea Field U Seled Secdon Selaclt Section Evldente of No Evfdencs of Oye Teat Contominallen Contamktatlon CyaTeat SeiectReach Proceed Neat povemerrem Juncturo Select Secdon Gye Test Figure 53: A Process for Following Discharges Down the Pipe (Source: Jewell, 2001) Illicit Discharge Detection and Elimination:A Guidance Manual 151 Chapter 13: Tracking Discharges To a Source Dye Testing to Create a Storm Drain crews need to be careful about how they will Map safely divert traffic (Figure 54). Other safety considerations include proper lifting of As noted earlier, storm drain network manhole covers to reduce the potential for investigations are extremely difficult to back injuries, and testing whether any toxic perform if accurate storm drain maps are not or flammable fumes exist within the manhole available. In these situations, field crews before the cover is removed. Wayne County, may need to resort to dye testing to MI has developed some useful operational determine the flowpath within the storm procedures for inspecting manholes, which drain network. Fluorescent dye is introduced are summarized in Table 55. into the storm drain network and suspected manholes are then inspected to trace the path Table 54: Basic Field Equipment Checklist of flow through the network(U.S. EPA, 1990 . Two or three member crews are Camera and film Storm drain, stream, or digital camera and street maps needed for dye testing. One person drops the dye into the trunk while the other(s) looks 0 Clipboards 0 Reflective safety vests for evidence of the dye down pipe. Field sheets 0 Rubber/ latex gloves To conduct the investigation, a point of 0 Field vehicle 0 Sledgehammer interest or down pipe"stopping point" is 0 First aid kit . Spray paint identified. Dye is then introduced into manholes upstream of the stopping point to Flashlight or spotlight 0 Tape measures determine if they are connected. The process continues in a systematic manner until an Gas monitor and probe Traffic cones upstream manhole can no longer be determined, whereby a branch or trunk of Manhole hook/ 0 Two-way radios the system can be defined, updated or crow bar corrected. More information on dye testing . Mirror • Waterproof methods is provided in Section 13.3. marker/pen Hand held global positioning satellite (GPS) system receiver (best resolution available within Manhole Inspection: Visual budget, at least 6' accuracy) Observations and Indicator Sampling Two primary methods are used to MA& characterize discharges observed during manhole inspections—visual observations and indicator sampling. In both methods, field crews must first open the manhole to 4 _ determine whether an illicit discharge is present. Manhole inspections require a crew of two and should be conducted during dry weather conditions. Basic field equipment and safety procedures Figure 54: Traffic cones divert traffic required for manhole inspections are from manhole inspection area outlined in Table 54. In particular, field 152 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 13: Tracking Discharges To a Source FieldTable 55: Procedure for Removal of Manhole Covers (Adapted from:Pomeroy et a L, 1996) Field Procedures: 1. Locate the manhole cover to be removed. 2. Divert road and foot traffic away from the manhole using traffic cones. 3. Use the tip of a crowbar to lift the manhole cover up high enough to insert the gas monitor probe. Take care to avoid creating a spark that could ignite explosive gases that may have accumulated under the lid. Follow procedures outlined for the gas monitor to test for accumulated gases. 4. If the gas monitor alarm sounds, close the manhole immediately. Do not attempt to open the manhole until some time is allowed for gases to dissipate. 5. If the gas monitor indicates the area is clear of hazards, remove the monitor probe and position the manhole hook under the flange. Remove the crowbar. Pull the lid off with the hook. 6. When testing is completed and the manhole is no longer needed, use the manhole hook to pull the cover back in place. Make sure the lid is settled in the flange securely. 7. Check the area to ensure that all equipment is removed from the area prior to leaving. Safety Considerations: 1. Do not lift the manhole cover with your back muscles. 2. Wear steel-toed boots or safety shoes to protect feet from possible crushing injuries that could occur while handling manhole covers. 3. Do not move manhole covers with hands or fingers. 4. Wear safety vests or reflective clothing so that the field crew will be visible to traffic. 5. Manholes may only be entered by properly trained and equipped personnel and when all OSHA and local rules are followed. Visual Observations During Manhole drain network to look for contaminated Inspection e flows. Key visual observations that are made Visual observations are used to observe during manhole inspections include: conditions in the manhole and look for any signs of sewage or dry weather flow. Visual • Presence of flow observations work best for obvious illicit • Colors discharges that are not masked by • Odors groundwater or other"clean" discharges, as • Floatable materials shown in Figure 55. Typically, crews • Deposits or stains (intermittent flows) progressively inspect manholes in the storm 1 � Figure 55: Manhole observation (left) indicates a sewage discharge. Source is identified at an adjacent sewer manhole that overflowed into the storm drain system (right). Illicit Discharge Detection and Elimination:A Guidance Manual 153 Chapter 13: Tracking Discharges To a Source Indicator Sampling Figure 57 profiles a storm drain network If dry weather flow is observed in the investigation that used ammonia as the manhole, the field crew can collect a sample indicator parameter and a benchmark by attaching a bucket or bottle to a tape concentration of 1.0 mg/L. At both the measure/rope and lowering it into the outfall and the first manhole up the trunk, manhole (Figure 56). The sample is then field crews recorded finding"hits" for immediately analyzed in the field using ammonia of 2.2 mg/L and 2.3 mg/L, probes or other tests to get fast results as to respectively. Subsequent manhole whether the flow is clean or dirty. The most inspections further up the network revealed common indicator parameter is ammonia, one manhole with no flow, and a second although other potential indicators are with a hit for ammonia(2.4 mg/L). The crew described in Chapter 12. then tracked the discharge upstream of the second manhole, and found a third manhole Manhole indicator data is analyzed by with a low ammonia reading (0.05 mg/L) looking for"hits,"which are individual and a fourth with a much higher reading (4.3 samples that exceed a benchmark mg/L). The crew then redirected its effort to concentration. In addition, trends in sample above the fourth manhole with the indicator concentrations are also examined 4.3 mg/L concentration, only to find another throughout the storm drain network. low reading. Based on this pattern, the crew concluded the discharge source was located between these two manholes, as nothing else could explain this sudden increase in concentration over this length of pipe. The results of storm drain network investigations should be systematically documented to guide future discharge investigations, and describe any infrastructure maintenance problems �k encountered. An example of a sample manhole inspection field log is displayed in - Figure 58. Figure 56: Techniques to Sample from the Storm Drain 154 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 13: Tracking Discharges To a Source 0.07 4.30 2.40 "" No Flow 2.20 Legend: Manhole �\ Outfall Storm Drain-Discharge Unlikely Storm Drain-Probable Discharge Sampling Point with Concentration ..., (NH3) X Sampling Point with a"Hit" Figure 57: Use of Ammonia as a Trace Parameter to Identify an Illicit Discharge Illicit Discharge Detection and Elimination:A Guidance Manual 155 Chapter 13: Tracking Discharges To a Source BOSTON WATER AND SEWER COMMISSION Manhole MANHOLE INSPECTION LOG ID No. Inspectdon Date: Tributary Area Street: Manhole Type: Inspection: Not Found_Surface_Internal_ Sanitary Sewer Storm Drain Follow Up Inspection High Outlet Lovejoy Time Since Last Rain: Inspector: a 48 hours 48-72 hours >72 hours Observations: Standing Water in Manhole: Yes_No—Color of Water. Clear—Cloudy____Other Flow in Manhole: Yes_No_Velocity: Slow_Medium_Fast_Depth of Flow: in, Color of Flow, No Flow: Clear Cloudy Suspended Solids r____Other Blockages: Yes,No_Sediment in Manhole: Yes_No_ If Yes: Percent of Pipe Fitled: % Floatables: None______ Sewage_Oily Sheen Foam_Other Odor: None_Sewage Oil —soap Other Field Testing: pH Temp_ Spec.C*n4-_ SinFacteats Yes— No^ Arnnwnia Yes No Contamination: Found During Inspection Yes_ Check one: Observation positive Test Kit Result No Sandbagged Placed No_ Yes_ Give Pare Sandbag Checked(Date): Flow was Captured _Not Captured: Condition of Manhole: Common Manholes: Grade: At Above—Below High Outlet:Blocked Yes No— NA Lovejoy:Cover Plate in Place Yes_ No NA Good Fair Poor Comments Pavement Coves Construction Matcrw: Frame Brick Precast Other Corbel — Walls Floor — Comments: Manhole Correct as Mapped Yes No Nr Plan of Manhole Figure 58: Boston Water and Sewer Commission Manhole Inspection Log (Source: Jewell, 2001) 156 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 13: Tracking Discharges To a Source Methods to isolate intermittent Sandbags are typically left in place for no discharges in the storm drain network more than 48 hours, and should only be installed when dry weather is forecast. Intermittent discharges are often challenging Sandbags should not be left in place during a to trace in the storm drain network, although heavy rainstorm. They may cause a four techniques have been used with some blockage in the storm drain, or,they may be success. washed downstream and lost. The biggest downside to sandbagging is that it requires Sandbags at least two trips to each manhole. This technique involves placement of sandbags or similar barriers within strategic Optical Brightener Monitoring (OBM) manholes in the storm drain network to form Traps a temporary dam that collects any Optical brightener monitoring (OBM)traps, intermittent flows that may occur. Any flow profiled in Chapter 12, can also be used to collected behind the sandbag is then detect intermittent flows at manhole assessed using visual observations or by junctions. When these absorbent pads are indicator sampling. Sandbags are lowered on anchored in the pipe to capture dry weather a rope through the manhole to form a dam flows, they can be used to determine the along the bottom of the storm drain, taking presence of flow and/or detergents. These care not to fully block the pipe (in case it OBM traps are frequently installed by rains before the sandbag is retrieved). lowering them into an open-grate drop inlet Sandbags are typically installed at junctions or storm drain inlet, as shown in Figure in the network to eliminate contributing 60.The pads are then retrieved after 48 hours branches from further consideration (Figure and are observed under a fluorescent light 59). If no flow collects behind the sandbag, (this method is most reliable for undiluted the upstream pipe network can be ruled out washwaters). as a source of the intermittent discharge. Sandia Sand Sandbag Flow Sandbm Flow IF Flow Figure 59: Example Sandbag Placement (Source: Jewell, 2001) Illicit Discharge Detection and Elimination:A Guidance Manual 157 Chapter 13: Tracking Discharges To a Source _. 13.2 Drainage Area { Investigations The source of some illicit discharges can be _ determined through a survey or analysis of the drainage area of the problem outfall. The w simplest approach is a rapid windshield JV _ surveyof the drainage area to find the g potential discharger or generating sites. A more sophisticated approach relies on an {� analysis of available GIS data and permit Figure 60: Optical Brightener Placement in the Storm Drain databases to identify industrial or other (Source:Sargent and Castonguay, 1998) generating sites. In both cases, drainage area investigations are only effective if the Automatic Samplers discharge observed at an outfall has distinct A few communities have installed or unique characteristics that allow crews to automated samplers at strategic points quickly ascertain the probable operation or within the storm drain network system that business that is generating it. Often, are triggered by small dry weather flows and discharges with a unique color, smell, or off- collect water quality samples of intermittent the-chart indicator sample reading may point discharges. Automated sampling can be to a specific industrial or commercial extremely expensive, and is primarily used source. Drainage area investigations are not in very complex drainage areas that have helpful in tracing sewage discharges, since severe intermittent discharge problems. they are often not always related to specific Automated samplers can pinpoint the land uses or generating sites. specific date and hours when discharges occur, and characterize its chemical Rapid Windshield Survey composition, which can help crews fingerprint the generating source. A rapid drive-by survey works well in small drainage areas,particularly if field crews are Observation of Deposits or Stains already familiar with its business operations. Intermittent discharges often leave deposits Field crews try to match the characteristics or stains within the storm drain pipe or of the discharge to the most likely type of manhole after they have passed. Thus, crews generating site, and then inspect all of the should note whether any deposits or stains sites of the same type within the drainage are present in the manhole, even if no dry area until the culprit is found. For example, weather flow is observed. In some cases,the if fuel is observed at an outfall, crews might origin of the discharge can be surmised by quickly check every business operation in collecting indicator samples in the water the catchment that stores or dispenses fuel. ponded within the manhole sump. Stains and Another example is illustrated in Figure 61 deposits,however, are not always a where extremely dense algal growth was c observed in a small stream during the conclusive way to trace intermittent discharges in the storm drain network. winter. Field crews were aware of a fertilizer storage site in the drainage area, and a quick inspection identified it as the culprit. 158 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 13: Tracking Discharges To a Source F' ,i 111 ii .4 r Figure 61: Symptom (left): Extreme algal growth; Diagnosis (right): Cracked fertilizer storage is the phosphorus source A third example of the windshield survey approach is shown in Figure 62, where a operations or generating sites that could be very thick, sudsy and fragrant discharge was potential dischargers. Some of the key noted at a small outfall. The discharge discharge indicators that are associated with appeared to consist of wash water, and the hotspots and specific industries are reviewed only commercial laundromat found in Appendix K. upstream was confirmed to be the source. On-site testing may still be needed to 13.3 On-site Investigations identify the specific plumbing or connection generating the discharge. On-site investigations are used to pinpoint the exact source or connection producing a Detailed Drainage Area Investigations discharge within the storm drain network. The three basic approaches are dye, video and In larger or more complex drainage areas, smoke testing. While each approach can GIS data can be analyzed to pinpoint the determine the actual source of a discharge, source of a discharge. If only general land each needs to be applied under the right use data exist, maps can at least highlight conditions and test limitations(see Table 56). suspected industrial areas. If more detailed It should be noted that on-site investigations SIC code data are available digitally, the are not particularly effective in finding GIS can be used to pull up specific hotspot indirect discharges to the storm drain network. LON Figure 62: The sudsy, fragrant discharge (left) indicates that the laundromat is the more likely culprit than the florist(right). Illicit Discharge Detection and Elimination:A Guidance Manual 159 Chapter 13: Tracking Discharges To a Source Table • • Locate the Discharge Technique Best Applications Limitations • Discharge limited to a very small drainage area (<10 properties is ideal) Dye Testing Discharge probably caused by a May be difficult gain access connection from an individual property to some properties • Commercial or industrial land use Continuous discharges Relatively expensive equipment • Discharge limited to a single pipe Cannot capture non-flowing Video segment discharges Testing Communities who own equipment for • Often cannot capture other investigations discharges from pipes submerged in the storm drain • Cross-connection with the sanitary sewer 0 Poor notification to public can Smoke Testing Identifying other underground sources cause alarm (e.g., leaking storage techniques)caused 9 Cannot detect all illicit by damage to the storm drain discharges TIP The Wayne County Department of the ,� a Environment provides excellent training materials on on-site investigations, as well a as other illicit discharge techniques. More information about this training can be accessed from their website: Http://www.wcdoe.org/Watershed/Program , s Srvcs /IDEP/idep.htm. Figure 63: Dye Testing Plumbing Dye Testing (NIWPC, 2003) Dye testing is an excellent indicator of illicit document their legal authority to gain access connections and is conducted by introducing to the property. If time permits, the letter can non-toxic dye into toilets, sinks, shop drains be sent in advance of the dye testing. For and other plumbing fixtures (see Figure 63). residential properties, communication can be The discovery of dye in the storm drain, more challenging. Unlike commercial rather than the sanitary sewer, conclusively properties, crews are not guaranteed access determines that the illicit connection exists. to homes, and should call ahead to ensure that the owner will be home on the day of Before commencing dye tests, crews should testing. review storm drain and sewer maps to identify lateral sewer connections and how Communication with other local agencies is they can be accessed. In addition,property also important since any dye released to the owners must be notified to obtain entry storm drain could be mistaken for a spill or permission. For industrial or commercial pollution episode. To avoid a costly and properties, crews should carry a letter to embarrassing response to a false alarm, 160 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 13: Tracking Discharges To a Source crews should contact key spill response three staff may be preferred, with two staff agencies using a"quick fax"that describes entering the private residence or building for when and where dye testing is occurring both safety and liability purposes. (Tuomari and Thomson, 2002). In addition, crews should carry a list of phone numbers The basic equipment to conduct dye tests is to call spill response agencies in the event listed in Table 57 and is not highly dye is released to a stream. specialized. Often, the key choice is the type of dye to use for testing. Several options are At least two staff are needed to conduct dye profiled in Table 58. In most cases, liquid tests —one to flush dye down the plumbing dye is used, although solid dye tablets can fixtures and one to look for dye in the also be placed in a mesh bag and lowered downstream manhole(s). In some cases, into the manhole on a rope (Figure 64). Table . Equipment for • (Source: - County, MI, 2000) Maps, Documents • Sewer and storm drain maps (sufficient detail to locate manholes) • Site plan and building diagram • Letter describing the investigation • Identification (e.g., badge or ID card) • Educational materials (to supplement pollution prevention efforts) • List of agencies to contact if the dye discharges to a stream. • Name of contact at the facility Equipment to Find and Lift the Manhole Safely (small manhole often in a lawn) • Probe • Metal detector • Crow bar • Safety equipment (hard hats, eye protection, gloves, safety vests, steel-toed boots, traffic control equipment, protective clothing, gas monitor) Equipment for Actual Dye Testing and Communications • 2-way radio • Dye (liquid or"test strips") • High powered lamps or flashlights • Water hoses • Camera 47 1. f N Figure 64: Dye in a mesh bag is placed into an upstream manhole (left); Dye observed at a downstream manhole traces the path of the storm drain (right) Illicit Discharge Detection and Elimination:A Guidance Manual 161 Chapter 13: Tracking Discharges To a Source If a longer pipe network is being tested, and The basic drill for dye tests consists of three dye is not expected to appear for several simple steps. First, flush or wash dye down hours, charcoal packets can be used to detect the drain, fixture or manhole. Second,pop the dye (GCHD, 2002). Charcoal packets open downgradient sanitary sewer manholes can be secured and left in place for a week and check to see if any dye appears. If none or two, and then analyzed for the presence is detected in the sewer manhole after an of dye. Instructions for using charcoal hour or so, check downgradient storm drain packets in dye testing can be accessed at the manholes or outfalls for the presence of dye. following website: Although dye testing is fairly straightforward, hgp://bayinfo.tamug.tamu.edu/gbeppubs/ms some tips to make testing go more smoothly 4.pdf. are offered in Table 59. TestingTable 58: Dye Options Product Applications • Compressed powder, useful for releasing dye over time • Less messy than powder form • Easy to handle, no mess, quick dissolve Dye Tablets 0 Flow mapping and tracing in storm and sewer drains • Plumbing system tracing • Septic system analysis • Leak detection • Very concentrated, disperses quickly • Works well in all volumes of flow Liquid Recommended when metering of input is required Concentrate Flow mapping and tracing in storm and sewer drains • Plumbing system tracing • Septic system analysis • Leak detection Dye Strips Similar to liquid but less messy • Can be very messy and must dissolve in liquid to reach full potential Powder Recommended for very small applications or for very large applications where liquid is undesirable • Leak detection Dye Wax Recommended for moderate-sized bodies of water Cakes Flow mapping and tracing in storm and sewer drains Dye Wax Recommended for large sized bodies of water(lakes, rivers, ponds) Donuts Flow mapping and tracing in storm and sewer drains • Leak detection 162 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 13: Tracking Discharges To a Source •le 59: Tips for • (Adapted from Tdomad and Thompson,2002) Dye Selection • Green and liquid dyes are the easiest to see. • Dye test strips can be a good alternative for residential or some commercial applications. (Liquid can leave a permanent stain). • Check the sanitary sewer before using dyes to get a "base color." In some cases, (e.g., a print shop with a permitted discharge to the sanitary sewer), the sewage may have an existing color that would mask a dye. • Choose two dye colors, and alternate between them when testing multiple fixtures. Selecting Fixtures to Test • Check the plumbing plan for the site to isolate fixtures that are separately connected. • For industrial facilities, check most floor drains (these are often misdirected). • For plumbing fixtures, test a representative fixture (e.g., a bathroom sink). • Test some locations separately (e.g., washing machines and floor drains), which may be misdirected. • If conducting dye investigations on multiple floors, start from the basement and work your way up. • At all fixtures, make sure to flush with plenty of water to ensure that the dye moves through the system. Selecting a Sewer Manhole for Observations • Pick the closest manhole possible to make observations (typically a sewer lateral). • If this is not possible, choose the nearest downstream manhole. Communications Between Crew Members • The individual conducting the dye testing calls in to the field person to report the color dye used, and when it is dropped into the system. • The field person then calls back when dye is observed in the manhole. • If dye is not observed (e.g., after two separate flushes have occurred), dye testing is halted until the dye appears. Locating Missing Dye • The investigation is not complete until the dye is found. Some reasons for dye not appearing include: • The building is actually hooked up to a septic system. • The sewer line is clogged. • There is a leak in the sewer line or lateral pipe. Video Testing Video testing is useful when access to properties is constrained, such as residential Video testing works by guiding a mobile neighborhoods. Video testing can also be video camera through the storm drain pipe expensive, unless the community already to locate the actual connection producing an owns and uses the equipment for sewer illicit discharge. Video testing shows flows inspections. This technique will not detect and leaks within the pipe that may indicate all types of discharges,particularly when the an illicit discharge, and can show cracks and illicit connection is not flowing at the time other pipe damage that enable sewage or of the video survey. contaminated water to flow into the storm drain pipe. Different types of video camera equipment are used, depending on the diameter and condition of the storm sewer being tested. Illicit Discharge Detection and Elimination:A Guidance Manual 163 Chapter 13: Tracking Discharges To a Source Field crews should review storm drain maps, and 66).If the storm drain has ponded water, and preferably visit the site before selecting the camera should be attached to a raft, the video equipment for the test. A field visit which floats through the storm sewer from helps determine the camera size needed to one manhole to the next. To see details of fit into the pipe, and if the storm drain has the sewer,the camera and lights should be standing water. able to swivel both horizontally and vertically. A video record of the inspection In addition to standard safety equipment should be made for future reference and required for all manhole inspections, video repairs (see Figure 67). testing requires a Closed-Circuit Television (CCTV) and supporting items. Many Smoke Testing commercially available camera systems are specifically adapted to televise storm Smoke testing is another"bottom up" sewers,ranging from large truck or van- approach to isolate illicit discharges. It mounted systems to much smaller portable works by introducing smoke into the storm cameras. Cameras can be self-propelled or drain system and observing where the smoke towed. Some specifications to look for surfaces. The use of smoke testing to detect include: illicit discharges is a relatively new application, although many communities • The camera should be capable of have used it to check for infiltration and radial view for inspection of the top, inflow into their sanitary sewer network. bottom, and sides of the pipe and for Smoke testing can find improper looking up lateral connections. connections, or damage to the storm drain • The camera should be color. • Lighting should be supplied by a lamp on the camera that can light the entire periphery of the pipe. When inspecting the storm sewer, the CCTV is oriented to keep the lens as close as possible to the center of the pipe. The camera can be self-propelled through the pipe using a tractor or crawler unit or it may be Figure 66: Tractor-mounted towed through on a skid unit(see Figures 65 Camera Figure 65: Camera being towed Figure 67: Review of an Inspection Video 164 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 13: Tracking Discharges To a Source system (Figure 68). This technique works newspaper, and radio). On the actual day of best when the discharge is confined to the testing, local fire,police departments and upper reaches of the storm drain network, 911 call centers should be notified to handle where pipe diameters are to small for video any calls from the public (Hurco testing and gaining access to multiple Technologies, Inc., 2003). properties renders dye testing infeasible. The basic equipment needed for smoke Notifying the public about the date and testing includes manhole safety equipment, a purpose of smoke testing before starting is smoke source, smoke blower, and sewer critical. The smoke used is non-toxic, but plugs. Two smoke sources can be used for can cause respiratory irritation, which can be smoke testing. The first is a smoke "bomb," a problem for some residents. Residents or"candle"that burns at a controlled rate should be notified at least two weeks prior to and releases very white smoke visible at testing, and should be provided the relatively low concentrations (Figure 69). following information (Hurco Technologies, Smoke bombs are suspended beneath a Inc., 2003): blower in a manhole. Candles are available in 30 second to three minute sizes. Once • Date testing will occur opened, smoke bombs should be kept in a • Reason for smoke testing dry location and should be used within one • Precautions they can take to prevent year. smoke from entering their homes or businesses The second smoke source is liquid smoke, • What they need to do if smoke enters which is a petroleum-based product that is their home or business, and any health injected into the hot exhaust of a blower concerns associated with the smoke where it is heated and vaporized (Figure 70). • A number residents can call to relay The length of smoke production can vary any particular health concerns (e.g., depending on the length of the pipe being chronic respiratory problems) tested. In general, liquid smoke is not as consistently visible and does not travel as far Program managers should also notify local as smoke from bombs (USA Blue Book). media to get the word out if extensive smoke testing is planned (e.g., television, SA00KE 3 _ — r 'A A'vHGLE � rr 'Y C F .r E• cP Lyre' - 1`ti--.•'7 __ `+''• - �Aa - Figure 68: Smoke Testing System Figure 69: Smoke Candles Schematic Illicit Discharge Detection and Elimination:A Guidance Manual 165 Chapter 13: Tracking Discharges To a Source available, and may be inserted from the . ground surface. 'r Blowers should be set up next to the open manhole after the smoke is started. Only one manhole is tested at a time. If smoke candles -77n" are used, crews simply light the candle, place it in a bucket, and lower it in the manhole. The crew then watches to see where smoke escapes from the pipe. The __:..�.. �� �'� ` two most common situations that indicate an illicit discharge are when smoke is seen Figure 70: Smoke Blower rising from internal plumbing fixtures (typically reported by residents) or from Smoke blowers provide a high volume of air sewer vents (Figure 71). Sewer vents extend that forces smoke through the storm drain upward from the sewer lateral to release gas pipe. Two types of blowers are commonly buildup, and are not supposed to be used: "squirrel cage"blowers and direct- connected to the storm drain system. drive propeller blowers. Squirrel cage blowers are large and may weigh more than 100 pounds, but allow the operator to generate more controlled smoke output. Direct-drive propeller blowers are considerably lighter and more compact, which allows for easier transport and positioning. Three basic steps are involved in smoke testing. First, the storm drain is sealed off by plugging storm drain inlets. Next, the smoke is released and forced by the blower through the storm drain system. Lastly, the crew Figure 71: Smoke Rising from looks for any escape of smoke above-ground Sewer Vent to find potential leaks. One of three methods can be used to seal off 13.4 Septic System Investigations the storm drain. Sandbags can be lowered into place with a rope from the street The techniques for tracing illicit discharges surface. Alternatively, beach balls that have are different in rural or low-density a diameter slightly larger than the drain can residential watersheds. Often, these be inserted into the pipe. The beach ball is watersheds lack sanitary sewer service and then placed in a mesh bag with a rope storm water is conveyed through ditches or attached to it so it can be secured and swales,rather than enclosed pipes. retrieved. If the beach ball gets stuck in the Consequently, many illicit discharges enter pipe, it can simply be punctured, deflated the stream as indirect discharges, through and removed. Finally, expandable plugs are surface breakouts of septic fields or through 166 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 13: Tracking Discharges To a Source straight pipe discharges from bypassed Table 60 highlights some common questions septic systems. to ask in the survey,which inquire about resident behaviors, system performance and The two broad techniques used to find maintenance activity. individual septic systems -- on-site investigations and infrared imagery—are Surface Condition Analysis described in this section. The surface condition analysis is a rapid site assessment where field crews look for On-Site Septic Investigations obvious indicators that point to current or potential production of illicit discharges by Three kinds of on-site investigations can be the septic system (Figure 72). Some of the performed at individual properties to key surface conditions to analyze have been determine if the septic system is failing, described by Andrews et al., (1997) and are including homeowner survey, surface described below: condition analysis and a detailed system inspection. The first two investigations are • Foul odors in the yard rapid and relatively simple assessments • Wet, spongy ground; lush plant typically conducted in targeted watershed growth; or burnt grass near the drain areas. Detailed system inspections are a field much more thorough investigation of the • Algal blooms or excessive weed functioning of the septic system that is growth in adjacent ditches, ponds and conducted by a certified professional. streams Detailed system inspections may occur at • Shrubs or trees with root damage time of sale of a property, or be triggered by within 10 feet of the system poor scores on the rapid homeowner survey • Cars, boats, or other heavy objects or surface condition analysis. located over the field that could crush lateral pipes Homeowner Survey • Storm water flowing over the drain The homeowner survey consists of a brief field interview with the property owner to • Cave-ins or exposed system determine the potential for current or future components failure of the septic system, and is often • Visible liquid on the surface of the done in conjunction with a surface condition drain field(e.g., surface breakouts) analysis. • Obvious system bypasses (e.g., straight pipe discharges) Table .0: Septic System HomeownerQuestions (Adapted from Andrews et al., 1997 and Holmes Inspection Services) • How many people live in the house?' • What is the septic tank capacity?z • Do drains in the house empty slowly or not at all? • When was the last time the system was inspected or maintained? • Does sewage back up into the house through drain lines? • Are there any wet, smelly spots in the yard? • Is the septic tank effluent piped so it drains to a road ditch, a storm sewer, a stream, or is it connected to a farm drain tile? Water usage ranges from 50 to 100 gallons per day per person. This information can be used to estimate the wastewater load from the house (Andrews et. al, 1997). 2 The septic tank should be large enough to hold two days' worth of wastewater (Andrews et. al, 1997). Illicit Discharge Detection and Elimination:A Guidance Manual 167 Chapter 13: Tracking Discharges To a Source Figure 72: (a)Wet, spongy ground. Grass may be bright green or burnt due to high nutrient loading. (b) Straight pipe discharge to nearby stream. (c)Algal bloom in a nearby pond. (Sources:a-Anish Jantrania;b-Snohomish County, WA c-King County, WA) Detailed System Inspection r� ' The detailed system inspection is a much -AMP-= more thorough inspection of the t performance and function of the septic system, and must be completed by a certified professional. The inspector certifies the structural integrity of all components of the system, and checks the depth of solids in the septic tank to determine if the system needs to be pumped out. The inspector also Figure 73: Dye surfacing in a septic sketches the system, and estimates distance field to groundwater, surface water, and drinking Infrared Imagery water sources. An example septic system inspection form from Massachusetts can be Infrared imagery is a special type of found at photography with gray or color scales that htt2://www.state.ma.us/dep/bp2/wwm/soilsy represent differences in temperature and s.htm. emissivity of objects in the image Although not always incorporated into the (www.stocktoninfrared.com), and can be inspection, dye testing can sometimes point used to locate sewage discharges. Several to leaks from broken or direct different infrared imagery techniques can be pipes, used to identify illicit discharges. The discharges through straight pipes that might following discussion highlights two of these: be missed during routine inspection. Dye aerial infrared thermography13 and color can be introduced into plumbing fixtures in infrared aerial photography. the home, and flushed with sufficient running water. The inspector then watches the septic field,nearby ditches, watercourses Infrared Thermoaraph� and manholes for any signs of the dye Infrared thermography is increasingly being (Figure 73). The dye may take several hours used to detect illicit discharges and failing septic systems. The technique uses the to appear, so crews may want to place charcoal packets in adjacent waters to capture dye until they can return later to retrieve them. is Infrared thermography is also being used by communities such as Mecklenburg County and the City of Charlotte in NC to detect illicit discharges at outfalls. 168 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 13: Tracking Discharges To a Source temperature difference of sewage as a between receiving water and discharge marker to locate these illicit discharges. temperatures, and interference from Figure 74 illustrates the thermal difference vegetation is minimized (Stockton, 2004b). between an outfall discharge (with a higher In addition, flights should take place at night temperature) and a stream. to minimize reflected and direct daylight The equipment needed to conduct aerial solar radiation that may adversely affect the infrared thermography includes an aircraft imagery (Stockton, 2004b). (plane or helicopter); a high-resolution, large format, infrared camera with appropriate Color Infrared Aerial Photo_.rq aphV mount; a GPS unit; and digital recording Color infrared aerial photography looks for equipment. If a plane is used, a higher changes in plant growth, differences in soil resolution camera is required since it must moisture content, and the presence of operate at higher altitudes. Pilots should be standing water on the ground to primarily experienced since flights take place at night, identify failing septic systems (Figure 75). slowly, and at a low altitude. The camera may be handheld, but a mounted camera will The Tennessee Valley Authority (TVA)uses provide significantly clearer results for a color infrared aerial photography to detect larger area. The GPS can be combined with failing septic systems in reservoir a mobile mapping program and a video watersheds. Local health departments encoder-decoder that encodes and displays conduct follow-up ground-truthing surveys the coordinates, date, and time (Stockton, to determine if a system is actually failing 2000). The infrared data are analyzed after (Sagona, 1986). Similar to thermography, it the flight by trained analysts to locate is recommended that flights take place at suspected discharges, and field crews then night, during leaf-off conditions, or when inspect the ground-truthed sites to confirm the water table is at a seasonal high (which the presence of a failing septic system. is when most failures typically occur(U.S. EPA, 1999). Late fall,winter, and early spring are typically the best times of year to conduct these investigations in most regions of the country. This allows for a bigger difference Source:Mecklenburg County(NC) Water Quality Sdm » 1 4 ' 9 1 1 1 ! i 1 ' Figure 75: Dead vegetation and surface effluent Figure 74: Aerial Thermography Showing are evidence of a septic system surface failure. Sewage Leak (Source:U.S. EPA, 1999) Illicit Discharge Detection and Elimination:A Guidance Manual 169 Chapter 13: Tracking Discharges To a Source Costs for Dye, Video, and Smoke 13.5 The Cost to Trace Illicit Testing Discharge Sources The cost of smoke, dye, and video testing Tracing illicit discharges to their source can can be substantial and staff intensive, and be an elusive and complex process, and often depend on investigation specific precise staffing and budget data are difficult factors, such as the complexity of the drainage network, density and age of to estimate. Experience of Phase I NPDES communities that have done these buildings, and complexity of land use. Wayne County, MI, has estimated the cost investigations in the past can shed some of dye testing at$900 per facility. Video light on cost estimates. Some details on unit testing costs range from $1.50 to $2.00 per costs for common illicit discharge foot, although this increases by $1.00 per investigations are provided below. foot if pipe cleaning is needed prior to testing. Table 61 summarizes the costs of start-up equipment for basic manhole entry and inspection, which is needed regardless of which type of test is performed. Tables 62 through 64 provide specific equipment costs for dye, video and smoke testing, respectively. Table 61: Common Field Equipment Needed for Dye, • • and SmokeTesting Item Cost 1 Digital Camera $200 Clipboards, Pens, Batteries $25 1 Field vehicle $15,000 -$35,000 1 First aid kit $30 1 Spotlight $40 1 Gas monitor and probe $900- $2,100 1 Hand-held GPS Unit $150 2 Two-way radios $250- $750 1 Manhole hook $80- $130 1 Mirror $70- $130 2 Reflective safety vests $40 Rubber/latex gloves (box of 100) $25 1 Can of Spray Paint $5 4 Traffic Cones $50 170 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 13: Tracking Discharges To a Source Table • • • for • Product Water Volume Cost Dye Strips 1 strip /500 gallons $75 - $94 per 100 strips Dye Tablets 0—50,000 gallons $40 per 200 tablets Liquid Concentrate $80 - $90 per gallon (Rhodamine WT) 0—50,000 gallons $15 - $20 per pint Powder 50,000 + gallons $77 per lb Dye Wax Cakes 20,000—50,000 gallons $12 per one 1.25 ounce cake Dye Wax Donuts 50,000 + gallons $104 - $132 per 42 oz. donut Price Sources: Aquatic Eco-Systems http.//www.aquaticeco.com/ Cole Parmer http.-Iwww.coleparmer.com USA Blue Book http.-Iwww.usabluebook.com Table • Equipment Cost GEN-EYE 2TM B&W Sewer Camera with VCR& 200' $5,800 Push Cable 100' Push Rod and Reel Camera for 2"— 10" Pipes $5,300 200' Push Rod and Reel Camera for 8"—24" Pipes $5,800 Custom Saturn III Inspection System $32,000 500' cable for 6-16" Lines ($33,000 with 1000 foot cable) OUTPOST $6,000 • Box with build-out $2,000 • Generator $1,000 • Washdown system Video Inspection Trailer $18,500 • 7'xl0' trailer& build-out $15,000 • Hardware and software package $5,000 • Incidentals Sprinter Chassis Inspection Vehicle • Van (with build-out for inspecting 6"—24" pipes) $130,000 • Crawler(needed to inspect pipes >24") $18,000 • Software upgrade (optional but helpful for $8,000 extensive pipe systems) Sources: USA Blue Book and Envirotech Table Equipment Cost Smoke Blower $1,000 to $2,000 each Liquid Smoke $38 to $45 per gallon Smoke Candles, 30 second (4,000 cubic feet) $27.50 per dozen Smoke Candles, 60 Second (8,000 cubic feet) $30.50 per dozen Smoke Candles, 3 Minute (40,000 cubic feet) $60.00 per dozen Sources:Hurco Tech, 2003 and Cherne Industries, 2003 Illicit Discharge Detection and Elimination:A Guidance Manual 171 Chapter 13: Tracking Discharges To a Source Costs for Septic System Investigations Aerial Infrared Thermography The equipment needed to conduct aerial Most septic system investigations are infrared thermography is expensive; cameras relatively low cost, but factors such as alone may range from $250,000 to $500,000 private property access,notification, and the (Stockton, 2004a). However, private total number of sites investigated can contractors provide this service. In general, increase costs. Unit costs for the three major the cost to contract an aerial infrared septic system investigations are described thermography investigation depends on the below. length of the flight(flights typically follow streams or rivers);how difficult it will be to Homeowner Survey and Surface fly the route; the number of heat anomalies Condition Analysis expected to be encountered; the expected Both the homeowner survey and the surface post-flight processing time (typically, four to condition analysis are relatively low cost five hours of analysis for every hour flown); investigation techniques. Assuming that a and the distance of the site from the plane's staff person can investigate one home per "home" (Stockton, 2004a). The cost range is hour, the average cost per inspection is typically $150 to $400 per mile of stream or approximately $25. A substantial cost river flown, which includes the flight and savings can be realized by using interns or post-flight analyses (Stockton, 2004a). volunteers to conduct these simple investigations. As an alternative, local police departments may already own an infrared imaging Detailed System Inspection system that may be used. For instance, the Septic system inspections are more Arkansas Department of Health used a state expensive, but a typical unit cost is about police helicopter with a Forward Looking $250, and may also include an additional Infrared (FLIR) imaging system, GPS, video cost of pumping the system, at roughly equipment, and maps (Eddy, 2000). The $150, if pumping is required to complete the disadvantage to this is that the equipment inspection (Wayne County, 2003). This cost may not be available at optimal times to is typically charged to the homeowner as conduct the investigation. In addition, part of a home inspection. infrared imaging equipment used by police departments may not be sensitive enough to detect the narrow range of temperature difference (only a few degrees) often expected for sewage flows (Stockton, 2004a). 172 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 14: Techniques to Fix Discharges Chapter 1 4: Techniques to Fix Discharges Quick and efficient correction of illicit • How long will it take? discharges begins with having well defined • How will removal be confirmed? legal authority and responsibilities coupled with strong enforcement and follow-up The answer to each of these questions measures. Chapter 4 discussed important depends on the source of the discharge. considerations with respect to legal authority Illicit discharges generally originate from and responsibility and Appendix B contains one of the following sources: a model illicit discharge ordinance that provides language on violations, An internal plumbing connection (e.g., enforcement and penalties. the discharge from a washing machine is directed to the building's storm lateral; Most illicit discharge corrective actions the floor drain in a garage is connected involve some form of infrastructure to the building's storm lateral) modification or repair. These structural • A service lateral cross-connection(e.g., repairs are used to eliminate a wide variety the sanitary lateral from a building is of direct discharges such as sewage cross- connected to the MS4) connections, straight pipes, industrial cross- • An infrastructure failure within the connections, and commercial cross- sanitary sewer or MS4 (e.g., a collapsed connections. Fixes range from simple sanitary line is discharging into the plumbing projects to excavation and MS4) replacement of sewer lines. In some cases, • An indirect transitory discharge structural repairs are necessary when resulting from leaks, spills, or overflows. indirect discharges, such as sewage from a sewer break or pump station failure enter the Financial responsibility for source removal MS4 through an inlet, or flows directly into will typically fall on property owners,MS4 receiving waters. Most transitory operators, or some combination of the two. discharges are corrected simply with spill containment and clean-up procedures. Who's responsible for fixing the problem? Section 8.3 previously discussed an overview of the correction process. The Ultimate responsibility for removing the following section discusses more specific source of a discharge is generally that of correction considerations. either the property owner or the municipality/utility (e.g., primary 14.1 Implementation Considerations owner/operator of the MS4). Once the source of an illicit discharge has Internal Plumbing Connection been identified, steps should be taken to fix The responsibility for correcting an internal or eliminate the discharge. The following plumbing connection is generally the four questions should be answered for each responsibility of the building owner. individual illicit discharge to determine how Communities may wish to develop a list of to proceed: certified contractors that property owners can hire for corrections. • Who is responsible? • What methods will be used to fix it? Illicit Discharge Detection and Elimination:A Guidance Manual 173 Chapter 14: Techniques to Fix Discharges Service Lateral locations that occur outside of the building, As with internal plumbing connections, the such as service laterals or infrastructure in responsibility for correcting a problem the right of way, costs tend to be within a service lateral is typically that of significantly more due to specialized the property owner being served by the equipment needs. Certified contractors are lateral. However, the cost of correcting a recommended for these types of repairs. service lateral problem can be significantly Table 65 provides a summary of a range of higher than that of fixing an internal methods for fixing these more significant plumbing problem, so communities may problems along with estimated costs. The want to consider alternative remedial last six techniques described in Table 68 are approaches than those for internal plumbing used for sanitary sewer line repair and corrections. For example, communities can rehabilitation. These activities are typically have on-call contractors fix lateral used when there is evidence of significant connections allowing the problem to be seepage from the sanitary system to the fixed as soon as it is discovered. The storm drain system. community can then: 1)pay for correction costs through the capital budget, or state or How long should it take? federal funding options, or 2) share the cost with the owner, or 3)pass on the full cost to The timeframe for eliminating a connection the property owner. or discharge should depend on the type of connection or discharge and how difficult Infrastructure Failure Within the Sanitary elimination will be. A discharge that poses a Sewer or MS4 significant threat to human or environmental Illicit discharges related to some sort of health should be discontinued and infrastructure failure within the sanitary eliminated immediately. Clear guidance sewer or MS4 should be corrected by the should be provided in the local ordinance on jurisdiction, utility, or agency responsible the timeframe for removing discharges and for maintenance of the sewers and drains. connections. Typically, discharges should be stopped within seven days of notification by Transitory Discharge the municipality, and illicit connections Repair of transitory discharge sources will should be repaired within 30 days of usually be the responsibility of the property notification. owner where the discharge originates. Ordinances should clearly stipulate the time How is the removal or correction frame in which these discharges should be confirmed? repaired. Removal and correction of a discharge or What methods will be used to fix the connection should be confirmed both at the problem? source,to ensure that the correction has been made, and downstream, to ensure that it is The methods used to eliminate discharges the only local discharge present. will vary depending on the type of problem and the location of the problem. Internal For discharges resulting from internal plumbing corrections can often be plumbing and lateral connections, dye performed using standard plumbing supplies testing can confirm the correction. Also, for relatively little cost. For correction sandbagging should be done in the first 174 Illicit Discharge Detection and Elimination:A Guidance Manual Chapter 14: Techniques to Fix Discharges accessible storm drain manhole downstream sanitary sewer or MS4 can be verified by of the correction to verify that this was the dye testing or televising the line in only discharge present. conjunction with sandbagging and sampling at an accessible downstream manhole. The correction of discharges resulting from some sort of infrastructure failure in the Table •• • Eliminate Discharges Technique Application Description Estimated Cost 1. Service Lateral Lateral is connected to the Lateral is disconnected and Disconnection, wrong line reconnected to appropriate line $2,500 Reconnection Flushing (sending a high pressure 2. Cleaning Line is blocked or capacity water jet through the line); pigging $1 /linear foot2 diminished (dragging a large rubber plug through the lines); or rodding For 14" line, $504100 Line is collapsed, severely Existing pipe is removed, new pipe /linear foot (higher 3. Excavation and placed in same alignment; Existing number is associated blocked, significantly Replacement pipe abandoned in place, replaced with repaving or misaligned, or undersized by new pipe in parallel alignment deeper excavations, if necessary Decrease ponding; prevent Raise frame and lid above grade; Vary widely, from 4. Manhole flow of surface water into install lid inserts; grout, mortar or $250 to raise a frame Repair manhole; prevent apply shortcrete inside the walls; and cover to — $2,000 groundwater infiltration install new precast manhole. to replace manhole 5. Corrosion Improve resistance to Spray-or brush-on coating applied < $10/linear foot2 Control Coating corrosion to interior of pipe. 6. Grouting Seal leaking joints and Seals leaking joints and small For a 12" line, 2$36- small cracks cracks. $54/linear foot Existing pipe used as guide for inserting expansion head; expansion head increases area Line is collapsed, severely For 8" pipe, $40-$80/ 7. Pipe Bursting blocked, or undersized available for new pipe by pushing linear foot4 existing pipe out radially until it cracks; bursting device pulls new pipeline behind it Pipe has numerous cracks, leaking joints, but is Pulling of a new pipe through the For 12" pipe, $50-$75 8. Slip Lining continuous and not old one. /linear foot2 misaligned Similar to sliplining but is easier to install, uses existing manholes for 9. Fold and Pipe has numerous cracks, insertion; a folded thermoplastic For 8-12" pipe, $60- Formed Pipe leaking joints pipe is pulled into place and $78/linear foot3 rounded to conform to internal diameter of existing pipe Illicit Discharge Detection and Elimination:A Guidance Manual 175 Chapter 14: Techniques to Fix Discharges •le 65: Methods to Eliminate Discharges Technique Application Description Estimated Cost Similar to sliplining but is easier to Pipe has numerous cracks, install, uses existing manholes for 10. Inversion Lining leaking joints; can be used insertion; a soft resin impregnated $75-$125 /linear foot, where there are felt tube is inserted into the pipe, misalignments inverted by filling it with air or water at one end, and cured in place. 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Illicit Discharge Detection and Elimination:A Guidance Manual R-5 References R-6 Illicit Discharge Detection and Elimination:A Guidance Manual APPENDIX H NEW YO K Department of sTATr Environmental Conservation NEW YORK STATE DEPARTMENT OF ENVIRONMENTAL CONSERVATION (NYSDEC) SPDES GENERAL PERMIT FOR STORMWATER DISCHARGES From CONSTRUCTION ACTIVITY Permit No. GP-0-25-001 Construction General Permit (CGP) Issued Pursuant to Article 17, Titles 7, 8 and Article 70 of the Environmental Conservation Law Effective Date: January 29, 2025 Expiration Date: January 28, 2030 Scott E. Sheeley Chief Permit Administrator ��Wtzxr 45��- 11-11���� A0 . Z 2S Authorized Signature Date Address: NYSDEC Division of Environmental Permits 625 Broadway, 4th Floor Albany, N.Y. 12233-1750 PREFACE Pursuant to Section 402 of the Clean Water Act (CWA), and 40 CFR 122.26(b)(14)(x), (15)(i), and (15)(ii), stormwater discharges from certain construction activities are unlawful unless they are authorized by a National Pollutant Discharge Elimination System (NPDES) permit or by a state permit program. New York State administers the approved State Pollutant Discharge Elimination System (SPDES) program with permits issued in accordance with the New York State Environmental Conservation Law (ECL) Article 17, Titles 7 and 8, and Article 70, as well as 6 NYCRR Parts 621 and 750. Construction activities constitute construction of a point source and, therefore, pursuant to ECL sections 17-0505, 17-0701, and 17-0803, the owner or operator must have coverage under a SPDES permit prior to commencement of construction activities. The owner or operator cannot wait until there is an actual discharge from the construction site to obtain permit coverage. *Note: The italicized words/phrases within this permit are defined in Appendix A. NEW YORK STATE DEPARTMENT OF ENVIRONMENTAL CONSERVATION SPDES CONSTRUCTION GENERAL PERMIT (CGP) GP-0-25-001 FOR STORMWATER DISCHARGES FROM CONSTRUCTION ACTIVITIES Table of Contents Part I. How to Obtain Coverage and General Requirements ..................................... 5 A. Eligibility Requirements...................................................................................... 5 B. Types of Discharges Authorized ........................................................................ 9 C. Prohibited Discharges...................................................................................... 10 D. Electronic Notice of Intent (eNO1) Submittal..................................................... 10 E. General Requirements for Owners or Operators with Permit Coverage .......... 14 F. Permit Coverage for Discharges Authorized Under GP-0-20-001 .................... 18 G. Change of Owner or Operator.......................................................................... 19 Part II. Water Quality-Based Effluent Limitations..................................................... 20 A. Maintaining Water Quality................................................................................ 20 B. Effluent Limitations Applicable to Discharges from Construction Activities ...... 20 C. Post-Construction Stormwater Management Practice (SMP) Requirements ... 23 Part III. Stormwater Pollution Prevention Plan (SWPPP)......................................... 28 A. General SWPPP Requirements ....................................................................... 28 B. Required SWPPP Contents ............................................................................. 32 C. Required SWPPP Components by Project Type.............................................. 37 Part IV. Inspection and Maintenance Requirements ................................................ 37 A. General Construction Site Inspection and Maintenance Requirements ........... 37 B. Contractor Maintenance Inspection Requirements .......................................... 37 C. Qualified Inspector Inspection Requirements................................................... 38 Part V. How to Terminate CGP Coverage.................................................................. 43 A. Electronic Notice of Termination (eNOT) Submittal.......................................... 43 Part VI. Record Retention and Reporting.................................................................. 45 A. Record Retention ............................................................................................. 46 B. Reporting ......................................................................................................... 46 Part VII. Standard Permit Requirements ................................................................... 46 A. Duty to Comply................................................................................................. 46 B. Need to Halt or Reduce Activity Not a Defense................................................ 46 C. Penalties .......................................................................................................... 46 D. False Statements ............................................................................................. 47 E. Re-Opener Clause ........................................................................................... 47 F. Duty to Mitigate ................................................................................................ 47 G. Requiring Another General Permit or Individual SPDES Permit....................... 47 H. Duty to Provide Information.............................................................................. 49 I. Extension ......................................................................................................... 49 J. Signatories and Certification ............................................................................ 50 K. Inspection and Entry ........................................................................................ 52 L. Confidentiality of Information............................................................................ 53 M. Other Permits May Be Required ...................................................................... 53 N. NYSDEC Orders or Civil Decrees/Judgments.................................................. 53 O. Property Rights ................................................................................................ 53 P. Compliance with Interstate Standards.............................................................. 53 Q. Oil and Hazardous Substance Liability............................................................. 54 R. Severability....................................................................................................... 54 S. NYSDEC Approved Forms............................................................................... 54 APPENDIX A —Abbreviations and Definitions.......................................................... 55 Abbreviations............................................................................................................. 55 Definitions.................................................................................................................. 56 APPENDIX B — Required SWPPP Components by Project Type............................. 64 Table1 ....................................................................................................................... 64 Table2....................................................................................................................... 66 APPENDIX C —Watersheds Requiring Enhanced Phosphorus Removal............... 68 APPENDIX D — Impaired Waterbodies (by Construction Related Pollutants)........ 74 APPENDIX E — List of NYSDEC Regional Offices..................................................... 80 APPENDIX F — SWPPP Preparer Certification Form ................................................ 81 APPENDIX G — MS4 SWPPP Acceptance Form........................................................ 83 APPENDIX H — NYCDEP SWPPP Acceptance/Approval Form ................................ 86 APPENDIX I — MS4 No Jurisdiction Form.................................................................. 89 APPENDIX J — Owner/Operator Certification Form.................................................. 91 Part I. Part I. How to Obtain Coverage and General Requirements To be covered under this permit, the owner or operator must meet all eligibility requirements in Part I.A. and follow the requirements for obtaining permit coverage in Part I.D., F., or G. A. Eligibility Requirements For a common plan of development or sale, the phase(s) that meet the eligibility requirements in Part I.A. may obtain coverage under this permit even if other phase(s) of the same common plan of development or sale do not meet the eligibility requirements and require an individual SPDES permit. 1. The owner's or operator's construction activities involve soil disturbances of: a. one or more acres; or b. less than one acre which are part of a common plan of development or sale that will ultimately disturb one or more acres; or c. less than one acre where NYSDEC has determined that a SPDES permit is required for stormwater discharges based on the potential for contribution to a violation of a water quality standard or for significant contribution of pollutants to surface waters of the State. i. 5,000 square feet or more, but less than one acre, and are in the New York City Watershed located east of the Hudson River, Appendix C Figure 1; or ii. 20,000 square feet or more, but less than one acre, within the municipal boundaries of the City of New York (NYC); or iii. less than 20,000 square feet which are part of a common plan of development or sale that will ultimately disturb 20,000 square feet or more, but less than one acre, within the municipal boundaries of NYC; or iv. that creates 5,000 square feet or more of impervious area within the municipal boundaries of NYC. 5 Part I.A.2. 2. Discharges from the owner's or operator's construction activities are/were not: a. already covered by a different SPDES permit; or b. covered under a different SPDES permit that was denied, terminated, or revoked; or c. identified in an expired individual SPDES permit that was not renewed; or d. required to obtain an individual SPDES permit or another general SPDES permit in accordance with Part VII.K. 3. If construction activities may adversely affect a species that is endangered or threatened, the owner or operator must obtain a: a. permit issued pursuant to 6 NYCRR Part 182 for the project; or b. letter issued by NYSDEC of non-jurisdiction pursuant to 6 NYCRR Part 182 for the project. 4. If construction activities have the potential to affect an historic property, the owner or operator must obtain one of the following: a. documentation that the construction activity is not within an archeological buffer area indicated on the sensitivity map, and that the construction activity is not located on or immediately adjacent to a property listed or determined to be eligible for listing on the National or State Registers of Historic Places, and that there is no new permanent building on the construction site within the following distances from a building, structure, or object that is more than 50 years old, or if there is such a new permanent building on the construction site within those parameters that NYS Office of Parks, Recreation and Historic Preservation (OPRHP), a Historic Preservation Commission of a Certified Local Government, or a qualified preservation professional has determined that the building, structure, or object more than 50 years old is not historically/archeologically significant: i. 1-5 acres of disturbance - 20 feet; or ii. 5-20 acres of disturbance - 50 feet; or 6 Part I.A.4.a.iii. iii. 20+ acres of disturbance - 100 feet. b. NYSDEC consultation form sent to OPRHP,' and copied to NYSDEC's Agency Historic Preservation Officer (APO), and i. the State Environmental Quality Review Act (SEAR) Environmental Assessment Form (EAF) with a negative declaration or the Findings Statement, with documentation of OPRHP's agreement with the resolution; or ii. documentation from OPRHP that the construction activity will result in No Impact; or iii. documentation from OPRHP providing a determination of No Adverse Impact; or iv. a Letter of Resolution signed by the owner or operator, OPRHP and the DEC APO which allows for this construction activity to be eligible for coverage under the general permit in terms of the State Historic Preservation Act (SHPA). c. documentation of satisfactory compliance with Section 106 of the National Historic Preservation Act for a coterminous project area: i. No Affect; or ii. No Adverse Affect; or iii. Executed Memorandum of Agreement. d. documentation that SHPA Section 14.09 has been completed by NYSDEC or another state agency. 5. If construction activities are subject to SEAR, the owner or operator must obtain documentation that SEAR has been satisfied. 6. If construction activities are not subject to SEAR, but subject to the equivalent environmental review from another New York State or federal agency, the 1 The consultation form can be submitted, along with other project information, through OPRHP's Cultural Resource Information System (CRIS) portal. If submitted through CRIS, paper copies of the consultation form need not be mailed. 7 Part I.A.6. owner or operator must obtain documentation that project review, pursuant to a process equivalent to SEAR from another New York State or federal agency, has been satisfied. 7. If construction activities require Uniform Procedures Act (UPA) Permits (see 6 NYCRR Part 621) from NYSDEC, or the equivalent from another New York State or federal agency, the owner or operator must: a. obtain all such necessary permits; or b. receive notification from NYSDEC pursuant to 6 NYCRR 621 .3(a)(4) excepting Part I.A.7.a. 8. Construction activities are not eligible if they meet the following criteria in Part I.A.8.a. or b.: a. For linear transportation and linear utility project types, the construction activities: i. are within the watershed of surface waters of the State classified as AA or AA-S identified utilizing the Stormwater Interactive Map on NYSDEC's website; and ii. are undertaken on land with no existing impervious cover; and iii. disturb two or more acres of steep slope. b. For all other project types, the construction activities: i. are within the watershed of surface waters of the State classified as AA or AA-S identified utilizing the Stormwater Interactive Map on NYSDEC's website; and ii. are undertaken on land with no existing impervious cover; and iii. disturb one or more acres of steep slope. 8 Part I.B. B. Types of Discharges Authorized 1. The following stormwater discharges are authorized under this permit: a. Stormwater discharges, including stormwater runoff, snowmelt runoff, and surface runoff and drainage, associated with construction activity, are authorized under this permit provided that appropriate stormwater controls are designed, installed, and maintained in accordance with Part II. and Part III. b. Stormwater discharges from construction support activities at the construction site (including concrete or asphalt batch plants, equipment staging yards, material storage areas, excavated material disposal areas, and borrow areas) if the following requirements are met: i. The support activity is directly related to the construction site required to have permit coverage for stormwater discharges; and ii. The support activity is not a commercial operation, nor does it serve multiple unrelated construction sites; and iii. The support activity does not continue to operate beyond the completion of the construction activity at the site it supports; and iv. Stormwater controls are implemented in accordance with Part II. and Part III. for discharges from the support activity areas. 2. The following non-stormwater discharges associated with construction activity are authorized under this permit: a. Non-stormwater discharges listed in 6 NYCRR 750-1 .2(a)(29)(vi), with the following exception: "Discharges from firefighting activities are authorized only when the firefighting activities are emergencies/unplanned"; and b. Non-stormwater discharges of waters to which other components have not been added that are used in accordance with the SWPPP to control dust or irrigate vegetation in stabilized areas; and c. Uncontaminated discharges from dewatering operations 9 Part I.B.3. 3. Authorized discharges of stormwater or authorized discharges of non- stormwater, commingled with a discharge authorized by a different SPDES permit and/or a discharge that does not require SPDES permit authorization, are also authorized under this permit. C. Prohibited Discharges 1 . Non-stormwater discharges prohibited under this permit include but are not limited to: a. Wastewater from washout of concrete; and b. Wastewater from washout and cleanout of stucco, paint, form release oils, curing compounds, and other construction materials; and c. Fuels, oils, or other pollutants used in vehicle and equipment operation and maintenance; and d. Soaps, solvents, or detergents used in vehicle and equipment washing or external building washdown; and e. Toxic or hazardous substances from a spill or other release. D. Electronic Notice of Intent (eNO1) Submittal To receive authorization in accordance with Part I.D.3.b., the owner or operator must submit a complete eNOI in accordance with the requirements in Part I.D. The eNOI contains questions to: ensure eligibility requirements in Part I.A. have been met; obtain owner or operator contact information; obtain the total area to be disturbed and the existing/future impervious areas (rounded to the nearest tenth of an acre); confirm Traditional Land Use Control MS4 Operator j u risd iction over construction projects; satisfy the EPA eRule requirements; confirm that the Water Quality-Based Effluent Limitations in Part 11. have been met; demonstrate consideration of the future risks due to climate change in accordance with Part I I I.A.2.; and confirm that the other Stormwater Pollution Prevention Plan (SWPPP) requirements in Part III. have been met. 1. An eNOl may be submitted for: a. construction activities that are not part of a common plan of development or sale; or 10 Part I.D.1 .b. b. an entire common plan of development or sale; or c. separate phase(s) of a common plan of development or sale if the following requirements are met: i. the common plan of development or sale meets the eligibility requirements of Part I.A.5. or 6.; and ii. the phase(s) meet(s) all other eligibility requirements of Part I.A.; and iii. Part III.C. Required SWPPP Components by Project Type is based on the common plan of development or sale, not the phase(s); or d. tree clearing that is associated with, or will support, a renewable energy generation, transmission, or storage project that meets Part I.A.5. and 6., if the tree clearing: i. meets all other eligibility requirements of Part I.A.; and ii. will occur in NYSDEC's Regions 3-9; and iii. is not within 1/4 mile of a bat hibernaculum protected pursuant to 6 NYCRR Part 182; and iv. will occur between November 1st and March 31st 2. As prerequisites for submitting an eNOI, the owner or operator must: a. prepare a SWPPP for Part I.D.1 .a., b., c., or d. in accordance with Part III.; and b. based on the following criteria, upload the following signature forms signed in accordance with Part VII.J. to the eNOI prior to submission: i. for all eNOls: 1 . the SWPPP Preparer Certification Form, Appendix F, signed by the SWPPP preparers and 11 Part I.D.2.b.i.2. 2. the Owner/Operator Certification Form, Appendix J, signed by the owner or operator, and ii. if an eNO1 includes construction activities within the municipal boundary(ies) of Traditional Land Use Control MS4 Operator(s) that will discharge to the MS4(s): 1. determine if the Traditional Land Use Control MS4 Operator(s) have review authority. A Traditional Land Use Control MS4 Operator does not have review authority where: a. the owner or operator of the construction activities in Part I.D.2.b.ii. is the same entity as the Traditional Land Use Control MS4 Operator identified in Part I.D.2.b.ii.; or b. there is a statute exempting the owner or operator from zoning review by the Traditional Land Use Control MS4 Operator, or c. there is no such statute per Part I.D.2.b.ii.1.b., the Traditional Land Use Control MS4 Operator concludes, after public hearing, that it does not have zoning review authority in accordance with Legal Memorandum LU14 Updated January 2020 "Governmental Immunity from Zoning and Other Legislation"; and 2. if the Traditional Land Use Control MS4 Operator(s) have review authority, submit the SWPPPto the Traditional Land Use Control MS4 Operator(s) for review and have: a. if outside the municipal boundaries of NYC: the MS4 SWPPP Acceptance Form, Appendix G, signed by the principal executive officer or ranking elected official from the Traditional Land Use Control MS4 Operator, or by a duly authorized representative of that person in accordance with Part VII.J.2.; or 12 Part I.D.2.b.ii.2.b. b. if within the municipal boundaries of NYC: The City of New York Department of Environmental Protection (NYCDEP) SWPPP Acceptance/Approval Form, Appendix H, signed by the principal executive officer or ranking elected official from the Traditional Land Use Control MS4 Operator, or by a duly authorized representative of that person in accordance with Part VII.J.2.-I and 3. if the Traditional Land Use Control MS4 Operator does not have review authority, have the MS4 No Jurisdiction Form, Appendix I, signed by the principal executive officer or ranking elected official from the Traditional Land Use Control MS4 Operator, or by a duly authorized representative of that person in accordance with Part VII.J.2. 3. Submitting an eNO1: a. The owner or operator must submit a complete Notice of Intent electronically using a NYSDEC approved form.2 b. The owner or operator is authorized to commence construction activity as of the authorization date indicated in the Letter of Authorization (LOA), which is sent by NYSDEC after a complete eNO1 is submitted. i. If an eNO1 is received for a SWPPP that deviates from one of the technical standards but demonstrates equivalence in accordance with Part III.B.1 .a.ii. or Part III.B.2.b.ii., if the SWPPP includes construction activities that are not within the municipal boundary(ies) of Traditional Land Use Control MS4 Operator(s), and/or if the SWPPP includes construction activities within the municipal boundary(ies) of Traditional Land Use Control MS4 Operator(s) that do not have review authority in accordance with Part I.D.2.b.ii.1 ., the authorization date indicated in the LOA will be 60 business days after the eNO1 submission date. 2 Unless NYSDEC grants a waiver in accordance with 40 CFR 127.15(c) or (d). All waiver requests must be submitted to Stormwater_info@dec.ny.gov or NYSDEC, Bureau of Water Permits, 625 Broadway, 4t" Floor, Albany, New York 12233-3505. 13 Part I.D.3.c. c. If Traditional Land Use Control MS4 Operator(s) have review authority in accordance with Part I.D.2.b.ii.2., the owner or operator must, within five business days of receipt of the LOA, send an electronic copy of the LOA to the Traditional Land Use Control MS4 Operator(s) with review authority. E. General Requirements for Owners or Operators with Permit Coverage 1. As of the date the LOA is received, the owner or operator must make the eNOI, SWPPP, and LOA available for review and copying in accordance with the requirements in Part VII.H. When applicable, as of the date an updated LOA is received, the owner or operator must make the updated LOA available for review and copying in accordance with the requirements in Part VII.H. 2. The owner or operator must ensure compliance with all requirements of this permit and that the provisions of the SWPPP, including any changes made to the SWPPP in accordance with Part III.A.5., are properly implemented and maintained from the commencement of construction activity until: a. all areas of disturbance have achieved final stabilization, and b. the owner's or operator's coverage under this permit is terminated in accordance with Part V.A.5.a. 3. As of the date of the commencement of construction activities until Part I.E.2.a. and b. have been met, the owner or operator must maintain at the construction site, a copy of: a. all documentation necessary to demonstrate eligibility with this permit; and b. this permit; and c. the SWPPP; and d. the signed SWPPP Preparer Certification Form; and e. the signed MS4 SWPPP Acceptance Form or signed NYCDEP SWPPP Acceptance/Approval Form or signed MS4 No Jurisdiction Form (when applicable); and f. the signed Owner/Operator Certification Form; and 14 Part I.E.3.g. g. the eN01; and h. the LOA; and i. the LOA transmittal to the Traditional Land Use Control MS4 Operator in accordance with Part I.D.3.c. (when applicable). 4. The owner or operator must maintain at the construction site, until Part I.E.2.a. and b. have been met, as of the date the documents become final or are received, a copy of the: a. responsible contractor's or subcontractor's certification statement(s) in accordance with Part III.A.7.; and b. inspection reports in accordance with Part IV.C.4. and 6.; and c. Request to Disturb Greater Than Five Acres and the Authorization Letter to Disturb Greater Than Five Acres in accordance with Part I.E.6. (when applicable); and d. Request to Continue Coverage and the Letter of Continued Coverage (LOCC) in accordance with Part I.F.2. and 4. (when applicable); and e. The updated LOA(s) in accordance with Part I.E.9. (when applicable). 5. The owner or operator must maintain the documents in Part I.E.3. and 4. in a secure location, such as a job trailer, on-site construction office, or mailbox with lock. The secure location must be accessible during normal business hours to an individual performing a compliance inspection. The documents must be paper documents unless electronic documents are accessible to the inspector during an inspection to the same extent as a paper copy stored at the site would be. If electronic documents are kept on site, the owner or operator must maintain functional equipment on site available to an inspector during normal hours of operation such that an inspector may view the electronic documents in a format that can be read in a similar manner as a paper record and in a legally dependable format with no less evidentiary value than their paper equivalent. 6. The owner or operator must meet the following requirements prior to disturbing greater than five acres of soil at any one time: a. The owner or operator must submit a written Request to Disturb Greater Than Five Acres to: 15 Part I.E.6.a.i. i. NYSDEC's Regional Office Division of Water staff based on the project location, Appendix E, if a Traditional Land Use Control MS4 Operator does not have review authority in accordance with Part I.D.2.b.ii.1.; or ii. the Traditional Land Use Control MS4 Operator, if a Traditional Land Use Control MS4 Operator has review authority in accordance with Part I.D.2.b.ii.1.; or iii. NYSDEC's Regional Office Division of Water staff based on the project location, Appendix E, and each involved Traditional Land Use Control MS4 Operator, if the project spans multiple municipalities with more than one Traditional Land Use Control MS4 Operator involved with review authority in accordance with Part I.D.2.b.ii.1. b. The written Request to Disturb Greater Than Five Acres must include: i. The SPDES permit identification number (Permit ID); and ii. Full technical justification demonstrating why alternative methods of construction that would result in five acres of soil disturbance or less at any one time are not feasible; and iii. The phasing plan for the project and sequencing plans for all phases from the SWPPP in accordance with Part III.B.1.d.; and iv. Plans with locations and details of erosion and sediment control practices such that the heightened concern for erosion when disturbing greater than five acres at one time has been addressed; and v. Acknowledgment that "the owner or operator will comply with the requirements in Part N.C.2.b.", and vi. Acknowledgment that "the owner or operator will comply with the requirements in Part II.13.1.b." c. The owner or operator must be in receipt of an Authorization Letter to Disturb Greater Than Five Acres, which will include when the 16 Part I.E.6.c. authorization begins and ends and indicate a maximum area (acres) of soil disturbance allowed at any one time, from: i. NYSDEC, if Part I.E.6.a.i. or iii. apply; or ii. the Traditional Land Use Control MS4 Operator, if Part I.E.6.a.ii. applies. 7. Upon a finding of significant non-compliance with the practices described in the SWPPP or violation of this permit, NYSDEC may order an immediate stop to all construction activity at the site until the non-compliance is remedied. The stop work order must be in writing, describe the non-compliance in detail, and be sent to the owner or operator. 8. If any human remains or archaeological remains are encountered during excavation, the owner or operator must immediately cease, or cause to cease, all construction activity in the area of the remains and notify the appropriate Regional Water Engineer (RWE).3 Construction activity shall not resume until written permission to do so has been received from the RWE. 9. To be authorized to implement modifications to the information previously submitted in the eNO1, the owner or operator must: a. notify NYSDEC via email at Stormwater_info@dec.ny.gov requesting access to update the eNO1; and b. update the eNO1 to reflect the modifications and resubmit the eNO1 in accordance with Part I.D.; and c. receive an updated LOA. 10.The eNO1, SWPPP, LOA, updated LOAs (when applicable), and inspection reports required by this permit are public documents that the owner or operator must make available for review and copying by any person within five business days of the owner or operator receiving a written request by any such person to review these documents. Copying of documents will be done at the requester's expense. s The Regional Water Manager where a DEC Region does not have a RWE. 17 Part I.F. F. Permit Coverage for Discharges Authorized Under GP-0-20-001 When applicable: 1 . Upon the effective date of this permit, an owner or operator of a construction activity, with coverage under GP-0-20-001 , will have interim coverage under GP-0-25-001 for 45 calendar days starting on the effective date of GP-0-25- 001 so long as the owner or operator maintains compliance with all applicable requirements of this permit. 2. Within 30 calendar days of the effective date of this permit, the owner or operator, with coverage under GP-0-20-001, must submit a complete Request to Continue Coverage electronically using a NYSDEC approved form,4 which contains the information identified in Part I.F.3. below, if: a. the owner or operator continues to implement the SMP component in conformance with the technical standards in place at the time of initial project authorization; and b. the owner or operator will comply with all non-design requirements of GP- 0-25-001 . 3. The Request to Continue Coverage form contains questions to: ensure eligibility requirements in Part I.A. have been met; verify owner or operator contact information; verify the permit identification number; verify the original eNO1 submission ID, if applicable; verify Part I.F.2.a. and b.; verify the version of the Design Manual that the technical/design components conform to; and receive an updated Owner/Operator Certification Form, Appendix I. 4. The owner or operator has obtained continued coverage under GP-0-25-001 as of the date indicated in the LOCC, which is sent by NYSDEC after a complete Request to Continue Coverage form is submitted. 5. If the owner or operator does not submit the Request to Continue Coverage form in accordance with Part I.F.2. and 3., coverage under this permit is automatically terminated after interim coverage expires. 4 Unless NYSDEC grants a waiver in accordance with 40 CFR 127.15(c) or (d). All waiver requests must be submitted to Stormwater_info@dec.ny.gov or NYSDEC, Bureau of Water Permits, 625 Broadway, 4t" Floor, Albany, New York 12233-3505. 18 Part I.G. G. Change of Owner or Operator When applicable: 1. When property ownership changes, or when there is a change in operational control over the construction plans and specifications, the following process applies: a. The new owner or operator must meet the applicable prerequisites for submitting an eNOI in accordance with Part I.D.2.; and b. The new owner or operator must submit an eNOI in accordance with Part I.D.3.; and c. Permit coverage for the new owner or operator will be effective upon receipt of the LOA in accordance with Part I.D.3.b.; and d. The new owner or operator, upon receipt of their LOA, must provide their Permit ID to the original owner or operator; and e. If the original owner or operator will no longer be the owner or operator of the construction activity identified in the original owner's or operator's eNOI, the original owner or operator, upon receipt of the new owner's or operator's Permit ID in accordance with Part I.G.1 .d., must submit to NYSDEC a completed eNOT in accordance with Part V. that includes the name and Permit ID of the new owner or operator; or f. If the original owner or operator maintains ownership of a portion of the construction activity, the original owner or operator must maintain their coverage under the permit by modifying their eN01; modifications to the eNOI must include: i. the revised area of disturbance and/or impervious area(s); and ii. the revised SMP information, if applicable; and iii. a narrative description of what has changed; and iv. the new owner's or operator's Permit ID for the portion of the project removed from the eNOI. Owners or operators must follow Part I.E.9. to modify the eNOI. 19 Part II. Part II. Water Quality-Based Effluent Limitations A. Maintaining Water Quality NYSDEC expects that compliance with the requirements of this permit will control discharges necessary to meet applicable water quality standards. It shall be a violation of the ECL for any discharge to either cause or contribute to a violation of the following water quality standards as contained in Parts 700 through 705 of Title 6 of the Official Compilation of Codes, Rules and Regulations of the State of New York: 1. There must be no increase in turbidity that will cause a substantial visible contrast to natural conditions; and 2. There must be no increase in suspended, colloidal or settleable solids that will cause deposition or impair the waters for their best usages; and 3. There must be no residue from oil and floating substances, nor visible oil film, nor globules of grease. If there is evidence indicating that the stormwater discharges authorized by this permit are causing, have the reasonable potential to cause, or are contributing to a violation of the water quality standard, the owner or operator must take appropriate corrective action in accordance with Part IV.C.5. of this permit and document in accordance with Part IV.C.4. of this permit. To address the water quality standard violation the owner or operator must include and implement appropriate controls in the SWPPP to correct the problem or obtain an individual SPDES permit. If, despite compliance with the requirements of this permit, it is demonstrated that the stormwater discharges authorized by this permit are causing or contributing to a violation of water quality standards, or if NYSDEC determines that a modification of this permit is necessary to prevent a violation of water quality standards, the authorized discharges will no longer be eligible for coverage under this permit, and the owner or operator must obtain an individual SPDES permit prior to further discharges from the construction site. B. Effluent Limitations Applicable to Discharges from Construction Activities Discharges authorized by this permit must achieve, at a minimum, the effluent limitations in Part II.13.1.a., b., c., d., and e. These limitations represent the 20 Part II.B. degree of effluent reduction attainable by the application of best practicable technology currently available. 1 . Erosion and Sediment Control Requirements - The owner or operator must select, design, install, implement, and maintain control measures to minimize the discharge of pollutants and prevent a violation of the water quality standards. The selection, design, installation, implementation, and maintenance of these control measures must meet the non-numeric effluent limitations in Part II.B.1 .a., b., c., d., and e. and be in accordance with the New York State Standards and Specifications for Erosion and Sediment Control (BB), dated November 2016, using sound engineering judgment. Where control measures are not designed in conformance with the design criteria included in the technical standard, the owner or operator must include in SWPPP the reason(s) for the deviation, or alternative design, and provide information in the SWPPP demonstrating that the deviation or alternative design is equivalent to the technical standard. a. Erosion and Sediment Controls. At a minimum, erosion and sediment controls must be selected, designed, installed, implemented, and maintained to: i. Minimize soil erosion through application of runoff control and soil stabilization control measure to minimize pollutant discharges; and ii. Control stormwater discharges, including both peak flow rates and total stormwater volume, to minimize channel and streambank erosion and scour in the immediate vicinity of the discharge points; and iii. Minimize the amount of soil exposed during construction activity; and iv. Minimize the disturbance of steep slope; and v. Minimize sediment discharges from the site; and vi. Provide and maintain natural buffers around surface waters, direct stormwater to vegetated areas and maximize stormwater infiltration to reduce pollutant discharges, unless infeasible; and vii. Minimize soil compaction. Minimizing soil compaction is not required 21 Part II.B.1 .a.vii. where the intended function of a specific area of the site dictates that it be compacted; and viii. Unless infeasible, preserve a sufficient amount of topsoil to complete soil restoration and establish a uniform, dense vegetative cover; and ix. Minimize dust. On areas of exposed soil, minimize dust through the appropriate application of water or other dust suppression techniques to control the generation of pollutants that could be discharged from the site. b. Soil Stabilization. In areas where soil disturbance activity has ceased, whether permanently or temporarily ceased, the application of soil stabilization measures must be initiated by the end of the next business day and completed within 14 calendar days from the date the current soil disturbance activity ceased. For construction sites that directly discharge to one of the 303(d) segments listed in Appendix D, or are located in one of the watersheds listed in Appendix C, or are authorized to disturb greater than five acres in accordance with Part I.E.5.a.viii., the application of soil stabilization measures must be initiated by the end of the next business day and completed within seven calendar days from the date the soil disturbance activity ceased. c. Dewatering. Discharges from dewatering activities, including discharges from dewatering of trenches and excavations, must be managed by appropriate control measures. d. Pollution Prevention Measures. Select, design, install, implement, and maintain effective pollution prevention measures to minimize the discharge of pollutants and prevent a violation of the water quality standards. At a minimum, such measures must be selected, designed, installed, implemented, and maintained to: i. Minimize the discharge of pollutants from equipment and vehicle washing, wheel wash water, and other wash waters. Soaps, detergents and solvents cannot be used; and ii. Minimize the exposure of building materials, building products, construction wastes, trash, landscape materials, fertilizers, pesticides, herbicides, detergents, sanitary waste, hazardous and toxic waste, and other materials present on the site to precipitation 22 Part II.B.1.d.ii. and to stormwater. Minimization of exposure is not required in cases where the exposure to precipitation and to stormwater will not result in a discharge of pollutants, or where exposure of a specific material or product poses little risk of stormwater contamination (such as final products and materials intended for outdoor use); and iii. Prevent the discharge of pollutants from spills and leaks and implement chemical spill and leak prevention and response procedures. e. Surface Outlets. When discharging from basins and impoundments, the surface outlets must be designed, constructed, and maintained in such a manner that sediment does not leave the basin or impoundment and that erosion at or below the outlet does not occur. C. Post-Construction Stormwater Management Practice (SMP) Requirements 1. The owner or operator of a construction activity that requires post- construction SMPs, in accordance with Part III.C., must select, design, install, implement, and maintain the SMPs to meet the performance criteria in the New York State Stormwater Management Design Manual, dated July 31 , 2024 (DM), using sound engineering judgment. Where SMPs are not designed in conformance with the performance criteria in the DM, the owner or operator must include in the SWPPP the reason(s) for the deviation or alternative design and provide information which demonstrates that the deviation or alternative design is equivalent to the technical standard. 2. The owner or operator of a construction activity, that requires SMPs in accordance with Part III.C., must design the practices to meet the applicable sizing criteria in Part II.C.2.a., b., c., or d. a. Sizing Criteria for New Development i. Runoff Reduction Volume (RRv) and Water Quality Volume (WQv): 1. Reduce the total WQv by application of RR techniques and standard SMPs with RRv capacity. The total WQv must be calculated in accordance with the criteria in Section 4.2 of the DM; or 23 Part II.C.2.a.i.2. 2. Minimum RRv and Treatment of Remaining Total WQv: Construction activities that cannot meet the requirements in Part II.C.2.a.i.1 . due to site limitations must direct runoff from all newly constructed impervious areas to a RR technique or standard SMP with RRv capacity unless infeasible. The specific site limitations that prevent the reduction of 100% of the WQv must be documented in the SWPPP. For each impervious area that is not directed to a RR technique or standard SMP with RRv capacity, the SWPPP must include documentation which demonstrates that all options were considered and for each option explains why it is considered infeasible. In no case shall the runoff reduction achieved from the newly constructed impervious areas be less than the Minimum RRv as calculated using the criteria in Section 4.4 of the DM. The remaining portion of the total WQv that cannot be reduced must be treated by application of standard SMPs. ii. Channel Protection Volume (CPv): Provide 24 hour extended detention of the post-developed 1-year, 24-hour storm event, remaining after runoff reduction. Where a CPv control orifice is provided, the minimum orifice size must be 3 inches, with acceptable external trash rack or orifice protection. The CPv requirement does not apply when: 1 . Reduction of the entire CPv is achieved by application of runoff reduction techniques or infiltration systems; or 2. The 1-year post-development peak discharge is less than or equal to 2.0 cfs without detention or velocity controls; or 3. The site directly discharges into a fifth order or larger water body (stream, river, or lake), or tidal waters, where the increase in smaller flows will not impact the stream bank or channel integrity. However, the point of discharge must be adequately protected against scour and erosion by the increased peak discharge. 24 Part II.C.2.a.iii. iii. Overbank Flood Control Criteria (Qp): Requires storage to attenuate the post-development 10-year, 24-hour peak discharge rate (Qp) to predevelopment rates. The Qp requirement does not apply when: 1. the site directly discharges to tidal waters or fifth order or larger streams, or 2. A downstream analysis reveals that overbank control is not required. iv. Extreme Flood Control Criteria (Qf): Requires storage to attenuate the post-development 100-year, 24-hour peak discharge rate (Qf) to predevelopment rates. The Qf requirement does not apply when: 1 . the site directly discharges to tidal waters or fifth order or larger streams, or 2. A downstream analysis reveals that overbank control is not required. b. Sizing Criteria for New Development in Enhanced Phosphorus Removal Watersheds i. Runoff Reduction Volume (RRv) and Water Quality Volume (WQv): 1 . Reduce the WQv by application of RR techniques and standard SMPs with RRv capacity. The total WQv is the runoff volume from the 1-year, 24-hour design storm over the post-developed watershed and must be calculated in accordance with the criteria in Section 4.3 of the DM; or 2. Minimum RRv and Treatment of Remaining Total WQv: Construction activities that cannot meet the criteria in Part II.C.2.b.i.1. due to site limitations must direct runoff from all newly constructed impervious areas to a RR technique or standard SMP with RRv capacity unless infeasible. The specific site limitations that prevent the reduction of 100% of the WQv must be documented in the SWPPP. For each impervious area that is not directed to a RR technique or standard SMP with RRv capacity, the SWPPP must include 25 Part II.C.2.b.i.2. documentation which demonstrates that all options were considered and for each option explains why it is considered infeasible. In no case shall the runoff reduction achieved from the newly constructed impervious areas be less than the Minimum RRv as calculated using the criteria in Section 4.5 of the DM. The remaining portion of the total WQv that cannot be reduced must be treated by application of standard SMPs. ii. Channel Protection Volume (CPv): Provide 24 hour extended detention of the post-developed 1-year, 24-hour storm event, remaining after runoff reduction. Where a CPv control orifice is provided, the minimum orifice size must be 3 inches, with acceptable external trash rack or orifice protection. The CPv requirement does not apply when: 1 . Reduction of the entire CPv is achieved by application of runoff reduction techniques or infiltration systems; or 2. The 1-year post-development peak discharge is less than or equal to 2.0 cfs; or 3. The site directly discharges to tidal waters, or a fifth order or larger water body (stream, river, or lake) where the increase in smaller flows will not impact the stream bank or channel integrity. However, the point of discharge must be adequately protected against scour and erosion by the increased peak discharge. iii. Overbank Flood Control Criteria (Qp): Requires storage to attenuate the post-development 10-year, 24-hour peak discharge rate (Qp) to predevelopment rates. The Qp requirement does not apply when: 1 . the site directly discharges to tidal waters or fifth order or larger streams; or 2. A downstream analysis reveals that overbank control is not required. 26 Part II.C.2.b.iv. iv. Extreme Flood Control Criteria (Qf): Requires storage to attenuate the post-development 100-year, 24-hour peak discharge rate (Qf) to predevelopment rates. The Qf requirement does not apply when: 1. the site directly discharges to tidal waters or fifth order or larger streams; or 2. A downstream analysis reveals that overbank control is not required. c. Sizing Criteria for Redevelopment Activity i. Water Quality Volume (WQv): The WQv treatment objective for redevelopment activity must be addressed by one of the following options, as outlined in Section 9.2.1. Redevelopment activities located in an Enhanced Phosphorus Removal Watershed (see Part III.B.3. and Appendix C) must calculate the WQv in accordance with Section 4.3 of the DM. All other redevelopment activities must calculate the WQv in accordance with Section 4.2 of the DM. 1 . Reduce the existing impervious cover by a minimum of 25% of the total disturbed, impervious area. The Soil Restoration criteria in Section 5.1 .6 of the DM must be applied to all newly created pervious areas; or 2. Capture and treat 100% of the required WQv, for a minimum of 25% of the disturbed redevelopment impervious area, by implementation of standard SMPs or reduced by application of runoff reduction techniques; or 3. Capture and treat 100% of the required WQv, for a minimum of 75% of the disturbed redevelopment impervious area, by implementation of a volume-based alternative SMP, as defined in Section 9.4 of the DM; or 4. Capture and treat 100% of the required WQv, for a minimum of 75% of the disturbed redevelopment impervious area, by implementation of a flow-through alternative SMP sized to treat the peak rate of runoff from the WQv design storm; or 27 Part II.C.2.c.i.5. 5. Application of a combination of 1 through 4 above that provide a weighted average of at least two of the above methods. Application of this method must be in accordance with the criteria in Section 9.2.1(A)(V) of the DM; or 6. If there is an existing SMP located on the site that captures and treats runoff from the impervious area that is being disturbed, the WQv treatment option selected must, at a minimum, provide treatment equal to the treatment that was being provided by the existing practice(s) if that treatment is greater than the treatment required by options 1 through 5 above. ii. Channel Protection Volume (CPv) is not required if there is 0% change to hydrology that increases the discharge rate and volume from the project site. iii. Overbank Flood Control (Qp) is not required if there is 0% change to hydrology that increases the discharge rate from the project site. iv. Extreme Flood Control (Qf) is not required if there is 0% change to hydrology that increases the discharge rate from the project site. d. Sizing Criteria for Combination of Redevelopment Activity and New Development Construction projects, that include both new development and redevelopment activity, must use SMPs that meet the sizing criteria calculated as an aggregate of the sizing criteria in Part II.C.2.a. or b. for the new development portion of the project and Part II.C.2.c. for the redevelopment activity portion of the project. Part III. Stormwater Pollution Prevention Plan (SWPPP) A. General SWPPP Requirements 1. A SWPPP must be prepared and implemented by the owner or operator of all construction activity covered by this permit. All authorized discharges must be identified in the SWPPP. The SWPPP must document the selection, design, installation, implementation and maintenance of the control measures and 28 Part III.A.1 . practices that will be used to meet the effluent limitations in Part II.B. and, where applicable, the SMP requirements in Part II.C. 2. The SWPPP must demonstrate consideration in narrative format of the future physical risks due to climate change pursuant to the Community Risk and Resiliency Act (CRRA), 6 NYCRR Part 490, and associated guidance. a. The owner or operator must consider: i. the following physical risks due to climate change: (i) increasing temperature; and (ii) increasing precipitation; and (iii) increasing variability in precipitation, including chance of drought; and (iv) increasing frequency and severity of flooding; and (v) rising sea level; and (vi) increasing storm surge; and (vii) shifting ecology. ii. for each of the following: (i) overall site planning; and (ii) location, elevation, and sizing of: a. control measures and practices; and b. conveyance system(s); and c. detention system(s). 3. The SWPPP must describe the erosion and sediment control practices and where required, SMPs that will be used and/or constructed to reduce the pollutants in stormwater discharges and to assure compliance with the 29 Part III.A.3. requirements of this permit. In addition, the SWPPP must identify potential sources of pollution which may reasonably be expected to affect the quality of stormwater discharges. 4. All SWPPPs, that require the SMP component in accordance with Part III.B.2., must be prepared by a qualified professional. 5. The owner or operator must keep the SWPPP current so that, at all times, it accurately documents the erosion and sediment control practices that are being used or will be used during construction, and all SMPs that will be constructed on the site. At a minimum, the owner or operator must modify the SWPPP, including construction drawings: a. whenever the current provisions prove to be ineffective in minimizing pollutants in stormwater discharges from the site; and b. whenever there is a change in design, construction, or operation at the construction site that has or could have an effect on the discharge of pollutants; and c. to address issues or deficiencies identified during an inspection by the qualified inspector, NYSDEC, or other regulatory authority; and d. to document the final construction conditions in an as-built drawing. 6. NYSDEC may notify the owner or operator at any time that the SWPPP does not meet one or more of the minimum requirements of this permit. The notification must be in writing and identify the provisions of the SWPPP that require modification. Within fourteen (14) calendar days of such notification, or as otherwise indicated by NYSDEC, the owner or operator must make the required changes to the SWPPP and submit written notification to NYSDEC that the changes have been made. If the owner or operator does not respond to NYSDEC's comments in the specified time frame, NYSDEC may suspend the owner's or operator's coverage under this permit or require the owner or operatorto obtain coverage under an individual SPDES permit in accordance with Part II.D.4. 7. Prior to the commencement of construction activity, the owner or operator must identify the contractor(s) and subcontractor(s) that will be responsible for installing, constructing, repairing, replacing, inspecting, and maintaining the erosion and sediment control practices included in the SWPPP and the 30 Part III.A.7. contractor(s) and subcontractor(s) that will be responsible for constructing the SMPs included in the SWPPP. The owner or operator must have each of the contractors and subcontractors identify at least one person from their company to be trained contractor that will be responsible for implementation of the SWPPP. The owner or operator must ensure that at least one trained contractor is on site daily when soil disturbance activities are being performed. The owner or operator must have each of the contractors and subcontractors identified above sign a copy of the following certification statement below before the commencement of construction activities: "I hereby certify under penalty of law that I understand and agree to comply with the requirements of the SWPPP and agree to implement any corrective actions identified by the qualified inspector during a site inspection. I also understand that the owner or operator must comply with the requirements of the most current version of the New York State Pollutant Discharge Elimination System (SPDES) Construction General Permit (CGP) for Stormwater Discharges from Construction Activities and that it is unlawful for any person to cause or contribute to a violation of water quality standards. Furthermore, I am aware that there are significant penalties for submitting false information, that I do not believe to be true, including the possibility of fine and imprisonment for knowing violations" In addition to providing the certification statement above, the certification page must also identify the specific elements of the SWPPP that each contractor and subcontractor will be responsible for and include the name and title of the person providing the signature; the name and title of the trained contractor responsible for SWPPP implementation; the name, address and telephone number of the contracting firm; the address (or other identifying description) of the site; and the date the certification statement is signed. The owner or operator must attach the certification statement(s) to the copy of the SWPPP that is maintained at the construction site. If new or additional contractors are hired to implement measures identified in the SWPPP after the commencement of construction activities, they must also sign the certification statement and provide the information listed above prior to performing construction activities. 31 Part III.B. B. Required SWPPP Contents 1. Erosion and sediment control component - The owner or operator must prepare a SWPPP that includes erosion and sediment control practices. a. Erosion and sediment control practices must be designed: i. in conformance with the BB; or ii. equivalent to the BB if deviating from Part III.B.1.a.i. b. If the erosion and sediment control practices are designed in conformance with Part III.B.1 .a.ii., the SWPPP must include a demonstration of equivalence to the BB. c. At a minimum, the erosion and sediment control component of the SWPPP must include the following: i. Background information about the scope of the project, including the location, type and size of project; and ii. A site map/construction drawing(s) with north arrows for the project, including a general location map. At a minimum, the site map must show the total site area; all improvements; areas of disturbance; areas that will not be disturbed; existing vegetation; on-site and adjacent off-site surface water(s); floodplain/floodway boundaries; wetlands and drainage patterns that could be affected by the construction activity; existing and final contours; locations of different soil types with boundaries; material, waste, borrow or equipment storage areas located on adjacent properties; and location(s) of the stormwater discharge(s) and receiving surface water(s); and iii. A description of the soil(s) present at the site, including an identification of the Hydrologic Soil Group (HSG); and iv. A phasing plan for the project and sequencing plans for all phases, both of which must address clearing and grubbing, excavation and grading, utility and infrastructure installation, final stabilization, 32 Part III.B.1 .c.iv. and any other construction activity at the site that will result in soil disturbance. 1 . The phasing plan must include: a. a map delineating and labeling the limits of soil disturbance for all phases of a project; and b. a table identifying the order and intended schedule of when each phase will begin and end its sequencing plan. The table must identify the total disturbed area for each phase at any one time and the total disturbed area for the overall project at any one time all on one timeline showing all overlapping quantities of disturbed area at any one time; and 2. A sequencing plan for a specific phase must include: a. a table indicating the order and intended schedule of construction activities within a phase, and corresponding construction drawings with a description of the work to be performed; and b. all permanent and temporary stabilization measures; and v. A description of the minimum erosion and sediment control practices to be installed or implemented for each construction activity that will result in soil disturbance. Include a schedule that identifies the timing of initial placement or implementation of each erosion and sediment control practice and the minimum time frames that each practice should remain in place or be implemented; and vi. A site map/construction drawing(s) showing the specific Iocation(s), size(s), and length(s) of each erosion and sediment control practice; and vii. The dimensions, material specifications, installation details, and operation and maintenance requirements for all erosion and sediment control practices. Include the location and sizing of any 33 Part III.B.1.c.vii. temporary sediment basins and structural practices that will be used to divert flows from exposed soils; and viii. A maintenance inspection schedule for the contractor(s) and subcontractor(s) identified in Part III.A.7. to ensure continuous and effective operation of the erosion and sediment control practices. The maintenance inspection schedule must be in accordance with the requirements in the BB technical standard; and ix. A description of the pollution prevention measures that will be used to control litter, construction chemicals and construction debris from becoming a pollutant source in the stormwater discharges; and x. A description and location of any stormwater discharges associated with industrial activity other than construction at the site, including, but not limited to, stormwater discharges from asphalt plants and concrete plants located on the construction site; and xi. Identification of any elements of the design that are not in conformance with the design criteria in the BB technical standard. Include the reason for the deviation or alternative design and provide information which demonstrates that the deviation or alternative design is equivalent to the technical standard. 2. SMP component — The owner or operator of construction activity identified in Table 2 of Appendix B must prepare a SWPPP that includes SMPs. a. SMPs must be designed in conformance with the applicable sizing criteria in Part II.C.2.a., c., or d.; and b. SMPs must be designed in conformance with the performance criteria: i. in the DM; or ii. equivalent to the DM if deviating from Part III.B.2.b.i.; or iii. in the New York State Stormwater Management Design Manual, dated January 2015 (2015 Design Manual), or equivalent to it, if the following criteria are met: 34 Part III.B.2.b.iii.1. 1. The eNO1 is submitted in accordance with Part I.D. before January 29, 2027 for construction activities that are either: a. subject to governmental review and approval: i. where the owner or operator made any application to that governmental entity prior to the effective date of this permit; and ii. such application included a SWPPP developed using the 2015 Design Manual or equivalent to it; or b. not subject to governmental review and approval: i. where a fiscal allocation for the construction activities has been developed and approved by a governmental entity; and ii. the SWPPP was developed using the 2015 Design Manual or equivalent to it; and c. If SMPs are designed in conformance with Part III.B.2.b.ii., the SWPPP must include the reason(s) for the deviation or alternative design and a demonstration of equivalence to the DM; and d. If SMPs are designed in conformance with Part III.B.2.b.iii., the SWPPP must include supporting information or documentation demonstrating that Part III.B.2.b.iii.1.a. or b. apply; and e. The SMP component of the SWPPP must include the following: i. Identification of all SMPs to be constructed as part of the project, including which option the SMP designs conform to, either Part III.B.2.b.i., ii., or iii. Include the dimensions, material specifications and installation details for each SMP; and ii. A site map/construction drawing(s) showing the specific location and size of each SMP; and 35 Part III.B.2.e.iii. iii. A Stormwater Modeling and Analysis Report that includes: (i) Map(s) showing pre-development conditions, including watershed/subcatchments boundaries, flow paths/routing, and design points; and (ii) Map(s) showing post-development conditions, including watershed/subcatchments boundaries, flow paths/routing, design points and SMPs; and (iii) Results of stormwater modeling (i.e. hydrology and hydraulic analysis) for the required storm events. Include supporting calculations (model runs), methodology, and a summary table that compares pre- and post-development runoff rates and volumes for the different storm events; and (iv) Summary table, with supporting calculations, which demonstrates that each SMP has been designed in conformance with the sizing criteria included in the DM; and (v) Identification of any sizing criteria that is not required based on the requirements included in Part II.C.; and (vi) Identification of any elements of the design that are not in conformance with the performance criteria in the DM. Include the reason(s) for the deviation or alternative design and provide information which demonstrates that the deviation or alternative design is equivalent to the DM. iv. Soil testing results and locations (test pits, borings); and v. Infiltration test results, when required in accordance with Part III.B.2.a.; and vi. An operations and maintenance plan that includes inspection and maintenance schedules and actions to ensure continuous and effective operation of each SMP. The plan must identify the entity 36 Part III.B.2.e.vi. that will be responsible for the long-term operation and maintenance of each practice; and 3. Enhanced Phosphorus Removal Standards - The owner or operator of construction activity identified in Table 2 of Appendix B that is located in a watershed identified in Appendix C must prepare a SWPPP that includes SMPs designed in conformance with the applicable sizing criteria in Part II.C.2.b., c., or d. and the performance criteria Enhanced Phosphorus Removal Standards included in the DM. At a minimum, the SMP component of the SWPPP must meet the requirements of Part III.B.2. C. Required SWPPP Components by Project Type Owners or operators of construction activities, identified in Table 1 of Appendix B, are required to prepare a SWPPP that only includes erosion and sediment control practices designed in accordance with Part III.B.1 . Owners or operators of the construction activities, identified in Table 2 of Appendix B, must prepare a SWPPP that also includes SMPs designed in accordance with Part III.B.2 or 3. For the entire area of disturbance, including the entire common plan of development or sale if applicable, the owner or operator must evaluate every bullet from Appendix B Table 1 and Table 2 separately. If bullets from both Table 1 and Table 2 apply, the SWPPP must include erosion and sediment control practices for all construction activities but SMPs for only those portions of the construction activities that fall under Table 2 bullet(s). Part IV. Inspection and Maintenance Requirements A. General Construction Site Inspection and Maintenance Requirements 1. The owner or operator must ensure that all erosion and sediment control practices (including pollution prevention measures), and all SMPs identified in the SWPPP, are inspected and maintained in accordance with Part IV.B. and C. B. Contractor Maintenance Inspection Requirements 1. The owner or operator of each construction activity, identified in Tables 1 and 2 of Appendix B, must have a trained contractor inspect the erosion and sediment control practices and pollution prevention measures being 37 Part IV.13.1. implemented within the active work area daily to ensure that they are being maintained in effective operating condition at all times. If deficiencies are identified, the contractor must: a. if the corrective action does not require engineering design: i. begin implementing corrective actions within one business day; and ii. complete the corrective actions within five business days; or b. if the corrective action requires engineering design: i. begin the engineering design process within five business days; and ii. complete the corrective action in a reasonable time frame but no later than within 60 calendar days. 2. For construction sites where soil disturbance activities have been temporarily suspended (e.g. winter shutdown) and temporary stabilization measures have been applied to all disturbed areas, the trained contractor can stop conducting the maintenance inspections in accordance with Part IV.13.1 . The trained contractor must begin conducting the maintenance inspections in accordance with Part IV.13.1 . as soon as soil disturbance activities resume. 3. For construction sites where soil disturbance activities have been shut down with partial project completion, the trained contractor can stop conducting the maintenance inspections in accordance with Part IV.13.1. if all areas disturbed as of the project shutdown date have achieved final stabilization and all SMPs required for the completed portion of the project have been constructed in conformance with the SWPPP and are operational. C. Qualified Inspector Inspection Requirements 1. With the exception of the following construction activities identified in Tables 1 and 2 of Appendix B, a qualified inspector must conduct site inspections for all other construction activities identified in Tables 1 and 2 of Appendix B: a. the construction of a single-family residential subdivision with 25% or less impervious cover at total site build-out that involves a soil disturbance of one (1) or more acres of land but less than or equal to five (5) acres and is 38 Part IV.C.1 .a. not located in one of the watersheds listed in Appendix C and not directly discharging to one of the 303(d) segments listed in Appendix D; and b. the construction of a single-family home that involves soil disturbances of one (1) or more acres but less than or equal to five (5) acres and is not located in one of the watersheds listed in Appendix C and not directly discharging to one of the 303(d) segments listed in Appendix D; and c. construction on agricultural property that involves soil disturbances of one (1) or more acres but less than five (5) acres; and d. construction activities located in the New York City Watershed located east of the Hudson River, see Appendix C Figure 1, that involve soil disturbances of 5,000 square feet or more, but less than one acre. 2. The qualified inspector must conduct site inspections in accordance with the following timetable: a. For construction sites where soil disturbance activities are on-going, the qualified inspector must conduct a site inspection at least once every seven (7) calendar days; or b. For construction sites where soil disturbance activities are on-going and the owner or operator has received authorization in accordance with Part I.E.6. to disturb greater than five (5) acres of soil at any one time, the qualified inspector must conduct at least two (2) site inspections every seven (7) calendar days. The two (2) inspections must be separated by a minimum of two (2) full calendar days; or c. For construction sites where soil disturbance activities have been temporarily suspended (e.g. winter shutdown) and temporary stabilization measures have been applied to all disturbed areas, the qualified inspector must conduct a site inspection at least once every thirty (30) calendar days. The owner or operator must notify the DOW Water (SPDES) Program contact at the Regional Office (see contact information in Appendix E) or, in areas under the jurisdiction of a Traditional Land Use Control MS4 Operator, the Traditional Land Use Control MS4 Operator (provided the Traditional Land Use Control MS4 Operator is not the owner or operator of the construction activity) by hard copy or email prior to reducing the inspections to this frequency and again by hard copy or email prior to re-commencing construction; or 39 Part IV.C.2.d. d. For construction sites where soil disturbance activities have been shut down with partial project completion, the requirement to have the qualified inspector conduct inspections ceases if all areas disturbed as of the project shutdown date have achieved final stabilization and all SMPs required for the completed portion of the project have been constructed in conformance with the SWPPP and are operational. The owner or operator must notify the DOW Water (SPDES) Program contact at the Regional Office (see contact information in Appendix E) or, in areas subject to the review authority of Traditional Land Use Control MS4 Operator(s) in accordance with Part I.D.2.b.ii.1., the Traditional Land Use Control MS4 Operator(s) (provided the Traditional Land Use Control MS4 Operator(s) are not the owners or operators of the construction activity) in writing prior to the shutdown and again in writing prior to resuming construction activity. If soil disturbance activities are not resumed within 2 years from the date of shutdown, the owner or operator must terminate coverage by meeting the requirements of Part V; or e. For construction sites involving soil disturbance of one (1) or more acres that directly discharge to one of the 303(d) segments listed in Appendix D or is located in one of the watersheds listed in Appendix C, the qualified inspector must conduct at least two (2) site inspections every seven (7) calendar days. The two (2) inspections must be separated by a minimum of two (2) full calendar days. 3. At a minimum, the qualified inspector must inspect: a. all erosion and sediment control practices and pollution prevention measures to ensure integrity and effectiveness; and b. all SMPs under construction to ensure that they are constructed in conformance with the SWPPP; and c. all areas of disturbance that have not achieved final stabilization; and d. all points of discharge to surface waters of the State located within, or immediately adjacent to, the property boundaries of the construction site; and e. all points of discharge from the construction site. 40 Part IV.C.4. 4. The qualified inspector must prepare an inspection report subsequent to each and every inspection. At a minimum, the inspection report must include and/or address all of the following, for all construction activities except those listed in Part IV.C.1 .: a. Permit identification number; and b. Date and time of inspection; and c. Name and title of person(s) performing inspection; and d. A description of the weather and soil conditions (e.g. dry, wet, saturated) at the time of the inspection, including the temperature at the time of the inspection; and e. A description of the condition of the runoff at all points of discharge from the construction site. This must include identification of any discharges of sediment from the construction site. Include discharges from conveyance systems (i.e. pipes, culverts, ditches, etc.) and overland flow; and f. A description of the condition of all surface waters of the State located within, or immediately adjacent to, the property boundaries of the construction site which receive runoff from disturbed areas. This must include identification of any discharges of sediment to the surface waters of the State; and g. Identification of all erosion and sediment control practices and pollution prevention measures that need repair or maintenance; and h. Identification of all erosion and sediment control practices and pollution prevention measures that were not installed properly or are not functioning as designed and need to be reinstalled or replaced; and i. Description and sketch (map) of areas with active soil disturbance activity, areas that have been disturbed but are inactive at the time of the inspection, and areas that have been stabilized (temporary and/or final) since the last inspection; and j. Estimates, in square feet or acres, of the following areas: 41 Part IV.C.4.j.i. i. Total area with active soil disturbance (not requiring either temporary stabilization or final stabilization); and ii. Total area with inactive soil disturbance (requiring either temporary stabilization or final stabilization); and iii. Total area that has achieved temporary stabilization; and iv. Total area that has achieved final stabilization; and k. Current stage of construction of all SMPs and identification of all construction activity on site that is not in conformance with the SWPPP and technical standards; and I. Corrective action(s) that must be taken to install, repair, replace or maintain erosion and sediment control practices and pollution prevention measures; and to correct deficiencies identified with the construction of the SMP(s); and m. Identification and status of all corrective actions that were required by previous inspection; and n. Digital photographs, with date stamp, that clearly show the condition of all practices that have been identified as needing corrective actions. The qualified inspector must attach color copies of the digital photographs to the inspection report being maintained onsite within seven (7) calendar days of the date of the inspection. The qualified inspector must also take digital photographs, with date stamp, that clearly show the condition of the practice(s) after the corrective action has been completed. The qualified inspector must attach paper color copies of the digital photographs to the inspection report that documents the completion of the corrective action work within seven (7) calendar days of that inspection. 5. Within one business day of the completion of an inspection, the qualified inspector must notify the owner or operator, and appropriate contractor or subcontractor identified in Part III.A.7., of any corrective actions that need to be taken. The contractor or subcontractor must: a. if the corrective action does not require engineering design: 42 Part IV.C.5.a.i. i. begin implementing corrective actions within one business day; and ii. complete the corrective actions within five business days; or b. if the corrective action requires engineering design: i. begin the engineering design process within five business days; and ii. complete the corrective action in a reasonable time frame but no later than within 60 calendar days. 6. All inspection reports must be signed by the qualified inspector. In accordance with Part I.E.3., the inspection reports must be maintained on site with the SWPPP. Part V. How to Terminate CGP Coverage A. Electronic Notice of Termination (eNOT) Submittal The eNOT contains questions to ensure requirements in Part V.A. have been met. 1 . An owner or operator must terminate coverage when one or more of the following requirements have been met: a. Total project completion: i. all construction activity identified in the SWPPP has been completed; and ii. all areas of disturbance have achieved final stabilization; and iii. all temporary, structural erosion and sediment control measures have been removed; and iv. all SMPs have been constructed in conformance with the SWPPP and are operational; and v. an as-built drawing has been prepared; or 43 Part V.A.1 .b. b. Planned shutdown with partial project completion: i. all soil disturbance activities have ceased; and ii. all areas disturbed as of the project shutdown date have achieved final stabilization; and iii. all temporary, structural erosion and sediment control measures have been removed; and iv. all SMPs required for the completed portion of the project have been constructed in conformance with the SWPPP and are operational; and v. an as-built drawing has been prepared; or c. In accordance with Part I.G. Change of Owner or Operator; or d. The owner or operator has obtained coverage under an alternative general SPDES permit or an individual SPDES permit. 2. For construction activities that require qualified inspector inspections in accordance with Part N.C.1. and have met Part V.A.1 .a. or b., the owner or operator must have the qualified inspector perform a final site inspection prior to submitting the eNOT. The qualified inspector must, by signing the "Final Stabilization" and "Post-Construction Stormwater Management Practice(s)" certification statements on the eNOT, certify that all the requirements in Part V.A.1.a. or b. have been achieved. 3. For construction activities that are subject to the review authority of Traditional Land Use Control MS4 Operator(s) in accordance with Part I.D.2.b.ii.1 . and meet Part V.A.1 .a. or b., the owner or operator must have the Traditional Land Use Control MS4 Operator(s) sign the "MS4 Acceptance" statement on the eNOT in accordance with the requirements in Part VII.J. A Traditional Land Use Control MS4 Operator official, by signing this statement, determined that it is acceptable for the owner or operator to submit the eNOT in accordance with the requirements of this Part. A Traditional Land Use Control MS4 Operator can make this determination by performing a final site inspection themselves or by accepting the qualified inspector's final site inspection certification(s) when required in Part V.A.2. 44 Part V.A.4. 4. For construction activities that require SMPs and meet Part V.A.1.a. or b., the owner or operator must, prior to submitting the eNOT, ensure one of the following: a. for SMP(s) that were constructed by a private entity, but will be owned, operated, and maintained by a public entity, the SMP(s) and any right-of- way(s) needed to operate and maintain such practice(s) have been deeded to the municipality in which the practice(s) is located; or b. for SMP(s) that are privately owned, but will be operated and maintained by a public entity, an executed operation and maintenance agreement is in place with the municipality that will operate and maintain the SMP(s); or c. for SMP(s) that are privately owned, the owner or operator has a mechanism in place that requires operation and maintenance of the practice(s) in accordance with the operation and maintenance plan, such as a deed covenant in the owner or operator's deed of record; or d. for SMP(s) that are owned by a public or private institution (e.g. school, university, hospital), government agency or authority, or public utility, the owner or operator has policies and procedures in place that ensure operation and maintenance of the practices in accordance with the operation and maintenance plan. 5. An owner or operatorthat has met the requirements of Part V.A.1 ., 2., 3., and 4. must request termination of coverage under this permit by submitting a complete Notice of Termination form electronically using a NYSDEC approved form.5 a. The owner's or operator's coverage is terminated as of the termination date indicated in the Letter of Termination (LOT), which is sent by NYSDEC after a complete eNOT is submitted. 5 Unless NYSDEC grants a waiver in accordance with 40 CFR 127.15(c) or (d). All waiver requests must be submitted to Stormwater_info@dec.ny.gov or NYSDEC, Bureau of Water Permits, 625 Broadway, 4t" Floor, Albany, New York 12233-3505. 45 Part VI. Part VI. Record Retention and Reporting A. Record Retention The owner or operator must retain a copy of the documents listed in Part I.E.3. and a copy of the LOT for a period of at least five years from the date that NYSDEC accepts a complete NOT submitted in accordance with Part V. B. Reporting Except for the eNOI, the signature forms associated with the eNOI, and the eNOT, all other written correspondence requested by NYSDEC, including individual permit applications, must be sent to the address of the appropriate DOW (SPDES) Program contact at the Regional Office listed in Appendix E. Part VII. Standard Permit Requirements For the purposes of this permit, examples of contractors and subcontractors include: third-party maintenance and construction contractors. A. Duty to Comply The owner or operator, and all contractors or subcontractors, must comply with all requirements of this permit. Any non-compliance with the requirements of this permit constitutes a violation of the New York State Environmental Conservation Law (ECL), and its implementing regulations, and is grounds for enforcement action. Filing of a request for termination of coverage under this permit, or a notification of planned changes or anticipated non-compliance, does not limit, diminish or stay compliance with any requirements of this permit. B. Need to Halt or Reduce Activity Not a Defense The necessity to halt or reduce the construction activity regulated by this permit, in order to maintain compliance with the requirements of this permit, must not be a defense in an enforcement action. C. Penalties There are substantial criminal, civil, and administrative penalties associated with violating the requirements of this permit. Fines of up to $37,500 per day for each 46 Part VII.C. violation and imprisonment for up to 15 years may be assessed depending upon the nature and degree of the offense. D. False Statements Any person who knowingly makes any false material statement, representation, or certification in any application, record, report, or other document filed or required to be maintained under this permit, including monitoring reports or reports of compliance or noncompliance must, upon conviction, be punished in accordance with ECL §71-1933 and or New York State Penal Law Articles 175 and 210. E. Re-Opener Clause Upon issuance of this permit, a determination has been made on the basis of a submitted Notice of Intent, plans, or other available information, that compliance with the specified permit requirements will reasonably protect classified water use and assure compliance with applicable water quality standards. Satisfaction of the requirements of this permit notwithstanding, if operation pursuant to this permit causes or contributes to a condition in contravention of State water quality standards or guidance values, or if NYSDEC determines that a modification is necessary to prevent impairment of the best use of the waters or to assure maintenance of water quality standards or compliance with other provisions of ECL Article 17 or the Clean Water Act (CWA), or any regulations adopted pursuant thereto, NYSDEC may require such modification and the Commissioner may require abatement action to be taken by the owner or operator and may also prohibit such operation until the modification has been implemented. F. Duty to Mitigate The owner or operator, and its contractors and subcontractors, must take all reasonable steps to minimize or prevent any discharge in violation of this permit which has a reasonable likelihood of adversely affecting human health or the environment. G. Requiring Another General Permit or Individual SPDES Permit NYSDEC may require any owner or operator authorized to discharge in accordance with this permit to apply for and obtain an individual SPDES permit or apply for authorization to discharge in accordance with another general SPDES permit. 1. Cases where an individual SPDES permit or authorization to discharge in accordance with another general SPDES permit may be required include, but is not limited to the following: 47 Part VII.G.1 .a. a. the owner or operator is not in compliance with the conditions of this permit or does not meet the requirements for coverage under this permit; and b. a change has occurred in the availability of demonstrated technology or practices for the control or abatement of pollutants applicable to the point source; and c. new effluent limitation guidelines or new source performance standards are promulgated that are applicable to point sources authorized to discharge in accordance with this permit; and d. existing effluent limitation guidelines or new source performance standards that are applicable to point sources authorized to discharge in accordance with this permit are modified; and e. a water quality management plan containing requirements applicable to such point sources is approved by NYSDEC; and f. circumstances have changed since the time of the request to be covered so that the owner or operator is no longer appropriately controlled under this permit, or either a temporary or permanent reduction or elimination of the authorized discharge is necessary; and g. the discharge is in violation of section 17-0501 of the ECL; and h. the discharge(s) is a significant contributor of pollutants. In making this determination, NYSDEC may consider the following factors: i. the location of the discharge(s) with respect to surface waters of the State; and ii. the size of the discharge(s); and iii. the quantity and nature of the pollutants discharged to surface waters of the State; and iv. other relevant factors including compliance with other provisions of ECL Article 17, or the CWA. 2. When NYSDEC requires any owner or operator authorized by this permit to apply for an individual SPDES permit as provided for in this subdivision, it must notify the owner or operator in writing that a permit application is required. This notice must include a brief statement of the reasons for this decision, an application 48 Part VII.G.2. form, a statement setting a time for the owner or operator to file the application for an individual SPDES permit, and a deadline, not sooner than 180 days from the owner's or operator's receipt of the notification letter, whereby the authorization to discharge under this permit must be terminated. NYSDEC may grant additional time upon demonstration, to the satisfaction of the RWE,6 that additional time to apply for an alternative authorization is necessary or where NYSDEC has not provided a permit determination in accordance with 6 NYCRR Part 621. 3. When an individual SPDES permit is issued to an owner or operator authorized to discharge under this permit for the same discharge(s), this permit authorization for construction activities authorized under the individual SPDES permit is automatically terminated on the effective date of the individual SPDES permit unless termination is earlier in accordance with 6 NYCRR Part 750. H. Duty to Provide Information The owner or operator must furnish to NYSDEC, within five business days, unless otherwise set forth by NYSDEC, any information that NYSDEC may request to determine whether cause exists to determine compliance with this permit or to determine whether cause exists for requiring an individual SPDES permit in accordance with 6 NYCRR 750-1.21(e) (see Part VII.G. Requiring Another General Permit or Individual Permit). The owner or operator must make available to NYSDEC, for inspection and copying, or furnish to NYSDEC within 25 business days of receipt of a NYSDEC request for such information, any information retained in accordance with this permit. Except for Part I.DA. and 5. and Part I.G., the following applies: where the owner or operator becomes aware that it failed to submit any relevant facts on the Notice of Intent, or submitted incorrect information in a Notice of Intent or in any report to NYSDEC, the owner or operator must submit such facts or corrected information to NYSDEC within five business days. I. Extension In the event a new permit is not issued and effective prior to the expiration of this permit, and this permit is extended pursuant to the State Administrative Procedure Act and 6 NYCRR Part 621, then the owner or operator with coverage under this permit may continue to operate and discharge in accordance with the requirements of this permit until a new permit is issued and effective. s The Regional Water Manager where a DEC Region does not have a RWE. 49 Part VII.J. J. Signatories and Certification The Notice of Intent, Notice of Termination, and reports required by this permit must be signed as provided in 40 CFR §122.22. 1. All Notices of Intent and Notices of Termination must be signed as follows: a. For a corporation. By a responsible corporate officer. For the purpose of this section, a responsible corporate officer means: (i) a president, secretary, treasurer, or vice-president of the corporation in charge of a principal business function, or any other person who performs similar policy- or decision-making functions for the corporation; or (ii) the manager of one or more manufacturing, production or operating facilities, provided, the manager is authorized to make management decisions which govern the operation of the regulated facility including having the explicit or implicit duty of making major capital investment recommendations, and initiating and directing other comprehensive measures to assure long term environmental compliance with environmental laws and regulations; the manager can ensure that the necessary systems are established or actions taken to gather complete and accurate information for Notice of Intent or Notice of Termination requirements; and where authority to sign documents has been assigned or delegated to the manager in accordance with corporate procedures. Note: NYSDEC does not require specific assignments or delegations of authority to responsible corporate officers identified in 40 CFR §122.22(a)(1)(i). NYSDEC will presume that these responsible corporate officers have the requisite authority to sign the Notice of Intent or Notice of Termination unless the corporation has notified NYSDEC to the contrary. Corporate procedures governing authority to sign a Notice of Intent or Notice of Termination may provide for assignment or delegation to applicable corporate positions under 40 CFR §122.22(a)(1)(ii) rather than to specific individuals. b. For a partnership or sole proprietorship. By a general partner or the proprietor, respectively. 50 Part VII.J.1 .c. c. For a municipality, State, Federal, or other public agency. By either a principal executive officer or ranking elected official. For purposes of this section, a principal executive officer of a Federal agency includes: 1 . the chief executive officer of the agency; or 2. a senior executive officer having responsibility for the overall operations of a principal geographic unit of the agency (e.g., Regional Administrators of EPA). 2. All reports required by this permit, and other information requested by NYSDEC, must be signed by a person described in Part VII.J.1., or by a duly authorized representative of that person. A person is a duly authorized representative only if: a. The authorization is made in writing by a person described in Part VII.J.1. or using the Duly Authorized Form, found on the DEC website; and b. The authorization specifies either an individual or a position having responsibility for the overall operation of the regulated facility or activity, position of equivalent responsibility, or an individual or position having overall responsibility for environmental matters for the company. (A duly authorized representative may thus be either a named individual or any individual occupying a named position); and c. The written authorization is submitted to NYSDEC. 3. Changes to authorization. If an authorization under Part VII.J.2. is no longer accurate because a different individual or position has responsibility for the overall operation of the construction activity, a new authorization satisfying the requirements of Part VII.J.2. must be submitted to NYSDEC prior to or together with any reports, information, or applications to be signed by an authorized representative. 4. Certification. Any person signing a document under Part VII.J.1. or 2. must make the following certification: 1 certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons who 51 Part VII.J.4. manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations. 5. Electronic reporting. If documents described in Part VII.J.1. or 2. are submitted electronically by or on behalf of the construction activity with coverage under this permit, any person providing the electronic signature for such documents must meet all relevant requirements of this section, and must ensure that all of the relevant requirements of 40 CFR Part 3 (including, in all cases, subpart D to Part 3) (Cross-Media Electronic Reporting) and 40 CFR Part 127 (NPDES Electronic Reporting Requirements) are met for that submission. K. Inspection and Entry The owner or operator must allow NYSDEC, the USEPA Regional Administrator, the applicable county health department, or any authorized representatives of those entities, or, in the case of a construction site which discharges through an MS4, an authorized representative of the MS4 receiving the discharge, upon the presentation of credentials and other documents as may be required by law, to: 1. enter upon the owner's or operator's premises where a regulated facility or activity is located or conducted or where records must be kept under the requirements of this permit; and 2. have access to and copy at reasonable times, any records that must be kept under the requirements of this permit, including records required to be maintained for purposes of operation and maintenance; and 3. inspect at reasonable times any facilities, equipment (including monitoring and control equipment), practices or operations regulated or required under this permit; and 4. sample or monitor at reasonable times, for the purposes of assuring general SPDES permit compliance or as otherwise authorized by the CWA or ECL, any substances or parameters at any location; and 5. enter upon the property of any contributor to the regulated facility or activity under authority of the owner or operator. 52 Part VII.L. L. Confidentiality of Information The following must not be held confidential: this permit, the fact sheet for this permit, the name and address of any owner or operator, effluent data, the Notice of Intent, and information regarding the need to obtain an individual permit or an alternative general SPDES permit. This includes information submitted on forms themselves and any attachments used to supply information required by the forms (except information submitted on usage of substances). Upon the request of the owner or operator, NYSDEC must make determinations of confidentiality in accordance with 6 NYCRR Part 616, except as set forth in the previous sentence. Any information accorded confidential status must be disclosed to the Regional Administrator upon his or her written request. Prior to disclosing such information to the Regional Administrator, NYSDEC will notify the Regional Administrator of the confidential status of such information. M. Other Permits May Be Required Nothing in this permit relieves the owner or operator from a requirement to obtain any other permits required by law. N. NYSDEC Orders or Civil Decrees/Judgments The issuance of this permit by the NYSDEC, and the coverage under this permit by the owner or operator, does not supersede, revoke, or rescind any existing order on consent or civil Decree/Judgment, or modification to any such documents or to any order issued by the Commissioner, or any of the terms, conditions, or requirements contained in such order or modification therefore, unless expressly noted. O. Property Rights Coverage under this permit does not convey any property rights in either real or personal property, or any exclusive privileges, nor does it authorize any injury to private property or any invasion of personal rights, nor any infringement of Federal, State, or local laws or regulations, nor does it obviate the necessity of obtaining the assent of any other jurisdiction as required by law for the discharge authorized. P. Compliance with Interstate Standards If the construction activity covered by this permit originates within the jurisdiction of an interstate water pollution control agency, then the construction activity must also comply with any applicable effluent standards or water quality standards promulgated by that interstate agency and as set forth in this permit for such construction activities. 53 Part VII.Q. Q. Oil and Hazardous Substance Liability Coverage under this permit does not affect the imposition of responsibilities upon, or the institution of any legal action against, the owner or operator under section 311 of the CWA, which must be in conformance with regulations promulgated pursuant to section 311 governing the applicability of section 311 of the CWA to discharges from facilities with NPDES permits, nor must such issuance preclude the institution of any legal action or relieve the owner or operator from any responsibilities, liabilities, or penalties to which the owner or operator is or may be subject pursuant to the Comprehensive Environmental Response, Compensation and Liability Act of 1980, 42 U.S.C. section 9601 et seq. (CERCLA). R. Severability The provisions of this permit are severable, and if any provision of this permit, or the application of any provision of this permit to any circumstance, is held invalid, the application of such provision to other circumstances, and the remainder of this permit, must not be affected thereby. S. NYSDEC Approved Forms The owner or operator must provide all relevant information that is requested by NYSDEC, and required by this permit, on all NYSDEC approved forms. 54 Appendix A APPENDIX A — Abbreviations and Definitions Abbreviations APO —Agency Preservation Officer BB — New York State Standards and Specifications for Erosion and Sediment Control (Blue Book), dated November 2016 BMP — Best Management Practice CPESC — Certified Professional in Erosion and Sediment Control CPv — Channel Protection Volume CWA — Clean Water Act (or the Federal Water Pollution Control Act, 33 U.S.C. §1251 et seq) DM — New York State Stormwater Management Design Manual (Design Manual), dated July 31, 2024 DOW— Division of Water EAF — Environmental Assessment Form ECL — chapter 43-B of the Consolidated Laws of the State of New York, entitled the Environmental Conservation Law EPA — U.S. Environmental Protection Agency HSG — Hydrologic Soil Group MS4 — Municipal Separate Storm Sewer System NOI — Notice of Intent NOT — Notice of Termination NPDES — National Pollutant Discharge Elimination System NYC — The City of New York NYCDEP — The City of New York Department of Environmental Protection NYSDEC — The New York State Department of Environmental Conservation OPRHP — Office of Parks, Recreation and Historic Places Qf— Extreme Flood Qp — Overbank Flood RR — Runoff Reduction RRv — Runoff Reduction Volume RWE — Regional Water Engineer SEAR — State Environmental Quality Review Act SHPA — State Historic Preservation Act SMP — Post-Construction Stormwater Management Practice SPDES — State Pollutant Discharge Elimination System SWPPP — Stormwater Pollution Prevention Plan TMDL — Total Maximum Daily Load UPA — Uniform Procedures Act USDA — United States Department of Agriculture WQv— Water Quality Volume 55 Appendix A Definitions All definitions in this section are solely for the purposes of this permit. If a word is not italicized in the permit, use its common definition. Agricultural Building — a structure designed and constructed to house farm implements, hay, grain, poultry, livestock or other horticultural products; excluding any structure designed, constructed or used, in whole or in part, for human habitation, as a place of employment where agricultural products are processed, treated or packaged, or as a place used by the public. Agricultural Property — the land for construction of a barn, agricultural building, silo, stockyard, pen or other structural practices identified in Table II in the "Agricultural Best Management Practice Systems Catalogue" (dated June 2023). Alter Hydrology from Pre- to Post-Development Conditions — the post-development peak flow rate(s) has increased by more than 5% of the pre-developed condition for the design storm of interest (e.g. 10 yr and 100 yr). Combined Sewer System — a sewer system which conveys sewage and stormwater through a single pipe system to a publicly owned treatment works. Commence (Commencement of) Construction Activities — the initial disturbance of soils associated with clearing, grading or excavation activities; or other construction related activities that disturb or expose soils such as demolition, stockpiling of fill material, and the initial installation of erosion and sediment control practices required in the SWPPP. See definition for "Construction Activity(ies)" also. Common Plan of Development or Sale — a contiguous area where multiple separate and distinct construction activities are occurring, or may occur, under one plan. The "common plan" of development or sale is broadly defined as any announcement or piece of documentation (including a sign, public notice or hearing, marketing plan, advertisement, drawing, permit application, State Environmental Quality Review Act (SEAR) environmental assessment form or other documents, zoning request, computer design, etc.) or physical demarcation (including boundary signs, lot stakes, surveyor markings, etc.) indicating construction activities may occur on a specific plot. A common plan of development or sale is comprised of two or more phases. Common plan of development or sale does not include separate and distinct construction activities that are occurring, or may occur, under one plan that are at least 1/4 mile apart provided any interconnecting road, pipeline or utility project that is part of the same "common plan" is not concurrently being disturbed. 56 Appendix A Construction Activity(ies) — identified within 40 CFR 122.26(b)(14)(x), 122.26(b)(15)(i), and 122.26(b)(15)(ii), any clearing, grading, excavation, filling, demolition or stockpiling activities that result in soil disturbance. Clearing activities can include, but are not limited to, mechanized logging equipment operation, the cutting and skidding of trees, stump removal and/or brush root removal. Construction activity does not include routine maintenance that is performed to maintain the original line and grade, hydraulic capacity, or original purpose of a facility, which is excluded from the calculation of the soil disturbance for a project. Routine maintenance includes, but is not limited to: ■ Re-grading of gravel roads or parking lots; and ■ Cleaning and shaping of existing roadside ditches and culverts that maintains the approximate original line and grade, and maintains or improves the hydraulic capacity of the ditch; and ■ Replacement of existing culverts that maintains the approximate original line and grade, and maintains or improves the hydraulic capacity of a ditch; and ■ Replacement of existing bridges that maintains the approximate original line and grade, and maintains or improves the hydraulic capacity beneath the bridges; and ■ Cleaning and shaping of existing roadside ditches that does not maintain the approximate original grade, hydraulic capacity and purpose of the ditch if the changes to the line and grade, hydraulic capacity or purpose of the ditch are installed to improve water quality and quantity controls (e.g. installing grass lined ditch); and ■ Placement of aggregate shoulder backing that stabilizes the transition between the road shoulder and the ditch or embankment; and ■ Full depth milling and filling of existing asphalt pavements, replacement of concrete pavement slabs, and similar work that does not expose soil or disturb the bottom six (6) inches of subbase material; and ■ Long-term use of equipment storage areas at or near highway maintenance facilities; and ■ Removal of sediment from the edge of the highway to restore a previously existing sheet-flow drainage connection from the highway surface to the highway ditch or embankment; and ■ Existing use of Canal Corp owned upland disposal sites for the canal, and ■ Replacement of curbs, gutters, sidewalks and guide rail posts; and ■ Maintenance of ski trails including brush hog use and mowing; and ■ Above ground snowmaking pipe replacement; and ■ Replacement of existing utility poles; etc. Construction Site — the land area where construction activity(ies) will occur. See also the definitions for "Commence (Commencement oo Construction Activities"and "Common Plan of Development or Sale." 57 Appendix A Dewatering — the act of draining rainwater and/or groundwater from building foundations, vaults or excavations/trenches. Directly Discharge(s)(ing) (to a specific surface waterbody) — runoff flows from a construction site by overland flow and the first point of discharge is the specific surface waterbody, or runoff flows from a construction site to a separate storm sewer system and the first point of discharge from the separate storm sewer system is the specific surface waterbody. Discharge(s)(d) — any addition of any pollutant to waters of the State through an outlet or point source. Embankment— an earthen or rock slope that supports a road/highway. Equivalent (Equivalence) — the practice or measure meets all the performance, longevity, maintenance, and safety objectives of the technical standard and will provide an equal or greater degree of water quality protection. Final Stabilization — all soil disturbance activities have ceased and a uniform, perennial vegetative cover with a density of eighty (80) percent over the entire pervious surface has been established; or other equivalent stabilization measures, such as permanent landscape mulches, rock rip-rap or washed/crushed stone have been applied on all disturbed areas that are not covered by permanent structures, concrete or pavement. Historic Property — any building, structure, site, object or district that is listed on the State or National Registers of Historic Places or is determined to be eligible for listing on the State or National Registers of Historic Places. Impervious Area (Cover) — all impermeable surfaces that cannot effectively infiltrate rainfall. This includes paved, concrete and compacted gravel surfaces (i.e. parking lots, driveways, roads, runways and sidewalks); building rooftops and miscellaneous impermeable structures such as patios, pools, and sheds. Infeasible — not technologically possible, or not economically practicable and achievable considering best industry practices. Minimize(ing)(ation) — reduce and/or eliminate to the extent achievable using control measures (including best management practices) that are technologically available and economically practicable and achievable in light of best industry practices. Municipal Separate Storm Sewer System (MS4) - a conveyance or system of conveyances (including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, man-made channels, or storm drains): 58 Appendix A 1. owned or operated by a State, city, town, village, borough, county, parish, district, association, or other public body (created by or pursuant to State law) having jurisdiction over disposal of sewage, industrial wastes, stormwater, or other wastes, including special districts under State law such as a sewer district, flood control district or drainage district, or similar entity, or an Indian tribe or an authorized Indian tribal organization, or a designated and approved management agency under section 208 of the CWA, that discharges to surface waters of the State; and 2. designed or used for collecting or conveying stormwater, and 3. which is not a combined sewer system; and 4. which is not part of a Publicly Owned Treatment Works (POTW) as defined at 40 CFR 122.2. Natural Buffer(s) — an undisturbed area with natural cover running along a surface water (e.g. wetland, stream, river, lake, etc.). New Development — any land disturbance that does not meet the definition of Redevelopment Activity included in this appendix. New York State Erosion and Sediment Control Certificate Program — a certificate program that establishes and maintains a process to identify and recognize individuals who are capable of developing, designing, inspecting and maintaining erosion and sediment control plans on projects that disturb soils in New York State. The certificate program is administered by the New York State Conservation District Employees Association. Nonpoint Source(s) — any source of water pollution or pollutants which is not a discrete conveyance or point source permitted pursuant to Title 7 or 8 of Article 17 of the Environmental Conservation Law (see ECL Section 17-1403). Overbank — flow events that exceed the capacity of the stream channel and spill out into the adjacent floodplain. Owner or Operator —the person, persons, or legal entity which owns or leases the property on which the construction activity is occurring; an entity that has operational control over the construction plans and specifications, including the ability to make modifications to the plans and specifications; and/or an entity that has day-to-day operational control of those activities at a project that are necessary to ensure compliance with the permit requirements. 59 Appendix A Performance Criteria — the six performance criteria for each group of SMPs in Chapters 5 and 6 of the technical standard, New York State Stormwater Management Design Manual (DM), dated July 31 , 2024. These include feasibility, conveyance, pretreatment, treatment, landscaping, and maintenance. It does not include the Sizing Criteria (i.e. WQv, RRv, CPv, Qp and Qf) in Part I.C.2. of the permit. Phase — a defined area in which construction activities are occurring or will occur separate from other defined area(s). Point Source — any discernible, confined, and discrete conveyance, including but not limited to any pipe, ditch, channel, tunnel, conduit, well, discrete fissure, container, rolling stock, concentrated animal feeding operation, vessel or other floating craft, or landfill Ieachate collection system from which pollutants are or may be discharged. Pollutant(s) — dredged spoil, filter backwash, solid waste, incinerator residue, sewage, garbage, sewage sludge, munitions, chemical wastes, biological materials, radioactive materials, heat, wrecked or discarded equipment, rock, sand and industrial, municipal, agricultural waste and ballast discharged into water; which may cause or might reasonably be expected to cause pollution of the waters of the state in contravention of the standards or guidance values adopted as provided in 6 NYCRR Parts 700 et seq. Qualified Inspector— a person that is knowledgeable in the principles and practices of erosion and sediment control, such as a licensed Professional Engineer, Certified Professional in Erosion and Sediment Control (CPESC), Registered Landscape Architect, New York State Erosion and Sediment Control Certificate Program holder or other NYSDEC endorsed individual(s). It can also mean someone working under the direct supervision of, and at the same company as, the licensed Professional Engineer or Registered Landscape Architect, provided that person has training in the principles and practices of erosion and sediment control. Training in the principles and practices of erosion and sediment control means that the individual working under the direct supervision of the licensed Professional Engineer or Registered Landscape Architect has received four (4) hours of NYSDEC endorsed training in proper erosion and sediment control principles from a Soil and Water Conservation District, or other NYSDEC endorsed entity. After receiving the initial training, the individual working under the direct supervision of the licensed Professional Engineer or Registered Landscape Architect shall receive four (4) hours of training every three (3) years. It can also mean a person that meets the Qualified Professional qualifications in addition to the Qualified Inspector qualifications. Note: Inspections of any SMPs that include structural components, such as a dam for an impoundment, shall be performed by a licensed Professional Engineer. 60 Appendix A Qualified Professional — a person that is knowledgeable in the principles and practices of stormwater management and treatment, such as a licensed Professional Engineer, Registered Landscape Architect or other NYSDEC endorsed individual(s). Individuals preparing SWPPPs that require the SMP component must have an understanding of the principles of hydrology, water quality management practice design, water quantity control design, and, in many cases, the principles of hydraulics. All components of the SWPPP that involve the practice of engineering, as defined by the NYS Education Law (see Article 145), shall be prepared by, or under the direct supervision of, a professional engineer licensed to practice in the State of New York. Redevelopment Activity(ies) — the disturbance and reconstruction of existing impervious area, including impervious areas that were removed from a project site within five (5) years of preliminary project plan submission to the local government (i.e. site plan, subdivision, etc.). Renewable Energy — electricity or thermal energy generated by renewable energy systems through use of the following technologies: solar thermal, photovoltaics, on land and offshore wind, hydroelectric, geothermal electric, geothermal ground source heat, tidal energy, wave energy, ocean thermal, and fuel cells which do not utilize a fossil fuel resource in the process of generating electricity. Site Limitations — site conditions that prevent the use of an infiltration technique and or infiltration of the total WQv. Typical site limitations include: seasonal high groundwater, shallow depth to bedrock, and soils with an infiltration rate less than 0.5 inches/hour. The existence of site limitations shall be confirmed and documented using actual field testing (i.e. test pits, soil borings, and infiltration test) or using information from the most current United States Department of Agriculture (USDA) Soil Survey for the County where the project is located. Sizing Criteria —the criteria included in Part I.C.2 of the permit that are used to size SMPs. The criteria include; Water Quality Volume (WQv), Runoff Reduction Volume (RRv), Channel Protection Volume (Cpv), Overbank Flood (Qp), and Extreme Flood (Qf). Steep Slope — land area designated on the current United States Department of Agriculture (USDA) Soil Survey as Soil Slope Phase D, (provided the map unit name or description is inclusive of slopes greater than 25%), or Soil Slope Phase E or F, (regardless of the map unit name), or a combination of the three designations. Stormwater—that portion of precipitation that, once having fallen to the ground, is in excess of the evaporative or infiltrative capacity of soils, or the retentive capacity of surface features, which flows or will flow off the land by surface runoff to waters of the State. 61 Appendix A Streambank —the terrain alongside the bed of a creek or stream. The bank consists of the sides of the channel, between which the flow is confined. Stormwater Pollution Prevention Plan (SWPPP) — a project specific report, including construction drawings, that among other things: describes the construction activity(ies), identifies the potential sources of pollution at the construction site; describes and shows the stormwater controls that will be used to control the pollutants (i.e. erosion and sediment controls; for many projects, includes SMPs); and identifies procedures the owner or operator will implement to comply with the requirements of the permit. See Part III of the permit for a complete description of the information that must be included in the SWPPP. Surface Waters of the State — shall be construed to include lakes, bays, sounds, ponds, impounding reservoirs, springs, rivers, streams, creeks, estuaries, marshes, inlets, canals, the Atlantic ocean within the territorial seas of the state of New York and all other bodies of surface water, natural or artificial, inland or coastal, fresh or salt, public or private (except those private waters that do not combine or effect a junction with natural surface waters), which are wholly or partially within or bordering the state or within its jurisdiction. Waters of the state are further defined in 6 NYCRR Parts 800 to 941. Temporarily Ceased — an existing disturbed area will not be disturbed again within 14 calendar days of the previous soil disturbance. Temporary Stabilization — exposed soil has been covered with material(s) as set forth in the technical standard, New York Standards and Specifications for Erosion and Sediment Control, to prevent the exposed soil from eroding. The materials can include, but are not limited to, mulch, seed and mulch, and erosion control mats (e.g. jute twisted yarn, excelsior wood fiber mats). Total Maximum Daily Load (TMDL) — the sum of the allowable loads of a single pollutant from all contributing point and nonpoint sources. It is a calculation of the maximum amount of a pollutant that a waterbody can receive and still meet water quality standards, and an allocation of that amount to the pollutant's sources. A TMDL stipulates Waste Load Allocations (WLA) for point source discharges, Load Allocations (LA) for nonpoint sources, and a margin of safety (MOS). Traditional Land Use Control MS4 Operator — a city, town, or village with land use control authority that is authorized to discharge under New York State DEC's SPDES General Permit For Stormwater Discharges from Municipal Separate Stormwater Sewer Systems (MS4s) or the City of New York's Individual SPDES Permit for their Municipal Separate Storm Sewer Systems (NY-0287890). Trained Contractor — an employee from the contracting (construction) company, identified in Part III.A.7., that has received four (4) hours of NYSDEC endorsed training 62 Appendix A in proper erosion and sediment control principles from a Soil and Water Conservation District, or other NYSDEC endorsed entity. After receiving the initial training, the trained contractor shall receive four (4) hours of training every three (3) years. It can also mean an employee from the contracting (construction) company, identified in Part I I I.A.7., that meets the qualified inspector qualifications (e.g. licensed Professional Engineer, Certified Professional in Erosion and Sediment Control (CPESC), Registered Landscape Architect, New York State Erosion and Sediment Control Certificate Program holder, or someone working under the direct supervision of, and at the same company as, the licensed Professional Engineer or Registered Landscape Architect, provided they have received four (4) hours of NYSDEC endorsed training in proper erosion and sediment control principles from a Soil and Water Conservation District, or other NYSDEC endorsed entity). The trained contractor is responsible for the day-to-day implementation of the SWPPP. Tree Clearing — construction activities limited to felling and removal of trees. Tree clearing does not include hand felling and leaving the trees in place with no support from mechanized equipment, which is not considered construction activity requiring coverage under this permit. Water Quality Standard — such measures of purity or quality for any waters in relation to their reasonable and necessary use as promulgated in 6 NYCRR Part 700 et seq. 63 Appendix B APPENDIX B — Required SWPPP Components by Project Type Table 1 CONSTRUCTION ACTIVITIES THAT REQUIRE THE PREPARATION OF A SWPPP THAT ONLY INCLUDES EROSION AND SEDIMENT CONTROLS The following construction activities that involve soil disturbances of one (1) or more acres of land, but less than five (5) acres: • Single-family home not located in one of the watersheds listed in Appendix C and not directly discharging to one of the 303(d) segments listed in Appendix D • Single-family residential subdivisions with 25% or less impervious cover at total site build-out and not located in one of the watersheds listed in Appendix C and not directly discharging to one of the 303(d) segments listed in Appendix D • Construction of a barn or other agricultural building, silo, stock yard or pen. • Structural agricultural conservation practices as identified in Table II in the "Agricultural Best Management Practice Systems Catalogue" (dated June 2023) that include construction or reconstruction of impervious area or alter hydrology from pre-to post-development conditions. The following construction activities that involve soil disturbances between five thousand (5000) square feet and one (1) acre of land: • All construction activities located in the New York City Watershed located east of the Hudson River, see Appendix C Figure 1, that involve soil disturbances between five thousand (5,000) square feet and one (1) acre of land. Within the municipal boundaries of NYC: • Stand-alone road reconstruction, where the total soil disturbance from only that road construction, is less than one (1) acre of land. The following construction activities: • Installation of underground linear utilities; such as gas lines, fiber-optic cable, cable TV, electric, telephone, sewer mains, and water mains • Environmental enhancement projects, such as wetland mitigation, stormwater retrofits, stream restoration, and resiliency projects that reconstruct shoreline areas to address sea level rise • Pond construction • Linear bike paths running through areas with vegetative cover, including bike paths surfaced with an impervious cover • Cross-country ski trails, walking/hiking trails, and mountain biking trails, including a de minimis parking lot (maximum 10 spaces total, sized for passenger cars)with 35 feet minimum preservation of undisturbed area downgradient from the parking lot • Dam rehabilitation (the structure of the dam itself) • Sidewalks, bike paths, or walking paths, surfaced with an impervious cover, that are not part of residential, commercial, or institutional development; • Sidewalks, bike paths, or walking paths, surfaced with an impervious cover, that include incidental shoulder or curb work along an existing highway to support construction of the sidewalk, bike path, or walking path. 64 Appendix B Table 1 (Continued) CONSTRUCTION ACTIVITIES THAT REQUIRE THE PREPARATION OF A SWPPP THAT ONLY INCLUDES EROSION AND SEDIMENT CONTROLS The following construction activities: • Slope stabilization • Slope flattening that changes the grade of the site, but does not significantly change the runoff characteristics • Spoil areas that will be covered with vegetation • Vegetated open space (i.e. recreational parks, lawns, meadows, fields, downhill ski trails)that do not alter hydrology from pre- to post-development conditions • Athletic fields (natural grass)that do not include the construction or reconstruction of impervious area and do not alter hydrology from pre-to post-development conditions • Demolition where vegetation will be established, and no redevelopment activity is planned' • Installation or replacement of either an overhead electric transmission line or a ski lift tower that does not include the construction of permanent access roads or parking areas surfaced with impervious cover. • Solar array field areas that have tables elevated off the ground, spaced one table width apart, do not alter hydrology from pre- to post-development conditions, and address water quality volume and runoff reduction volume by maintaining sheet flow on slopes less than 8%. • Structural agricultural conservation practices as identified in Table II in the "Agricultural Best Management Practice Systems Catalogue" (dated June 2023) that do not include construction or reconstruction of impervious area and do not alter hydrology from pre-to post-development conditions. • Temporary access roads, median crossovers, detour roads, lanes, or other temporary impervious areas that will be restored to pre-construction conditions once the construction activity is complete (in this context, "temporary" means the impervious area will be in place for two years or less) • Other construction activities that do not include the construction or reconstruction of impervious area, and do not alter hydrology from pre-to post-development conditions, and are not listed in Table 2. 1. If the site is redeveloped in the future,a new eNOI must be submitted. 65 Appendix B Table 2 CONSTRUCTION ACTIVITIES THAT REQUIRE THE PREPARATION OF A SWPPP THAT INCLUDES POST-CONSTRUCTION STORMWATER MANAGEMENT PRACTICES (SMPS) The following construction activities: • Single-family home located in one of the watersheds listed in Appendix C or directly discharging to one of the 303(d) segments listed in Appendix D • Single-family home that disturbs five (5) or more acres of land • Single-family residential subdivisions located in one of the watersheds listed in Appendix C or directly discharging to one of the 303(d) segments listed in Appendix D • Single-family residential subdivisions that involve soil disturbances of between one (1) and five (5) acres of land with greater than 25% impervious cover at total site build-out • Single-family residential subdivisions that involve soil disturbances of between 20,000 square feet and one (1) acre of land within the municipal boundaries of NYC with greater than 25% impervious cover at total site build-out • Single-family residential subdivisions that involve soil disturbances of five (5) or more acres of land, and single-family residential subdivisions that involve soil disturbances of less than five (5) acres that are part of a common plan of development or sale that will ultimately disturb five (5) or more acres of land • Multi-family residential developments; includes duplexes, townhomes, condominiums, senior housing complexes, apartment complexes, and mobile home parks • Creation of 5,000 square feet or more of impervious area in the municipal boundaries of NYC • Airports • Amusement parks • Breweries, cideries, and wineries, including establishments constructed on agricultural land • Campgrounds • Cemeteries that include the construction or reconstruction of impervious area (>5% of disturbed area) or alter the hydrology from pre- to post-development conditions • Commercial developments • Churches and other places of worship • Construction of a barn or other agricultural building (e.g. silo) that involves soil disturbance greater than five acres. • Structural agricultural conservation practices as identified in Table II in the "Agricultural Best Management Practice Systems Catalogue" (dated June 2023) that involves soil disturbance greater than five acres and include the construction or reconstruction of impervious area or alter hydrology from pre- to post-development conditions. • Facility buildings, including ski lodges, restroom buildings, pumphouses, ski lift terminals, and maintenance and groomer garages • Institutional development; includes hospitals, prisons, schools and colleges • Industrial facilities; includes industrial parks • Landfills; including creation of landfills or capping landfills. • Municipal facilities; includes highway garages, transfer stations, office buildings, POTWs, water treatment plants, and water storage tanks • Golf courses • Office complexes 66 Appendix B Table 2 (Continued) CONSTRUCTION ACTIVITIES THAT REQUIRE THE PREPARATION OF A $WPPP THAT INCLUDES POST-CONSTRUCTION STORMWATER MANAGEMENT PRACTICES (SMPS) The following construction activities: • Permanent laydown yards and equipment storage lots • Playgrounds that include the construction or reconstruction of impervious area • Sports complexes • Racetracks; includes racetracks with earthen (dirt) surfaces • Road construction or reconstruction, outside the municipal boundaries of NYC • Road construction within the municipal boundaries of NYC • Stand-alone road reconstruction, within the municipal boundaries of NYC where the total soil disturbance from that road reconstruction involves soil disturbance of one (1) acre or more of land • Parking lot construction or reconstruction (as with all Table 2 bullets, this includes parking lots constructed as part of the construction activities listed in Table 1, unless a Table 1 bullet specifies otherwise) • Athletic fields (natural grass)that include the construction or reconstruction of impervious area (>5% of disturbed area) or alter the hydrology from pre- to post-development conditions • Athletic fields with artificial turf • Permanent access roads, parking areas, substations, compressor stations, and well drilling pads, surfaced with impervious cover, and constructed as part of an overhead electric transmission line, wind-power, cell tower, oil or gas well drilling, sewer or water main, ski lift, or other linear utility project • Sidewalks, bike paths, or walking paths, surfaced with an impervious cover, that are part of a residential, commercial or institutional development • Sidewalks, bike paths, or walking paths, surfaced with an impervious cover, that are part of highway construction or reconstruction • Solar array field areas on slopes greater than 8% that cannot maintain sheet flow using management practices identified in the BB or the DM • Solar array field areas on slopes less than 8% that will alter the hydrology from pre-to post- development conditions • Solar array field areas with tables that are not elevated high enough to achieve final stabilization beneath the tables • Traditional impervious areas associated with solar development (e.g. roads, buildings, transformers) • Utility pads surfaced with impervious cover, including electric vehicle charging stations • All other construction activities that include the construction or reconstruction of impervious area or alter the hydrology from pre-to post-development conditions, and are not listed in Table 1 67 Appendix C APPENDIX C —Watersheds Requiring Enhanced Phosphorus Removal Watersheds where owners or operators of construction activities identified in Table 2 of Appendix B must prepare a SWPPP that includes SMPs designed in conformance with the Enhanced Phosphorus Removal Standards included in the DM technical standard. • Entire New York City Watershed located east of the Hudson River— Figure 1 • Onondaga Lake Watershed — Figure 2 • Greenwood Lake Watershed — Figure 3 • Oscawana Lake Watershed — Figure 4 • Kinderhook Lake Watershed — Figure 5 68 Appendix C Figure 1 - New York City Watershed East of the Hudson EEKMAN EAST FISHKILL PAW LI NG I ATTERSON KENT SOUTHEAST PUT AM VALLE [' w CARMEL BIR WSTER N RTH SALEM SOMERS COR A T WISBORO RKTOW EDFORD OUN K CO C N RIDG W TLE RTH CAST M U LEASAN { HA SON 0 EOH Watershed 69 Appendix C Figure 2 - Onondaga Lake Watershed CLAY CICERO NO H US VAN BUREN LI OL SALINA M N US LV EAST SE AM12US G DD ELBRIDG SYRACU DEWITT A�ELLUS SKAN ATEL S ONONDAGA LAFAYE E OTISCO PAFF D TULLY 0 Phosphorus Wate s e REBLE 70 Appendix C Figure 3 - Greenwood Lake Watershed WARWICK / Jr: J f f J J� .J GREENWOOD LAKE Phosphorus Watershed 71 Appendix C Figure 4 - Oscawana Lake Watershed PHILIPSTON KENT PUTNAM 'VALLEY OSCAWANA LAKE CAR I'll E L Phosphorus Watershed 72 Appendix C Figure 5 - Kinderhook Lake Watershed SAND LADE .L;T cjoxL LNk3 U,5 i �.a NAS SAU S HODACK NEW LEBANON KINVERHOOK CF-EATHA Pd CAJ+LAAN vA1 ATIF II Town_Villags. or Crty Boundary for New York S4ate Kindc-Mc*k La-kc WatcmhM I r 73 APPENDIX D — Impaired Waterbodies (by Construction Related Pollutants) List of waterbodies impaired by pollutants related to construction activity, including turbidity, silt/sediment, and nutrients (e.g. nitrogen, phosphorus). This list is a subset of"The Final New York State 2018 Section 303(d) List of Impaired Waters Requiring a TMDL" dated June 2020. County Waterbody Pollutant Albany Ann Lee (Shakers) Pond, Stump Pond (1201-0096) Phosphorus Albany Lawsons Lake (1301-0235) Phosphorus Allegany Amity Lake, Saunders Pond (0403-0054) Phosphorus Allegany Andover Pond (0403-0056) Phosphorus Bronx Reservoir No.1/Lake Isle (1702-0075) Phosphorus Bronx Van Cortlandt Lake (1702-0008) Phosphorus Broome Blueberry, Laurel Lakes (1404-0033) Phosphorus Broome Fly Pond, Deer Lake (1404-0038) Phosphorus Broome Minor Tribs to Lower Susquehanna (0603-0044) Phosphorus Broome Whitney Point Lake/Reservoir(0602-0004) Phosphorus Cattaraugus Allegheny River/Reservoir(0201-0023) Phosphorus Cattaraugus Beaver Lake/Alma Pond (0201-0073) Phosphorus Cattaraugus Case Lake (0201-0020) Phosphorus Cattaraugus Linlyco/Club Pond (0201-0035) Phosphorus Cayuga Duck Lake (0704-0025) Phosphorus Cayuga Owasco Inlet, Upper, and tribs (0706-0014) Nutrients Chautauqua Chadakoin River and tribs (0202-0018) Phosphorus Chautauqua Hulburt/Clymer Pond (0202-0079) Phosphorus Chautauqua Middle Cassadaga Lake (0202-0002) Phosphorus Clinton Great Chazy River, Lower, Main Stem (1002-0001) Silt/Sediment Columbia Robinson Pond (1308-0003) Phosphorus Cortland Dean Pond (0602-0077) Phosphorus Dutchess Fallkill Creek(1301-0087) Phosphorus Dutchess Hillside Lake (1304-0001) Phosphorus Dutchess Wappingers Lake (1305-0001) Phosphorus Dutchess Wappingers Lake (1305-0001) Silt/Sediment Erie Beeman Creek and tribs (0102-0030) Phosphorus Erie Delaware Park Pond (0101-0026) Phosphorus Erie Ellicott Creek, Lower, and tribs (0102-0018) Phosphorus Erie Ellicott Creek, Lower, and tribs (0102-0018) Silt/Sediment Erie Green Lake (0101-0038) Phosphorus Erie Little Sister Creek, Lower, and tribs (0104-0045) Phosphorus Erie Murder Creek, Lower, and tribs (0102-0031) Phosphorus Erie Rush Creek and tribs (0104-0018) Phosphorus Erie Scajaquada Creek, Lower, and tribs (0101-0023) Phosphorus Erie Scajaquada Creek, Middle, and tribs (0101-0033) Phosphorus Erie Scajaquada Creek, Upper, and tribs (0101-0034) Phosphorus Erie South Branch Smoke Cr, Lower, and tribs Phosphorus (0101-0036) South Branch Smoke Cr Lower, and tribs Erie Silt/Sediment (0101-0036) Genesee Bigelow Creek and tribs (0402-0016) Phosphorus Genesee Black Creek, Middle, and minor tribs (0402 0028) Phosphorus Genesee Black Creek, Upper, and minor tribs (0402-0048) Phosphorus Genesee Bowen Brook and tribs (0102-0036) Phosphorus Genesee LeRoy Reservoir(0402-0003) Phosphorus Genesee Mill Pond (0402-0050) Phosphorus Genesee Oak Orchard Cr, Upper, and tribs (0301-0014) Phosphorus Genesee Oatka Creek, Middle, and minor tribs (0402-0031) Phosphorus Genessee Tonawanda Cr, Middle, Main Stem (0102-0002) Phosphorus Greene Schoharie Reservoir (1202-0012) Silt/Sediment Greene Sleepy Hollow Lake (1301-0059) Silt/Sediment Herkimer Steele Creek tribs (1201-0197) Phosphorus Herkimer Steele Creek tribs (1201-0197) Silt/Sediment Kings Hendrix Creek (1701-0006) 18 Nitrogen Kings Prospect Park Lake (1701-0196) Phosphorus Lewis Mill Creek/South Branch, and tribs (0801-0200) Nutrients Livingston Christie Creek and tribs (0402-0060) Phosphorus Livingston Conesus Lake (0402-0004) Phosphorus Livingston Mill Creek and minor tribs (0404-0011) Silt/Sediment Monroe Black Creek, Lower, and minor tribs (0402-0033) Phosphorus Monroe Buck Pond (0301-0017) Phosphorus Monroe Cranberry Pond (0301-0016) Phosphorus Monroe Durand, Eastman Lakes (0302-0037) Phosphorus Monroe Lake Ontario Shoreline, Western (0301-0069) 9 Phosphorus Monroe Long Pond (0301-0015) Phosphorus Monroe Mill Creek and tribs (0302-0025) Phosphorus 2 Monroe Mill Creek/Blue Pond Outlet and tribs (0402-0049) Phosphorus Monroe Minor Tribs to Irondequoit Bay (0302-0038) Phosphorus Monroe Rochester Embayment - East (0302-0002) [9] Phosphorus Monroe Rochester Embayment -West (0301-0068) 9 Phosphorus Monroe Shipbuilders Creek and tribs (0302-0026) Phosphorus 2 Monroe Thomas Creek/White Brook and tribs (0302-0023) Phosphorus 75 Nassau Bannister Creek/Bay (1701-0380) Nitrogen Nassau Beaver Lake (1702-0152) Phosphorus Nassau Browswere Bay (1701-0383) Nitrogen Nassau Camaans Pond (1701-0052) Phosphorus Nassau East Meadow Brook, Upper, and tribs (1701-0211) Silt/Sediment Nassau East Rockaway Channel (1701-0381) Nitrogen Nassau Glen Cove Creek, Lower, and tribs (1702-0146) Silt/Sediment Nassau Grant Park Pond (1701-0054) Phosphorus Nassau Hempstead Bay, Broad Channel (1701-0032) Nitrogen Nassau Hempstead Lake (1701-0015) Phosphorus Nassau Hewlett Bay (1701-0382) Nitrogen Nassau Hog Island Channel (1701-0220) Nitrogen Nassau Massapequa Creek, Upper, and tribs (1701-0174) Phosphorus Nassau Milburn/Parsonage Creeks, Upp, and tribs (1701- Phosphorus 0212) Nassau Reynolds Channel, East(1701-0215) [12] Nitrogen Nassau Reynolds Channel, West (1701-0216) 12 Nitrogen Nassau Tidal Tribs to Hempstead Bay (1701-0218) Nitrogen Nassau Tribs (fresh)to East Bay(1701-0204) Silt/Sediment Nassau Tribs (fresh)to East Bay(1701-0204) Phosphorus Nassau Tribs to Smith Pond/Halls Pond (1701-0221) Phosphorus Nassau Woodmere Channel (1701-0219) Nitrogen New York Harlem Meer(1702-0103) Phosphorus New York The Lake in Central Park (1702-0105) Phosphorus Niagara Bergholtz Creek and tribs (0101-0004) Phosphorus Niagara Hyde Park Lake (0101-0030) Phosphorus Niagara Lake Ontario Shoreline, Western (0301-0053) 9 Phosphorus Niagara Lake Ontario Shoreline, Western (0301-0072) 9 Phosphorus Oneida Ballou, Nail Creeks (1201-0203) Phosphorus Onondaga Ley Creek and tribs (0702-0001) 10 Nutrients (phosphorus) Onondaga Minor Tribs to Onondaga Lake (0702-0022) 10 Nutrients (phosphorus) Onondaga Minor Tribs to Onondaga Lake (0702-0022) 10 Nitrogen (NH3, NO2) Onondaga Onondaga Creek, Lower(0702-0023) 10 Nutrients (phosphorus) Onondaga Onondaga Creek, Lower, and tribs (0702-0023) Turbidity Onondaga Onondaga Creek, Middle, and tribs (0702-0004) Turbidity Onondaga Onondaga Creek, Upper, and tribs (0702-0024) Turbidity Ontario Great Brook and minor tribs (0704-0034) Phosphorus 2 Ontario Great Brook and minor tribs (0704-0034) Silt/Sediment 76 Ontario Hemlock Lake Outlet and minor tribs (0402-0013) Phosphorus Ontario Honeoye Lake (0402-0032) Phosphorus Orange Brown Pond Reservoir(1303-0013) Phosphorus Orange Lake Washington (1303-0012) Phosphorus Orange Minor Tribs to Middle Wallkill (1306-0061) Phosphorus Orange Monhagen Brook and tribs (1306-0074) Phosphorus Orange Orange Lake (1301-0008) [16] Phosphorus Orange Quaker Creek and tribs (1306-0025) Phosphorus Orange Wallkill River, Middle, Main Stem (1306-0038) Phosphorus Orange Wallkill River, Upper, and Minor tribs (1306-0017) Phosphorus Orleans Glenvwood Lake (0301-0041) Phosphorus Orleans Lake Ontario Shoreline, Western (0301-0070) 9 Phosphorus Orleans Lake Ontario Shoreline, Western (0301-0071) 9 Phosphorus Oswego Lake Neatahwanta (0701-0018) Nutrients (phosphorus) Oswego Pleasant Lake (0703-0047) Phosphorus Putnam Lost Lake, Putnam Lake (1302-0053) Phosphorus Putnam Minor Tribs to Croton Falls Reservoir(1302-0001) Phosphorus Queens Bergen Basin (1701-0009) 18 Nitrogen Queens Jamaica Bay, Eastern, and tribs, Queens (1701- Nitrogen 0005) 18 Queens Kissena Lake (1702-0258) Phosphorus Queens Meadow Lake (1702-0030) Phosphorus Queens Shellbank Basin (1701-0001) 18 Nitrogen Queens Willow Lake (1702-0031) Phosphorus Rensselaer Nassau Lake (1310-0001) Phosphorus Rensselaer Snyders Lake (1301-0043) Phosphorus Richmond Grassmere Lake/Bradys Pond (1701-0357) Phosphorus Rockland Congers Lake, Swartout Lake (1501-0019) Phosphorus Rockland Rockland Lake (1501-0021) Phosphorus Saratoga Ballston Lake (1101-0036) Phosphorus Saratoga Dwaas Kill and tribs (1101-0007) Phosphorus Saratoga Dwaas Kill and tribs (1101-0007) Silt/Sediment Saratoga Lake Lonely(1101-0034) Phosphorus Saratoga Round Lake (1101-0060) Phosphorus Saratoga Tribs to Lake Lonely(1101-0001) Phosphorus Schenectady Collins Lake (1201-0077) Phosphorus Schenectady Duane Lake (1311-0006) Phosphorus Schenectady Lake Mariaville Lake (1201-0113) Phosphorus Schuyler Cayuta Lake (0603-0005) Phosphorus 77 Seneca Reeder Creek and tribs (0705-0074) Phosphorus St.Lawrence Black Lake Outlet, Black Lake (0906-0001) Phosphorus St.Lawrence Fish Creek and minor tribs (0906-0026) Phosphorus Steuben Smith Pond (0502-0012) Phosphorus Suffolk Agawam Lake (1701-0117) Phosphorus Suffolk Big/Little Fresh Ponds (1701-0125) Phosphorus Suffolk Canaan Lake (1701-0018) Phosphorus Suffolk Canaan Lake (1701-0018) Silt/Sediment Suffolk Fresh Pond (1701-0241) Phosphorus Suffolk Great South Bay, East (1701-0039) Nitrogen Suffolk Great South Bay, Middle (1701-0040) Nitrogen Suffolk Great South Bay, West(1701-0173) Nitrogen Suffolk Lake Ronkonkoma (1701-0020) Phosphorus Suffolk Mattituck/Marratooka Pond (1701-0129) Phosphorus Suffolk Mill and Seven Ponds (1701-0113) Phosphorus Suffolk Millers Pond (1702-0013) Phosphorus Suffolk Moriches Bay, East (1701-0305) Nitrogen Suffolk Moriches Bay, West (1701-0038) Nitrogen Suffolk Quantuck Bay(1701-0042) Nitrogen Suffolk Shinnecock Bay and Inlet (1701-0033) Nitrogen Suffolk Tidal Tribs to West Moriches Bay (1701-0312) Nitrogen Sullivan Bodine, Mongomery Lakes(1401-0091) Phosphorus Sullivan Davies Lake (1402-0047) Phosphorus Sullivan Evens Lake (1402-0004) Phosphorus Sullivan Pleasure Lake (1402-0055) Phosphorus Sullivan Swan Lake (1401-0063) Phosphorus Tompkins Cayuga Lake, Southern End (0705-0040) Phosphorus Tompkins Cayuga Lake, Southern End (0705-0040) Silt/Sediment Ulster Ashokan Reservoir(1307-0004) Silt/Sediment Ulster Esopus Creek, Lower, Main Stem (1307-0010) [17] Turbidity Ulster Esopus Creek, Middle, Main Stem (1307-0003) 17 Turbidity Ulster Esopus Creek, Upper, and minor tribs Silt/Sediment (1307-0007)[3] Ulster Wallkill River, Lower, Main Stem (1306-0027) Phosphorus Warren Hague Brook and tribs (1006-0006) Silt/Sediment Warren Huddle/Finkle Brooks and tribs (1006-0003) Silt/Sediment Warren Indian Brook and tribs (1006-0002) Silt/Sediment Warren Lake George (1006-0016) and tribs Silt/Sediment Warren Tribs to Lake George, East Shore (1006-0020) Silt/Sediment Warren Tribs to Lake George, Lk.George Village (1006-0008) Silt/Sediment 78 Washington Wood Cr/Champlain Canal and tribs (1005-0036) Phosphorus Westchester Lake Katonah (1302-0136) Phosphorus Westchester Lake Lincolndale (1302-0089) Phosphorus Westchester Lake Meahagh (1301-0053) Phosphorus Westchester Lake Mohegan (1301-0149) Phosphorus Westchester Lake Shenorock (1302-0083) Phosphorus Westchester Mamaroneck River, Lower(1702-0071) Silt/Sediment Westchester Mamaroneck River, Upp, & minor tribs (1702-0123) Silt/Sediment Westchester Saw Mill River (1301-0007) Phosphorus Westchester Saw Mill River, Middle, and tribs (1301-0100) Phosphorus Westchester Sheldrake River(1702-0069) Phosphorus Westchester Sheldrake River(1702-0069) Silt/Sedimnt Westchester Silver Lake (1702-0040) Phosphorus Westchester Teatown Lake (1302-0150) Phosphorus Westchester Truesdale Lake (1302-0054) Phosphorus Westchester Wallace Pond (1301-0140) Phosphorus 79 APPENDIX E — List of NYSDEC Regional Offices DIVISIONOF DIVISIONOF COVERINGRegion - • FOLLOWING COUNTIES: ■ PERMIT ) WATER(SPDES) PROGRAM •. 50 CIRCLE ROAD 50 CIRCLE ROAD NASSAU AND SUFFOLK STONY BROOK,NY 11790 STONY BROOK,NY 11790-3409 TEL.(631)444-0365 TEL.(631)444-0405 1 HUNTERS POINT PLAZA, 1 HUNTERS POINT PLAZA, 2 BRONX,KINGS,NEW YORK, 47-40 21 ST ST. 47-40 21 ST ST. QUEENS AND RICHMOND LONG ISLAND CITY,NY 11101-5407 LONG ISLAND CITY,NY 11101-5407 TEL.(718)482-4997 TEL.(718)482-4933 DUTCHESS,ORANGE,PUTNAM, 21 SOUTH PUTT CORNERS ROAD 220 WHITE PLAINS ROAD,SUITE 110 3 ROCKLAND,SULLIVAN,ULSTER NEW PALTZ,NY 12561-1696 TEL.(914)428-2505 AND WESTCHESTER TEL.(845)256-3059 I ALBANY,COLUMBIA, DELAWARE,GREENE, 1130 NORTH WESTCOTT ROAD 1130 NORTH WESTCOTT ROAD 4 MONTGOMERY,OTSEGO, SCHENECTADY,NY 12306-2014 SCHENECTADY,NY 12306-2014 RENSSELAER,SCHENECTADY TEL.(518)357-2069 TEL.(518)357-2045 AND SCHOHARIE CLINTON,ESSEX,FRANKLIN, 1115 STATE ROUTE 86, PO BOX 296 232 GOLF COURSE ROAD 5 FULTON,HAMILTON, RAY BROOK,NY 12977-0296 WARRENSBURG,NY 12885-1172 SARATOGA,WARREN AND TEL.(518)897-1234 TEL.(518)623-1200 WASHINGTON HERKIMER,JEFFERSON, STATE OFFICE BUILDING I STATE OFFICE BUILDING 6 LEWIS,ONEIDA AND 317 WASHINGTON STREET 207 GENESEE STREET ST. LAWRENCE WATERTOWN, NY 13601-3787 UTICA, NY 13501-2885 TEL.(315)785-2245 TEL.(315)793-2554 BROOME,CAYUGA, CHENANGO,CORTLAND, 5786 WIDEWATERS PARKWAY 5786 WIDEWATERS PARKWAY 7 MADISON,ONONDAGA, SYRACUSE, NY 13214-1867 SYRACUSE, NY 13214-1867 OSWEGO,TIOGA AND TEL.(315)426-7438 TEL.(315)426-7500 TOMPKINS CHEMUNG,GENESEE, LIVINGSTON,MONROE, 6274 EAST AVON-LIMA 6274 EAST AVON-LIMA RD. 8 ONTARIO,ORLEANS, ROADAVON, NY 14414-9519 AVON, NY 14414-9519 SCHUYLER,SENECA, TEL.(585)226-2466 TEL.(585)226-2466 STEUBEN,WAYNE AND YATES ALLEGANY, 700 DELAWARE AVENUE 700 DELAWARE AVENUE 9 CATTARAUGUS, BUFFALO, NY 14209-2999 BUFFALO, NY 14209-2999 CHAUTAUQUA,ERIE, TEL.(716)851-7165 TEL.(716)851-7070 i NIAGARA AND WYOMING 80 APPENDIX F — SWPPP Preparer Certification Form The SWPPP Preparer Certification Form required by this permit begins on the following page. 81 EW Department of YORK STATE Environmental Conservation SWPPP Preparer Certification Form SPDES General Permit for Stormwater Discharges from Construction Activity, GP-0-25-001 (CGP) (In accordance with CGP Part I.D.2.b., the completed form must be attached to the eNOI and submitted to NYSDEC electronically.) Project/Site Name: eNOl Submission ID: Owner/Operator Name: Certification Statement — SWPPP Preparer I hereby certify that the Stormwater Pollution Prevention Plan (SWPPP) has been prepared in accordance with the requirements of GP-0-25-001. I certify under penalty of law that the SWPPP and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations. SWPPP Preparer First Name MI SWPPP Preparer Last Name Signature Date Revised:January 2025 APPENDIX G — MS4 SWPPP Acceptance Form The MS4 SWPPP Acceptance Form required by this permit begins on the following page. 83 Department of RK STATE Environmental Conservation MS4 SWPPP Acceptance Form for construction activities seeking authorization under the SPDES General Permit for Stormwater Discharges from Construction Activity, GP-0-25-001 (CGP) (In accordance with CGP Part I.D.2.b., the completed form must be attached to the eNO1 and submitted to NYSDEC electronically.) I. Project Owner/Operator Information 1. Owner/Operator Name: 2. Contact Person: 3. Street Address: 4. City/State/Zip: II. Project Site Information 5. Project/Site Name: 6. Street Address: 7. City/State/Zip: III. Stormwater Pollution Prevention Plan (SWPPP) Review and Acceptance Information 8. SWPPP Reviewed by: 9. Title/Position: 10. Date Final SWPPP Reviewed and Accepted: IV. Regulated MS4 Information 11. Name of MS4 Operator: 12. MS4 SPDES Permit Identification Number: NYR20A 13. Street Address: 14. City/State/Zip: 15. Telephone Number: Page 1 of 2 MS4 SWPPP Acceptance Form - continued V. Certification Statement - MS4 Official (principal executive officer or ranking elected official) or Duly Authorized Representative I hereby certify that the final Stormwater Pollution Prevention Plan (SWPPP) for the construction project identified in section 11. of this form has been reviewed and meets the substantive requirements in the SPDES General Permit for Stormwater Discharges from Construction Activity, GP-0-25-001 (CGP). Note: The MS4 Operator, through the acceptance of the SWPPP, assumes no responsibility for the accuracy and adequacy of the design included in the SWPPP. In addition, review and acceptance of the SWPPP by the MS4 Operator does not relieve the owner/operator or their SWPPP preparer of responsibility or liability for errors or omissions in the plan. Printed Name': Title/Position: Signature: Date: VI. Additional Information ' Printed name of the principal executive officer or ranking elected official for the MS4 Operator or their duly authorized representative in accordance with CGP Part VII.J.2. (NYSDEC - MS4 SWPPP Acceptance Form - January 2025) Page 2 of 2 APPENDIX H — NYCDEP SWPPP Acceptance/Approval Form The City of New York Department of Environmental Protection (NYCDEP) SWPPP Acceptance/Approval form required by this permit begins on the following page. 86 r THE CITY OF NEW YORK DEPARTMENT OF ENVIRONMENTAL PROTECTION e Envlronmerrtal Bureau of Environmental Planning and Analysis Protection 59-17 Junction Blvd., 9th Floor,Flushing, NY 11373 SWPPP Acceptance/Approval Application Number: I. Project Owner/Operator Information 1. Owner/Operator Name: 2. Contact Person: 3. Street Address: 4. City/State/Zip: II. Project Site Information 5. Project/Site Name: 6. Street Address: 7. City/State/Zip: III. Stormwater Pollution Prevention Plan (SWPPP) Review and Acceptance/Approval 8. SWPPP Reviewed by: 9. Title/Position: / 10. Date Final SWPPP Reviewed and Accepted: 11. Acceptance/Approval Expiration Date: IV. Regulated MS4 Information for projects that require coverage under the NY State Pollution Discharge Elimination System General Permit for Stormwater Discharges from Construction Activity 12. Name of MS4: CITY OF NEW YORK 13. MS4 SPDES Permit Identification Number: NY-0287890 14. Contact Person: 15. Street Address: 59-77 Junction Blvd. 9th Floor 16. City/State/Zip: Flushing, NY 77373 17. Telephone Number: NEWYORI( Projects in the MS4 area must submit a copy of this SWPPP Acceptance with a Notice of STATE OF OPPORTUNITY Intent for coverage under the NY SPDES General Permit for Stormwater Discharges from Department of Construction Activity to: NYS Department of Environmental Conservation, Division of Water; Environmental 625 Broadway, 4th Floor; Albany, New York 12233-3505. Conservation Page 1 Of 2 r THE CITY OF NEW YORK DEPARTMENT OF ENVIRONMENTAL PROTECTION e Envlronmerrtal Bureau of Environmental Planning and Analysis Protection 59-17 Junction Blvd., 9th Floor,Flushing, NY 11373 V. Certification Statement - MS4 Official (principal executive officer or ranking elected official) or Duly Authorized Representative I hereby certify that the final Stormwater Pollution Prevention Plan (SWPPP) for the construction project identified in question 5 has been reviewed and meets the substantive requirements in the SPDES General Permit For Stormwater Discharges from Municipal Separate Storm Sewer Systems (MS4s). Note: The MS4, through the acceptance of the SWPPP, assumes no responsibility for the accuracy and adequacy of the design included in the SWPPP. In addition, review and acceptance of the SWPPP by the MS4 does not relieve the owner/operator or their SWPPP preparer of responsibility or liability for errors or omissions in the plan. Printed Name: Title/Position: Signature: Date: VI. Conditions of Acceptance/Approval and Additional Information ',4NEWYORN Projects in the MS4 area must submit a copy of this SWPPP Acceptance with a Notice of STATE OF OPPORTUNITY Intent for coverage under the NY SPDES General Permit for Stormwater Discharges from Department of Construction Activity to: NYS Department of Environmental Conservation, Division of Water; Environmental 625 Broadway, 4th Floor; Albany, New York 12233-3505. Conservation Page 2Of2 APPENDIX I — MS4 No Jurisdiction Form The MS4 No Jurisdiction Form required by this permit begins on the following page. 89 NEW Department of YORK STATE Environmental Conservation MS4 No Jurisdiction Form for construction activities seeking authorization under the SPDES General Permit for Stormwater Discharges from Construction Activity, GP-0-25-001 (CGP) (In accordance with CGP Part I.D.2.b.,the completed form must be attached to the eNOI and submitted to NYSDEC electronically.) I. Project Owner/Operator Information a. Owner/Operator Name: b. Contact Person: c. Street Address: d. City/State/Zip: II. Project Site Information a. Project/Site Name: b. Street Address: c. City/State/Zip: d. eNCI Submission ID: III. Traditional Land Use Control MS4 Operator Information a. Name of MS4 Operator: b. MS4 SPDES Permit ID Number: NYR20A c. Street Address: d. City/State/Zip: e. Telephone Number: IV. Certification Statement In accordance with CGP Part I.D.2.b.ii.3., I hereby certify that the Traditional Land Use Control MS4 Operator identified in section III. of this form does not have review authority over the construction project identified in section II. of this form,which is owned/operated by the entity identified in section I. of this form. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations. a. Printed name of the principal executive officer or ranking elected official for the MS4 Operator or their duly authorized representative in accordance with CGP Part VI1.J.2.: b. Title/Position: c. Signature: d. Date: APPENDIX J — Owner/Operator Certification Form The Owner/Operator Certification Form required by this permit begins on the following page. 91 NEW Department of STATE Environmental Conservation Owner/Operator Certification Form SPDES General Permit for Stormwater Discharges from Construction Activity, GP-0-25-001 (CGP) (In accordance with CGP Part I.D.2.b. or Part I.F.2. and 3., the completed form must be attached to the eNOI or the Request to Continue Coverage, and submitted to NYSDEC electronically. Project/Site Name: eNO1 Submission ID: eNO1 Submitted by: Owner/Operator SWPPP Preparer Other Certification Statement - Owner/Operator I hereby certify that I read, and will comply with, the GP-0-25-001 permit requirements. I understand that authorization to discharge under the permit for the project/site named above is dependent on receipt of a Letter of Authorization (LOA) or a Letter of Continued Coverage (LOCC) from the New York State Department of Environmental Conservation (NYSDEC) in accordance with CGP Part I.D.3.b. or Part I.F.4. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations. Owner/Operator First Name MI Owner/Operator Last Name Signature Date Revised:January 2025 FINAL New York State Standards and Specifications for Erosion and Sediment Control 1 i 1 November 2016 NEW YOR K CepartI�ment of pp, mi rr Environmental Conservation November 2016 Blue Book Corrections Page Number Change 3.19 Inserted missing language under item 7.1)."Mowing",right-hand column. 3.42 Removed"R"values(Riprap size)from figures 3.16 3.43 Removed"R"values(Riprap size)from figures 3.17 4.52 The fourth sentence under Item 1 of the"Specification for Full Soil Restoration" section has been updated to state"The physical parameters of the compost shall meet the standards listed in Table 5.2—Compost Standards Table,except for "Particle Size" 100%will pass the ''/2"sieve". 5.8 The"Particle size"in Table 5.2—Compost Standards Table now reads"100% passing a 1"screen". NEW YORK STATE STANDARDS AND SPECIFICATIONS FOR EROSION AND SEDIMENT CONTROL Prepared By: Donald W.Lake Jr.,P.E.,CPESC,CPSWQ Adjunct Visiting Professor,SUNY College of Environmental Science and Forestry Former Engineering Specialist,NYS Soil and Water Conservation Committee State Conservation Engineer,USDA-NRCS,Retired And the New York State Department of Environmental Conservation 625 Broadway Albany,NY 12233 Contributing Agencies: Center for Integrated Waste Management,Cornell University New York State Conservation District Employees Association New York State Department of Environmental Conservation New York City Department of Environmental Protection New York State Department of State New York State Department of Transportation New York State Soil&Water Conservation Committee United States Department of Agriculture Natural Resources Conservation Service—formerly the Soil Conservation Service General Disclaimer The mention of trade names,products,proprietary processes,or companies does not constitute an endorsement by the New York State Department of Environmental Conservation. References are used for the purposes of information sources and alternative concepts. This manual is intended for periodic update and thus,sections may be changed or added as criteria for Binder Copies Printed By: For: Empire State Chapter New York State Soil and Water Conservation Society Department of Environmental AND MTER Conservation r-'( >r SOCIETY DEDICATION Since 1993 there has been a relatively small group of dedicated individuals within NYS DEC Division of Water who were charged with the responsibility to protect the state's surface waters from pollution from construction site runoff. Their environmental vision, passion and energy have led us to this advanced document. It is for this we thank and acknowledge the following individuals: N. G. Kaul (deceased) Philip DeGaetano Robin Warrender (deceased) William Morton Kenneth Stevens Angus Eaton Shohreh Karimipour Patrick Ferracane ACKNOWLEDGEMENTS The latest revisions and additions to the New York State • Joseph Damrath,CPESC,CPSWQ,PWS,NYC Standards and Specification for Erosion and Sediment Department of Environmental Protection Control have been prepared through the efforts of many • Blue Neils,CPESC,CPMSM,Cornell Cooperative individuals and organizations.Their contributions have been Extension,Saratoga County numerous and detailed. Several key individuals in these • Ken Barber,PE,Barber Engineering organizations comprised the core team responsible for the completion of this updated book of standards. A number of NYS DEC staff from different divisions assisted with the revisions to this document by providing • Carol Lamb-LaFay,PE,NYS DEC,provided overall review,comments,suggestions,sketches,and details.We project management,guidance,and provided dedicated acknowledge the following individuals for their staff resources to complete this document. contributions: Kathy Czajkowski,Carrie Buetow,Tom Lincoln,Dave Adams,Leslie Surprenant,Gary Feinland, • David Gasper,PE,NYS DEC,coordinated all aspects of Sally Rowland,Josh Thiel,Roy Jacobson,Karen Gaidasz, compiling these standards into a comprehensive Thomas Noll,Peter Briggs,Chris Monaco,Eric Rodriquez, document,including the incorporation of drawings, Holly Kneeshaw,and Scott Dietzel. charts,graphs and correlation of the document to other DEC program areas.He was also responsible for the There were also a number of individuals from other DEC,public agency and peer review process and led the agencies that assisted by reviewing and commenting on the resolution and incorporation of review comments. different drafts of the document.We acknowledge the following individuals for their contribution:Mary Galasso • Ryan Waldron,PE,NYS DEC,is the logistical expert (NYC DEP),Matt Giannetta(NYC DEP),Joseph Damrath behind the document.He was responsible for (NYC DEP),Peter Wright(USDA NRCS),Tim Clark developing new CADD drawings for the book as well as (NYS SWCC),James Austin(NYS DPS),Andrew Davis updating all of the older drawings to meet current (NYS DPS),Jeremy Flaum(NYS DPS),Andrew Dangler, criteria.He incorporated all of the design charts and (ALOE);Kelly Emerick(Monroe County SWCD),Jo-Anne specifications and put the entire document in its current Humphreys(Oneida County SWCD)and Daniel Hitt,RLA publisher format. (NYS DOT). • Ellen Hahn Kubek,CPESC,CPSWQ,NYS DOT, A special thanks to Britt Faucette,Filtrexx International,for formerly a NYS DEC employee when this project his assistance with details on the compost filter sock began,she provided editorial review throughout the standard and providing guidance on the compost material standards development process and provided many specifications. photos for the book that enhance the completed work. Another special thanks to the Washington State,Whatcom She also coordinated field visits to a number of different Soil and Water Conservation District for providing types of construction projects where we gathered photographic documentation for percentages of ground valuable information for this book. cover by grasses. • Donald W.Lake Jr.,PE,CPESC,CPSWQ,worked Also our thanks to the following individuals for their closely with NYS DEC staff to prepare new technical comments during the public/peer review process:John standards and revise and update existing standards.He Dunkle,PE,CPESC,CPMSM;Kimberly Boyd,CPESC, was engaged in providing technical review throughout CPMSM;Kevin Franke;Tom Jarret,PE;John Ellis;Philip the process and participated in the evaluation of peer Kozoil,PE;William Buetow;Maryann Ashworth,Andrew review comments and outside agency input. Fetherston,PE;Kurt Kelsey,Margaret Holden,Esquire; The following individuals greatly assisted in the Karl Schoeberl;and Karen Morrison,PE. development of this revised book of standards by arranging, In addition,a special acknowledgement to the developers of coordinating and conducting field visits to a variety of active the following documents which served as valuable construction site: resources for the revisions and updates to this book of • Kyle Buelow,CPESC,CPSWQ,O'Brien&Gere standards,and from which some related material was used Engineers with permission: • David Graves,CPESC,CPSWQ,NYS Department of • Delaware Erosion and Sediment Control Handbook Transportation • Pennsylvania Erosion&Sediment Pollution Control • Janine Shepherd,NYS Department of Transportation Program Manual • Patrick Ferracane, NYS,Department of Environmental • Maryland Standards and Specifications for Soil Erosion Conservation and Sediment Control • Matt Gianetta,CPSWQ,NYC Department of • Environmental Management and Construction Environmental Protection Standards and Practices for Underground Transmission and Distribution Facilities in New York State PREFACE The parent document,"Guidelines for Erosion and Specifications for Erosion and Sediment Control,August Sediment Control in Urban Areas of New York State,"was 2005. originally published by the USDA Soil Conservation Service in 1972 to provide information on minimizing Since the 2005 New York Standards and Specifications erosion and sediment problems on land undergoing were published,the Constriction General Permit has been development. These guidelines were used by soil and water re-issued twice.In 2008 the General Permit incorporated conservation districts,planning boards,property owners, regulations for construction on slopes steeper than 25% land developers,contractors,and consultants. with limits for over-lot and linear construction.It also excluded coverage from construction that impacted sites Based upon the experience gained in the use of this that were on national or state Historic Registers;and document, a committee was formed in 1978 to update this included a requirement that any disturbance that exceeded guide. This committee contained specialists and five(5)acres at one time had to have a letter from representatives from government,academia and the private NYSDEC accepting the proposed work plan.The 2008 sector. revision also provided standards for three watersheds that required the use of enhanced phosphorous removal This committee completed their draft document,"Sediment techniques. and Erosion Control for Developing Areas,"in May 1980. Before this document could be finalized,technological The 2010 version of the Construction General Permit advances and increased demand for natural resource added an additional phosphorous-impaired watershed as planning due to increased urban pressure on rural areas, well as incorporated additional SWPPP requirements. caused an additional need for revision and expansion of the Items incorporated in the SWPPP by reference to the New technical chapters. York State Stormwater Management Design Manual include soil restoration of over compacted construction In March 1985, work resumed on the guide to expand areas and source control green infrastructure practices to the standards and specifications to include temporary and promote runoff reduction and water quality maintenance. permanent structural measures for erosion and water control,update the discipline vocabulary,incorporate the The 2015 version of the Construction General Permit most recent methods and procedures available,and to added EPA's Construction and Development Effluent provide local planners and legislators with examples of Limit Guidelines(ELGs)as required by 40 CFR 450.21. public administration.This guidance document was The ELGs apply primarily to the selection,design,and completed and published in February 1987. The guide was implementation of erosion and sediment controls(i.e. again revised in mid-1991 to incorporate general updates,a during-construction controls)to be used on a construction chapter on calculating runoff,a chapter on bio-engineering, site.ELGs are technology-based effluent limitations that the addition of temporary and permanent practices and a represent the degree of reduction attainable by the site-specific example demonstrating the planning and application of best practicable technology currently design process. available.These non-numeric effluent limits require an owner or operator to ensure that water quality standards are A General State Pollution Discharge Elimination System being met and the discharge of pollutants are minimized (SPDES) permit for construction activities was through the selection,design and implementation of approved for New York State by the Environmental erosion and sediment control measures. Protection Agency(USEPA) on August 1, 1993. The purpose of this book of standards and specifications is A General SPDES permit was required for any to provide site developers with the minimum design construction site that disturbed five or more acres.It standards for erosion and sediment control to protect required that a Stormwater Pollution Prevention Plan water quality from adverse impacts due to construction (SWPPP)be prepared for each specific site. The activity and reduce sediment damage and associated SWPPP was required to address erosion and sediment maintenance costs of road ditches,storm sewers,streams, control and stormwater management. lakes,and flood control structures. It is distributed by the Empire State Chapter of the Soil and Water Conservation The General SPDES permit was revised in January,2003 Society and also available on the New York State to incorporate the USEPA's-National Pollutant Discharge Department of Environmental Conservation's stormwater Elimination System(NPDES) Phase 2 requirements. web site. These required construction sites disturbing one or more acres to have an erosion and sediment control plan. The This book of standards and specifications should be used guidance document was re-written to incorporate the by site developers in preparing their erosion and sediment most recent developments in the discipline at that time control plans,and by local municipalities in preparing and and became the New York State Standards and implementing their soil erosion and sediment control programs,reviewing proposed site development plans, establishing or encouraging uniformity through standards in applying erosion control techniques,and helping developers,private engineers,and planners make maximum use of potential development sites by proper management of their natural resources. This book of standards and specifications was prepared with and under the direction of,the New York State Department of Environmental Conservation,Division of Water. It is issued by the New York State Department of Environmental Conservation as minimum standards for erosion and sediment control plans prepared for state permits. TABLE OF CONTENTS SECTION 1:INTRODUCTION Purposeand Scope..................................................................................................................................................... 1.1 Authority....................................................................................................................................................................1.1 Erosion and Sediment Hazards Associated with Construction.................................................................................. 1.1 Howto Use This Book of Standards..........................................................................................................................1.2 Basic Principles of Erosion and Sediment Control.................................................................................................... 1.4 PredictingSoil Losses................................................................................................................................................ 1.5 EstimatingSediment Yield......................................................................................................................................... 1.5 Determining Stormwater Runoff................................................................................................................................1.5 ProfessionalCertification...........................................................................................................................................1.5 ESC Ordinances and Subdivision Regulation............................................................................................................1.5 SupplementalStandards.............................................................................................................................................1.5 SECTION 2:EROSION CONTROL PLANNING AND SITE MANAGEMENT Natural Resource and Watershed Planning................................................................................................................2.1 Environmental Site Design Plan................................................................................................................................2.1 Erosion and Sediment Control Plan Components .....................................................................................................2.1 TechnicalData Requirements ............................................................................................................................2.1 GeneralDesign Process .....................................................................................................................................2.2 Constructionof ESCs .........................................................................................................................................2.3 Inspection&Maintenance ........................................................................................................................................2.4 ConstructionActivities...............................................................................................................................................2.4 LinearProjects....................................................................................................................................................2.5 ResidentialDevelopment Projects .....................................................................................................................2.9 Commercial and Industrial Development.........................................................................................................2.10 Institutional Development Projects...................................................................................................................2.11 WaterResources Projects..................................................................................................................................2.12 Large Bulk Overlot Grading Projects................................................................................................................2.12 Design Process for Erosion and Sediment Control Plans.........................................................................................2.13 Erosion and Sediment Control Practices Matrix......................................................................................................2.15 Section Standards Construction Road Stabilization ......................................................................................................................2.23 ConcreteTruck Washout .................................................................................................................................2.24 DustControl .....................................................................................................................................................2.25 Protecting Vegetation During Construction .....................................................................................................2.26 SitePollution Prevention .................................................................................................................................2.29 StabilizedConstruction Access ........................................................................................................................2.30 Temporary Access Waterway Crossing ...........................................................................................................2.32 WinterStabilization ........................................................................................................................................2.38 SECTION 3:EROSION CONTROL PART 1 -RUNOFF CONTROL Scopeand Discussion................................................................................................................................................3.1 CheckDam.........................................................................................................................................................3.2 ConstructionDitch .............................................................................................................................................3.4 DewateringSump Pit .........................................................................................................................................3.7 Diversion.............................................................................................................................................................3.9 EarthDike ........................................................................................................................................................3.14 FlowDiffuser ...................................................................................................................................................3.16 FlowSpreader ..................................................................................................................................................3.19 GradeStabilization Structure............................................................................................................................3.21 GrassedWaterway............................................................................................................................................3.23 LinedWaterway ...............................................................................................................................................3.27 PavedFlume .....................................................................................................................................................3.31 PerimeterDike/Swale ......................................................................................................................................3.35 PipeSlope Drain ..............................................................................................................................................3.37 RockOutlet Protection .....................................................................................................................................3.39 StormDrain Diversion .....................................................................................................................................3.47 SubsurfaceDrain...............................................................................................................................................3.48 WaterBar .........................................................................................................................................................3.52 TABLE OF CONTENTS SECTION 4:EROSION CONTROL PART 2- SOIL STABILIZATION Scopeand Discussion ...............................................................................................................................................4.1 Principles of Bioteclmical Practices ..........................................................................................................................4.1 PlanningConsiderations ...........................................................................................................................................4.3 PlantMaterials ..........................................................................................................................................................4.3 AnchoredStabilization Matting ................................................................................................................................4.5 Armored Slope and Channel Stabilization.................................................................................................................4.7 BranchPacking ......................................................................................................................................................4.15 BrushLayer.............................................................................................................................................................4.17 BrushMattress ........................................................................................................................................................4.19 FertilizerApplication ..............................................................................................................................................4.21 FiberRoll ................................................................................................................................................................4.22 Landgrading ............................................................................................................................................................4.24 LimeApplication ....................................................................................................................................................4.29 LiveCrib Wall.........................................................................................................................................................4.30 LiveFascines ..........................................................................................................................................................4.32 LiveStakes...............................................................................................................................................................4.34 LooseStabilization Blankets ...................................................................................................................................4.37 Mulching .................................................................................................................................................................4.39 Pennanent Construction Area Planting ...................................................................................................................4.42 RecreationArea Seeding .........................................................................................................................................4.45 RetainingWalls .......................................................................................................................................................4.48 SoilRestoration .......................................................................................................................................................4.52 StabilizationWith Sod ............................................................................................................................................4.54 SurfaceRoughening ................................................................................................................................................4.56 TemporaryConstruction Area Seeding ...................................................................................................................4.58 Topsoiling ...............................................................................................................................................................4.59 TreeRevetment .......................................................................................................................................................4.61 Trees,Shrubs, and Vines ........................................................................................................................................4.63 VegetatedRock Gabions .........................................................................................................................................4.66 Vegetating Sand and Gravel Borrow Areas ............................................................................................................4.68 Vegetating Sand Dunes and Tidal Banks ................................................................................................................4.70 VegetatingWaterways ............................................................................................................................................4.78 SECTION 5: SEDIMENT CONTROL Scopeand Discussion ............................................................................................................................................... 5.1 ChemicalTreatment .................................................................................................................................................. 5.1 BufferFilter Strip ...................................................................................................................................................... 5.3 CofferdamStructure .................................................................................................................................................. 5.5 CompostFilter Sock.................................................................................................................................................. 5.7 DewateringDevice .................................................................................................................................................. 5.10 GeotextileFilter Bag ............................................................................................................................................... 5.16 RockDam................................................................................................................................................................ 5.17 SedimentBasin ....................................................................................................................................................... 5.19 SedimentDike ......................................................................................................................................................... 5.42 SedimentTank-Portable......................................................................................................................................... 5.44 SedimentTrap.......................................................................................................................................................... 5.46 SiltFence ................................................................................................................................................................ 5.54 StormDrain Inlet Protection ................................................................................................................................... 5.57 StrawBale Dike ...................................................................................................................................................... 5.63 TurbidityCurtain .................................................................................................................................................... 5.65 TABLE OF CONTENTS APPENDICIES Appendix A:Revised Universal Soil Loss Equation................................................................................................A.1 Appendix B:Design Process for Erosion& Sediment Control Practices ................................................................B.1 Appendix C: Cost Analysis of Erosion& Sediment Control Practices .................................................................... C.1 Appendix D:Erosion Control for Small Residential Sites .......................................................................................D.1 Appendix E: Sample Checklist for Reviewing Erosion and Sediment Control Plans ...............................................E.I Appendix F: Construction Site Inspection&Maintenance Site Log Book ...............................................................F.I Appendix G:Tree Species for New York State .......................................................................................................G.1 AppendixH: Glossary ..............................................................................................................................................H.1 Appendix1:Directories ..............................................................................................................................................1.1 SECTION 1-INTRODUCTION CONTENTS Page Purpose& Scope .............................................................................................................................................................1.1 Authority .........................................................................................................................................................................1.1 Erosion and Sediment Hazards Associated with Development.......................................................................................1.1 Howto Use This Book of Standards ...............................................................................................................................1.2 Basic Principles of Erosion and Sediment Control .........................................................................................................1.4 PredictingSoil Losses .....................................................................................................................................................1.5 EstimatingSediment Yield .............................................................................................................................................1.5 DetenniningStormwater Runoff.....................................................................................................................................1.5 ProfessionalCertification ................................................................................................................................................1.5 ESC Ordinances and Subdivision Regulations ...............................................................................................................1.5 SupplementalStandards ..................................................................................................................................................1.5 Section prepared by: Donald W.Lake Jr.,P.E.,CPESC,CPSWQ Former Engineering Specialist New York State Soil&Water Conservation Committee Adjunct Assistant Professor State University of New York,College of Environmental Fo Science and restry SECTION I-INTRODUCTION Purpose & Scope Note:Performing activities within or adjacent to wetlands,streams and waterbodies may require The purpose of this document is to provide minimum permits from the New York State Department of standards and specifications for meeting criteria set forth by Environmental Conservation(NYSDEC)pursuant to the New York State Department of Environmental Article 15(Protection of Waters),Article 24 Conservation(NYS DEC)for stormwater discharges (Freshwater Wetlands)and Article 25(Tidal Wetlands) associated with construction activity.The standards and of the Environmental Conservation Law(ECL). specifications provide criteria on minimizing erosion and Project owners should contact NYSDEC's Regional sediment impacts from construction activity involving soil Division of Environmental Permits early in the site disturbance. They show how to use soil,water,plants,and planning process to discuss the requirements for products to protect the quality of our environment. These meeting permit issuance standards.Following the New standards and specifications were developed in cooperation York State Standards and Specifications for Erosion with the USDA Natural Resources Conservation Service, and Sediment Control may not ensure compliance with New York State Soil and Water Conservation Committee the above referenced sections of the ECL. (NYSSWCC),NYS DEC and other state and local agencies for use by planners,design engineers,developers, contractors,landscape architects,property owners,and Erosion and Sediment Hazards Associated resource managers. Proper use of these standards will with Development protect the waters of the state from sediment loads during runoff events. Many people may be adversely affected by development on relatively small areas of land. Uncontrolled erosion and Authority sediment from these areas may cause considerable economic damage to individuals and society in general. These standards and specifications apply to lands within Stream pollution and damages to public facilities and New York State where housing,industrial,institutional, private homes are examples. Hazards associated with recreational,or highway construction,and other land land disturbance include: disturbances are occurring or imminent. They are statewide in scope and,in some cases,are somewhat generalized due 1. A large increase of soil exposed to erosion from to variations in climate,topography,geology, soils,and wind and water; plant requirements. Feasible ways to minimize erosion and sedimentation are varied and complex. Following these 2. Increased water runoff,soil movement,sediment standards and specifications is presumed to be in accumulation and peak flows caused by: compliance with the SPDES general permit for construction a. Removal of plant cover and topsoil; activities. Alternative methods may be explored on a case specific basis and shall be discussed with NYS DEC b. A decrease in the area of soil which can regional staff. absorb water because of construction of streets,buildings,sidewalks,and parking lots; The Environmental Protection Agency delegated stormwater responsibility for the National Pollutant c. Changes in drainage areas caused by grading Discharge Elimination System(NPDES)Permit to New operations,diversions,and streets; York on October 1, 1992. New York State issued its first d. Changes in volume and duration of water General Permit for stormwater discharges from construction concentrations caused by altering steepness, activities on August 1, 1993. This permit was issued distance,and surface roughness; pursuant to Article 17,Titles 7, 8 and Article 70 of Environmental Conservation Law. At a minimum,an e. Soil compaction by heavy equipment,which erosion and sediment control plan must be prepared for any can reduce the water intake of soils as much as construction activity that disturbs one or more acres and,in 90 percent of the original rate;and, some special watersheds,5,000 square feet. f. Prolonged exposure of unprotected sites and disturbed areas to poor weather conditions. 3. Altering the groundwater regime that may adversely affect drainage systems, slope stability, survival of existing vegetation and establishment of new plants; November 2016 Page 1.1 New York State Standards and Specifications For Erosion and Sediment Control 4. Exposing subsurface materials that are too rocky,too This section presents detailed standards and specifications acid,or otherwise unfavorable for establishing plants; for soil stabilization,the second part of erosion control.It includes standards for grading activities,stabilization with 5. Obstructing stream flow with new buildings, seeding and mulching,use of stabilization matting, dikes,and landfills; application of loose stabilization blankets and addresses special applications. Standards for lime and fertilizer 6. Improper riming and sequencing of construction application are also included.Bio-technical standards for and development activities;and, live fascines,brush mattress and others,are presented for 7. Abandonment of sites before completion of stabilizing steep slopes,road banks,and stream banks. Structural components are also included to aid where construction. vegetative applications alone are inadequate to stabilize an How to Use This Book of Standards area. Section 5. Sediment Control This book of standards is organized in a manner to emphasize good planning and environmental site design at This section addresses the capture,retention and control of the onset of a project,followed by the design process noting sediment within the boundaries of the disturbed the differences with different types of construction construction site. Standards and specifications are included operations.Standards are presented in the order of proper site management in the beginning followed by erosion for perimeter controls,storm drain inlet protection,buffer control,using runoff control and soil stabilization,and then filter strips,temporary sediment traps,tanks,tubes,bags sediment control practices. and sediment basins and dewatering devices.A standard for polymer flocculation of dispersive soils is also included in this section. The standards and specifications listed in this book have been developed over time to reduce the impact of soil Appendices loss from construction sites to receiving water bodies and adjacent properties. This book provides designers with Appendix A. Revised Universal Soil Loss Equation details on how to plan a site for erosion and sediment control and how to select,size,and design specific Soil types at construction sites play a predominant role in practices to meet these resource protection objectives. The how the site should be constructed to control erosion. appendices at the end of this book contain additional Knowledge of soil properties,particularly when soils are information as guidance for site plan design and review, highly erosive,is essential. This appendix discusses soil construction implementation,and site inspection.Review properties and provides a method to calculate potential soil and inspection checklists are provided to aid planners and loss and provide a measure of reduction depending on designers in meeting the standards requirements. slope,area,and protective cover. Section 2. Site Planning.Preparation,and Management Appendix B. Design Process for Erosion&Sediment Control Practices This section discusses the objectives of the erosion and sediment control plan. Site and off-site resources are This appendix demonstrates the design processes for a identified and incorporated into a seven step design process. number of standard practices presented in this book. In addition, special considerations for different types of Specific site examples are used to show step by step project development and their needs for erosion and procedures to complete detailed designs of the practices, sediment control planning are discussed.Typical site including the appropriate construction specifications, management standards are located in this section. maintenance,and inspection requirements.These processes will allow a designer to evaluate an existing condition or Section 3. Erosion Control Part 1-Runoff Control design to a specific level of performance higher than the minimum level presented in these standards. This section provides a number of specific runoff control standards to meet a variety of project needs. Both temporary and permanent practices are presented to manage Appendix Cost Analysis of Erosion&Sediment stormwater runoff to and within the site.The design of some Control Practices of these practices can be completed by selecting dimensions This appendix provides historical bid information for most based on tributary drainage areas;while others require more of the practices contained in the manual. Sources included detailed design analysis the NYS Department of Transportation,Monroe County Section 4. Erosion Control Part 2-Soil Stabilization SWCD,national periodicals,and erosion and sediment control cost data from other states. This information will assist a designer in preparing cost estimates for specific New York State Standards and Specifications Page 1.2 November 2016 For Erosion and Sediment Control erosion and sediment control plans. Appendix D. Erosion Control for Small Residential Sites Within New York State SPDES requirements,many small residential sites have to file for permit coverage.For those sites that require the preparation of a SWPPP which only requires erosion and sediment control plans,this appendix presents example plans for scenarios that can be used by the local authorities and site owners Attaching the appropriate plan to the building permit assists the owner with compliance with the provisions of the permit. Appendix E. Sample Checklist for Reviewing Erosion and Sediment Control Plans This appendix includes a comprehensive checklist for use by all site plan reviewers(including planning board members,conservation board members,conservation district personnel,engineers,consultants,approval authorities,and others)when reviewing erosion and sediment control plans for completeness and proper management. Appendix F. Construction Site Inspection&Maintenance Site Log Book A proper site inspection,whether conducted by local authorities or project staff,is necessary to assess the site conditions and the practices implemented. This appendix includes a detailed checklist to assist inspectors in conducting a thorough evaluation of the site when judging the effectiveness of the erosion and sediment control measures. Appendix G. Tree Species for New York State This appendix identifies tress suitable for landscape and conservation plantings in New York State. Appendix H. Glossary This appendix presents a list of terms commonly used in site planning,design,erosion and sediment control,soil science, construction activities,streambank stabilization and corridor restoration,vegetation,engineering,hydrology and water quality. Appendix L Directories This appendix presents listings of contact information and locations of federal,state,regional and local agencies,who may be involved with environmental and technical review of erosion and sediment control plans.These agencies may also provide data important to the development of stormwater management plans. November 2016 Page 1.3 New York State Standards and Specifications For Erosion and Sediment Control BASIC PRINCIPLES OF EROSION AND SEDIMENT CONTROL The Erosion and Sedimentation Processes Organic matter helps to maintain stable soil structure (aggregates). The standards,specifications,and planning procedures presented in this document are intended to be utilized when 2. Vegetative Cover—Vegetation protects soil from the development activities change the natural topography and erosive forces of raindrop impact and runoff scour in vegetative cover of an area.Erosion and sediment control several ways. Vegetation(top growth)shields the plans must be designed and constructed to minimize erosion soil surface from raindrop impact while the root mass and sediment problems associated with soil disturbance. To holds soil particles in place. Grass buffer strips can understand how erosion and sediment rates are increased be used to filter sediment from the surface runoff. requires an understanding of the processes themselves. Grasses also slow the velocity of runoff,and help maintain the infiltration capacity of a soil. The Soil erosion is the removal of soil by water,wind,ice,or establishment and maintenance of vegetation are gravity. This document deals primarily with the types of the most important factors in minimizing erosion soil erosion caused by rainfall and surface runoff during development. accelerated due to soil disturbance.Raindrops strike the soil surface at a velocity of approximately 25-30 feet per 3. Topography—Slope length and steepness greatly second and can cause splash erosion. Raindrop erosion influence both the volume and velocity of surface causes particles of soil to be detached from the soil mass runoff.Long slopes deliver more runoff to the base of and splash into the air. After the soil particles are slopes and steep slopes increase runoff velocity. Both dislodged,they can be transported by surface runoff, conditions enhance the potential for erosion to occur. which results when the soil becomes too saturated to absorb falling rain or when the rain falls at an intensity 4. Climate—Climate also affects erosion potential in an greater than the rate at which the water can enter area. Rainfall characteristics such as frequency, the soil. Scouring of the exposed soil surface by runoff can intensity,and duration directly influence the amount cause further erosion. Runoff can become concentrated into of runoff that is generated. As the frequency of rivulets or well-defined channels up to several inches deep. rainfall increases,water has less chance to drain This advanced stage is called rill erosion. If rills and through the soil between storms. The soil will remain grooves remain unrepaired,they may develop into gullies saturated for longer periods of time and stormwater when more concentrated runoff flows downslope. runoff volume may be potentially greater.Therefore, erosion risks are high where rainfall is frequent, Sediment deposition occurs when the rate of surface flow is intense,or lengthy. insufficient for the transport of soil particles. The heavier particles, such as sand and gravel,transport less readily than 5. Season—Seasonal variation in temperature and the lighter silt and clay particles. Previously deposited rainfall defines periods of high erosion potential sediment may be re-suspended by runoff from another during the year.High erosion potential may exist in storm and transported farther downslope. In this way, the spring when the surface soil first thaws and the sediment is carried intermittently downstream from its ground underneath remains frozen. A low intensity upland point of origin. rainfall may cause substantial erosion because the frozen subsoil prevents water infiltration. In addition, Factors That Influence Erosion the erosion potential increases during the summer The erosion potential of a site is determined by five factors; months due to more frequent,high intensity rainfall. soil erodibility,vegetative cover,topography,climate,and season. Although the factors are interrelated as determinants of erosion potential,they are discussed separately for easy understanding. 1. Soil Erodibility—The vulnerability of a soil to erosion is known as erodibility. The soil structure, texture,and percentage of organic matter influence its erodibility. The most erodible soils generally contain high proportions of silt and very fine sand. The presence of clay(except for dispersive clay)or organic matter,tends to decrease soil erodibility. Clays are sticky and tend to bind soil particles together. New York State Standards and Specifications Page 1.4 November 2016 For Erosion and Sediment Control Predicting Soil Losses International,Inc. administers a program to evaluate individuals as a CPESC. Such individuals have acquired Prediction of soil loss is a planning tool. The predictions specific training and passed an examination in erosion and guide planners on the degree of erosion and sediment sediment control(ESC). These individuals are generally control at specific sites. Predicted soil losses also creates available for site design and/or implementation oversight. awareness among developers,local governments and others Their website is http://www.envirocertind.oim/ct)esc. of the urgent need to install erosion and sediment control measures before,during and after construction activity. ESC Ordinances and Subdivision Regulations Soil losses can be predicted for a whole year,part of a year or on the basis of rainfall amounts. The Revised Local ESC Laws and land use regulations protect the Universal Soil Loss Equation(RUSLE)is used to public welfare by saving money on public infrastructure estimate soil losses on construction sites from sheet and and maintenance,increasing public safety,protecting rill erosion. The equation uses site-specific rainfall water supplies(including groundwater),providing flood intensity,soil erodibility and slope factors(see Appendix control protection and preserving aquatic and riparian A). Other soil losses, such as gully erosion or wind wildlife habitat.All ESC plans shall meet or exceed all erosion,are calculated separately. local and state laws,ordinances and regulations. There are over 440 different soils in New York State. Supplemental Standards These soils are made up of different percentages of gravel, sand,silt,clay and organic material.Thus,they erode at The standards set forth in this manual should be different rates.Table 2.5 in Section 2 provides a general appropriately incorporated into all ESC plans unless the characterization of erosion risk based on slope and designer shows that alteration of these standards or associated physical factors. inclusion of practices not included in this document will perform to or exceed the level of performance of the current Estimating Sediment Yield practices.Proposed supplemental standards or procedures must be submitted to the regional NYSDEC office and Sediment yield involves both soil erosion on the site and include the following information: the transport mechanism acting to carry the eroded 1. The name of the product and type of control if a brand material off the site. name is used. Where sediment yields from a developing area are needed 2. The proposed use(e.g.runoff control),reason for use, for estimating sediment basin design volumes, the method calculated level of performance(e.g.impact at the 1 in Appendix A can be used for determining the amount of year 24 hour storm),field test performance results,and the eroded material that will leave the site as sediment. specifications conforming to any manufacturer's recommendations. Determining Stormwater Runoff 3. The definition of product failure should be clearly Stormwater hydrology should be calculated using the stated. hydrologic data and rainfall distributions published by the 4. Sufficient installation information should be provided Northeast Regional Climate Center(NRCC)on their website to ensure its proper use.This shall include a clear, httn://Drecip.eas.cornell.edu/. These data can be concise sequence and a typical detail(s)showing all imported into HydroCAD,USDA NRCS TR20,and other critical dimensions and elevations. computer models for use in watershed evaluations and stormwater management practice design.Detailed soils 5. The plan maps shall show all locations where the information,such as the appropriate Hydrologic Soil Group proposed new product or procedure will be used.All for drainage analysis,should be obtained from the USDA receiving waters shall be identified. NRCS Web Soil Survey at their website htt):// 6. A suitable maintenance program shall be provided websoilsurvey.sc.egov.usda.gov/Auu/HomePage.htm which shall include instructions for remedy of potential problems. An alternative conventional erosion control Professional Certification practice should be specified for immediate installation It is important that erosion and sediment control plans be should the innovative product or procedure fail. prepared by qualified individuals.State licensed engineers, Proposed standards,products or procedures which meet the registered landscape architects and Certified Professional in above criteria will be reviewed on a case-by-case basis until Erosion and Sediment Control(CPESC)provide the their effectiveness has been sufficiently demonstrated by technical skills required to design erosion and sediment successful use in the field. control plans and inspect construction sites. EnviroCert November 2016 Page 1.5 New York State Standards and Specifications For Erosion and Sediment Control SECTION 2 EROSION CONTROL PLANNING AND SITE MANAGEMENT CONTENTS Page List of Tables and Figures Natural Resource and Watershed Planning ......................................................................................................................2.1 EnvironmentalSite Design Plan.......................................................................................................................................2.1 Erosion and Sediment Control Plan Components ............................................................................................................2.1 TechnicalData Requirements ............................................................................................................................2.1 GeneralDesign Process .....................................................................................................................................2.2 Constructionof ESCs ........................................................................................................................................2.3 Inspection&Maintenance ...............................................................................................................................................2.4 ConstructionActivities ....................................................................................................................................................2.4 LinearProjects ...................................................................................................................................................2.5 ResidentialDevelopment Projects .....................................................................................................................2.9 Commercial and Industrial Development Projects ..........................................................................................2.10 Institutional Development Projects ..................................................................................................................2.11 WaterResources Projects ................................................................................................................................2.12 Large Bulk,Overlot Grading Projects .............................................................................................................2.12 Design Process for Erosion&Sediment Control Plans .................................................................................................2.13 Erosion and Sediment Control Practices Matrices .........................................................................................................2.15 Section Standards Construction Road Stabilization ......................................................................................................................2.23 ConcreteTruck Washout .................................................................................................................................2.24 DustControl .....................................................................................................................................................2.25 Protecting Vegetation During Construction .....................................................................................................2.26 SitePollution Prevention .................................................................................................................................2.29 StabilizedConstruction Access ........................................................................................................................2.30 Temporary Access Waterway Crossing ...........................................................................................................2.32 WinterStabilization ........................................................................................................................................2.38 References ......................................................................................................................................................................2.39 Section prepared by: Donald W.Lake Jr.,P.E.,CPESC,CPSWQ Former Engineering Specialist New York State Soil&Water Conservation Committee Adjunct Assistant Professor State University of New York,College of Environmen- tal Science and Forestry List of Tables and Figures Table Title Page 2.1 Erosion and Sediment Control Practices Matrix- Site Planning,Preparation and Management.........2.16 2.2 Erosion and Sediment Control Practices Matrix-Erosion Control Part 1 -Runoff Control ...............2.17 2.3 Erosion and Sediment Control Practices Matrix-Erosion Control Part 2- Soil Stabilization............2.18 2.4 Erosion and Sediment Control Practices Matrix- Sediment Control ..................................................2.20 2.5 Erosion Risk ........................................................................................................................................2.22 2.6 Susceptibility of Tree Species to Compaction .....................................................................................2.28 Figure Title Page 2.1 Stabilized Construction Access ..........................................................................................................2.31 2.2 Temporary Access Bridge ...................................................................................................................2.36 2.3 Temporary Access Culvert ..................................................................................................................2.37 SITE PLANNING PREPARATION AND MANAGEMENT Natural Resource &Watershed Planning runoff, and increasing infiltration. Erosion and sediment control needs to be considered from the beginning planning stages and the design and review of erosion and sediment The most effective solutions to erosion and sediment control and stormwater management plans. This includes problems begin with natural resource and watershed elements for the preservation of natural features and green planning. This type of planning can guide and control infrastructure techniques for the reduction of impervious development growth,preventing wasteful and haphazard cover which must be integrated into the site plan approval development.The natural resource planning process process (refer to NYS Stormwater Management Design integrates ecological(natural resource),economic,and Manual,Chapters 3 and 5). social considerations to meet private and public needs.This Natural resources need to be identified in the planning approach,which emphasizes identifying desired future process in order to design an appropriate ESC plan. The conditions,improves natural resource management, plan should have resource protection at its core and minimizes conflict,and addresses problems and emphasize EROSION CONTROL(controlling runoff and opportunities. stabilizing soil),first as its main component and sediment control, second as a management practice. The reduction of Watershed planning is another useful tool for building a soil loss decreases the cost and maintenance of sediment community's land use plans because watersheds are defined control practices,reduces the risk of degrading natural by natural hydrology,representing the most logical basis for resources and improves the overall appearance of the managing water resources. The resource becomes the focal construction site. point,and planners are able to gain a more complete understanding of overall conditions in an area and the Erosion and Sediment Control Plan stressors which affect those conditions. Components Regional,county and local planning agencies,Soil and L Technical Data Requirements Water Conservation Districts(SWCD),and the Natural Resource Conservation Service(MRCS)have technical Features of the site including location,site boundaries, expertise,resource data and information that can assist accessibility,present land use,delineation of areas decision making by local authorities. These decisions protected by local,state and federal regulations(e.g. should consider reserving quality agricultural areas for wetlands and streams),size of proposed tract(s), cropland;maintaining the economic viability of agriculture; topography,drainage pattern,geology,hydrology, soils, protecting historical,scenic,and natural beauty areas; vegetation and climate need to be assembled. Such protecting wetlands and stream corridors;providing for information is obtained from on-site examinations and open spaces and parks;developing attractive residential, existing technical reports,maps,records,and other institutional and industrial areas;and maintaining documented material usually floodplains for flood storage,groundwater recharge,water available from local sources. supply source protection,critical habitat preservation by connecting wildlife populations in fractured landscapes, This technical data provides the framework necessary to recreation buffer zones,and conservation education uses. make informed decisions about a site's ultimate use and Environmental quality is enhanced when open spaces, the types of erosion and sediment controls that will work. parks,recreational areas,ponds,wildlife habitat and other Soils information such as detailed soil maps and areas of public use become integral parts of the plan. These interpretations are available on the USDA NRCS areas should be well delineated and protected from damage website,http://websoilsurvey.sc.egov.usda.gov/Al) that may occur from nearby construction. Selections of HomePage.htm and will specifically provide the such areas should be based upon soils,vegetation,water, following soils information: topography,accessibility,wildlife,and aesthetic values. a. Descriptions,erodibility,limitations,capabilities, Environmental Site Design (ESD) Plan and hydrologic soil groups; As land is subdivided or proposals brought forward for land b. Engineering properties of soils; development, an assessment of suitability of the site for the proposed development needs to be made. ESD is using c. Suitability of the soil as a resource material for small scale stormwater management practices, non- topsoil,gravel,highway sand,dams and levees; structural techniques, and site planning to mimic natural hydrologic runoff characteristics and minimize the impact d. Site suitability for buildings,roads,winter soil of land development on water resources. ESD emphasizes disturbance,foundations,septic tank disposal fields, conserving natural features, drainage patterns, and sanitary land fills,vegetation,reservoirs,dams, vegetation; minimizing impervious surfaces; slowing down New York State Standards and Specifications Page 2.1 November 2016 For Erosion and Sediment Control artificial drainage,recreational areas and wildlife 3. Determine Limits of Clearing and Grading development. Decide exactly which areas must be disturbed in order to IL General Design Process accommodate the proposed construction. Pay special attention to critical areas(e.g. steep slopes,highly erodible 1. Plan the Development to Fit the Site soils, surface water bodies),which must be disturbed. Additional erosion and sediment controls are often Assess the physical characteristics of the site during a necessary to mitigate the potential impacts to critical or site visit to determine how it can be developed with the sensitive areas. Staged clearing and grading is necessary to lowest risk of environmental impact. Minimize grading keep unprotected areas of disturbance to less than 5 acres at by utilizing the existing topography wherever possible. one time. Delineate and avoid disturbing wetlands,stream corridors and,to the extent practicable,wood lots,steep 4. Design The Erosion and Sediment Control(ESC)Plan slopes and other environmentally sensitive areas. Minimize impacts by maintaining vegetative buffer An ESC plan shows the site's existing topography,and how strips between disturbed area and water resources. and when it will be altered. It also shows the ESC Existing woody or State protected vegetation on a measures that will be used to reduce sediment pollution and project site should be delineated,retained,and protected how and when they will be constructed and maintained. as required. Planning of streets and lots should relate to The coordination of ESC practices with construction site conditions. Streets laid out at right angles to activities is explained on the plan by a phasing and contours often have excessive grades that increase construction sequencing schedule.All projects shall have erosion hazards and sedimentation. ESC plans prepared for each phase of the work. 2. Divide the Site into Natural Drainage Areas In addition to regulatory control, an ESC plan should be prepared for all land development and construction activity Determine how runoff will drain from the site. Natural when uncontrolled erosion and sedimentation is waterbodies should not be altered or relocated without the anticipated. At a minimum,this includes: proper approvals. Pursuant to Article 15 of the Environmental Conservation Law(ECL),a protected a. sites on slopes that exceed 15%; waterbody and the bed and banks thereof should not be altered or relocated without the approval of the Department b. sites in areas of severe erosion potential; of Environmental Conservation. Section 10 of the Rivers c. sites within 100 ft.and draining to wetland; and Harbors Act and Section 404 of the Clean Water Act also protects water resources and proposed disturbances d. sites within 100 ft.and draining to a watercourse; may require approvals from The US Army Corps of and/or; Engineers. e. sites with a high percentage of colloidal solids Integrated surface and storm drainage systems are an It is essential for the ESC designer to remember that essential part of any planned development. The plan should sediment control facilities, even when designed and clearly specify:location and capacity of diversions and constructed properly, rarely exceed 80 percent removal stormwater basins;paved or other types of lined channels, rates for sediment. A properly designed ESC plan for a outlets and waterways;drop inlets;open or closed drains; large scale commercial or industrial site will typically stream channel protection and bank erosion structures. involve several phases, possibly more than one ESC stage Consider how erosion and sedimentation can be controlled and utilize many different practices. in each small drainage area before looking at the entire site. Diversion of offsite surface water run on away from ESC practices are categorized as vegetative and/or exposed soils provides the most economic and effective structural controls. While more details on these practices erosion control possible since it is more advantageous to are contained in other sections of this book of standards, control erosion at the source than to design controls to general information on vegetative and structural controls is trap suspended sediment. However,attempting to outlined below: divert large drainage areas can be problematic. Therefore,the channel should be stabilized and A. Vegetative Controls—The best way to protect the conveyed to a stable outlet/receiving stream. The soil surface and limit erosion is to preserve the receiving stream should be evaluated to ensure that its existing vegetative groundcover. Where land flow regime will not be disrupted. Whenever possible disturbance is necessary,temporary seeding or the diversion should be temporary to restore the natural mulching must be used on areas which will be drainage patterns. exposed for more than 14 days. Permanent stabilization should be performed as soon as possible November 2016 Page 2.2 New York State Standards and Specifications For Erosion and Sediment Control after completion of final grading. ESC plans must requirements,for all erosion and sediment control contain provisions for permanent stabilization of practices,including the locations and size of any disturbed areas. Seed type,application rates, soil temporary sediment traps,basins,or structural amendments,seedbed preparation in accordance with practice. standards contained in this book,mulch,and mulch anchoring must be described on the plans. Selection 5. Notes regarding temporary ESC facilities which of permanent vegetation will include the following will be converted to permanent stormwater considerations for each plant species: management facilities. 1) establishment requirements; 6. A schedule to establish the construction sequence 2) adaptability to site conditions; 3) aesthetic and natural resource values; of temporary and permanent practices and their timing relative to other construction activities. 4) maintenance requirements. B. Structural Controls—Structural erosion control 7. An inspection and maintenance schedule for soil practices may be necessary when disturbed areas ESC facilities which describes maintenance cannot be promptly stabilized with vegetation. activities to be performed. Structural practices shall be constructed and maintained in accordance with the standards and 8. Dewatering practices for subsurface construction specifications in this document. Structural activities. practices may be temporary or permanent. Temporary practices are removed after site A sample ESC checklist is contained in Appendix E. stabilization is completed. Permanent practices, such as diversions,are an integral part of the site III. Construction of ESCs design and are left in place. Effective erosion and sediment control requires good construction site management. Proper management can The ESC plans shall include the following elements: reduce the need for maintenance of structural controls, regrading of severely eroded areas,and reconstruction of 1. Existing and proposed contours shown at two foot controls that were improperly or poorly constructed or intervals or less. Other scales or contour intervals maintained. Good construction site management also may be favored for special types of land results in efficient use of manpower,financial savings and disturbance projects(i.e.plans are often drawn to improves the overall site appearance. scales of 1 in.=200 ft.or 1 in.=500 ft.with Good construction site management includes the following contour intervals of 5 to 20 feet). The following site phasing and construction sequencing measures: scales are recommended for use on ESC plans because they facilitate the review process for site 1. Physically mark limits of land disturbance on the specific detailed plans: 1 in.=20 ft., 1 in.=30 ft., site with tape,signs,or orange construction fence, 1 in.=40 ft.,or 1 in.=50 ft. so that workers can see the areas to be protected. 2. Details of temporary and permanent structural and 2. Divert runoff from adjacent land away from vegetative measures that will be used to control exposed highly erodible soils and steep slopes on erosion and sedimentation for each stage of the the construction site toward stable vegetated areas. project from land clearing to the finished stage. Stabilizing land with plant materials or mulches 3. Clear only what is required for immediate shall be part of a planned development. Retention construction activity. Large projects should be of existing natural vegetation in strategic areas is cleared and graded as construction progresses. beneficial,desirable,and cost efficient. Areas exceeding two acres in size should not be disturbed without a sequencing plan that requires 3. The location of structural ESC measures with practices to be installed and the soil stabilized,as standard symbols to facilitate the understanding disturbance beyond the two acres continues. Mass and review of plans. Symbols should have a clearings and grading of the entire site should be consistent line weight and be easily discernible on avoided. the plans. 4. Re-stabilize disturbed areas as soon as possible after construction is completed.Fourteen days 4. The dimensions,material specifications, (seven days in certain cases)shall be the installation details,and operation and maintenance maximum exposure period. Waiting until all New York State Standards and Specifications Page 2.3 November 2016 For Erosion and Sediment Control disturbed areas are ready for seeding is practices. unacceptable. Maintenance must be performed as necessary to ensure continued stabilization.Except 5. Where temporary work roads or haul roads cross as noted below,all sites shall be seeded and stream channels,adequate waterway openings stabilized with erosion control materials,such as shall be constructed using spans,culverts,washed straw mulch,jute mesh,or excelsior,including rock backfill,or other acceptable,clean methods areas where construction has been suspended or that will ensure that road construction and their use sections completed: do not result in turbidity and sediment downstream. All crossing activities and a. For active construction areas such as borrow or appurtenances on streams regulated by Article stockpile areas,roadway improvements and areas 15 of the Environmental Conservation Law within 50 ft.of a building under construction,a shall be in compliance with a permit issued down-slope perimeter sediment control system pursuant to Article 15 of the ECL. consisting,for example,silt fencing,shall be installed and maintained to contain soil.Exposed 6. Make sure that the contractor(s)responsible for the disturbed areas adjacent to a conveyance that implementation of the Stormwater Pollution provides rapid offsite discharge of sediment, such Prevention Plan(SWPPP),understands the ESC as a cut slope at an entrance, shall be covered with plan and signs the certification statement required plastic or geotextile to prevent soil loss until it can by NYSDEC SPDES General Permit for be stabilized. Stabilized construction access will be Stormwater Discharges from Construction Activity maintained to control vehicle tracking material off (GP). site. Inspection & Maintenance b. On the cut side of roads,ditches shall be stabilized immediately with rock rip-rap or other The implementation of an erosion and sediment control non-erodible liners(e.g.Rolled Erosion Control inspection and maintenance program is critical for the Products(RECP)),or where appropriate, proper operation of the plan and protection of water vegetative measures such as sod. resources.Without proper vigil and timely repair and support for the installed erosion and sediment control c. Permanent seeding should optimally be measures,the practices can easily be overwhelmed and lose undertaken in the spring from March through May, their functional effectiveness.To ensure the performance of and in late summer and early fall from September the erosion and sediment control measures,the contractor(s) to October 15.During the peak summer months that has been identified by the owner as being responsible and in the fall after October 15,when seeding is for the implementation of the SWPPP shall inspect the found to be impracticable, an appropriate practices within the active work area daily and after every temporary mulch shall be applied. Permanent stormwater event that generates runoff.If deficiencies are seeding may be undertaken during the sutntner if identified,the contractor shall implement the necessary plans provide for adequate watering.Temporary corrective actions within one business day of the inspection. seeding with rye can be utilized through November. Maintenance for all erosion and sediment control practices shall be in accordance with the specific details included in d. All slopes steeper than 3:1 (h:v),or 33.3%,as the SWPPP and incorporated on the ESC plan drawings as well as perimeter dikes,sediment basins or traps, appropriate. and embankments shall,upon completion,be immediately stabilized with sod, seed and Construction Activities anchored straw mulch,or other approved stabilization measures(e.g.RECP). Areas outside There is a wide array of different types of construction of the perimeter sediment control system shall not be disturbed.Maintenance shall be performed as activities.These projects can be grouped into separate necessary to ensure continued stabilization. categories for the purpose of developing an erosion and sediment control strategy.These generalized categories of e. Temporary sediment trapping devices shall not land development are: be removed until permanent stabilization(i.e. 80% uniform density of permanent vegetation or permanent mulch/stone)is established in all 1. Linear Projects contributory drainage areas. Similarly, a. Highway and Road Construction b. Gas and Oil Pipeline,Water Supply Line,and stabilization shall be established prior to Sanitary Sewer Line Construction converting sediment traps/basins into permanent c. Wind Farm and Power Line Construction (post-construction)stormwater management November 2016 Page 2.4 New York State Standards and Specifications For Erosion and Sediment Control d.Stream Restoration and Streambank Stabilization In developing plans for highway and road construction, e. Shoreline Stabilization the plan designer will encounter design situations f. Flood Dike Systems ranging from new highway construction,existing road expansion,intersection and drainage improvements and 2. Residential Projects bridge and culvert rehabilitation;to shoulder widening a.Small scale and overlay projects.While these types of projects b.Large scale differ greatly in their scope and complexity,they all 3. Commercial/Industrial Development Projects share similar challenges to the ESC plan designer. a.Small scale b.Large scale 4. Institutional Construction Projects 5. Water Resources Projects 6. Large Overlot Grading Projects Any one individual project may fall into more than one generalized category but these are offered to guide the development of an overall successful site erosion and sediment control plan for the project. Site variables such as topography,depth to groundwater, soil types,and rights-of-way(ROW)constraints all affect the methods of construction including choices of equipment These construction projects are typically linear in to accomplish the work,phasing and sequencing of nature,with limited ROW.Given the limited space construction,and the appropriate erosion and sediment within the ROW it may be necessary to obtain control practices to be employed on the project.In addition, temporary easements for control practices such as site attributes such as very steep slopes,perched sediment basins.Working around waterways,streams, groundwater tables,tidal water fluctuations,stream corridor or drainage channels within a ROW will also require management,and traffic control requirements impose extra that special attention be given to the construction challenges in preparing a comprehensive erosion and details and methods of construction being used in and sediment control plan. around the waterways. Note:Performing activities within or adjacent to wetlands,streams and waterbodies may require permits from the New York State Department of Environmental Conservation(NYSDEC)pursuant to Article 15(Protection of Waters),Article 24 (Freshwater Wetlands)and Article 25(Tidal Wetlands) of the Environmental Conservation Law(ECL). Project owners should contact NYSDEC's Regional Division of Environmental Permits early in the site planning process to discuss the requirements for _ meeting permit issuance standards.Following the New York State Standards and Specifications for Erosion A and Sediment Control may not ensure compliance with the above referenced sections of the ECL. ' The following are examples of projects,with important considerations for plan evaluation,which illustrate the When an existing roadway is under construction,traffic generalized land development categories shown above: must often times continue around and through the work area.In these situations,the ESC plan designer needs to 1. Linear Proiects address lane shifts,interim access roads being a. Highway and Road Construction constructed,and other efforts taken to minimize the travel time delay when designing ESC practices.The ESC plan will also need to address the issue of highway New York State Standards and Specifications Page 2.5 November 2016 For Erosion and Sediment Control safety from sediment leaving the construction area,and open for multiple processes of pipe staging,welding, employ a dust control strategy.The use of tire wash testing and placement.Construction methods must be facilities and street brooms may also become part of the employed to protect these natural resources. Sanitary ESC plan.Proper ESC planning will be necessary to sewer lines typically rely on gravity or a combination ensure that the use of storm drain inlet devices do not of gravity with lift stations as needed to operate pose a flooding hazard or risk to existing travel lanes. efficiently.As such they are often sited in lower areas Highway work is typically more dynamic than other near wetlands,flood plains,and along stream corridors. types of construction with disturbed areas usually not Where streams must be crossed for utility line being left inactive for long periods of time.This may construction,the designer must plan for waterway require the use of rolled erosion control products construction permits as well as prepare detailed (RECP's)or plastic in order to address temporary methods for temporary stream diversions,de-watering stabilization requirements.The following ESC operations,and stream or wetland crossings as measures must be addressed in the ESC plan: appropriate. • Sequence the work to minimize disturbance • Protect existing drainage ways • Evaluate de-watering needs and methods • Minimize access locations • Stabilize the exposed areas as each phase is completed b. Gas and Oil Pipeline,Water Supply Line,and Sanitary Sewer Line Construction The construction of underground pipelines for gas and oil conveyance,water supply lines,or sanitary sewer lines,can result in potentially adverse impacts to natural and cultural resources.Through advance planning of the pipeline construction work,working in the appropriate season,application of erosion and sediment control practices and appropriate construction techniques, Smaller utility projects often include servicing natural resources will be protected and adverse impacts residential development with water,sewer,telephone, minimized. electricity,gas,and cable TV.While the trend is toward using a common trench for several or more of these utilities,the installation of separate utilities can disrupt the overall sequence of construction,especially with street construction and stabilizing adjacent ROW areas. Direct bury techniques may be used to install electric lines,cable or fiber optic cables,which limits land disturbances by not requiring an open trench. In a residential plan,the installation of utilities must be coordinated,and ESC planned for,especially the restoration and stabilization of disturbed areas.The following objectives,where applicable,must be incorporated in the ESC plan: • Consider the location of wetland stream resources during the design and planning phase of the project to minimize crossings of such resources; Utility construction is generally performed in narrow • Limit vegetation clearing in accordance with safe ROW on a specified width.There are several unique construction practices to minimize adverse aspects of utility work that pose challenges to the ESC environmental and ecological impacts; plan designer and need to be recognized.Large utility • Construction ROW has to be sized properly,with projects pose the greatest risk for ESC problems during careful consideration of limiting disturbance yet construction.Gas and oil transmission lines may be providing sufficient space for safe operation of large located across multiple watersheds,wetlands,streams, equipment.Areas adjacent to river or large wetland and up and down steep slopes.Pipeline construction crossings need to be large enough so that all involving welded steel pipe requires the trench to be November 2016 Page 2.6 New York State Standards and Specifications For Erosion and Sediment Control operations have sufficient space to support work trucks. The individual weights of trucks require special tasks.Confining the crossing staging areas into permits and road structures must be considered. locations of insufficient space is inefficient and may create extensive damage; • Confine construction activities to the ROW and _. vehicular use to designated access roads, construction paths,and staging areas; - • Schedule construction for time periods when sensitive resources are least susceptible to damage or disruption; • Use construction and pipe laying equipment that _ minimizes damage and disruption of soils during wet periods or in areas with high ground-water tables, y and use the smallest sized equipment to complete the work; • Limit equipment movement in or near sensitive resources.Phase and sequence the work to limit exposure of work areas such as road crossings, Transmission line substations require delivery of large, stream and river crossings,wetlands,steep slopes, heavy components that also require special rocky terrain,and agricultural land; consideration. Of particular concern are the access • Minimize topsoil loss and general soil erosion by routes to reach the wind farm pads and power-line limiting ROW grading and other soil scarifying activities,and promptly stabilize disturbed soil; towers,the construction at the turbine pad and power- • Minimize traffic disruption on public roads during line tower foundations,and the impact on natural pipeline construction by providing adequate traffic resources at these sites.The following items,where controls; applicable,must be included in the ESC plan: • Provide adequate space for construction paths adjacent to trench systems,temporary sites for • Design permanent access roads to avoid wetland and material storage and construction staging,and stream resources; designate the disposition of construction waste • Limit the amount of clearing and grubbing to that material; needed to provide access,staging and site • Incorporate adequate trench and site de-watering construction; facilities; • The construction ROW will have to accommodate • Provide provisions for site clean-up and a soil and large cranes and delivery of long components that area restoration plan on a phase by phase basis as will require additional clearing to provide space for practical;and turning movements; • Provide for pipeline ROW maintenance that includes • Confine construction to the ROW and vehicular use vegetative treatment,maintenance of erosion and to the designated access road and staging areas; sediment control practices,and landowner • Phase and sequence the work for time periods when improvements as detailed in individual easement sensitive resources and land uses are least sensitive agreements. to damage; • Design appropriate ESC practices to control runoff c. Wind Farm and Power Line Construction The construction of wind farms and power transmission lines has many similarities to the utility construction methods noted previously. Wind turbine construction, ' and to a lesser extent transmission line construction will require delivery of both large or long components and very heavy equipment. Wind turbine blades delivery requires a wide turning radius,which requires work at ` road intersections along the delivery route. Due to the .. . length of blades,both horizontal and vertical profiles of _ access roads have to be considered. Cranes for wind farms typically arrive on three to five large flat bed New York State Standards and Specifications Page 2.7 November 2016 For Erosion and Sediment Control during and after construction,and sediment loss while soils are disturbed; • Provide for the handling of construction waste materials,proper site clean-up,and site stabilization plan;and • Provide for an operations and maintenance,and inspection plan for the project. d. Stream Restoration and Streambank Stabilization -- Stream corridors and streambanks and their respective buffer areas are extremely sensitive areas and must be adequately protected during construction operations. Diligent planning is required to properly phase the work with particular attention paid to accessing the work locations,dewatering the work areas,providing adequate staging area for construction equipment and operation,and handling construction waste such as cleared and grubbed material and excess spoil. e. Shoreline Stabilization Stabilization projects for eroded or undermined To protect fish spawning,timing restrictions may be shorelines can range in scope from shallow grading of imposed for all instream work as well as any adjacent beach areas to very high steep banks.These sites can work that may result in suspension of sediment in a extend from small lot type applications to several stream. In general,instream work should occur during hundred feet long.A major concern is the protection the low flow conditions,typically between June and water resource and any surrounding resource attributes September,to minimize impacts to fisheries and water such as buffers and wetlands. Slope stability should be quality. For additional information on timing assured prior to constructing a project on steep or very restrictions,please contact the regional NYS DEC high slopes.Consideration of overland surface drainage office for the county in which the project is located. must be incorporated in the site plan. The following measures,where applicable,must be incorporated in the ESC plan: Additional items that must be included in the ESC plan are: • Implement an appropriate de-watering scheme • Utilize existing former channels where available • Utilize turbidity curtains or appropriate structural • Plan and conduct work in phases upstream to barriers in close proximity to the work area downstream • Phase and conduct the work in lateral sections • Utilize pumps to remove standing turbid water to • Permanently stabilize one section prior to disturbing treatment areas such as traps,basins or filters the next section. appropriately sized and stabilized to reduce turbidity • Stabilize each phase as the work moves downstream • Timing of planting work is critical for successful vegetative stream bank stabilization November 2016 Page 2.8 New York State Standards and Specifications For Erosion and Sediment Control f. Flood Dike Systems family home construction are shown in Appendix D. These linear structures are usually placed in close b. Large Scale-This activity involves large areas of proximity to a stream or river extending significant disturbance for developing interior road access to distances to protect the interior area from flood waters. p g multiple home sites.Mass or bulk grading is usually The construction,repair,or rehabilitation of these performed to complete the infrastructure,individual structures requires that the water resources and adjacent lots,and the stormwater management practices.There areas be protected from sediment from all disturbance are three stages to a large scale residential activities.Management of the interior drainage water development: during construction is critical.Clean water should be bypassed or otherwise diverted around or through the • Bulk Grading work area.Materials handling should also be • Site improvements recognized and specified.This will include spoil, • Home Construction earthfill,topsoil,as well as waste such as cleared and grubbed vegetative material. Each stage is unique with respect to erosion and Key measures that must be included in the ESC plan sediment control,and the management of stormwater are: during construction.Residential projects will often include multiple phases that may take years to • Phase and conduct the work based on the topography complete.Depending on the size of the development, and cut and fill needs the developer may not construct the infrastructure(i.e. • Sequence the operations to minimize disturbed area roads,stormwater conveyance system,other utilities, exposure etc.)for all the phases at the same time.For this reason, • Install perimeter controls to protect adjacent it is important that the ESC plans include the necessary resources integration of the different phases of the project. • Delineate stockpile areas,construction staging areas, and access points Bulk Grading Stage: Bulk or mass grading • Bypass clean water around or through the (sometimes referred to as overlot grading) would construction site with a stable outlet require a separate ESC component for that stage. As • Standing turbid water should be captured or pumped basins and traps are constructed, there is the added to a treatment device such as a trap,basin,or filter. consideration for the planner that home lots will • Utilize temporary surface stabilization as the work eventually become part of the plan, and the siting of progresses and apply final stabilization as each phase these facilities needs to consider their long term use.As is completed earthwork progresses,the road areas will be "roughed" or"boxed"out if the roadway is in cut;or earth brought in if the road area is in fill. The amount of bulk grading 2. Residential Develoument Proiects will depend on the earthwork balance for the site. If cuts and fills are balanced within a phase,typically,the a. Small Scale-This generally involves the bulk grading stage will be easier to manage. Once this development of interior roads only or single lot grading stage is completed, the major infrastructure stage for home construction.Typical ESC plans for single begins. New York State Standards and Specifications Page 2.9 November 2016 For Erosion and Sediment Control such as cable, electric, and telephone are generally Site Improvements Stage: The next stage involves installed in a common trench along the mad right-of- the installation of roads, major utilities such as sewer way. This installation will sometimes interfere with and water, and drainage systems. The ESC designer previously installed silt fence and other ESC controls. will need to realize that the construction of the roadway Ideally, the utilities are installed before the home and drainage system will alter the interception of construction begins, and before the road right-of-way stormwater runoff and, in many cases, that the sheet area is stabilized. When utility installation requests are flow occurring during the bulk grading is now high however, the installation priority may be tied to concentrated.Energy dissipation with check dams,drop the number of building permits issued in a given structures, and possibly turf reinforcement in swales development phase. This may necessitate the road right and ditches is now necessary.Putting the base course of -of-way areas having to be stabilized twice. stone on the mad as soon as possible will also reduce erosion potential. As the roadway cuts and fills are completed and drainage established, temporary stabilization may take place on the lot areas and many of the roadway swales and completed drainage channels are ready for _ - permanent stabilization treatment. It is still too early in _ the construction phase to activate any of the permanent infiltration/filtration facilities or systems that may have been installed. If located underground the storm drain system must be protected to prevent soil from migrating to the infiltration system. The contributing drainage area including lot areas must be stabilized before - permanent infiltration/filtration facilities are put on- line. After the infrastructure is installed and before the site contractor leaves the site, the sediment basins and traps, and the rest of the site, should be checked to determine if maintenance is needed. Although the site should be inspected during the entire construction 3. Commercial and Industrial Development process, it is crucial to ensure that any major work is performed before the site contractor leaves. Often the These development projects share many of the attributes of building lots and homes are constructed by different large scale residential development; that is significant sub-contractors that may not have the proper equipment overlot grading and drainage challenges. It is important that the stormwater management systems and treatments be installed for the project site early in the development process to assure proper control. Particular care should be - . taken to stabilize access locations and control dust during the construction operations. a. Small Scale- These sites are generally less than 3 acres with a building footprint of 5,000 to 20,000 square feet, such as convenience stores, gas stations, fast food restaurants, individual retail outlets or _ industrial park building pad sites. Typically, perimeter controls such as silt fence may be employed. _ A stabilized construction access to all point of ingress and egress is important and will need constant attention to maintenance due to frequent traffic from trucks hauling structural building materials. Depending on the permanent stormwater design of the site, a stormwater pond may be utilized as a temporary sediment basin. If to perform the necessary maintenance. not, a temporary sediment trap may be employed with Home Construction Stage: The final stage involves perimeter berms to direct sediment laden runoff to the the home construction. The lot areas of the site that trap. These berms may be constructed from the topsoil have been previously stabilized will be disturbed during stripped from the site. Used as berms around the the construction of the homes. Minor utility installation perimeter, the topsoil does not take up room as a November 2016 Page 2.10 New York State Standards and Specifications For Erosion and Sediment Control stockpile, which is often a problem on a small site. while simultaneously clearing and grading another After final grades are established, the topsoil should phase. While phasing is an important tool in managing then be restored to areas of the site that will be ESC activities, the plan needs to consider some permanently vegetated. flexibility among phases. If a sediment basin is to be Generally, the building foot area or pad site is constructed in Phase 1,it may be necessary to place the excavated first,with rough grading taking place around excavated material at a central location, possibly in the remainder of the site. While the building area is another phase. Phasing also works well if the phases being constructed, the stormwater system is installed are broken into separate drainage areas. and inlet protection is constructed. If the remainder of the site requires extensive grading later, temporary A well designed ESC plan for commercial/industrial stabilization will be applied initially. Once stabilized, development will reflect that the site will likely be mass this site should require simple routine maintenance or bulk graded. There are typically very few areas of until the remainder of the site area is final graded for these sites that will remain undisturbed except for areas parking and landscaping. If only minor grading on the that are protected. In some cases extreme changes in site is required, the sequence may be such that grading grading are necessary to ensure a relatively flat building and base course stone could occur early in the site. In other cases multiple drainage areas will be construction. This would also reduce the amount of graded to one control point, or drainage areas may be bare soil exposure. One important note; some small divided to outlet at different locations. commercial sites rely on infiltration, filtration, or bio- retention for their permanent stormwater management. During the bulk grading of a large site, the phasing is The function of these facilities is often compromised clearly the key to managing ESC activity. However, when they are utilized for sediment control,compacted even within a phase of construction, it may be by heavy equipment, or installed prematurely and necessary to develop two ESC plans. The first plan allowed to become clogged with sediment. The ESC would be developed for the bulk grading activity. Since portion of the plan has to be developed to complement the stormwater or drainage collection system is not the post-development stormwater management installed at this time, the ESC plan will rely on strategy. temporary berms, swales, and diversions to convey sediment laden water to traps and basins.A second plan b. Large Scale-These projects are greater than 3 acres would be necessary when rough grading nears in area, such as shopping centers, office complexes, completion, buildings, roads, and parking areas are industrial parks,transportation facilities,and multi- under construction,and now drain to the same traps and use development projects. The designer can basins through an improved stormwater conveyance introduce phasing into the site planning process even system. The ESC strategies are very different during when the site is less than 20 acres to make complex the bulk grading and infrastructure development stages. sites more manageable. In discussing phasing it is important to define the clearing, grubbing, and grading It is essential for the ESC designer to remember that stages of construction. Land disturbing activities sediment control facilities, even when designed and include land change such as clearing, grading, constructed properly,rarely exceed 80 percent removal excavating, transporting and filling of land. On a rates for sediment. A properly designed ESC plan for a wooded site, cutting down or clearing trees is a land large scale commercial or industrial site will typically disturbing activity. There is a way through proper involve several phases, possibly more than one ESC sequencing, to develop a portion or phase of a site stage and utilize many different practices. 4. Institutional Development Proiects These projects include the development of structures, facilities, and infrastructure such as roads, utilities and ■-'-6 stormwater drainage systems in institutional settings such as college campuses, correctional facilities, public and private school construction, and transportation terminals such as bus stations. Many of the key points previously discussed for ESC plans are applicable here as well. It is especially important to note that often institutional construction projects are undertaken in close proximity to ongoing public activities and the drainage from these projects is often tied into the existing stormwater system.The following measures shall be incorporated in the New York State Standards and Specifications Page 2.11 November 2016 For Erosion and Sediment Control ESC plan: • Establish safe, stabilized,controlled access points for the construction limits • Develop a materials handling protocol for all potential pollutants and construction waste generated by construction activities • Control dust from construction operations and vehicular traffic • Maintain noise levels of the construction operations to acceptable levels for the surrounding environment • Utilize temporary stabilization and permanently stabilize each phase as soon as its work is completed -W „ v - _5. Water Resources Proiects 6. Large Bulk,Overlot Grading Proiects These projects are unique in that they are generally constructed within or in very close proximity to water These projects include construction of golf courses, resources. These include dam construction for lakes,ponds, recreational ski areas and facilities,large municipal projects or reservoirs, whose purposes may be flood protection, such as airports and sewage treatment plants, and steep energy creation or recreational for fish and wildlife. It also slope stabilization areas. The majority of these projects includes embankments and grading for wetland restoration share many of the same attributes, concerns and ESC plan projects as well as construction activities for requirements as large scale residential, commercial, and agricultural support such as agricultural waste storage and industrial projects. However, the stabilization of steep management facilities such as lagoons, waste treatment slopes is unique and deserves separate evaluation. Many wetlands, barnyard runoff treatment systems and factors will determine the engineering treatment for composting facilities. The ESC plan for these projects stabilizing an unstable steep slope. These include, but are should contain many of the points listed previously for not limited to, soil type, gradation, groundwater levels and general grading activities. In addition, key elements of the seepage, slope steepness and length, surface drainage, construction sequence for earthen dam embankments shall active erosive forces, and the proposed use of the area include the following: within the bigger site complex. Key measures that must be included in the ESC plan and construction sequence are: • Divert the stream flow in stable manner • Construct the cutoff trench and service spillway • Divert surface runoff at the top of the slope system • Divert water by use of water bars • Utilize earthfill from the auxiliary spillway first • Make sure the slope and its toe area are stable • Permanently stabilize the auxiliary spillway • Utilize slope drains as necessary to control seepage • Re-locate the stream flow through the service • Bench the slope as needed for stability, access, and spillway system surface drainage • Complete the earthfill and permanently stabilize all • Plan and conduct the work to minimize exposure disturbed areas • Stabilize exposed areas as soon as possible as the work progresses November 2016 Page 2.12 New York State Standards and Specifications For Erosion and Sediment Control In summary, these six categories of construction activities Design Process for Erosion and Sediment highlight some of the variables that should be addressed in Control Plans ESC plans. The design of erosion and sediment control needs to be integrated with the stormwater plan for the project. Since every project is different in its topography, soils, geometry, hydrology, groundwater depths, and intended purpose, it is important to consider all of these attributes as well as post construction stormwater management as ESC plans are - developed. A firm knowledge of the New York State Stormwater Management Design Manual criteria and requirements is helpful when integrating green infrastructure planning and practices for runoff reduction such as preservation of natural areas and soil restoration as well as the implementation of standard stormwater treatment practices such as infiltration basins and others. The following design steps detail the process and required Recognize that every construction project is unique. It may elements for developing an ESC plan: involve a totally new land disturbance or re-configuring and re-developing previous work. It could be located in an urban,suburban or rural area and may involve working with Step Identify existing drainage patterns, drainage existing impervious areas. Regardless of these area boundaries,and slopes circumstances, the erosion and sediment control plan must be prepared to deal with all the potential adverse impacts Current drainage information for the project site, as well as that could occur to on-site and off-site water resources. off-site, needs to be obtained and verified through a site The majority of the standards contained in this book are visit and survey. Field check drainage patterns, drainage applicable and adaptable to most of the construction area boundaries,vegetation and land use. Look for existing activities previously discussed. However, some of the storm drains, culverts, underground utilities, and other standards will not be applicable for all activities. The drainage features. Evaluate flow onto, through, and off of Erosion and Sediment Control Practices Matrix, Table 2.1, the site for existing conditions. Examine the drainage areas indicates which construction activities summarized above, to determine the size, slope, slope length, flow path, and, where a particular standard practice is most likely suited for for areas with concentrated flow, the discharge. Decide if implementation. off-site flow can be diverted through or around the site. Using ESD principles and green infrastructure techniques, maintain or mimic the existing drainage patterns that give preference to sheet flow and small drainage areas. Step 2. Identify areas of special concern Areas of particular environmental concern, such as wetlands, streams,buffers,wooded areas, slopes 15 percent or steeper, and highly erodible and unique soils, need to be identified within both the project site and adjacent areas and shown on the plan. Other considerations include phosphorous impaired watershed areas; National Wetland Inventory; natural heritage areas; rare, threatened, and endangered species habitat; and impaired stream segments with a Total Maximum Daily Load for sediment. Areas of special concern must be verified with a site visit. Note any erosion, lack of vegetation, drainage problems, and other features that may be pertinent to the design.If an unmapped resource is found, contact the appropriate authority to determine additional regulatory requirements. Step 3. Inventory site and layout development The initial assessment of the layout needs to be based on the New York State Standards and Specifications Page 2.13 November 2016 For Erosion and Sediment Control existing features and proposed construction,minimizing the Each practice application needs to be evaluated on a case- project's impervious area,acreage of soil disturbance and by-case basis for its associated practices due to the the encroachment on natural resources in accordance with changing characteristics of the project. the green infrastructure planning principles described in chapters 3 and 5 of the New York State Stormwater The sequencing of a site must take into account the time Management Design Manual and the environmental site and access needed to install the initial sediment controls. If design techniques noted earlier in this section. A site earth dikes and a sediment basin are designed as initial program plan has to provide space for the project water, controls, these must be completed before beginning other sewer,stormwater facilities,parking,recreation areas and grading. This could require stockpiling the excavated green space. A comprehensive approach to developing the material from the basin rather than using it immediately for erosion and sediment control and stormwater management fill on the site. Sequencing is also important to ensure that plans will minimize changes from the natural hydrology.In the basin is completed and stabilized prior to the addition,expansion of forest,wetland,and stream buffers construction of the berms. Additional sediment controls needs to be considered for enhanced sediment control and may be required if extensive clearing is needed to reach the improved water quality. proposed basin location. Step 4. Determine phasing requirements and design Step 5. Identify interim drainage patterns, drainage initial erosion and sediment controls areas,slopes; and design interim controls Depending on the scope of the project,phasing of sediment Interim conditions are often overlooked yet are important considerations for erosion and sediment control design. control and grading may be necessary (e.g., initial, interim, Typically,and final phase). Initial controls need to consider existing Typically, evaluating interim conditions is more difficult topography, drainage areas, ground cover, and access than evaluating initial phase or final phase. Project plans throughout the site. If possible, sediment controls installed always include existing and proposed site conditions. Unlike the initial or during the initial phase should be designed to function for final phases, interim conditions are not all phases of the project. The best designs incorporate definitive; they represent the in-between. Due to the shifts careful phasing and sequencing into the overall erosion and in drainage areas and changes in slope and exposure of sub- sediment control plan and construction strategy. This is surface soils, drainage patterns and discharges for an often evident in the project's contract construction schedule. interim phase may be entirely different from initial or final phase, and therefore the erosion and sediment controls may In designing erosion and sediment controls, consider also need to be different. To design interim controls, apply possible locations for staging and stockpile areas and access the same procedures used to design initial phase sediment or haul roads. If staging/stockpile areas are within the controls. Initial and final phase controls may need to be project's limit of disturbance, the proposed perimeter adjusted or modified to better correlate with the interim controls may suffice. However, if a soil stockpile creates a phase controls. Depending on the scope of the project, an longer slope length or steeper slope, perimeter controls interim phase erosion and sediment control plan may not be must be adjusted accordingly. Additionally, an access road required. may be required down a slope thereby concentrating flow that was previously sheet flow. Considerations must be Step 6. Identify proposed drainage patterns, drainage made for handling this concentrated flow and stabilizing areas,slopes; and design final controls and maintaining the access road. The design and installation of erosion and sediment control practices must not impact Follow the same procedures used to design the initial phase areas identified for green infrastructure purposes. For erosion and sediment controls. Initial and interim phase example, compacting soils in areas designated for controls may need to be adjusted or modified to better infiltration, or removing trees or other vegetation identified correlate with the final phase plans. As construction for stormwater management, is not permissible. However, progresses, consider impacts to staging and stockpile areas infiltration basin locations may be used as sediment basins/ and access roads. Also, consideration needs to be given to traps where partial excavation is performed to a minimum how the controls implemented for the final phase will be limit of 18"above the bottom of the infiltration basin. removed. Table 2.1 identifies the erosion and sediment control practices contained in this book of standards and lists the Step 7. Prepare the Construction Sequence primary purpose of each practice along with design criteria and associated practices that might be found used in The sequence of construction describes how the plan will combination with the listed practice. For example, rock progress. It directs the installation and removal of the outlet protection, sediment trap, and storm drain inlet are different erosion and sediment controls shown on the plan. listed as associated practices for the earth dike practice. Sequencing of the project needs to be considered throughout the entire design process. When writing a November 2016 Page 2.14 New York State Standards and Specifications For Erosion and Sediment Control sequence of construction, consider whether additional • Final fine grading,landscaping and stabilization instructions will be helpful to ensure that the controls • Removal of temporary erosion and sediment controls function as intended. Different types of construction • Restore and stabilize any disturbed areas remaining activities will require different sequences for construction. upon removal of temporary ESC measures If the disturbed area in any one particular phase of the construction work exceeds 5 acres at any one time, Most sequences of construction will be more detailed, additional control efforts will be required and written especially for plans requiring stream diversion, ground acceptance of this plan from the Regional NYSDEC office water management, or the coordination between the or MS4(for projects subject to a traditional land use control removal of controls in one phase and the installation of MS4) must be received and incorporated in the project different controls in a subsequent phase. If traffic control is documents. a factor, then the erosion and sediment control plan should coordinate with the maintenance of the traffic plan. For Writing a sequence of construction requires the visualizing subdivision projects, the sequence of construction must and the progression and connection of various site identify lots having sediment control practices that preclude development activities (e.g. clearing, grubbing, grading, the lot from being developed until the contributing drainage utility installation,maintenance of traffic,drainage systems, area has been final graded and stabilized. Each project is building systems, stream diversions, erosion and sediment unique and the level of detail in the sequence of control, stormwater management, etc.) to ensure that the construction needs to be tailored to each specific project. erosion and sediment control practices will be installed and removed at the proper times, and function properly. The Erosion and Sediment Control Practices Matrix was Depending on the project's complexity,the sequence can be prepared as a quick reference for designers and reviewers to relatively simple or it can involve many small steps. obtain major pertinent information about a practice. The Multiple steps can occur concurrently,while others must be matrix is alphabetical and is sectioned by each major sequential. Large projects that have been segmented into control group in this book of standards. Each practice has phases should have a separate sequence for each phase. listed its primary use on the site, the important site Large projects often follow a prescribed critical path for the characteristics and criteria for application, the type of construction work. These paths are helpful in developing construction activity where it is best applied, and other narratives to explain to contractors and inspectors why a associated practices that are often used with it to certain erosion and sediment control practice was selected complement its performance. or why following the sequence is imperative to the proper progression of the construction and erosion control The Construction Activity Key, shown below, assigns a effectiveness. number or number and letter to indicate a specific construction activity. Those symbols are listed in the The sequence of construction, at a minimum, must include Construction Activity column of the matrix to indicate the the following: applicability of a practice to a particular type of construction. This information is presented as a guide for • Schedule a pre-constmction meeting with appropriate use and is not to be considered as limiting any particular peirnitting authority practice to the activity listed. • Delineate resources to protect • Establish staging area, construction entrance, topsoil Erosion and Sediment Control Practice Matrix Con- stockpile,and concrete truck washout areas struction Activity Kev • Protect post-construction practice areas during 1. Linear Projects construction to preserve native soil permeability, install SMP's only after site is stabilized a.Highway and Road Construction b.Gas and Oil Pipeline,Water Supply Line,and San- Clearing and grubbing as necessary for the itary Sewer Line Construction installation of perimeter controls c.Wind Farm and Power Line Construction • Establish method of spoils disposal(on-site or off) d.Stream Restoration and Streambank Stabilization • Construction and stabilization of perimeter controls e.Shoreline Stabilization • Install initial runoff controls and stabilization f. Flood Dike Systems • Remaining clearing and grubbing within perimeter 2. Residential Projects • Road grading a.Small scale • Grading for the remainder of the site or phase b. Large scale • Utility installation and connections 3. Commercial/Industrial Development Projects • Construction of buildings, roads, and other a. Small scale construction b. Large scale • Installation of permanent stormwater management 4. Institutional Construction Projects measures 5. Water Resource Projects • Conduct soil restoration 6. Large Overlot Grading Projects New York State Standards and Specifications Page 2.15 November 2016 For Erosion and Sediment Control Table 2.1 Erosion and Sediment Control Practices Matrix Site Planning, Preparation and Management Practice Primary Purpose Site Characteristics Construction Associated Practices Activity Concrete Truck Washout Collect Waste Concrete construc- All Stabilized Access tion Construction Road Stabiliza- All construction Dust control,temporary swales, tion Control sediment routes All temporary or permanent seed- ing Access points, con- Stabilized construction access, Dust Control Stabilize soil struction roads la,lb,2,3,4,6 construction road stabilization Protecting Vegetation During Preserve existing Site specific All Recreational area improvement Construction vegetation Site Pollution Prevention Manage waste Site logistics All Those in this section Stabilized Construction Ac- Control sediment Access points All Filter fence,construction road cess stabilization Temporary Access Waterway prevent sediment Streams and banks All Construction mad stabilization, Crossing streambank protection Winter Stabilization Soil stabilization Disturbed areas All Seeding,mulching,buffer strips * See Erosion and Sediment Control Practice Matrix Construction Activity Key on page 2.15 November 2016 Page 2.16 New York State Standards and Specifications For Erosion and Sediment Control Table 2.2 Erosion and Sediment Control Practices Matrix Erosion Control Part 1 - Runoff Control (See Section 3) Practice Primary Puruose Site Characteristics Construe- Associated Practices tion Activity Check Dam Control runoff Drainage area<2 Ac. All Lined waterway,rock outlet protection Sediment traps,storm drain inlet Construction Ditch Divert runoff Drainage area< 10 Ac. All protection,sediment basin,level spreader Dewatering Sump Pit Control sediment Site specific All Sediment trap,sediment basin Intercept and divert run- Minimum 10 year de- Permanent seeding,rock outlet Diversion off sign Q la,2b,3b,4,5,6 protection,flow spreader, sedi- ment basin Earth Dike Control runoff Drainage area< 10 ac. la,lb,lc,2,3,4 Sediment trap,rock outlet pro- 15,6, tection,sediment basin Flow Diffuser Control runoff Minimum design Q= la,lb,lc,5,6 Seeding,sodding,land grading, 10 yr.24 hr. diversion Flow Spreader Control runoff Minimum design Q= la,lb,lc,5,6 Diversion,grassed waterway, 10 yr.24 hr. construction ditch Grade Stabilization Minimum design Q= Permanent seeding,rock slope Structure Prevent erosion 10 yr.24 hr. ld,le,5,6 protection,structural stream- bank protection Minimum 10 year de- Rock outlet protection,vegetat- Grassed Waterway Convey runoff sign Q 2a,3b,5,6 ed waterways,sediment basin, flow spreader Lined Waterway(rock Convey runoff Minimum design Q= la-c,2,3,4,5,6 Rock outlet protection,subsur- materials) 10 yr.24 hr. face drain Minimum design Q= Paved Flume Convey runoff 10 yr.24 hr. 1a,3,4,6 Rock outlet protection Perimeter Dike/Swale Divert runoff Drainage area<5 Ac. la-c,2a,3a,5,6 Sediment trap,flow spreader, check dam,temporary seeding Pipe Slope Drain Convey runoff down Drainage area<3.5 Ac. la,ld,5,6 Rock outlet protection slope Rock Outlet Protection Prevent erosion Rock varies with pipe All Diversion,grassed waterway, discharge sediment basin, sediment traps Storm Drain Diversion Divert runoff On-site drainage area> la,2,3,4,6 Sediment trap/basin 50%total drainage area Intercept and convey Rock outlet protection,land Subsurface Drain drainage water 1"Drainage Coefficient 1a,2,3,4,6 grading,retaining wall Water Bars Divert runoff Slope areas< 100 ft. lb,lc,5 Rock outlet protection,flow width spreader * See Erosion and Sediment Control Practice Matrix Construction Activity Key on page 2.15 New York State Standards and Specifications Page 2.17 November 2016 For Erosion and Sediment Control Table 2.3 Erosion and Sediment Control Practices Matrix Erosion Control Part 2 - Soil Stabilization (See Section 4) Practice Primary Purpose Site Characteristics Construction Associated Practices Activity Anchored Stabilization Stabilize soil Site specific All,steep Seeding,topsoiling Matting slopes Q= Armored Slope and Chan- Minimum designLive facines,live stakes, Prevent erosion 10 yr.24 hr.,velocity 1 d,l e,l f nel Stabilization >6 feet per second retaining walls Branch Packing Stabilize soil Maximum 1.5:1 slopes 1d,5,6 Diversion, subsurface drain, temporary swale Rock slope protection,ar- Brush Layer Stabilize soil Site specific slopes ld,le,3,4,5,6 mored streambank protec- tion Brush Mattress Stabilize soil Stream bank slopes la, 6 Rock slope protection Establishing Trees,Shrubs, Stabilize soil Site specific All Topsoiling, seeding,ferti- and Vines lizer application Fertilizer Application Promote seeding Site specific All Seeding,mulching,topsoil- ing,land grading Fiber Roll Provide growth medium Site specific ld,le,5 Live facines,live stakes Land Grading Stabilize soil Site specific shaping All Topsoiling, subsurface drain, seeding Lime Application Stabilize soil Site specific All Topsoiling, seeding Live Crib Wall Stabilize soil Site specific All Retaining walls Live Fascines Stabilize soil Max. 1.5:1 slope la,ld,le,5,6 Diversion, seeding Live Stakes Stabilize soil Site specific ld,le,415,6 Armored streambank pro- tection, fiber roll Loose Stabilization Blan- Stabilize soil Site Specific All Permanent and temporary kets seeding,Recreation area Mulching Stabilize soil Site specific All Permanent and temporary seeding,Recreation area Permanent Seeding for Stabilize soil Site specific All Surface roughening,top Construction Areas soiling, sodding Recreation Area Seeding Protect areas/soils Site specific All Permanent seeding,mulch- ing,topsoiling Site specific con- Rock slope protection,per- Retaining Walls Stabilize soil straints la,2,3,4,6 manent seeding, subsurface drain * See Erosion and Sediment Control Practice Matrix Construction Activity Key on page 2.15 November 2016 Page 2.18 New York State Standards and Specifications For Erosion and Sediment Control Table 2.3 (Continued) Erosion and Sediment Control Practices Matrix Erosion Control Part 2 - Soil Stabilization (See Section 4) Practice Primary Purpose Site Characteristics ConstructionActivi Associated Practices Soil Restoration Stabilize soil,promote Compacted areas All Topsoiling,seeding infiltration Stabilization of Sand and Stabilize soil Site specific la,lc,3,4,5,6 Topsoiling,seeding Gravel Pits Stabilization With Sod Stabilize soil Need quick cover, 2 3 4 Inlet protection,top soil- aesthetics ing,permanent seeding Surface Roughening Stabilize soil Construction slopes All Temporary seeding,per- manent seeding,mulching Temporary Seeding for Surface roughening,top Construction Areas Stabilize soil Site specific All soiling,sodding Topsoiling and Amend- Enhance growing condi- Poor site soil charac- Surface roughening,tem- ments tions teristics All porary seeding,permanent seeding Tree Revetment Stabilize soil Site specific ld,le Armored streambank pro- tection Vegetated Gabions Stabilize soil Site specific la-e,2,3,4,5,6 Live cribwall,retaining wall Vegetating Sand Dunes Stabilize sand dunes Sand dune reinforce- le,2,3,4,5,6 Sediment trap,rock outlet, and Tidal Banks ment storm drain inlet protection Vegetating Waterways Stabilize soil Site specific 2a,3b,5,6 Grassed waterways,per- manent seeding * See Erosion and Sediment Control Practice Matrix Construction Activity Key on page 2.15 New York State Standards and Specifications Page 2.19 November 2016 For Erosion and Sediment Control Table 2.4 Erosion and Sediment Control Practices Matrix Sediment Control (See Section 5) Practice Primary Purpose Site Characteristics Construction Associated Practices Activity Buffer Filter Strip Filter sediment Turbid sheet flow All Storm drain inlets,water conveyances Compost Filter Sock Filter sediment Turbid sheet flow All Storm drain inlets,water conveyances Dewatering Device Discharge clean water Turbidity in sediment All Sediment basins,sediment basin traps Subsurface drain,dewater- Geotextitle Filter Bag Filter sediment Small areas,pumped All ing sump pit,buffer filter strip Portable Sediment Tank Retain sediment 16 times pump dis- 2a,3a,4 Sediment trap,sediment charge basin Rock Dam Trap sediment Drainage area<50 la,lb,lc,2b3b Rock outlet protection Ac. ,4,5,6 Sediment Basin Capture sediment Drainage area<50 la,2b,3b,4,5, Rock outlet protection, Ac. 6 temporary seeding Sediment Dike Capture sediment Small disturbed areas 2a,2b,3a Buffer filter strip,filter bag Sediment Trap- Compost Trap sediment Drainage area<5 Ac. All Seeding,sodding Sock Sediment Trap- Pipe Out- Trap sediment Drainage area<5 Ac. All Sediment basin,rock outlet let protection Sediment Trap-Stone Trap sediment Drainage area<5 Ac. All Rock outlet protection Outlet Silt Fence Control sediment 2:1 slopes maximum, All Straw bale dike 50 ft.spacing Storm Drain Inlet Protec- Trap sediment Drainage area<1 Ac. l a,2,3,4,6 Sediment traps,storm drain tion-Excavated diversion Storm Drain Inlet Protec- Trap sediment Drainage area< 1 Ac. la,2,3,4,6 Sediment traps,storm drain tion -Fabric diversion Storm Drain Inlet Protec- Trap sediment Drainage area<1 Ac. la,2,3,4,6 Sediment traps,storm drain tion-Inserts diversion Storm Drain Inlet Protec- Trap sediment Drainage area<1 Ac. la Sediment traps,storm drain tion -Paved Surface diversion Storm Drain Inlet Protec- Trap sediment Drainage area<1 Ac. 2,3,4,6 Sediment traps,storm drain tion -Stone and Block diversion Straw Bale Dike Control sediment 2:1 slopes maximum, All Silt fence 25 ft.spacing * See Erosion and Sediment Control Practice Matrix Construction Activity Key on page 2.15 November 2016 Page 2.20 New York State Standards and Specifications For Erosion and Sediment Control Table 2.4 (Continued) Erosion and Sediment Control Practices Matrix Sediment Control (See Section 5) Practice Primary Puruose Site Characteristics Construction Activi Associated Practices Turbidity Curtain Control sediment Calm water lb,ld,le,lf,5 Sediment traps,basins, seeding,mulching Large area for place- Armored streambank pro- Water structures/barriers Control sediment ment 1d,le,lf,5 tection,retaining walls * See Erosion and Sediment Control Practice Matrix Construction Activity Key on page 2.15 New York State Standards and Specifications Page 2.21 November 2016 For Erosion and Sediment Control Table 2.5 Erosion Risk Soil Type Slope% and Parameters 0-5 5-15 >15 Gravelly,K<0.35 Med Non-cohesive Low Low PI=NP,Fines:0-10% Sandy,K>0.35 High PI=NP,Fines:0-30% Med High Silty,K>0.35 PI=NP,Fines: 50+% Med High Very High Clay,K<0.35 Cohesive Low Med High PI=7+, Fines: 50+% Dispersive Clay Soils High Very High Extreme Note:Erosion risk is the probability that the combination of parameters presented will generate a significant amount of soil loss. There are other factors that contribute to erosion,such as slope length and rainfall intensity and duration. Also,even though there may be low erosion risk,there can be a high risk to water quality when the soil disturbance is close to water resources.Each site needs to be evaluated on its own merit to determine actual soil loss.Methodology for this analy- sis is presented in Appendix A. November 2016 Page 2.22 New York State Standards and Specifications For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR CONSTRUCTION ROAD STABILIZATION Composition—Use a 6-inch layer of NYS DOT sub-base Types 1,2,3,4 or equivalent as specified in NYSDOT Standard Specifications. Construction Specifications 1. Clear and strip roadbed and parking areas of all vegetation,roots,and other objectionable material. 2. Locate parking areas on naturally flat areas as available. Keep grades sufficient for drainage,but not more than 2 to 3 percent. 3. Provide surface drainage and divert excess runoff to stabilized areas. 4. Maintain cut and fill slopes to 2:1 or flatter and stabilized with vegetation as soon as grading is accomplished. Definition & Scope 5. Spread 6-inch layer of sub-base material The stabilization of temporary construction access routes, evenly over the full width of the road and on-site vehicle transportation routes,and construction smooth to avoid depressions. parking areas to control erosion on temporary construction 6. Provide appropriate sediment control routes and parking areas. measures to prevent offsite sedimentation. Conditions Where Practice Applies Maintenance All traffic routes and parking areas for temporary use by Inspect construction roads and parking areas periodically construction traffic. for condition of surface. Top dress with new gravel as needed. Check ditches for erosion and sedimentation after Design Criteria rainfall events. Maintain vegetation in a healthy,vigorous condition. Areas producing sediment should be treated Construction roads should be located to reduce erosion immediately. potential,minimize impact on existing site resources,and maintain operations in a safe manner. Highly erosive soils, wet or rocky areas,and steep slopes should be avoided. Roads should be routed where seasonal water tables are deeper than 18 inches. Surface runoff and control should be in accordance with other standards. Road Grade—A maximum grade of 12%is recommended, although grades up to 15%are possible for short distances. Road Width— 12 foot minimum for one-way traffic or 24 foot minimum for two-way traffic. Side Slope of Road Embankment—2:1 or flatter. Ditch Capacity—On-site roadside ditch and culvert capacities shall be the 10 yr.peak runoff. New York State Standards and Specifications Page 2.23 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR CONCRETE TRUCK WASHOUT leaching of liquids into the ground.The liner shall be plastic sheeting with a minimum thickness of 10 mils with no holes - or tears,and anchored beyond the top of the pit with an earthen berm, sand bags, stone,or other structural appurtenance except at the access point. If pre-fabricated washouts are used they must ensure the capture and containment of the concrete wash and be sized based on the expected frequency of concrete pours.They shall be sited as noted in the location criteria. Maintenance • All concrete washout facilities shall be inspected daily. Damaged or leaking facilities shall be deactivated and repaired or replaced immediately. Excess rainwater that has accumulated over hardened concrete should be Definition & Scope pumped to a stabilized area,such as a grass filter strip. • Accumulated hardened material shall be removed when A temporary excavated or above ground lined constructed pit 75%of the storage capacity of the structure is filled. Any where concrete truck mixers and equipment can be washed excess wash water shall be pumped into a containment after their loads have been discharged,to prevent highly vessel and properly disposed of off site. alkaline runoff from entering storm drainage systems or • Dispose of the hardened material off-site in a leaching into soil. construction/demolition landfill. On-site disposal may be Conditions Where Practice Applies allowed if this has been approved and accepted as part of the projects SWPPP.In that case,the material should be Washout facilities shall be provided for every project where recycled as specified,or buried and covered with a concrete will be poured or otherwise formed on the site.This minimum of 2 feet of clean compacted earthfill that is facility will receive highly alkaline wash water from the permanently stabilized to prevent erosion. cleaning of chutes,mixers,hoppers,vibrators,placing • The plastic liner shall be replaced with each cleaning of equipment,trowels,and screeds.Under no circumstances will the washout facility. wash water from these operations be allowed to infiltrate into • Inspect the project site frequently to ensure that no the soil or enter surface waters. concrete discharges are taking place in non-designated areas. Design Criteria Capacity: The washout facility should be sized to contain solids,wash water, and rainfall and sized to allow for the evaporation of the wash water and rainfall. Wash water shall be estimated at 7 gallons per chute and 50 gallons per hopper of the concrete pump truck and/or discharging drum. The minimum size shall be 8 feet by 8 feet at the bottom and 2 feet deep.If excavated,the side slopes shall be 2 horizontal to 1 vertical. Location: Locate the facility a minimum of 100 feet from drainage swales,storm drain inlets,wetlands,streams and other surface waters.Prevent surface water from entering the structure except for the access road.Provide appropriate access with a gravel access road sloped down to the structure. Signs shall be placed to direct drivers to the facility after their load is discharged. Liner: All washout facilities will be lined to prevent November 2016 Page 2.24 New York State Standards and Specifications For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR DUST CONTROL dust control(see Section 3). �r Mulch(including gravel mulch)—Mulch offers a fast effective means of controlling dust. This can also include rolled erosion control blankets. Spray adhesives—These are products generally a composed of polymers in a liquid or solid form that are mixed with water to form an emulsion that is sprayed on the soil surface with typical hydroseeding ` equipment. The mixing ratios and application rates will be in accordance with the manufacturer's _ recommendations for the specific soils on the site.In no MO. case should the application of these adhesives be made on wet soils or if there is a probability of precipitation f within 48 hours of its proposed use.Material Safety Data Sheets will be provided to all applicators and Definition & Scope others working with the material. The control of dust resulting from land-disturbing activities, B. Driving Areas—These areas utilize water,polymer prevent surface and air movement of dust from disturbed emulsions,and barriers to prevent dust movement to p from the traffic surface into the air. soil surfaces that may cause off-site damage,health hazards, and traffic safety problems. Sprinkling—The site may be sprayed with water until the surface is wet. This is especially effective Conditions Where Practice Applies on haul roads and access route to provide short term limited dust control. On construction roads, access points, and other disturbed areas subject to surface dust movement and dust blowing Polymer Additives—These polymers are mixed with where off-site damage may occur if dust is not controlled. water and applied to the driving surface by a water truck with a gravity feed drip bar,spray bar or Design Criteria automated distributor truck.The mixing ratios and application rates will be in accordance with the manufacturer's recommendations.Incorporation of Construction operations should be scheduled to the emulsion into the soil will be done to minimize the amount of area disturbed at one time. the appropriate depth based on expected traffic. Buffer areas of vegetation should be left where practical. Compaction after incorporation will be by vibratory Temporary or permanent stabilization measures shall be roller to a minimum of 95%. The prepared surface installed. No specific design criteria is given; see shall be moist and no application of the polymer will construction specifications below for common methods of be made if there is a probability of precipitation within 48 hours of its proposed use.Material Safety Data dust control. Sheets will be provided to all applicators working with the material. Water quality must be considered when materials are selected for dust control. Where there is a potential for the Barriers—Woven geo-textiles can be placed on the material to wash off to a stream,ingredient information driving surface to effectively reduce dust throw and must be provided to the NYSDEC. particle migration on haul roads. Stone can also be used for construction roads for effective dust control. No polymer application shall take place without written windbreak—A silt fence or similar barrier can approval from the NYSDEC. control air currents at intervals equal to ten times the barrier height.Preserve existing wind barrier Construction Specifications vegetation as much as practical. A. Non-driving Areas—These areas use products and Maintenance materials applied or placed on soil surfaces to prevent airborne migration of soil particles. Maintain dust control measures through dry weather periods until all disturbed areas are stabilized. Vegetative Cover—For disturbed areas not subject to traffic,vegetation provides the most practical method of New York State Standards and Specifications Page 2.25 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR PROTECTING VEGETATION DURING CONSTRUCTION recommendations made for the vegetation to be saved. Minor adjustments in location of roads, " dwellings,and utilities may be needed. Construction on steep slopes,erodible soils, wetlands,and streams should be avoided. Clearing limits should be delineated(See "Determine Limits of Clearing and Grading"on page 2.2). 2) Areas to be seeded and planted should be F F' identified. Remaining vegetation should blend ti 4 with their surroundings and/or provide special function such as a filter strip,buffer zone,or r screen. 3) Trees and shrubs of special seasonal interest, such as flowering dogwood,red maple,striped maple,serviceberry,or shadbush,and valuable Definition & Scope potential shade trees should be identified and marked for special protective treatment as The protection of trees,shrubs,ground cover and other appropriate. vegetation from damage by construction equipment. In 4) Trees to be cut should be marked on the plans. order to preserve existing vegetation determined to be If timber can be removed for salable products,a important for soil erosion control,water quality forester should be consulted for marketing advice. protection,shade,screening,buffers,wildlife habitat, wetland protection,and other values. 5) Trees that may become a hazard to people, personal property,or utilities should be removed. Conditions Where Practices Applies These include trees that are weak-wooded, disease-prone,subject to windthrow,or those that have severely damaged root systems. On planned construction sites where valued vegetation exists and needs to be preserved. 6) The vigor of remaining trees may be improved by a selective thinning. A forester should be Design Criteria consulted for implementing this practice. 1. Planning Considerations 2. Measures to Protect Vegetation A. Limit soil placement over existing tree and shrub A. Inventory: roots to a maximum of 3 inches. Soils with loamy texture and good structure should be used. 1) Property boundaries,topography,vegetation and soils information should be gathered. Identify B. Use retaining walls and terraces to protect roots of potentially high erosion areas,areas with tree trees and shrubs when grades are lowered. Lowered windthrow potential,etc. A vegetative cover type grades should start no closer than the dripline of the map should be made on a copy of a topographic tree. For narrow-canopied trees and shrubs,the stem map which shows other natural and manmade diameter in inches is converted to feet and doubled, features. Vegetation that is desirable to preserve such that a 10 inch tree should be protected to 20 feet. because of its value for screening,shade,critical erosion control,endangered species,aesthetics,etc., C. Trenching across tree root systems should be the should be identified and marked on the map. same minimum distance from the trunk,as in`B". Tunnels under root systems for underground utilities 2) Based upon this data,general statements should should start 18 inches or deeper below the normal be prepared about the present condition,potential ground surface. Tree roots which must be severed problem areas,and unique features of the property. should be cut clean. Backfill material that will be in contact with the roots should be topsoil or a prepared B. Planning: planting soil mixture. 1) After engineering plans(plot maps)are prepared, D. Construct sturdy fences,or barriers,of wood, another field review should take place and steel,or other protective material around valuable November 2016 Page 2.26 New York State Standards and Specifications For Erosion and Sediment Control vegetation for protection from construction equipment. Place barriers far enough away from trees,but not less than the specifications in'B", so that tall equipment such as backhoes and dump trucks do not contact tree branches. E. Construction limits should be identified and clearly marked to exclude equipment. F. Avoid spills of oil/gas and other contaminants. G. Obstructive and broken branches should be pruned properly. The branch collar on all branches whether living or dead should not be damaged. The 3 or 4 cut method should be used on all branches larger than two inches at the cut. First cut about one-third the way through the underside of the limb(about 6-12 inches from the tree trunk). Then(approximately an inch further out)make a second cut through the limb from the upper side. When the branch is removed,there is no splintering of the main tree trunk.Remove the stub. If the branch is larger than 5-6 inches in diameter,use the four cut system. Cuts 1 and 2 remain the same and cut 3 should be from the underside of the limb,on the outside of the branch collar. Cut 4 should be from the top and in alignment with the 3rd cut. Cut 3 should be 1/4 to 1/3 the way through the limb. This will prevent the bark from peeling down the trunk. Do not paint the cut surface. H. Penalties for damage to valuable trees,shrubs,and herbaceous plants should be clearly spelled out in the contract. PROTECTING TREES IN HEAVY USE AREAS The compaction of soil over the roots of trees and shrubs by the trampling of recreationists,vehicular traffic,etc.,reduces oxygen,water,and nutrient uptake by feeder roots. This weakens and may eventually kill the plants. Table 2.6 rates the"Susceptibility of Tree Species to Compaction." Where heavy compaction is anticipated,apply and maintain a 3 to 4 inch layer of undecayed wood chips or 2 inches of No.2 washed,crushed gravel. In addition,use of a wooden or plastic mat may be used to lessen compaction,if applicable. New York State Standards and Specifications Page 2.27 November 2016 For Erosion and Sediment Control Table 2.6 Susceptibility of Tree Species to Compaction' Resistant: Box elder.................. Acer negundo Willows..................... Salix spp. Green ash................. Fraxinus pennsylvanica Honey locust............... Gleditsia triacanthos Red elm.................... Ulmus rubra Eastern cottonwood....... Populus deltoides Hawthornes............... Crataegus spp. Swamp white oak.......... Quercus bicolor Bur oak.................... Quercus macrocarpa Hophombeam...............Ostrya virginiana Northern white cedar.... Thuja occidentalis Intermediate: Red maple................ Acer rubrum Sweetgum...................Liquidambar styrac flua Silver maple.............. Acer saccharinum Norway maple............. Acer platanoides Hackberry................ Celtis occidentalis Shagbark hickory.......... Carya ovata Black gum............... Nyssa sylvatica London plane.............. Platanus x hybrida Red oak.................. Quercus rubra Pin oak...................... Quercus palustris Basswood................ Tilia americana Susceptible: Sugar maple................ Acer saccharum Austrian Pine............... Pinus nigra White pine.................. Pinus strobus White ash................... Fraxinus americana Blue spruce................. Picea pungens Paper birch................. Betula papyrifera White oak.................. Quercus alba Moutain ash................ Sorbus aucuparia Red pine.................... Pinus resinosa Japanese maple............ Acer palmatum 'If a tree species does not appear on the list,insufficient information is available to rate it for this purpose. November 2016 Page 2.28 New York State Standards and Specifications For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR SITE POLLUTION PREVENTION P J �T Y Definition & Scope A collection of management practices intended to control pollutants and contamination of groundwater and non-sediment pollutants associated with construction surface waters. activities to prevent the generation of pollutants due to improper handling,storage,and spills and prevent the 5. Develop and implement a spill prevention and movement of toxic substances from the site into surface control plan. The plan should include NYSDEC's waters. spill reporting and initial notification requirements. Conditions Where Practice Applies 6. Provide adequate disposal for solid waste including woody debris,stumps,and other construction waste On all construction sites where the earth disturbance exceeds and include these methods and directions in the 5,000 square feet,and involves the use of fertilizers, construction details on the site construction drawings. pesticides,petroleum based chemicals,fuels and lubricants, Fill,woody debris,stumps and construction waste as well as sealers,paints,cleared woody vegetation,garbage, shall not be placed in regulated wetlands,streams or and sanitary wastes. other surface waters. Design Criteria 7. Distribute or post informational material regarding proper handling,spill response,spill kit location,and The variety of pollutants on a particular site and the severity emergency actions to be taken,to all construction of their impacts depend on factors such as the nature of the personnel. construction activity,the physical characteristics of the g.Refueling equipment shall be located at least 100 construction site,and the proximity of water bodies and conveyances to the pollutant source. feet from all wetlands,streams and other surface waters. 1. All state and federal regulations shall be followed for �.,. the storage,handling,application,usage,and disposal of pesticides,fertilizers,and petroleum products. 2. Vehicle and construction equipment staging and maintenance areas will be located away from all drainage ways with their parking areas graded so the i runoff from these areas is collected,contained and treated prior to discharge from the site. 3. Provide sanitary facilities for on-site personnel. 4. Store,cover,and isolate construction materials including topsoil,and chemicals,to prevent runoff of New York State Standards and Specifications Page 2.29 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR STABILIZED CONSTRUCTION ACCESS inert to commonly encountered chemicals,hydro-carbons, mildew,rot resistant,and conform to the fabric properties as shown: Light Duty' z - Fabric Proper- Roads Heavy Duty Test Meth- -*' ties Grade Sub- Haul Roads Rough Graded od - grade Grab Tensile ASTM Strength(lbs) 200 220 D1682 3 Elongation at 50 60 ASTM Failure(%) D1682 sic Mullen Burst ASTM t. --- 7, h—N A Strength(lbs) 190 430 D3786 Definition & Scope Puncture 40 125 ASTM D751 Strength(lbs) Modified A stabilized pad of aggregate underlain with geotextile located Equivalent 40-80 40-80 US Std at any point where traffic will be entering or leaving a Sieve construction site to or from a public right-of-way, street,alley, sidewalk,or parking area. The purpose of stabilized Opening Size CW-02215 construction access is to reduce or eliminate the tracking of sediment onto public rights-of-way or streets. Depth 6 10 p Conditions Where Practice Applies 'Light Duty Road: Area sites that have been graded to subgrade and where most travel would be single axle vehicles and an occasional multi- A stabilized construction access shall be used at all points Of axle truck. Acceptable materials are Trevira Spunbond 1115,Mirafi construction ingress and egress. 100X,Typar 3401,or equivalent. 'Heavy Duty Road: Area sites with only rough grading,and where most Design Criteria travel would be multi-axle vehicles. Acceptable materials are Trevira Spunbond 1135,Mirafi 600X,or equivalent. See Figure 2.1 on page 2.31 for details. Fabrics not meeting these specifications maybe used only when design Aggregate Size: Use a matrix of 1-4 inch stone,Or procedure and supporting documentation are supplied to determine ag- reclaimed or recycled concrete equivalent. gregate depth and fabric strength. Thickness: Not less than six(6)inches. Maintenance Width: 12-foot minimum but not less than the full width of The access shall be maintained in a condition which will points where ingress or egress occurs. 24-foot minimum if prevent tracking of sediment onto public rights-of-way or there is only one access to the site. streets. This may require periodic top dressing with additional aggregate. All sediment spilled,dropped,or Length: As required,but not less than 50 feet(except on a washed onto public rights-of-way must be removed single residence lot where a 30 foot minimum would apply). immediately. Geotextile: To be placed over the entire area to be covered When necessary,wheels must be cleaned to remove with aggregate. Filter cloth will not be required on a single- sediment prior to entrance onto public rights-of-way. When family residence lot. Piping of surface water under entrance washing is required,it shall be done on an area stabilized shall be provided as required. If piping is impossible,a with aggregate,which drains into an approved sediment- mountable berm with 5:1 slopes will be permitted. trapping device. All sediment shall be prevented from entering storm drains,ditches,or watercourses. Criteria for Geotextile: The geotextile shall be woven or nonwoven fabric consisting only of continuous chain polymeric filaments or yams of polyester. The fabric shall be November 2016 Page 2.30 New York State Standards and Specifications For Erosion and Sediment Control Figure 2.1 Stabilized Construction Access SYMBOL ,� 1�1�Ih� � EKISTIN�i PAVEMENT �r EXISTING FIL 7ER HMAITaAELE BERM GROUND CLEFTIA PI�QFJL CEPTIHNAL] 7s4'kIN. iWHIN. E KISTING GROUND PAVEW—NT CONSTRUCTION PE IFI ATI❑N 1, STONE S E ZE USE L-4 INCH STONE, OR RECLAIMED OR RECYCLED CONCRETE EOUIVALENT. a. LENGTH - NOT LESS THAN 50 FEET LEXCEPT ()N A IHGLZ RE' MENCE LOT VHER A 30 FOOT MINIMUM LEUGTH WOULD APPLY)a S. THICKNESS — NOT LESS THAN SIX (.6) INCHES. 4. 'MOTH — TWELVE M) EIIOT MINIKJM, BUT NOT LESS THAN THE PULL WID7H AT POINTS WHERE INGRESS OR EGRESS OCCURS. TWENT'r-FOUR (E4) FWT IF SD4GLE ENTRANCE TO SITE. 15. GEOTEXTILE - FILL K PLACED OVER THE ENTIRE AREA PRIOR TO PLACING 'QF STQNE- & SURFACE VATER - ALL SURFACE WATER rLOWING OR DIVERTED TOWARD CON- STRUCTION ACCESS SHALL HE PIPED BENEATH THE ENTRANCE, IF PIPING IS IMPRACTICAL, A M❑L H47 ABLE HEFRM WITH 5d SLOPES WILL BE PEPMITTEIK 7. HAi NTENANCF - THE ENTRANCE SHALL BE Hr INTAINF D IN A COIN DI T I INN WHICH VILL PREVENT TRACKING OR FLOWING CF SEDIHENT ONTO PUBLIC RIGH7S—OF—WAY, ALL SEDIMENT SPILLED. DROPPED. WASHED O'q TRACKEI) ONTO PUJOL[t FIGHTS—CF—WAY MUST BE REMOVED INW'DIATELY. 6_ WHEN WASHING IS REWRED, IT SHALL 6E DONE ON A AREA STADILIZED WITH STONE .AND VNICH DRAINS INTO AN APPRIOVED SEDIMENT TRAPPING DEVICE. e�-- PERIODIC INSPECTION AND NEEDED MAINTENANCE SHALL BE PROVIDED AFTER EACH RAIN. AFLAP9ED F RLIN 1*-TAlLS RMVIDEh 9Y- USDA - NRUS, STA13ILIZED NEW YDI?K STATE ®EPARTNENT [IF TRANSPURTATiDN, ��� �R��T I❑� NEW Y❑RK STATE DEPARTMENT (IF ENVIRD�+IMCNTAL CONSERVATION, @sILV MURK STATE SOIL & vAru4 CONSERVATIUM aimmli fE ACCE New York State Standards and Specifications Page 2.31 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR TEMPORARY ACCESS WATERWAY CROSSING { waterway crossings are bridges,culverts,and t fords. General Requirements 1. In-Stream Excavation: In-Stream excavation shall be limited to only that necessary to allow installation of the standard methods as presented in Subsection "Temporary Access Waterway Crossing Methods." 2. Elimination of Fish Migration Barriers: Of the two basic methods presented in Subsection"Temporary Access Waterway Crossing Methods,"bridges pose the least potential for creating barriers to aquatic migration.The construction of any specific crossing method as presented in Subsection"Temporary Access Waterway Crossing Methods,"shall not cause Definition & Scope a significant water level difference between the upstream and downstream water surface elevations. A temporary access waterway crossing is a structure placed Fish spawning or migration within waterways across a waterway to provide access for construction generally occurs between October 1 to May 31 for purposes for a period of less than one year. Consideration water classified for trout and from March 15 to July should be given to stream flow capacity and velocity 15 for other streams. Fish spawning or migration anticipated during the period of time that the temporary dates can vary across New York and restrictions structures will be in place. Temporary access crossings imposed by the NYS Department of Environmental shall not be utilized to maintain traffic for the general public. Conservation may vary and must be checked. The purpose of the temporary access waterway crossing is to provide safe,environmentally sound access across a 3. Crossing Alignment: The temporary waterway waterway for construction equipment by establishing crossing shall be at right angles to the stream. Where minimum standards and specifications for the design, approach conditions dictate,the crossing may vary 15 construction,maintenance,and removal of the structure.This degrees from a line drawn perpendicular the standard and specification may represent a channel centerline of the stream at the intended crossing constriction,thus,the temporary nature of waterway access location. crossing must be stressed. They should be planned to be in service for the shortest practical period of time and removed 4. Road Approaches: The centerline of both roadway as soon as their function is completed. approaches shall coincide with the crossing alignment centerline for a minimum distance of 50 feet from Conditions Where Practice Applies each bank of the waterway being crossed. If physical or right-of-way restraints preclude the 50 feet minimum,a shorter distance may be provided. All fill This standard and specification for temporary materials associated with the roadway approach shall access waterway crossings is applicable in non-tidal be limited to a maximum height of 2 feet above the waterways. It provides designs based on waterway existing flood plain elevation. geometry rather than the drainage area contributing to the point of crossing. 5. Surface Water Diverting Structure: A water diverting structure such as a swale shall be The principal consideration for development of the standard constructed(across the roadway on both roadway and specifications is concern for erosion and sediment approaches)50 feet(maximum)on either side of the control,tracking soil into waterways,blocking fish passage waterway crossing. This will prevent roadway surface and destruction of aquatic habitat. Structural utility and runoff from directly entering the waterway. The 50 safety must also be considered when designing temporary feet is measured from the top of the waterway bank. access waterway crossings to withstand expected loads. Design criteria for this diverting structure shall be in The three types of standard temporary access accordance with the"Standard and Specification"for November 2016 Page 2.32 New York State Standards and Specifications For Erosion and Sediment Control the individual design standard of choice. If the roadway 5. Vehicular loads and traffic patterns: Vehicular approach is constructed with a reverse grade away from loads,traffic patterns,and frequency of crossing the waterway,a separate diverting structure is not should be considered in choosing a specific method. required. 6. Maintenance of crossing: The standard methods 6. Road Width: All crossings shall have one traffic will require various amounts of maintenance. The lane. The minimum width shall be 12 feet with a bridge method should require the least maintenance, maximum width of 20 feet. whereas the ford method will probably require more intensive maintenance. 7. Time of Operation: All temporary crossing shall be removed within 14 calendar days after the structure is no 7. Removal of the Structure: Ease of removal and longer needed. Unless prior written approval is subsequent damage to the waterway should be obtained,all structures shall be removed within one year primary factors in considering the choice of a from the date of the installation. standard method. 8. Materials Temporary Access Bridle (Figure 2.2 on a e 2.36 A. Aggregate: There shall be no earth or soil materials used for construction within the waterway A temporary access bridge is a structure made of wood, channel. NYS DOT specifications for coarse metal,or other materials,which provides access aggregate designation No.4(2"to 4"),also across a stream or waterway. referenced as AASHTO designation No. 1,shall be the minimum acceptable aggregate size for Considerations: temporary crossings. Larger aggregates will be allowed. 1. This is the preferred method for temporary access waterway crossings. Normally,bridge construction B. Filter Cloth: Filter cloth is a fabric consisting of causes the least disturbance to the waterway bed and either woven or nonwoven plastic,polypropylene, banks when compared to the other access waterway or nylon used to distribute the load,retain fines, crossings. allow increased drainage of the aggregate and reduce mixing of the aggregate with the subgrade 2. Most bridges can be quickly removed and reused. soil. The designer shall specify the appropriate filter fabric/cloth for a specific use. 3. Temporary access bridges pose the least chance for interference with fish migration when compared Temporary Access Waterway Crossing to the other temporary access waterway crossings. Methods 4. Span width will be limited by the length of the bridging material and weight of equipment that will The following criteria for erosion and sediment control shall drive over the temporary bridge. Spans of over 10 be considered when selecting a specific temporary access feet are difficult to construct. waterway crossing standard method: 5. Restrictions and Permits: A permit from the New 1. Site aesthetics: Select a standard design method that York State Department of Environmental will least disrupt the existing terrain of the stream reach. Conservation,Division of Environmental Permits, Consider the effort that will be required to restore the Regional Permit Administrator,will be needed to area after the temporary crossing is removed. install and remove temporary access culverts in streams with a classification of C(T)and higher. 2. Site location: Locate the temporary crossing where Installation and removal may not be permitted during there will be the least disturbance to the soils of the the period of time from the start of trout spawning existing waterway banks. When possible,locate the until the eggs have hatched. In some instances, crossing at a point receiving minimal surface runoff. restrictions may also be applied to bass spawning 3. Physical site constraints: The physical constraints of Waters. a site may preclude the selection of one or more of the Construction Specifications: standard methods. 4. Time of year: The time of year may preclude the 1. Restriction: Construction,use,or removal of a selection of one or more of the standard methods due to temporary access bridge will not normally have any fish spawning or migration restrictions. time of year restrictions if construction,use,or New York State Standards and Specifications Page 2.33 November 2016 For Erosion and Sediment Control removal does not disturb the stream or its banks. 2. Maintenance: Maintenance shall be performed,as needed to ensure that the structure complies with the 2. Bridge Placement: A temporary bridge structure standard and specifications. This shall include shall be constructed at or above bank elevation to removal and disposal of any trapped sediment or prevent the entrapment of floating materials and debris. debris. Sediment shall be disposed of outside of the floodplain and stabilized. 3. Abutments: Abutments shall be placed parallel to Bridge Removal and Clean-Up Requirements and on stable banks. 1. Removal: When the temporary bridge is no 4. Bridge Span: Bridges shall be constructed to span longer needed,all structures including abutments and the entire channel. If a footing,pier,or bridge support is other bridging materials shall be removed within 14 constructed within the waterway,a stream-disturbance calendar days. In all cases,the bridge materials shall permit may be required. be removed within one year of installation. 5. Stringers: Stringers shall either be logs,saw timber, 2. Final Clean-Up: Final clean-up shall consist of pre-stressed concrete beams,metal beams,or other removal of the temporary bridge from the waterway, approved materials. protection of banks from erosion,and removal of all construction materials.All removed materials shall 6. Deck Material: Decking shall be of sufficient be stored outside the waterway floodplain. strength to support the anticipated load. All decking 3. Method: Removal of the bridge and clean-up of members shall be placed perpendicular to the stringers, the area shall be accomplished without construction butted tightly,and securely fastened to the stringers. equipment working in the waterway channel. Decking materials must be butted tightly to prevent any soil material tracked onto the bridge from falling into 4. Final Stabilization: All areas disturbed during the waterway below. removal shall be stabilized within 14 calendar days of that disturbance in accordance with the Standard 7. Run Planks(optional): Run planking shall be and Specifications for Permanent Construction Area securely fastened to the length of the span. One run Planting on page 4.42. plank shall be provided for each track of the equipment wheels. Although run planks are optional,they may be Temporary Access Culvert(Figure 2.3 on necessary to properly distribute loads. page 2.37 8. Curbs or Fenders: Curbs or fenders may be installed A temporary access culvert is a structure consisting of along the outer sides of the deck. Curbs or fenders are a section(s)of circular pipe,pipe arches,or oval pipes an option,which will provide additional safety. of reinforcing concrete,corrugated metal,or structural plate,which is used to convey flowing water through the crossing. 9. Bridge Anchors: Bridges shall be securely anchored at only one end using steel cable or chain. Anchoring at Considerations only one end will prevent channel obstruction in the event that floodwaters float the bridge. Acceptable 1. Temporary culverts are used where a)the channel anchors are large trees,large boulders,or driven steel is too wide for normal bridge construction,b) anchors. Anchoring shall be sufficient to prevent the anticipated loading may prove unsafe for single span bridge from floating downstream and possibly causing bridges,or c)access is not needed from bank to an obstruction to the flow. bank. 10. Stabilization: All areas disturbed during 2. This temporary waterway crossing method is installation shall be stabilized within 14 calendar days normally preferred over a ford type of crossing, since of that disturbance in accordance with the Standard and disturbance to the waterway is only during Specification for Temporary Construction Area Seeding construction and removal of the culvert. on page 4.58. 3. Temporary culverts can be salvaged and reused. Bridge Maintenance Requirements Construction Specifications 1. Inspection: Periodic inspection shall be performed by the user to ensure that the bridge,streambed,and 1. Restrictions and Permits: A permit from the New streambanks are maintained and not damaged. York State Department of Environmental November 2016 Page 2.34 New York State Standards and Specifications For Erosion and Sediment Control Conservation,Division of Environmental Permits, ensure that the culverts, streambed,and streambanks Regional Permit Administrator,will be needed to install are not damaged,and that sediment is not entering and remove temporary access culverts in streams with a the stream or blocking fish passage or migration. classification of C(T)and higher. Installation and removal may not be permitted during the period of time 2. Maintenance: Maintenance shall be performed,as from the start of trout spawning until the eggs have needed in a timely manner to ensure that structures hatched. In some instances,restrictions may also be are in compliance with this standard and applied to bass spawning waters. specification.This shall include removal and disposal of any trapped sediment or debris. Sediment shall be 2. Culvert Strength: All culverts shall be strong enough disposed of and stabilized outside the waterway to support their cross sectional area under maximum flood plain. expected loads. Culvert Removal and Clean-Up Requirements 3. Culvert Size: The size of the culvert pipe shall be the largest pipe diameter that will fit into the existing 1. Removal: When the crossing has served its channel without major excavation of the waterway purpose,all structures,including culverts,bedding, channel or without major approach fills. If a channel and filter cloth materials shall be removed within width exceeds 3 feet,additional pipes may be used until 14 calendar days.In all cases,the culvert materials the cross sectional area of the pipes is greater than 60 shall percent of the cross sectional area of the existing be removed within one year of installation. No channel. The minimum size culvert that may be used is structure shall be removed during the spawning 12-inch diameter pipe. season(generally October 1 through May 31 for trout waters and March 15 through July 15 for 4. Culvert Length: The culvert(s)shall extend a other waters). minimum of one foot beyond the upstream and downstream toe of the aggregate placed around the 2. Final Clean-Up: Final clean-up shall consist of culvert. In no case shall the culvert exceed 40 feet in removal of the temporary structure from the length. waterway,removal of all construction materials, restoration of original stream channel cross 5. Filter Cloth: Filter cloth shall be placed on the section,and protection of the streambanks from streambed and streambanks prior to placement of the erosion. Removed material shall be stored outside pipe culvert(s)and aggregate. The filter cloth shall of the waterway floodplain. cover the streambed and extend a minimum six inches and a maximum one foot beyond the end of the culvert 3. Method: Removal of the structure and clean- and bedding material. Filter cloth reduces settlement up of the area shall be accomplished without and improves crossing stability. construction equipment working in the waterway channel. 6. Culvert Placement: The invert elevation of the culvert shall be installed on the natural streambed grade 4. Final Stabilization: All areas disturbed during to minimize interference with fish migration(free culvert removal shall be stabilized within 14 passage of fish). calendar days of the disturbance in accordance with the Standard for Permanent Construction Area 7. Culvert Protection: The culvert(s)shall be covered Plantings. with a minimum of one foot of aggregate. If multiple culverts are used,they shall be separated by at least 12 in.of compacted aggregate fill. At the minimum,the bedding and fill material used in the construction of the temporary access culvert crossings shall conform with NOTE: Any temporary access crossing shall conform the aggregate requirements cited in the General to the technical requirements of this Standard and Requirements subsection. Specifications as well as any specific requirement imposed by the New York State Department of 8. Stabilization: All areas disturbed during culvert Environmental Conservation and the US Army Corps installation shall be stabilized within 14 calendar days of of Engineers. Permits may be required for the disturbance in accordance with the Standard for streambank disturbance. Permanent Construction Area Plantings. Culvert Maintenance Requirements 1. hspection: Periodic inspection shall be performed to New York State Standards and Specifications Page 2.35 November 2016 For Erosion and Sediment Control Figure 2.2 Temporary Access Bridge SYMBOL NiZP - a`— ~~ z � TREE STUMP ACCEPTABLE STEEL CABLE HDR OR CHAIN 50' 50' S1TEEL CABILE ACCEPTABLE SURFACE WATE\ OR CHAIN ANCHaA DIVERTED BY SWALE TATEEr OM�fipD �y NS TADA Tr�ON. TEMPORARY ACCESS MEV '(ORK STATE DEPARTKNT ❑F ENVIR❑NMENIAL CCwSERVATHK 13Ri D G E NEW YOR< STATE SOIL :L WATER CUNNERVAiTION COMMITTEE New York State Standards and Specifications Page 2.36 November 2016 For Erosion and Sediment Control Figure 2.3 Temporary Access Culvert SYMBOL ~4 � FILLAGGREGATE r FILTER--, LEPT H AUERLGAIL HIGH FLOV AREA FILL FILTER FILTER AGATE CLOTH CLBTH FILL TEES BANKS H] F'LOW APEA AGGREGATE 1LL .�o. ram• A CjATE F1L TER QF .% r-11 T- FIL CLON [:I I I FLAT HAWS ADWTED FROM DETAILS PRDVIIIED BY, U54A - NR'CS, NEW Y ORK STATF EFPARTMFNT OF TRAl+1WORTATTnN, TEMPORARY ACCESS NEW YORK STATE DEPARTMENT OF CNVIRON14ENTAL CONSIERVATION, CULVERT NEB+ TURK 'STATE 501L � WATER QUNSLRVATIUN LOMMITT,LE New York State Standards and Specifications Page 2.37 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR WINTER STABILIZATION perimeter and sensitive locations. Silt fence and other _�. practices requiring earth disturbance must be installed before the ground freezes. 7. Soil stockpiles must be protected by the use of established vegetation,anchored straw mulch,rolled stabilization matting,or other durable covering.A barrier must be installed at least 15 feet from the toe of the stockpile to prevent soil migration and to capture loose soil. 8. In areas where soil disturbance activity has temporarily or permanently ceased,the application of soil stabilization measures should be initiated by the end of the next business day and completed within three(3) days. Rolled erosion control blankets must be used on all slopes 3 horizontal to 1 vertical or steeper. Definition & Scone 9. If straw mulch alone is used for temporary stabilization,it shall be applied at double the standard A temporary site specific,enhanced erosion and sediment rate of 2 tons per acre,making the application rate 4 control plan to manage runoff and sediment at the site during tons per acre.Other manufactured mulches should be construction activities in the winter months to protect off-site applied at double the manufacturer's recommended water resources. rate. Conditions Where Practice Applies 10. To ensure adequate stabilization of disturbed soil in advance of a melt event,areas of disturbed soil should This standard applies to all construction activities involved be stabilized at the end of each work day unless: with ongoing land disturbance and exposure between a_ work will resume within 24 hours in the same area November 15thto the following April 1st. and no precipitation is forecast or; Design Criteria b. the work is in disturbed areas that collect and retain runoff, such as open utility trenches, 1. Prepare a snow management plan with adequate storage foundation excavations,or water management for snow and control of melt water,requiring cleared areas. snow to be stored in a manner not affecting ongoing construction activities. 11. Use stone paths to stabilize access perimeters of buildings under construction and areas where 2. Enlarge and stabilize access points to provide for snow construction vehicle traffic is anticipated.Stone paths management and stockpiling. Snow management should be a minimum 10 feet in width but wider as activities must not destroy or degrade installed erosion necessary to accommodate equipment. and sediment control practices. Maintenance 3. A minimum 25 foot buffer shall be maintained from all perimeter controls such as silt fence. Mark silt fence The site shall be inspected frequently to ensure that the with tall stakes that are visible above the snow pack. erosion and sediment control plan is performing its winter stabilization function.If the site will not have earth 4. Edges of disturbed areas that drain to a waterbody within disturbing activities ongoing during the"winter season",all 100 feet will have 2 rows of silt fence, 5 feet apart, bare exposed soil must be stabilized by established installed on the contour. vegetation, straw or other acceptable mulch,matting,rock, or other approved material such as rolled erosion control 5. Drainage structures must be kept open and free of snow products. Seeding of areas with mulch cover is preferred and ice dams. All debris,ice dams,or debris from but seeding alone is not acceptable for proper stabilization. plowing operations,that restrict the flow of runoff and meltwater, shall be removed. Compliance inspections must be performed and reports filed properly in accordance with the SWPPP for all sites 6. Sediment barriers must be installed at all appropriate under a winter shutdown. November 2016 Page 2.38 New York State Standards and Specifications For Erosion and Sediment Control References 1. Northeastern Illinois Soil and Sedimentation Control Steering Committee.October 1981.Procedures and Standards for Urban Soil Erosion and Sediment Control in Illinois. 2. J.F.Rushing,V.M.Moore,J.S.Tingle,Q.Mason,and T.McCaffery,2005. Dust Abatement Methods for Lines of Communication and Base Camps in Temperate Climates. ERDC/GSL TR-05-23,October 2005. New York State Standards and Specifications Page 2.39 November 2016 For Erosion and Sediment Control SECTION 3 EROSION CONTROL - PART 1 RUNOFF CONTROL CONTENTS Page List of Tables and Figures Scopeand Discussion........................................................................................................................................................3.1 CheckDam........................................................................................................................................................................3.2 ConstructionDitch ............................................................................................................................................................3.4 DewateringSump Pit ........................................................................................................................................................3.7 Diversion ...........................................................................................................................................................................3.9 EarthDike .......................................................................................................................................................................3.14 FlowDiffuser ..................................................................................................................................................................3.16 FlowSpreader .................................................................................................................................................................3.19 GradeStabilization Structure...........................................................................................................................................3.21 GrassedWaterway ..........................................................................................................................................................3.23 LinedWaterway ..............................................................................................................................................................3.27 PavedFlume ....................................................................................................................................................................3.31 PerimeterDike/Swale .....................................................................................................................................................3.35 PipeSlope Drain .............................................................................................................................................................3.37 RockOutlet Protection ....................................................................................................................................................3.39 StormDrain Diversion ....................................................................................................................................................3.47 SubsurfaceDrain .............................................................................................................................................................3.48 WaterBar ........................................................................................................................................................................3.52 Section prepared by: Donald W.Lake Jr.,PE,CPESC,CPSWQ Former State Conservation Engineer USDA—Natural Resources Conservation Service Syracuse,New York Adjunct Assistant Professor State University of New York,College of Environmental Science and Forestry List of Tables and Figures Table Title Page 3.1 Diversion Maximum Permissible Design Velocities Table..................................................................3.10 3.2 Retardance Factors for Various Grasses and Legumes Table ..............................................................3.10 3.3 Parabolic Diversion Design,Without Freeboard Tables- 1..................................................................3.12 3.4 Parabolic Diversion Design,Without Freeboard Tables-2.................................................................3.13 Figure Title Page 3.1 Stone Check Dam Detail........................................................................................................................3.3 3.2 Construction Ditch Detail.......................................................................................................................3.6 3.3 Dewatering Sump Pit Detail ..................................................................................................................3.8 3.4 Diversion Detail ..................................................................................................................................3.11 3.5 Earth Dike Detail .................................................................................................................................3.15 3.6 Flow Diffuser Detail.............................................................................................................................3.18 3.7 Flow Spreader Detail............................................................................................................................3.20 3.8 Typical Waterway Cross Sections Details............................................................................................3.24 3.9 Parabolic Waterway Design Chart.......................................................................................................3.25 3.10 Grassed Waterway Detail ....................................................................................................................3.26 3.11 Determining"n7 for Riprap Lined Channel using Depth of Flow Chart..............................................3.30 3.12 Examples of Outlet Structures .............................................................................................................3.33 3.13 Paved Flume Detail..............................................................................................................................3.34 3.14 Perimeter Dike Swale Detail ...............................................................................................................3.36 3.15 Pipe Slope Drain Detail .......................................................................................................................3.38 3.16 Outlet Protection Design-Minimum Tailwater Condition Chart .......................................................3.42 3.17 Outlet Protection Design-Maximum Tailwater Condition Chart.......................................................3.43 3.18 Riprap Outlet Protection Detail(1)......................................................................................................3.44 3.19 Riprap Outlet Protection Detail(2)......................................................................................................3.45 3.20 Riprap Outlet Protection Detail(3)......................................................................................................3.46 3.21 Drain Chart-Corrugated Plastic Drain Tubing....................................................................................3.51 3.22 Waterbar Detail ...................................................................................................................................3.53 EROSION CONTROL - PART 1 RUNOFF CONTROL Scone and Discussion Water management on and above potentially eroding sites is Structural erosion control practices are generally considered extremely important and is the first step in controlling as temporary or permanent depending on how they are used. potential erosion on construction sites or disturbed,exposed Some are both.Temporary structural practices are used soil areas.Large watersheds above a site may require during construction to prevent onsite erosion and offsite extensive water control measures.Water flow paths must be migration of sediment.The length of time that temporary controlled to allow safe delivery of water to an outlet at the practices are functional varies from project to project,since side or bottom of a slope.Shallow ditches or diversions the sediment control strategy may change as construction across the slope and above the area to be disturbed is an activity progresses.Permanent structural practices are used effective method of avoiding rills and gullies in disturbed to convey surface water runoff to a safe outlet.They will areas and wash-out of the seed and soil.Diversions may be remain in place and continue to function after the constructed at a point where surface runoff water is completion of construction and final stabilization. intercepted and carried away from the slope to a safe outlet. Regardless of whether the practices are temporary or Within the construction area,surface runoff and permanent,runoff control measures should be the first groundwater must be managed to protect both the site practices constructed when grading begins,and be condition and offsite resources.Conveyances such as completely functional before downslope land disturbance swales,waterways,slope drains,dewatering methods and takes place.Earthen structures such as diversions,dikes, flow bypass systems need to be evaluated to meet design and swales must be stabilized before being considered objectives.These include both the management of clean functional.Only after runoff control structures are water as well as sediment laden water.In all cases,water operational and sediment control measures in place,should management practices should take into account clearing and grading on the rest of the construction site potential impacts to receiving waters and include stable begin. discharge elements. This may include armored or fabric lined conveyances,rock outlet aprons,flow dissipation,or Note:Performing activities within or adjacent to excavated plunge pools. wetlands,streams and waterbodies may require permits from the New York State Department of On large slopes benching may be necessary for drainage Environmental Conservation(NYSDEC)pursuant to and/or future maintenance access(see standard for Land Article 15(Protection of Waters),Article 24 Grading). Subsurface drainage is frequently included to (Freshwater Wetlands)and Article 25(Tidal Wetlands) prevent long term saturated soil conditions and sloughing. of the Environmental Conservation Law(ECL). Project owners should contact NYSDEC's Regional Division of Environmental Permits early in the site planning process to discuss the requirements for meeting permit issuance standards.Following the New York State Standards and Specifications for Erosion and Sediment Control may not ensure compliance with the above referenced sections of the ECL. New York State Standards and Specifications Page 3.1 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR CHECK DAM S _ h - Therefore: Where: S=spacing interval(ft.) _ h=height of check dam(ft.) s=channel slope(ft./ft.) Example: For a channel with a 4%slope and 2 ft.high stone _ 2 ft _ check dams, they are spaced as '� — ft — 5D$ follows: Definition & Scone 0•04 � Small barriers or dams constructed of stone,bagged sand or gravel,or other durable materials across a drainageway to reduce erosion in a drainage channel by reducing the veloci- ty of flow in the channel. For stone check dams: Use a well graded stone matrix 2 to 9 inches in size(NYS—DOT Light Stone Fill meets Conditions Where Practice Applies these requirements). This practice is used as a temporary and,in some cases,a The overflow of the check dams will be stabilized to resist permanent measure to limit erosion by reducing veloci- erosion that might be caused by the check dam. See Figure ties in open channels that are degrading or subject to ero- 3.1 on page 3.3 for details. sion or where permanent stabilization is impractical due to short period of usefulness and time constraints of construc- Check dams should be anchored in the channel by a cutoff tion. trench 1.5 ft.wide and 0.5 ft.deep and lined with filter fab- ric to prevent soil migration. Design Criteria For filter sock or fiber roll check dams:The check dams Drainage Area: Maximum drainage area above the will be anchored by staking the dam to the earth contact check dam shall not exceed two(2)acres. surface.The dam will extend to the top of the bank.The check dam will have a splash apron of NYS DOT#2 Height: Not greater than 2 feet. Center shall be main- crushed stone extending a minimum 3 feet downstream tained 9 inches lower than abutments at natural ground ele- from the dam and 1 foot up the sides of the channel.The vation. compost and materials for a filter sock check dam shall meet the requirements shown in the standard for Compost Side Slopes: Shall be 2:1 or flatter. Filter Sock on page 5.7. Spacing: The check dams shall be spaced as necessary Maintenance in the channel so that the crest of the downstream dam is at the elevation of the toe of the upstream dam. This spacing The check dams should be inspected after each runoff is equal to the height of the check dam divided by the chan- event. Correct all damage immediately. If significant ero- nel slope. sion has occurred between structures,a liner of stone or other suitable material should be installed in that portion of the channel or additional check dams added. Remove sediment accumulated behind the dam as needed to allow channel to drain through the stone check dam and prevent large flows from carrying sediment over the dam. November 2016 Page 3.2 New York State Standards and Specifications For Erosion and Sediment Control Figure 3.1 Stone Check Dam Detail SPACING VARIES SYMBOL DEPENDING ON HAWE L SLOPE Xx CUTOFF TRENCH S�MC EL€��T«N CREST 19" SIDE Tl�'E "'4 MAX 6' DEER H P CENTER PRDIFILE A NOT TO SCALE GROUND LINE 11r M1N. r H (F-0 MIN SLOPE (FT/FT) FILTER F A' 'IL DITCH EIDY 1 Clw DESIGN ROT-OM ] L 24. MAX SECTION A- CENTER NOT TO SCALE 1� 1 6'. FILTER FABRIC LIe� SECTION 8-9 NOT TO SCALE CONSTRUCTION ION PE TFILATTON i, STONE WILL BE PLACED ON A FILTER rABRIC F❑URDATI®NI TO THE LINES, GRADES AND LDCATEDNS SmOWN IN TmE PLAN. 2, SET SPACING OF CHECK .DAMS T❑ ASSUME THAT THE ELEVATIONS OF THE CREST OF THE DUWN TREAM; DAM 1S AT THE SAME ELEVATION OF THE TOE OF THE LJP:�TIREAMI DAM. B, EXTEND THE STONE .A HINT MUM OF 1.5 FEET BEYOND THE DITCH BANKS TO PREVENT OUT 7INO APOUND THC DAM- #. PROTECT THE CHrANNEL DOWNSTREAM OF THE LOWEST CHECK DAM FROM SOUR AND EROSI❑N WITH STONE OR LINER Aa APPROPRIATE. 5, ENSURE THAT CHANNEL APPURTENANCES SUCH AS CULVERT ENTRANCES BELOW CRECK DAMS ARE NOT SUBJECT TO DAMAGE OR BLOCKAGE FROM DISPLACED STUNE, MAXIMLKK DRAINAGE AREA 2 ACRES, ADAPTED FROM DETAILS PROVII1EL eYi USDA - NRES, NEW YORK STATE DEPARTMENT OF TRANSPORTATION, STONE ❑�E� DAM TUFW STALL ART14CHT W LNVERLW4MLNTAL C E�WAT10N. HEW YORK STATE SOIL & WATER C❑NSER ATIGN C❑MWLTTEE New York State Standards and Specifications Page 3.3 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR CONSTRUCTION DITCH General Ditch A Ditch B Drainage Area <5 Ac 5-10 Ac Bottom Width of Flow 4 ft. 6 ft. Channel Depth of Flow Channel 1 ft. 1 ft. Side Slopes 2:1 or flatter 2:1 or flatter Grade 0.5%Min. 0.5%Min. 10%Max. 10%Max. For drainage areas larger than 10 acres,refer to the Standard and Specification for Grassed Waterways on page Definition & Scope 3.23 and 3.24. A temporary excavated drainage way to intercept sediment Stabilization laden water and divert it to a sediment trapping device or to prevent runoff from entering disturbed areas by intercepting Stabilization of the ditch shall be completed within 2 days and diverting it to a stabilized outlet. of installation in accordance with the appropriate standard and specifications for vegetative stabilization or stabiliza- Conditions Where Practice Applies tion with mulch as determined by the time of year.The flow channel shall be stabilized as per the following criteria: Construction ditches are constructed: The seeding for vegetative stabilization shall be in accord- 1. to divert flows from entering a disturbed area. ance with the standard on Page 4.78. The seeded area will be mulched in accordance with the standard on Page 4.39. 2. intermittently across disturbed areas to shorten over- land flow distances. Type of Channel Flow Channel Treat- Grade' 3. to direct sediment laden water along the base of slopes ment A(<5 Ac.) B(5-10 Ac.) to a trapping device. Seed&Straw Seed&Straw 1 0.5-3.0% Mulch Mulch 4. to transport offsite flows across disturbed areas such as rights-of-way. Seed and cover ° Seed&Straw with RECPZ,Sod, Ditches collecting runoff from disturbed areas shall remain 2 3.1-5.0% Mulch or lined with in place until the disturbed areas are permanently stabilized. plastic or 2"stone Seed and cover Design Criteria with RECPZ, Line with 4-8 in. See Figure 3.2 on page 3.6 for details. 3 5.1-8.0% Sod,or line rip-rap or,geo- with plastic or textile 2 in.stone ° Line with 4-8 Site Specific De- 4 8.1-10/o in.rip-rap or geotextile sign 1 In highly erodible soils,as defined by the local approv- ing agency,refer to the next higher slope grade for type of stabilization. 2 Rolled Erosion Control Product. November 2016 Page 3.4 New York State Standards and Specifications For Erosion and Sediment Control Outlet Ditch shall have an outlet that functions with a minimum of erosion,and dissipates runoff velocity prior to discharge off the site. Runoff shall be conveyed to a sediment trapping device such as a sediment trap or sediment basin until the drainage area above the ditch is adequately stabilized. The on-site location may need to be adusted to meet field conditions in order to utilize the most suitable outlet condi- tion. If a ditch is used to divert clean water flows from entering a disturbed area,a sediment trapping device may not be need- ed. New York State Standards and Specifications Page 3.5 November 2016 For Erosion and Sediment Control Figure 3.2 Construction Ditch Detail STORAGE ARE. YM130L C MIN. ExIsTING r,R❑II40 A-2 E-3 SL[ E11 SLOPE 2d ❑R FLATTER FLATTERD FLIIsL LEVEL '� 2jA" A Siy CROSS SEC T IOF C I• 1' D # RDSIT IVE MANAGE- 0. OR S T E:EPER DEPEraDENr ON TEiPDGRAPHIr iurLET AS REOUIRED SEE ITEM 9 KLEI>J, CONSTRUCTION SPECIEICATI❑CIS I. ALL CON&TRUMON DITCmES ALL HAVF- UNINMUFTEU PWITNE GRACE TO PM OUTLET, 2, DIVERTED RUFF FROM .A DIS.TURFED AREA SHALL BE CONVEYED TI1 A SEDIME"T TRAPPINO DEVICE. 3, DIVERTED RUNUFF FROM AN UND]STLPSED AREA SAIL OUTLET DIRECTLY INTO! AN UNDIST`JR1RE11 S-ABIL[ZE❑ AREA AT NON-ER❑SivC VELMITY. 4, ALL TREES, BRUSH, STUMPS, OBSTRUCTIONS, AND 'OTHER UEJECTIONABL£ MATERIAL SHALL BE REMOVED AND DISPOSED OF SO AS NOT TO "INTERFERE WITW THE KOPER FUNCTIONING ❑F THE SWALE. 5. THE DITCH SHALL BE ExCAVATEO OR 'SHAPED Tp DINE. GRADE. A14D CRIJS5 SE;CTIUN AS REQUIREV TO MEET THE CR]TER]f) SrECIFIETI HERG[N AND BE rRCE OF BANK PR❑JECTION$ OR aTHER 1RREGLLAR`1T]E5 Wiq[CM WILL IKFEDE NORMAL FLOW. 6. FILLS SHALL 13E OOMPAOTED BY EARTH MOVING EDUIP RENT. 7. ALL EARTH RENDVED AND NOT NEEDED FDR 00H3TRUIrTI1jN SHALL FE PLACED SQ THAT IT WILL Nar- INTERFERE WITH THE rUNCTi[1NING OF TIE DITCH. 8, S TABILIZATICN SHALL BE AS PER THE FLOW CHANNEL STAR LIZATHIN CHART BELOW- T,PE,.)T -r CaAnr A€3 AC. M L rSS) a5-3 ' SEEM AND STRAW K CH SEED ANM STRAV RULCH J �L1-anx SLED ANA L'LVLE WJ1H K•CP LIKED 'SMITH 4-W RIP-RAP UR [,I:�TExa1LE �.t-Lb L E lIM 1�tT1H -9 1���-Kt sim �m[iriC msI ML TEX[ILE 9. PE R'O j'[E INSP'ECTICFI AND REQUIRED MAINTENANCE MUS- DE PROVIDED AFTER EACH RMN EVENT. ADAPTEDVORX STATE DETAILS p�'I�T OF TRAN A RT VIDED BY, USDA - I NEV DN.. CONSTRUCTION NEV iYORX STATE DEPARTkENT C= EWIRONWWAL CCNSERVATII7� L� NEB' Y'�RK STATE SOIL t WATER CONSI RVIkTIQR COMHTTTEE CH November 2016 Page 3.6 New York State Standards and Specifications For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR DEWATERING SUMP PIT Discharge of turbid water pumped from the standpipe ,• _ "'� should be to a sediment trap,sediment basin,filter bag or stabilized area,such as a filter strip. If water from the sump pit will be pumped directly to a storm drain system,filter as cloth with an equivalent sieve size between 40-80 should be wrapped around the standpipe to ensure clean water "' discharge. It is recommended that'/4 to '/2 inch hardware lip ." cloth be wrapped around and secured to the standpipe prior to attaching the filter cloth. This will increase the rate of water seepage into the standpipe. - Definition & Scope A temporary pit which is constructed using pipe and stone for pumping excessive water from excavations to a suitable discharge area. s*` Conditions Where Practice Applies Sump pits are constructed when water collects during the excavation phase of construction. This practice is particularly useful in urban areas during excavation for building foundations.It may also be necessary during construction activities that encounter high ground water tables in floodplain locations. Design Criteria The number of sump pits and their locations shall be determined by the contractor/engineer. A design is not required,but construction should conform to the general criteria outlined on Figure 3.3 on page 3.8. A perforated vertical standpipe is placed in the center of the pit and surrounded with a stone screening material to collect filtered water. Water is then pumped from the center of the pipe to a suitable discharge area. New York State Standards and Specifications Page 3.7 November 2016 For Erosion and Sediment Control Figure 3.3 Dewatering Sump Pit Detail SYMBOL CL EaL,' WATER Ptiml, GR❑UND WATER GROUND TABLE WATER TABLE 1e'-Z4+ DIAWTER PERFORATED CORRILIGATED OR S DE SLOPE PVC PIECE VARIABLE NYS DOT NZ OR EQUIVALENT CONSTRUCTION SPECIFICATIONS 1. PIT DIMENSI❑NS ARE VARIABLE. Z. THE Sri%Nl)r'IE'E SHOULD" BE CONSTRUCTED BY PERF•OR47ING A IZ-24" DIAMETER CURRUGATEE OR PVC PIPE, A BASE IF NYS M11 41P OR EOUIVALEMT AGGIEIGATE SHAD BE PLACED IN TINE PIT TO A ]DEPTH OF 2 . AFTER INSTALLING THE STANDPIPE, THE PIT �UUNDINU THE STANDPIPE SHOULD BE BACKFILLED V17H NYS DOT OP OR EGIJTVALENT AG EGATE- 4_ THE STANDPIPE SHMLI] r x ILND 18-18* ABOVE THE LIP OF THE PIT. 5, �F DISCHARGE WILL BE PUMPED DIRECTLY TO A STURM DRAENAGE :SYSTEM, THE STANDPIPE SHOM T) BE 'W1? PPk 0 V I Tw F IL TERCL.OTH BEFORE INSTALLATION- IT IS RECOWENDED T"AT 1/4'-1/2' FUMWARE CLOTH MAY DE PLACED AROUND THE STANDPIPE, PRI13R TO ATTACH[NG THE E[LTERCLDTK AsOAPTED FROM DETAILS RRI]VI TER, BY, U511A - NKS, NEW YORK STATE N rARTMLNT OF TRANWOR TATTIy DE W A T E R I N NEW YDRK STATE DEPARTREN7 [IF ENVIMNME.NT.AL CONSERVATION, IMP P I T NEV Y❑RK STATE 5❑]9 L WATER EUNSERVAT1UN COHMITTEE November 2016 Page 3.8 New York State Standards and Specifications For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR DIVERSION �s Capacity Peak rates of runoff values used in determining the capacity requirements shall be calculated using the most current hy- drologic data from the Northeast Regional Climate Center in an appropriate model. �. The constructed diversion shall have capacity to carry,as a minimum,the peak discharge from a 10 year frequency rainfall event with freeboard of not less than 0.3 feet. Diversions designed to protect homes,schools,industrial buildings,roads,parking lots,and comparable high-risk areas,and those designed to function in connection with other structures,shall have sufficient capacity to carry peak Definition & Scope runoff expected from a storm frequency consistent with the hazard involved. A drainage way of parabolic or trapezoidal cross-section with a supporting ridge on the lower side that is constructed Cross Section across the slope to intercept and convey runoff to stable outlets at non-erosive velocities. The diversion channel shall be parabolic or trapezoidal in shape. Parabolic Diversion design charts are provided in Conditions Where Practice Applies Tables 3.2,3.3 and 3.4 on pages 3.10,3.12 and 3.13. The diversion shall be designed to have stable side slopes. The Diversions are used where: side slopes shall not be steeper than 2:1 and shall be flat enough to ensure ease of maintenance of the diversion and 1. Runoff from higher areas has potential for damaging its protective vegetative cover. properties,causing erosion,or interfering with,or preventing the establishment of,vegetation on lower The ridge shall have a minimum width of four feet at the areas design water elevation;a minimum of 0.3 feet freeboard and a reasonable settlement factor shall be provided. 2. Surface and/or shallow subsurface flow is damaging Velocity and Grade sloping upland. 3. The length of slopes needs to be reduced so that soil The permissible velocity for the specified method of stabili- loss will be kept to a minimum. zation will determine the maximum grade. Maximum per- missible velocities of flow for the stated conditions of stabi- lization shall be as shown in Table 3.1 on page 3.10 of this Diversions are only applicable below stabilized or protected standard. areas. Avoid establishment on slopes greater than fifteen Diversions are not usually applicable below high sediment percent. Diversions should be used with caution on soils producing areas unless land treatment practices or structural subject to slippage. Construction of diversions shall be in measures,designed to prevent damaging accumulations of compliance with state and local drainage and water laws. sediment in the channels,are installed with,or before,the Design Criteria diversions. Location Outlets Each diversion must have an adequate outlet. The outlet Diversion location shall be determined by considering out- may be a grassed waterway,vegetated or paved area,grade let conditions,topography,land use,soil type,length of stabilization structure,flow spreader,flow diffuser,stable slope,seep planes(when seepage is a problem),and the watercourse,or subsurface drain outlet. In all cases,the development layout. outlet must convey runoff to a point where outflow will not cause damage. Vegetated outlets shall be installed before diversion construction,if needed,to ensure establishment of New York State Standards and Specifications Page 3.9 November 2016 For Erosion and Sediment Control vegetative cover in the outlet channel. Stabilization The design elevation of the water surface in the diversion Vegetated diversions shall be stabilized in accordance with shall not be lower than the design elevation of the water the following tables. surface in the outlet at their junction when both are operat- ing at design flow. Table 3.1 Diversion Maximum Permissible Design Velocities Table Permissible Velocity Soil Texture Retardance and Cover (ft/second)for Selected Channel Vegetation C-Kentucky 31 tall fescue and Sand,Silt,Sandy loam, Kentucky bluegrass 3.0 silty loam,loamy sand (ML,SM,SP,SW) D-Annuals' Small grain 2.5 (rye,oats,barley,millet)Ryegrass C-Kentucky 31 tall fescue Silty clay loam, and Kentucky bluegrass 4.0 Sandy clay loam (ML-CL,SC) D-Annuals' Small grain 3.5 (rye,oats,barley,millet)Ryegrass C-Kentucky 31 tall fescue and Kentucky bluegrass 5.0 Clay(CL) D-Annuals' Small grain 4.0 (rye,oats,barley,millet)Ryegrass 'Annuals—Use only as temporary protection until permanent vegetation is established. Table 3.2 - Retardance Factors for Various Grasses and Legumes Table Retardance Cover Condition A Reed canarygrass Excellent stand,tall(average 36 inches) Smooth bromegrass Good stand,mowed(average 12 to 15 inches) Tall fescue Good stand,unmowed(average 18 inches) B Grass-legume mixture—Timothy,smooth bromegrass,or Orchard Good stand,uncut(average 20 inches) grass with birdsfoot trefoil Reed canarygrass Good stand,mowed(average 12 to 15 inches) Tall fescue,with birdsfoot trefoil or ladino clover Good stand,uncut(average 18 inches) Redtop Good stand,headed(15 to 20 inches) C Grass-legume mixture—summer(Orchard grass,redtop,Annual Good stand,uncut(6 to 8 inches) ryegrass,and ladino or white clover) Kentucky bluegrass Good stand,headed(6 to 12 inches) Red fescue Good stand,headed(12 to 18 inches) D Grass-legume mixture—fall,spring(Orchard grass,redtop,Annual Good stand,uncut(4 to 5 inches) ryegrass,and white or ladino clover) November 2016 Page 3.10 New York State Standards and Specifica- For Erosion and Sediment Control Figure 3.4 Diversion Detail SYMBOL D i .-.. VITH TRAPEZOIDAL CROSS—SECf1L71� �• Tf2 VIDTH _ T PARAIMICCROSS—SECT1ON ❑N TI UCTION SPECIFICATIO 1. ALL TREES, BRUSH., STUMPS. 0STRUCTI❑NS, AND OTHER 02"TMMOLE MATERIAL SHALL BE REMQVED A1413 DISMSED OF S❑ AS NOT TO INTE `WTM THE PROPER FUNCTI❑NING OF THE DIVERSION.. 2. THE DIVERSI❑N SKALL BE E CAVATE ty OR SHAPED TO LINE, GRADE, AND CAS SECTION AS REQUIREII TD 14ECT THE CRITERIA SPECIFIED HEREIN, AND BE FREE OF DANK PROJECTI❑NS E1R OTHE)R IRREGULARITIES WHICH WILE IMPEDE NORMAL FLOW, 3. E-h U SHPu L BE CUMP, TEI) AS NEEDED TO PREVENT UNE❑UAL SETTLEMENT THAT 1 DAD CAUSE DAMAGE IN THE COMPLETE DIVERSION. 4_ ALL EARTH REM❑VE13 AND NOT NEEDED IN CONSTRUCTION SHALL BE SPREAD OP DISPOSED OF SO, THAT IT WILL NOT INTERrERE WITH TIE FUNCTIONING OF THE DIVERSION. 5. STA91LIZATION SHALL BE DRONE ACC❑RDING TO THE APPRMIATE STANDARD AND SPECIFICA71CM FM VEGETATIVE PRACTICES. k FOR DESIGN VIELOCIMS Or LESS THAN 3.5 FT. PER.. SEC., SEEDING AND MULCHING MAY BE RJSED FOR THE ESTA15LISHMENT CF TFIE VEGETATI❑N. IT IS RECO] NIIED THAT, WHEN ❑❑N:O 1`ON S PERMIT. TEMPORARY DIVERSIONS OIL QTHER MEANS SHOULD BE USED TO PK VE 1T LATER FROM ENTERING THE DIVERSION DURING THE ESTok]RLISHMENT OF THE VEGETATI❑N. D. FOR DESIC44 VELOCITIES OF MORE THAN 3-5 FT. PEP_ SEE., THE DIVERSI❑N SHALL BE STABILIZED VITH S❑L, ''KITH SEEDING POOTEC7ED BY DOTE OR EXCELSIOR 140 T I NG OR WITH SEEDING ANT) MULCHING D CLUDING TEMPORARY DIVERSICN OF THE VATER UNTIL THE VEGETAIJOH IS ESTABLISHED. ,DAPITED FROM DETAILS RRUVUK13 811 U 11A - FMCS, NEW VGRK STATE DEPARTMENT OF TRANSPORTATION, DIVERSION NEV YORK STATE DUARWRT [IF ENVIR)NKENTAL CGNZER;lr�'Ttx NEV TORK STATE SML L WATER DONSERVAi1UN COATrEE New York State Standards and Specifications Page 3.11 November 2016 For Erosion and Sediment Control Table 3.3 Parabolic Diversion Design, Without Freeboard Tables - 1 (USDA-MRCS) u - 4D La Be i # -7--p 7.3��ffi.9 Q eu o rr 6ti1 {Y a a41 ',+ .�..i LLJ F L■■ #S} }*r�■, Y 4 �rtij ■ LLLJL �#4 $fR th th tl1 �1 iL ar. F � Z � ' � tti��Lyv,*Afh!f.5e 15!��r-L r� arh (D Sa a5 +�. ti EfJ 9L rf i i+il''t f+t.fi tiJ �■ ■ a F f.�' °- }yam b f+ d-6 #���� � 4 .�. iy mu E46 L31 - 46.0 ~ .--a .tea 4�& $ .-+E4 W p'L�..` P%P%PL ear +L F A-'i•^tea A A A AAA 0 � ■ a %r 'L'11 71Ltft4r' 94 w ry wr iM+�f:44 ftir' ■a L t.'+ti,-+i r■a d4 n. P4 ft .�.�...■.■ Pirl - te r gEq,0atud�mo�Mba%0,0%ftj . . n ry W%%a r as aD aD Mp a,a%a<a%a,a. � a a .,t a ,,r aw`fii■�rw e:e i �: ..y� .Q$ �* �{�� ,,,■ ter~P�PI 4 �r+.,.�r:r:ri r�r:A i ' PtllI Iy 1�"Ir4 P4 R'L ttd :a7 ■ .�� _ N ra rl'^1N�1.Od _ + ua 4 Oz liii } .i�ti 1h LM Lti/ rn—Lq-livenyr7 rb r5 fttE tz 6:Ltii ZL'zp L; r�. E L� a �. . s r • , , r.l d4 PI PI P. ' PS PI"a,� API V. a�i ra 04 ri t■. ,f` .a.� t�av� W 3W P. PI Pt � V fa■AI UM r''Lr'6F Lr%%n%r%LrtiLnLnu%Lc%Lr%w%u%:6tiW%LVk6'%%ft . . . . . r . + i i F r: .a.-■.-6 .�..L ..,�. —i to rr j P. r■r■r■.-■.i.-.—1.-L A.-E_Tr-d r- b-d- ■ rs . ■ + . i '■ . i s + . . . . • — s. �-D'0 L$�O-0 L'L k''L V4 r P+PA A tV PI ri PI ry-4■ a r`r■ .i. aA.i .ia � to #'L I-d �1 ' '1 V %IM$ 27 O�• a V 9%a in L. CC CL CL November 2016 Page 3.12 New York State Standards and Specifica- For Erosion and Sediment Control Table 3.4 Parabolic Diversion Design, Without Freeboard Tables - 2 (USDA-MRCS) U tr v4 W3 yn■ yC` 4? a r t Z '# y r+s r • PI 4„I, r,.� Wl �„ '`EB.01 Q 0-4 041^� PI W,r.� r+►M�,.,�%ft hf►` &U IY C rr rr.m F% 7F 11 -i!t Vy Vy+ o 4l i. F L-s 5i A.4P7 Y�'a 41"'VL �fhti ' �.J'1 eR 4!'1 L'+'7 4�fh�/4 �4 I.�M1■ C.' 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C 6g'$00�a �€••}■�}u�g.}-6 r!,•r..�i 9!iir 9 P V.: 4+is in#I ~ .�i� 9 h A� �(A '�Z M1 44 -d ri��Two rf3 7!''hftI1IAM V%L+I V'Mrs f•9 rfi�"1i d"4J I'Ad�1 a r s al . s F re r+-4-4 Py A P-t Pa'a-F�-4 ri-F a-r � � } !"1 tp rl Pi A#"�+'■1:.�■r+.-+I rl PL- dL # 1+ d w r Vim'% I-so 9% 17 fy , � M4 rd u CL New York State Standards and Specifications Page 3.13 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR EARTH DIKE Stabilization - d -_ Stabilization of the dike shall be completed within 2 days of installation in accordance with the standard and specifica- tions for seed and straw mulch or straw mulch only if not in seeding season.The flow channel shall be stabilized as per the following criteria: Type of Flow Channel Treat- Channel w Grade ent A(<5 Ac.) B(5-10 Ac.) 4 °'` Seed&Straw Seed&Straw F- 1 0.5-3.0% - _- Mulch Mulch 4 't. Seed and cov- Definition & Scope Seed&Straw er with RECP, A temporary berm or ridge of compacted soil,located in 2 3.1-5.0% Mulch sod,or lined with plastic or such a manner as to channel water to a desired location. Its 2"stone purpose is to direct runoff to a sediment trapping device, thereby reducing the potential for erosion and off site sedi- Seed and cover mentation. Earth dikes can also be used for diverting clean with RECP, Line with 4-8 water away from disturbed areas. 3 5.1-8.0% Sod,or line in.rip-rap or, Conditions Where Practice Applies with plastic or geotextile 2 in. stone Earth dikes are often constructed across disturbed areas and Line with 4-8 Site Specific around construction sites such as graded parking lots and 4 8.1-10% in.rip-rap or p subdivisions. The dikes shall remain in place until the dis- geotextile Design turbed areas are permanently stabilized. L�h y erodible soils,as defined by the local approving agency, Design Criteria he next higher slope grade for type of stabilization. See Figure 3.5 on page 3.15 for details. Outlet General Earth dikes shall have an outlet that functions with a mini- mum of erosion. Dike A Dike B Runoff shall be conveyed to a sediment trapping device Drainage Area <5 Ac 5-10 Ac until the drainage area above the dike is adequately stabi- Dike Height 18 in. 36 in. lized. Dike Width 24 in. 36 in. The on-site location may need to be adjusted to meet field Flow Width 4 ft. 6 ft. conditions in order to utilize the most suitable outlet. Flow Depth in Channel 8 in. 15 in. Side Slopes 2:1 or flatter 2:1 or flatter Grade 0.5%Min. 0.5%Min. 10%Max. 10%Max. For drainage areas larger than 10 acres,refer to the Standard and Specifications for Diversion on page 3.9. November 2016 Page 3.14 New York State Standards and Specifica- For Erosion and Sediment Control Figure 3.5 Earth Dike Detail SYMBOL 2d SLOPE OR FLATTER 24 SLOPE OR FLATTER — � STABlLIZ+�TY[]N AS REQUIRED, ON STEEP CiRo'o F_ LINE SLOPES EXCAVATE TO FBI OVIDE REQUIRED FL13V WIDTH AT FLOW DEPTH. GUT 01? FILL SLOPE DIKE A DIKE 8 ERQ�� �TI!UN (5 AC, OR LESS) (5—kaAC,> hW TO SCAU A — XWE HEIGHT 18, 365' P — D[KE WIDTH 241 361, C — FLOV WIDTH 48, 72F E — FLDV DEPTH 8' 115, PflSITTVF DRARIAGE—GRADE SUFFICIENT TO DRAIN CUT OR FILL SLOPE V y CONSTRUCTION SPECIFICATIONS 1, ALL DIKES SHALL BE COMPACTED BY EARTR-NOVING EPUIPMENT, 2. ALL DIKES SHALL HAVE: POSITIVE DRAINAGE TO AN OUTLET. 1 TOP WIDTH MAY BE WIDEN AND SIDE SLOPES BE FLATTER IF DESIRED TO F ACIL P A T E C WLISS[NIG By GL wS 1 F UG r I UN T kAi 11U. 4, FIELD LOCATION SHOULD BE ADJUSTED AS NEEDED TO UTIL17E A STABILIZED SAFE DUTLET, 5, EARTH DIKES SHALL HAVE Al OUTLET THAT FUNCTIONS WITH A MINIMM ❑F EROSION. PUNOFF SHALL BE CONVEYED TO A SEDIMENT TRAPPING DEVICE SUCH AS A SEDIMENT TRAP CR SEDIMENT BASIN WHERE EITHER THE TAKE CHANNEL OR THE DRAINAGE AREA. ABOVE THE DIKE ARE NOT ADEQUATELY STABILIZED. 6, FILL STABILIZATION SHALL BE, <A> JN ACCORDANCE WITH STANDARD SPECIFIC4TID FOR SEED AND STRAW MULCH IF NOT IN SiCEDING SEASON, <0� FLOW CHANT STABILIZAT]DN PER THE STANDARD CHART BASED ON CH' #EL ISM ADAPTED FRU`1 DETAILS PROVIDED Ry, USDA — NRCS. NEW YORX STATE DEPARTWENT DF TRo4NSPDRTAfIDN, 'EARTH DIKE NEW YORK STATE PARTME-N T Ur E N VNIDNME N T AL C[DNSER VAT I1jN, HE'S WORrc STATE SOIL IL WATER CONSERVATIDH COMMITTEE New York State Standards and Specifications Page 3.15 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR FLOW DIFFUSER prevent undue flow concentration before entering a stable watercourse but it shall have a slope that is less than 30%. If the receiving area is not presently stable, then the receiving area shall be stabilized prior to con- struction of the flow diffuser. The receiving area be- ., low the flow diffuser shall be protected from harm dur- �''� ing construction. Sodding and/or turf reinforcement mat(TRM)in combination with vegetative measures •pe shall stabilize disturbed areas. The receiving area shall not be used by the flow diffuser until stabilization has been accomplished. A temporary diversion may be necessary in this case. 4. Cross-section:The minimum stone diffuser cross- section shall be trapezoidal with a height of 1 foot above natural ground;top width equal to 2 foot and Definition & Scope side slope equal to 1 horizontal to 1 vertical. The stor- age area behind the diffuser shall be excavated to a A permanent non-erosive outlet for concentrated runoff depth of 1 foot and overall width of storage area equal constructed to diffuse flow uniformly through a stone ma- to 6 feet minimum. trix onto a stablilized area in the form of shallow,low ve- locity,sheet flow. 5. Sizing the diffuser: The length of the stone diffuser is governed by the size of the stone in the structure,the Conditions Where Practice Applies height of the diffuser,and the flow length through it. The following equation is used to establish the design of the diffuser: Where sediment-free stormwater runoff can be released in low velocity sheet flow down stabilized areas without caus- kXW ing erosion;where the ground slope at the outlet of the dif- lea = fuser is less than 30%and the runoff will not re-concentrate K�) + 2.5 + La]9' after release;and where construction of a flow spreader is D not practicable. Where: Design Criteria Qa=Outflow through the stone diffuser(cfs) h=Ponding depth behind the diffuser(ft.) W=Linear length of the diffuser along centerline(ft.) 1. Drainage area:The maximum drainage area to the L=Average horizontal flow length through the diffuser diffuser may not exceed 0.10 acre per foot length of the perpendicular to the centerline(ft.) flow diffuser. The drainage area served by the diffuser D=Average stone diameter(d50)in the structure(ft.) discharging directly cannot be 10-20%more than half the size of the receiving buffer area. The maximum d5o size shall be 9"or 0.75'. 2. Discharge from diffuser onto receiving area:The The designer shall calculate the length of diffuser needed peak stormwater flow rate from a flow diffuser onto a depending on the geometry of the cross-section and rock receiving area from a 10-year 24-hour storm must be size to be used recognizing that the maximum allowable less than 0.25 cubic feet per second(0.25 cfs)per linear discharge through the diffuser shall be 0.25 cfs per foot of foot of weir crest length. length. 3. Receiving area of buffer: Each flow diffuser shall have a vegetated receiving area with a minimum con- Once the discharge is calculated for the 10 year storm for tinuous length of 150 feet and the capacity to pass the the drainage area to the diffuser(Q,o)it can be divided by flow without erosion. The receiving area shall be sta- the design discharge of the diffuser to determine the diffus- ble prior to the construction of the flow diffuser. The er length as follows: receiving area shall have topography regular enough to November 2016 Page 3.16 New York State Standards and Specifica- For Erosion and Sediment Control W = QIO Qd Where: Qd=Outflow through the stone diffuser(cfs/ft) Q,o=Discharge rate for the 10 year storm(cfs) W=Linear length of the diffuser along centerline(ft.) Design examples are shown in Appendix B. New York State Standards and Specifications Page 3.17 November 2016 For Erosion and Sediment Control Figure 3.6 Flow Diffuser Detail p1TE- TYPMAL ELEVAT SHOWN PCOC ARE TO ILLUSTRATE THE OPERATION OF THE FLOP D FF7US1_R (VAR 51 LENGTH A 4'ME.TATEIF III TiCH SLIDE SLOPE RECEIVIK AREA L]TC?i BOTTOM i 'JV/ SLIIPE- DRADVAE FABRTG �} EXTEND UP LEON� 3 6' jADDITIC++- ',BERM HEIG -- �AT RUH FND3 IF THE �, =L _— ��N ROLa. VAY PREVENT vASHQjT AT ENDS P93LUC AREA AM LEBRIS CULLECTIDItiM VIVM N S€ ALE Ex��T DRA[N A PA7 TERN GYP.} FL[In,P LIFFuS£1� waT.i LMTH NEASUREQ 14ATER[AL TYPICAL PL AN VIE 4� TO THIS POINT AT . LAGH CND �. MAMU F'ABRI,C ECTIUN H-B Ghr MIK MME °4 ARMS U YF. fti'' fIR d F 5 EXIET'ING [ROUND 6r` STCQKwaTER 0RAINAGE FABRIC Ate` Lai C04VEVANCE TO DWFUMM P13NdIKG ANA SECTION FI nw DIFFIA, ER November 2016 Page 3.18 New York State Standards and Specifica- For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR FLOW SPREADER entering a stable watercourse but it shall have a slope that is less than 10%. If the receiving area is not pres- ently stable,then the receiving area shall be stabilized prior to construction of the flow spreader. The receiv- ing area below the flow spreader shall be protected from harm during construction. Sodding and/or turf reinforced mat in combination with vegetative measures shall stabilize disturbed areas. The receiving area shall not be used by the flow spreader until stabili- zation has been accomplished. A temporary diversion " may be necessary in this case. 5. Weir: The weir of the flow spreader should consist K 4;1AA C ih6 of a pressure treated 2"xl2"timber plank laid on edge and set at level elevation perpendicular to flow. Alter- Definition & Scope nate hardened weir structures may be used as long as a hard,durable,continuous weir is maintained. A permanent or temporary,non-erosive outlet for con- centrated runoff,constructed to disperse concentrated 6. Channel:The flow spreader entrance channel shall flow uniformly over a hardened weir into a stabilized area be a minimum of 1 foot deep with a minimum 2 foot as shallow,low velocity,sheet flow. bottom width to trap sediment and reduce lateral flow velocities. Side slopes shall be 2:1 or flatter. The Conditions Where Practice Applies channel shall be constructed with a 0%grade to ensure uniform flow distribution. Velocity entering the chan- Where sediment-free storm runoff can be released in sheet nel shall be reduced to ensure non-erosive low ap- flow down a stabilized slope without causing erosion; proach velocity in the weir. where a hardened level weir can be constructed without 7. Maintenance: Long term maintenance of the flow filling;where the area below the weir is uniform with a spreader is essential to ensure its continued effective- slope of 10/o or less and the runoff will not re-concentrate ness. The following provisions should be followed. In after release;and where no traffic will disturb the flow the first year the flow spreader should be inspected spreader. semi annually and following major storm events for Design Criteria any signs of channelization and should be immediately repaired. After the first year,annual inspection should be sufficient. Spreaders constructed of wood,asphalt, 1. Drainage area:The maximum drainage area to the stone or concrete curbing require periodic inspection to spreader may not exceed 5 acres. check for damage and to be repaired as needed. 2. Discharge to a flow spreader:The peak stormwater A. Inspections:At least once a year,the spreader flow rate to a flow spreader due to runoff from a 10- pool should be inspected for sand accumulation year 24-hour storm must be less than 0.5 cubic feet per and debris that may reduce capacity. second(0.5 cfs)per foot length of flow spreader lip. B. Maintenance Access:Flow spreaders should be 3. Length of flow spreader: The flow spreader length sited to provide easy access for removal of accu- may not be more than 30 feet if flow is entering from mulated sediment and rehabilitation of the berm. one end of the spreader. Longer lengths require flow to C. Debris Removal:Debris buildup within the split evenly from the center of the spreader. channel should be removed when it has accumulat- ed to approximately 10 to 20%of design volume 4. Receiving area of buffer: Each flow spreader shall or channel capacity. Remove debris such as leaf have a vegetated receiving area with the capacity to litter,branches,tree growth and any sediment pass the flow without erosion. The receiving area shall build-up from the spreader and dispose of appro- be stable prior to the construction of the flow spreader. priately. The receiving area shall have topography regular enough to prevent undue flow concentration before D. Mowing:Vegetated spreaders may require mowing. New York State Standards and Specifications Page 3.19 November 2016 For Erosion and Sediment Control Figure 3.7 Flow Spreader Detail VIDI N VA-ZI S' A' SYMBOL 'Sc1e" ':'FTR PRESSURE JfMA%67TlNG TREA STAP. - IN PLACE D f` MIN. DEPTH 5' 15, 1O4)R'II�Ii EJIE £D' TRANSITJLJH CRDSS SEfTION N01 TO SCALE > ftft) E-1wfkP-0 DE-Pt) LCNGTWPt5 LOW Z FLOW z' 0-5 10 D.5 10 1 5-10 16 0.6 'n SLDIE 10-15 24 0.7 -o PLAN VIEW E.W. - rUTRANCI= WIDTH NOT T❑ SCALE j) DE,3'7 H ON T U TI❑N SPECIFICATIDNS 1, THE MATTING SHOULD BE A HDNIMUM Or #ET- WIDE EXTENDING 6 INCJ4ZS OVER THE WEIR AND BURIED 6 INCHES. DEEP IN A VERTICAL iRENEH UN THE LOWER EDGE. THE UPPER EDGE SHOULD BUTT AGAINST SMOOTHLY CUT SLID AND K SECURELY HELD IN �-,ACE WITH CLOSELY SPACED HEAV r DuTy WIRE STAPLES. AT LEAST 1C -IRCHES iW LENGTH, e. ENSUE THAT THE WEIR IS . ? 'vi• I i J UNWORMLY SFIkEAD DISCHARQL. 3, THE WEIR SMALL BE PL ACE: IN UNDISTURBED S❑IL NOT FILL- 4e A 20 F(3OT TRANSITION SEGTIDN WILL BE CONSTRUCTED FRGK THE DIVERSION EHAN#CL TE) THE SPREADER TO SMOOTHLY BLEND THE DIFFERENT 'DIMENSION AND CAADES- 15 THE RUNOFF DISCHARGE WILL BE ❑U d LETED ❑EMT❑ A SSTABILIZED VEGETATED SLOPE NUT EXCEEMN15 10. 6, SEED -,ND HIM CH THE DlT AR1~OL T.MMEDIATELY DETER CONSTRUCTION. ADAPTED FRI)M DETAIL H ;I' _ .r� u u�o - NW3S, NEW,:�W YU 5TGR TE STATE DEP DEF 'i'1FEhiTR�C]F EN1�1�: � PAL C[]NSERVAT]ON FLOW P LADLR NEW YORK STATE SELL $. WATER CONS-' �Z ri T1 pN CUMMI TTEE New York State Standards and Specifications Page 3.20 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR GRADE STABILIZATION STRUCTURE ceed safe velocities for vegetated channels due to in- creased grade or a change in channel cross section or where durability of vegetative lining is adversely af- fected by seasonal changes. Adequate protection will be provided to prevent erosion or scour of both ends of the channel lining. 2. Overfall structures of concrete,metal,rock riprap,or other suitable material is used to lower water from one elevation to another. These structures are applicable where it is desirable to drop the watercourse elevation over a very short horizontal distance. Adequate protec- tion will be provided to prevent erosion or scour up- . -, stream,downstream and along sides of overfall struc- tures. Structures should be located on straight sections of channel with a minimum of 100 feet of straight Definition & Scope channel each way. A permanent structure to stabilize the grade or to control 3. Pipe drops of metal pipe with suitable inlet and outlet head cutting in artificial channels by reduction of velocities structures. The inlet structure may consist of a vertical and grade in the watercourse or by providing channel lin- section of pipe or similar material,an embankment,or ings or structures that can withstand the higher velocities. a combination of both. The outlet structure will pro- vide adequate protection against erosion or scour at the Conditions Where Practice Applies pipe outlet. This practice applies to sites where the capability of earth Capacity and vegetative measures is exceeded in the safe handling of water at permissible velocities,where excessive grades or Structures that are designed to operate in conjunction with overfall conditions are encountered,or where water is to be other erosion control practices shall have,as a minimum, lowered structurally from one elevation to another. These capacity equal to the bankfull capacity of the channel deliv- structures should generally be planned and installed along ering water to the structures. The minimum design capacity with,or as a part of,other practices in an overall surface for structures that are not designed to perform in conjunc- water management system. tion with other practices shall be that required to handle the peak rate of flow from a 10-year,24-hour frequency storm Desin Criteria or bankfull,whichever is greater. Peak rates of runoff used in determining the capacity requirements shall be deter- Compliance with Laws and Regulations mined by appropriate methods. Design and construction shall be in compliance with state Set the rest of the structure at an elevation that will stabilize and local laws and regulations. Such compliance is the re- the grade of the upstream channel. The outlet should be set sponsibility of the landowner or developer. at an elevation to assure stability. Outlet velocities should be kept within the allowable limits for the receiving stream. General Structural drop spillways need to include a foundation drainage system to reduce hydrostatic loads. Designs and specifications shall be prepared for each struc- ture on an individual job basis depending on its purpose, Permanent structures which involve the retarding of flood- site conditions,and the basic criteria of the conservation water or the impoundment of water shall be designed using practice with which the structure is planned. Typical struc- the criteria set forth in the New York State DEC Guidelines tures are as follows: for the Design of Dams. 1. Channel linings of concrete,asphalt,half round metal pipe or other suitable lining materials. These linings should generally be used where channel velocities ex- New York State Standards and Specifications Page 3.21 November 2016 For Erosion and Sediment Control Construction Specifications Structures shall be installed according to lines and grades shown on the plan. The foundation for structures shall be cleared of all undesirable materials prior to the installation of the structure. Materials used in construction shall be in conformance with the design frequency and life expectancy of the practice. Earth fill,when used as a part of the struc- ture,shall be placed in 4-inch lifts and hand compacted within 2 feet of the structure. Seeding,fertilizing,and mulching shall conform to the ap- plicable standards and specifications in Section 4. Construction operations shall be carried out in such a man- ner that erosion and air and water pollution will be mini- mized. State and local laws concerning pollution abatement shall be complied with at every site. Locate emergency bypass areas so that floods in excess of structural capacity enter the channel far enough downstream so as not to cause damage to the structure. Maintenance Once properly installed,the maintenance for the grade sta- bilization structure should be minimal. Inspect the structure periodically and after major storm events. Check fill for piping or extreme settlement. Ensure a good vegetative cover. Check the channel for scour or debris and loss of rock from aprons. Repair or replace failing structures im- mediately. New York State Standards and Specifications Page 3.22 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR GRASSED WATERWAY Velocity Please see Table 3.1,Diversion Maximum Permissible Design Velocities on page 3.10,for seed,soil,and velocity variables. Cross Section The design water surface elevation of a grassed waterway receiving water from diversions or other tributary channels shall be equal to or less than the design water surface eleva- tion in the diversion or other tributary channels. The top width of parabolic waterways shall not exceed 30 feet and the bottom width of trapezoidal waterways shall Definition & Scope not exceed 15 feet unless multiple or divided waterways, stone center,or other means are provided to control mean- A natural or permanent man-made channel of parabolic or dering of low flows. trapezoidal cross-section that is below adjacent ground level and is stabilized by suitable vegetation. The flow channel is Structural Measures normally wide and shallow and conveys the runoff down the slope without causing damage by erosion. In cases where grade or erosion problems exist,special con- trol measures may be needed such as lined waterways(see Conditions Where Practice Applies page 3.27),or grade stabilization measures(see page 3.21). Where needed,these measures will be supported by ade- Grass waterways are used where added vegetative protec- quate design computations. For typical cross sections of tion is needed to control erosion resulting from concentrated Waterways with riprap sections or stone centers,refer to runoff. Figure 3.8 on page 3.24. Desisn Criteria The design procedures for parabolic and trapezoidal chan- nels are available in the NRCS Engineering Field Hand- book.Figure 3.9 on page 3.25 also provides a design chart Capacity for parabolic waterway. The minimum capacity shall be that required to confine the Outlets peak rate of runoff expected from a 10-year 24 hour fre- quency rainfall event or a higher frequency corresponding Each waterway shall have a stable outlet. The outlet may to the hazard involved. This requirement for confinement be another waterway,a stabilized open channel,grade stabi- may be waived on slopes of less than one(1)percent where lization structure,etc. In all cases,the outlet must discharge out-of-bank flow will not cause erosion or property damage. in such a manner as not to cause erosion. Outlets shall be Peak rates of runoff values used in determining the capacity constructed and stabilized prior to the operation of the wa- terway. requirements shall be computed by appropriate methods. Where there is base flow,it shall be handled by a stone cen- Stabilization ter,subsurface drain,or other suitable means since sus- tained wetness usually prevents adequate vegetative cover. Waterways shall be stabilized in accordance with the appro- The cross-sectional area of the stone center or subsurface priate vegetative stabilization standard and specifications, drain size to be provided shall be determined by using a and will be dependent on such factors as slope,soil class, flow rate of 0.1 cfs/acre or by actual measurement of the etc. See standard for Vegetating Waterways on Page 4.78. maximum base flow. Construction Specifications See Figure 3.10 on page 3.26 for details. New York State Standards and Specifications Page 3.23 November 2016 For Erosion and Sediment Control Figure 3.8 Typical Waterway Cross Sections Details T I Sul GRAVEL BEDDM3 OR FILTER CLOTH Waterway wi th stone c-Enter drain. "Q'' SertiOn shaped by motor grader. T IitS T D GRALVEL BEO@INO OR FILTER CLOTH Waterway with �tvnc center drain. Rounded section shaped by bviIdoaer. New York State Standards and Specifications Page 3.24 November 2016 For Erosion and Sediment Control 1 � ■ { �777:mcs"y-i• - ��! P E�_r+C�- I I p LI I I lil I 1 _. 1 r e r�Ic SLID .� ram r �c �.r• r I I riT'1�k N. i + dlll� l�� _ �. used, 1.or Imo. �iuis _� ��•� � -s�l.,'r a lt4 iJa# �arlor••- 1♦♦i 7k ■�i••J■ � T Aill� - "�iiiif'11i. l'JIM, �w a � EM EAF = _G.3r— — - -•_ E E VT --- ter ,:.• MCA iC F•i7g 77177i� va• �.... I :1-+�iii��r�'a •��... ur�rr.�r...•r��l�.l".,"""...."�wnenlyyii EN"7••i 777l1y Mil"1111711 Yafi••y••G.r n•n•oln ralu i"1171R�MIIIIFW iI€n•uu Irul7on7ur••r uu•••�7�1�7 ��1! ■�RiMFN mill6 11*11111aII MLLINI �Ri Ll loin . r. Figure 3.10 Grassed Waterway Detail YMB� T RA4PEZI❑D&L GRQSS ;EQIIEEM D T/2 T �PARARELIC CROSS SECTI❑Ihl CONSTRUCTION SPECIFI ATIO 1. ALL TREES. BRUSH, STumPS, OBSTI T[IONS, AND OTHER MECTLE ILE: MATT LZ;k SHALL K REMOVED AND DISPOSED DE SO AS NOT TO INTERFERE WITH THE PROPER FUNCTI❑NIN❑ OF THE WATERVAY, 2. THE WATERWAY SHALL 6E EXCAVATED NR SHAPED TU LINE, GRADE, AND CROSS SECTION AS REQUIRED TO MEET THE CR17ERIA SRECIFCED HEREIN, AND BE FREE C; BANK MOJE<CTIONS OR EITHER IRRECUL+ tTIES WHICH WILL IMPEDE NORMAL FLOW 3, FILLS SHALL BE COMPACTED AS NEEDED TO PREVENT UNEQUAL SETTLEMENT THAT WOULD CAUSE DAMAGE IN THE COMPLETE WATERWAY- 4. AL i, EARTH REMOVED AND NOT NEEDED IN CQNS mkiC r I N SMALL DE SPREAD OF? DISP❑SED ❑F S❑ THAT IT WILL NOT INTERFERE WIT" THE FUNCTIONING OF THE WATERWAY. 5, STABILIZATION SHALL BE DONE ACCORDING TO THE APPROPRIATE STANDARD AND SPECIFICATIONS Flab VEGETATIVE PRACTICES, A, F❑R DESIGN VELOC11FIES OF LESS THAN 3,5 FT, PER. SEC., SEE DING AND MULCHING MAY BE USED FOR THE E TARLTSHMEmr iDr THE VEGETATION. IT IS PECOMwMENDE D THAT, WHEN CONDITIONS PERNI T, T EHPdRARY WATERWAYS OR ❑TbER MEANS SHOULD BE USED TN PREVENT WA`E:� FROM ENTERING 7HL WATLRWAY DURINQ THL ESTABLISHMENT OF THL VLF;; IAIJUN. B, FOR IX SI:N VE:LOIC E T I E S OF MORE 7HAN 3,5 FT, FER. SEC., THE W e%-; R%,(AY SHALL OE STABILIZED WITH 500, 'WITH SEEDING TEF-TE;0 BY .;:. -i lid EXCELSHIR MATTING OR WITH SEEDING AND MULCHING INCLUDING TEMPORARY DIVE?RSIDN OF THE: WATER UNTIL TKE VEGETATION IS ESTABLISHED. C. STRUCTURAL — VEGETATIVE PROTECTION SUBSURFACE BRAIN FOR BASE FLOW SHILL BE CONSTRUCTED AS SHO " ON THE STANDARD DRAWING AND AS SPECIFIED IN THL STAND API) AND SFE<CIFICATtONS FOR SUBSURFACE DRAIN. ADAPTED FROM DETAILS PROVIDED PV1 USDA - Nk-CS, NEW YORK STATE DEPARTMENT OF rRANSPIDRrArIDN, GRASSED NEV YORK STATE IILPARTM!ENT OF F-MVIRUNNE- 1Ti4L CONSERVATION, WATERWAY NF`V YnRK STATE SU1L � WATER CONSERVATION COMIT11FE New York State Standards and Specifications Page 3.26 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR LINED WATERWAY ` lets. t 4. Soils are highly erosive or other soil and climate condi- tions preclude using vegetation. 5. High value property or adjacent facilities warrant the k extra cost to contain design runoff in a limited space. Design Criteria Capacity 1. The minimum capacity shall be adequate to carry the peak rate of runoff from a 10-year,24-hour storm. Velocity shall be computed using Manning's equation Definition & Scope with a coefficient of roughness"n"as follows: Lined Material A permanent waterway or outlet with a lining of concrete, stone,or other durable,hardened material. The lined sec- Concrete (Type): tion extends up the side slopes to the designed depth. The Trowel Finish 0.015 earth above the permanent lining may be vegetated or other- wise protected. Float Finish 0.019 The lined waterway is constructed to provide for the dispos- Gunite 0.019 al of concentrated runoff without damage from erosion or Flagstone 0.022 flooding,where grassed waterways would be inadequate due to high velocities. Riprap Determine from Figure 3.11 on page 3.30 Conditions Where Practice Applies Gabion 0.030 This standard applies to waterways or outlets with linings of 2. Riprap gradation and filter(bedding)are generally de- cast-in-place concrete,flagstone mortared in place,rock signed in accordance with criteria set forth in the Na- riprap,gabions,or similar permanent linings. It does not tional Cooperative Highway Research Program Report apply to irrigation ditch or canal linings,grassed waterways 108,available from the University Microfilm Intema- with stone centers or small lined sections that carry pro- tional,300 N. Zeeb Road,Ann Arbor,Michigan longed low flows,or to reinforced concrete channels. Lined 48106,Publication No.PB-00839;or the Hydraulic waterways should not be used if they are directly discharg- Engineering Circular No. 11,prepared by the U.S.Bu- ing to C(T)or higher streams unless thermal impacts are reau of Public Roads,available from Federal Highway mitigated by biotechnical practices(Section 4). The maxi- Administration,400 7a'Street,S.W.,Washington,D.C. mum capacity of the waterway flowing at design depth shall 20590,HNG-31,or the procedure in the USDA- not exceed 100 cubic feet per second. MRCS's Engineering Field Manual,Chapter 16. This practice applies where the following or similar condi- Velocity tions exist: 1. Maximum design velocity shall be as shown below. 1. Concentrated runoff is such that a lining is required to Except for short transition sections,flow with a control erosion. channel gradient within the range of 0.7 to 1.3 of this 2. Steep grades,wetness,prolonged base flow,seepage, flow's critical slope must be avoided unless the channel is straight. Velocities exceeding critical will or piping that would cause erosion. be restricted to straight reaches. 3. The location is such that damage from use by people or animals precludes use of vegetated waterways or out- New York State Standards and Specifications Page 3.27 November 2016 For Erosion and Sediment Control Design Flow Maximum Velocity Related Structures Depth(ft.) (ft./sec.) Side inlets,drop structures,and energy dissipaters shall 0.0-0.5 25 meet the hydraulic and structural requirements of the site. 0.5- 1.0 15 Filters or Bedding Greater than 1.0 10 Filters or bedding to prevent piping,reduce uplift pressure, 2. Waterways or outlets with velocities exceeding critical and collect water will be used as required and will be de- shall discharge into an energy dissipater to reduce ve- signed in accordance with sound engineering principles. locity to less than critical,or to a velocity the down- Weep holes and drains should be provided as needed. stream soil and vegetative conditions will allow. Concrete Cross Section Concrete used for lining shall be so proportioned that it is The cross section shall be triangular,parabolic,or trapezoi- plastic enough for thorough consolidation and stiff enough dal. Monolithic concrete or gabions may be rectangular. to stay in place on side slopes. A dense product will be required. A mix that can be certified as suitable to produce Freeboard a minimum strength of at least 3,000 pounds per square inch will be required. Cement used shall be Portland Ce- The minimum freeboard for lined waterways or outlets shall ment,Type I,II,IV,or V. Aggregate used shall have a be 0.25 feet above design high water in areas where erosion maximum diameter of 1 '/2 inches. resistant vegetation cannot be grown adjacent to the paved side slopes. No freeboard is required where good vegeta- Weep holes should be provided in concrete footings and tion can be grown and is maintained. retaining walls to allow free drainage of water. Pipe used for weep holes shall be non-corrosive. Side Slope Mortar Steepest permissible side slopes,horizontal to vertical will be as follows: Mortar used for mortared in-place flagstone shall consist of a mix of cement,sand,and water. Follow directions on the 1. Non-Reinforced Concrete bag of mortar for proper mixing of mortar and water. Hand-placed,formed concrete Height of lining, 1.5 ft or less .................Vertical Contraction Joints Hand placed screened concrete or mortared In-place flagstone Contraction joints in concrete linings,where required,shall Height of lining,less than 2 ft ....................1 to 1 be formed transversely to a depth of about one third the Height of lining,more than 2 ft ..................2 to 1 thickness of the lining at a uniform spacing in the range of 2. Slip form concrete: 10 to 15 feet. Height of lining,less than 3 ft ....................I to 1 3. Rock Riprap ......................................................2 to 1 Rock Riprap or Flagstone 4. Gabions .........................................................Vertical 5. Pre-cast Concrete Sections ............................Vertical Stone used for riprap or gabions shall be dense and hard enough to withstand exposure to air,water,freezing,and Lining Thickness thawing. Flagstone shall be flat for ease of placement and have the strength to resist exposure and breaking.Rock Minimum lining thickness shall be as follows: riprap maximum size shall be as follows: 1. Concrete ...................4 in.(In most problem areas, Velocity(f p.s.) d„,ag(in.) shall be 5 in.with welded wire fabric reinforcing) 5.0 6 2. Rock Riprap ............. 1.5 x maximum stone size plus 8.5 12 thickness of filter or bedding. 10 18 3. Flagstone ..................4 in.including mortar bed. 12 24 15 36 New York State Standards and Specifications Page 3.28 November 2016 For Erosion and Sediment Control A complete listing riprap gradations is provided in Table 4.1,page 4.9. Cutoff Walls Cutoff walls shall be used at the beginning and ending of concrete lining. For rock riprap lining,cutoff walls shall be keyed into the channel bottom and at both ends of the lin- ing. Construction Specifications 1. The foundation area shall be cleared of trees,stumps, roots,sod,loose rock,or other objectionable material. 2. The cross-section shall be excavated to the neat lines and grades as shown on the plans. Over-excavated areas shall be backfilled with moist soil compacted to the density of the surrounding material. 3. No abrupt deviations from design grade or horizontal alignment shall be permitted. 4. Concrete linings shall be placed to the thickness shown on the plans and trowel finished. Adequate precautions shall be taken to protect freshly placed concrete from extreme(hot or cold)temperatures,to ensure proper curing. 5. Filter bedding and rock riprap shall be placed to line and grade in the manner specified. 6. Construction operation shall be done in such a manner that erosion,air pollution,and water pollution will be minimized and held within legal limits. The completed job shall meet all design requirements for the appropri- ate finish. All disturbed areas shall be vegetated or otherwise protected against soil erosion. Maintenance Pavement or lining should be maintained as built to prevent undermining and deterioration. Existing trees next to pave- ments should be removed,as roots can cause uplift damage. Vegetation next to pavement should be maintained in good condition to prevent scouring if the pavement is overtopped. See Standard and Specifications for Permanent Construc- tion Area Planting on page 4.42. 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Concrete—Minimum strength of design mix shall be 3000 psi. Concrete thickness shall be a minimum of 6 inches reinforced with#3 reinforcing bars. Mix shall be dense, durable,stiff enough to stay in place on steep slopes,and sufficiently plastic for consolidation. Concrete mix should include an air-entraining admixture to resist freeze-thaw cycles. Cross Section—Flumes shall have minimum depth of 1 foot with 1.5:1 side slopes. Bottom widths shall be based on maximum flow capacity. Chutes will be maintained in a straight alignment because of supercritical flow velocities. Definition & Scope Drainage filters—Use a drainage filter with all paved flumes to prevent piping and reduce uplift pressures. Size A permanent small concrete-lined channel to convey water of the filter material will be dependent on the soil material from a higher to a lower elevation in a short distance such the flume is located in. as down the face of a cut or fill slope without causing ero- sion. Due to potential thermal impacts and the creation of Inlet Section—Design the inlet to the following minimum fish migration barriers,paved flumes shall not be used for dimensions: side walls 2 feet high,length 6 feet,width direct discharges to C(T)or higher streams. equal to the flume channel bottom,and side slopes the same Condition Where Practice Applies as the flume channel side slopes. Outlet Section—Outlets must be protected from erosion. Where concentrated storm runoff must be conveyed down a Usually an energy dissipater is used to reduce the high cut or fill slope as part of a permanent erosion control sys- chute velocities to lower non-erosive velocities. Rock tem. Paved flumes serve as stable outlets for diversions, riprap should be placed at the end of the dissipater to spread drainage channels,or natural drainageways,that are located flow evenly to the receiving channel. above relatively steep slopes. Paved flumes should be used on slopes of 1:5 to 1 or flatter. See Figure 3.12 on page 3.33 for examples of outlet struc- tures. Design Criteria Invert—Precast concrete sections may be used in lieu of Capacity—Minimum capacity should be the 10-year fre- cast in place concrete. The sections should be designed at quency storm. Freeboard or enough bypass capacity should the joint to be overlapped to prevent displacement between be provided to safeguard the structure from peak flows ex- sections. Joint sealing compound should be used to prevent pected for the life of the structure. migration of soil through a joint. Cutoff walls and anchor lugs should be cast in the appropriate sections to accommo- Slope—The slope should not be steeper than 1.5:1 (67%). date the design criteria. Cutoff Walls—Install cutoff walls at the beginning and end Small Flumes—Where the drainage area is 10 acres or less, of paved flumes. The cutoff should extend a minimum of the design dimensions for concrete flumes may be selected 18 inches into the soil and across the full width of the flume from those shown in the table on the following page: and be 6 inches thick. Cutoff walls should be reinforced with#3 reinforcing bars(3/8")placed on a 6-inch grid in the center of the wall. Anchor Lugs—Space anchor lugs a minimum of 10 feet on centers for the length of the flume. They will extend the width of the flume,extend 1 foot into subsoil,be a mini- mum of 6 inches thick,and be reinforced with#3 reinforc- New York State Standards and Specifications Page 3.31 November 2016 For Erosion and Sediment Control Drainage Area(Acres) 5 10 Min.Bottom Width(ft.) 4 8 Min.Inlet Depth(ft.) 2 2 Min.Channel Depth(ft.) 1.3 1.3 Max.Channel Slope 1.5:1 1.5:1 Max. Side Slope 1.5:1 1.5:1 See Figure 3.13 on page 3.34 for details. Construction Specifications 1. The subgrade shall be constructed to the lines and grades shown on the plans. Remove all unsuitable ma- terial and replace them if necessary with compacted stable fill materials. Shape subgrade to uniform sur- face. Where concrete is poured directly on subsoil, maintain it in a moist condition. 2. On fill slopes,the soil adjacent to the chute,for a mini- mum of 5 feet,must be well compacted. 3. Where drainage filters are placed under the structure, the concrete will not be poured on the filter. A plastic liner,a minimum of 4 mils thick,will be placed to pre- vent contamination of filter layer. 4. Place concrete for the flume to the thickness shown on the plans and finish according to details. Protect fresh- ly poured concrete from extreme temperatures(hot or cold)and ensure proper curing. 5. Form,reinforce,and pour together cutoff walls,anchor lugs and channel linings. Provide traverse joints to control cracking at 20-foot intervals. Joints can be formed by using a 1/8 inch thick removable template or by sawing to a minimum depth of 1 inch. Flumes long- er than 50 feet shall have preformed expansion joints installed. 6. Immediately after construction,all disturbed areas will be final graded and seeded. Maintenance Inspect flumes after each rainfall until all areas adjoining the flume are permanently stabilized. Repair all damage immediately. Inspect outlet and rock riprap to assure pres- ence and stability. Any missing components should be im- mediately replaced. New York State Standards and Specifications Page 3.32 November 2016 For Erosion and Sediment Control Figure 3.12 Examples of Outlet Structures ,'R '41A DEPARTMENT ❑, CONTRA COSTA CIMATY, CALIF HIGHWAIS AND TRARSPORIA-]-� USSR TYPE IV IASI ,l ST.. ANTH13NY FALLS STILLING BA&IJ1 y ri� �� ::C-2RAD❑ STATE UNIVERSE-Y STRAIGHT DROP SPILLWAY ISYILLING EAS1N Ili ABA"Ed rRow DETAILS PRDYIDED BYi USDA - MCS, OUTLET STRUCTURE NEW 'FIFK STATE AR'THeNT Qtf TIZANSPMTATION, NEV YCIRK STATE DEPARTMENT OF ENVIRUWZNTAL CENSERVATION, F— AMPLE NEV Y❑RK STATE SUIL & WATER CUNSERI AT)ION EEIHHITTEE New York State Standards and Specifications Page 3.33 November 2016 For Erosion and Sediment Control Figure 3.13 Paved Flume Detail SYM130L BYPASSFM - r i T i�i'i s i i�,•i S , , , 1 1 Tarr I)RA[NACi L MEN RU T T UM MIN CHANNEL MAX �J DE MIN INLET MAX CHANNEL AREA (AC) WIDTH (FT) IIEPTH (FT) SLUPIE (FT/FT) IILF- f (F 1) SLOPE (FT�FT) 5 # 1.3 1,511 C 1.5-1 10 a 113 1.511 1.511 CON TRUCTIDN SPECIFICATHINS I. SUBGRA OE SHALL BE CONSTRWICD To T'HE LINES ANJ) GRADES SHOWN ON THE PLANS, RCMOVE ALL UNSUITABLE MATERIAL AND REPLACE THCH IF NECESSARY WITH COMPACTED STABLE FELL MATERIALS. SHAPE SUBGRAOE TO UNIF❑RM SURFAC.E. WHERE CONCRETE IS POURED DIRECTLY ON SUBSOIL MAIN'TA[N IT IN A MOIST CONDITION. P, ON FILL SLOPES THE SOIL ADJACENT TO THE CHUTE FOR A MINIMUM OF 5 FEET SHALL BE VF 1 1 cnmPAc TE D. 3, WHERE ]DRAINAbE F LL TEF?S ARE PLACED UNDER THE: 5 TRUC TIRE THE CONCRETE WILL NOT TE PO1URED ON TKE FILTER. A PLASTIC LINER, RINII~UJM 4 MILS THECK, WILL BC PLACED TO PREVENT CONTAMINATION or T HC FILTER LAYER. 4. PLACE CONCRETE FOR THE FLUME TO THE THICKNESS SHOWN ON THE PLANS AND F.jN L'SH ACCIORDING TO DETAILS. PROTECT FRESHLY POURED CONCRETE FROM EXTREME TEMPERATURES (HOT ❑IR COLD) AND ENSURE PROPER CURING. 5. FORM, REINFORCE, AND POuR TOGETHER CUTOFF WALLS, ANaEN❑R LUGS AND, CHAt,INEL LCNLNGS- PROVIDE TRAVERSE JL CNT TO CONTiRiOL. CRACKING ING AT 20 FOOT 11yTERVAtiL 'S. J❑INTS CAN BE FORMED BY USING A LAH INCH THICIK REMOVABLE TEMPLATE OR By SAWING TO A MINIMUK DEPTH OF 1 INCH. FLUMES LONUER THAN 50 FEET SHALL HAVE PREFORMED EXPANSIDN J❑TNTS [NSTALLED. 6.. IMMEDIATELY AFTER CONSTRUCTION, ALL DISTURBED AREAS WILL FEE FINAL GRADED AND SEE DEID, 7. MAINTENANCE — INSPECT FLUMES AFTER EACH RAINFALL UNT]L ALL AREAS ADJOININ6 THE FLUME ARE PERK"T L Y STA19[L[ZED. REPAIR ALL DAM14GE IMMEDIATELY. INSPECT OUTLET AND ROCK R1PRAP TO ASSUME PRESENCE AND STABILITY- ANY MISSING CGMPONENT'� SHOULP 1 E IMMERIATELY REPLACED- ADAPTED FROM DETAILS PROVIDED Or- USDA - NRCS, NEXT YORK STATE IIEPARTNENT OF TRANSPORTATION, PAVED � �� FLUME NEV YORK STATE �IE.RARTICNT OF' ENV[R�ONMENTAL LONSERVATION NEW YORX STATE SOIL :L WATER CONSERVATION COMMITTEE New York State Standards and Specifications Page 3.34 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR PERIMETER DIKE/SWALE Width of swale—2 feet minimum. se= - Grade—Dependent upon topography,but shall have positive drainage(sufficient grade to drain)to an ade- quate outlet. Maximum allowable grade not to exceed 8 percent. Stabilization—The disturbed area of the dike and swale shall be stabilized within 2 days of installation,in accord- F °s ance with the standard and specifications for construction ditch(page 3.4). .. r � Outlet op 1. Perimeter dike/swale shall have a stabilized outlet. Definition & Scope 2. Diverted runoff from a protected or stabilized upland area shall outlet directly onto an undisturbed stabilized A temporary ridge of soil formed by excavating an ad- area. joining Swale located along the perimeter of the site or disturbed area.Its purpose is to prevent off site storm run- 3. Diverted runoff from a disturbed or exposed upland on from entering a disturbed area and to prevent sediment area shall be conveyed to a sediment trapping device laden storm runoff from leaving the construction site or such as a sediment trap,sediment basin,or to an area disturbed area. protected by any of these practices. Conditions Where Practice Applies 4. The on-site location may need to be adjusted to meet field conditions in order to utilize the most suitable Perimeter dike/swale is constructed to divert flows from outlet. entering a disturbed area,or along tops of slopes to prevent flows from eroding the slope,or along base of slopes to direct sediment laden flows to a trapping device. The perimeter dike/swale shall remain in place until the disturbed areas are permanently stabilized. Design Criteria See Figure 3.14 on page 3.36 for details. The perimeter dike/swale shall not be constructed outside property lines or setbacks without obtaining legal ease- ments from affected adjacent property owners. A design is not required for perimeter dike/swale. The following crite- ria shall be used: Drainage area—Less than 2 acres(for drainage areas larg- er than 2 acres but less than 10 acres,see earth dike or construction ditch;for drainage areas larger than 10 acres, see standard and specifications for diversion). Height— 18 inches minimum from bottom of swale to top of dike evenly divided between dike height and swale depth. Bottom width of dike—2 feet minimum. New York State Standards and Specifications Page 3.35 November 2016 For Erosion and Sediment Control Figure 3.14 Perimeter Dike/Swale Detail `,EED NOT BE C❑MPACTEL �'M]N, L, YMBDL 9'M[N. � E KI STI�I GROUND <Mlr�:, �'M[N. CROSS SECT[U NOT TO SCA V V V V PoSiT[VL BRAINAUL SUFFICIENT GRADE 70 DRAIN V V V V PLAN VIE1�' NOT TO SCALE CDNSTRUCTION SPECIFICATIONS I. ALL PERIMETER DIKE/SWALE, SHALL HAVE I+IINTERRUPTED POSITIVE GRADE TO AN' DUTLET. E, DIVERTED PUNOEr FQOM A Dl!STUQBED AREA SHALL BE CONvEYED TO A SEDIMENT IRAPPING DEVICE. 3, DIVERTED RUNOFF FROM AN UNDISTURBED AREA SFIALL OUTLET INTO AN UNDISTUREED STABILIZED AREA AT NON-EROSIVE VELOCITY. #, THE SWALE SHALL RE EXCAVATED CIR SHAPED TO LINE GRADE, AND ER❑SS CECTIUI AS REQUIRED TO MEET TI CRITERIA SPEC]FIED, IN THE 7STANDARD. 5, STA,BILIZATIDN OF THE AREA DISTURBED BY THE DIKE AND SWALE SHALL BE DONE IN ACCOPDANCE WITH THiE STANDARD AND SPECIFICATIONS MR TEmPORAKy SEEONG AND MULCHING, AND SHALL DE DOME W17HIN E DAYS. G. PERIODIC INSPECrIOI AND REQUIRED MAINTNANCE MUST BE PROVIDED AFTER EACH FAIN EVENT. MAX. DRAINAG AREA LIMIT- ACRU ADAPTED REM IIETAILS PRIOVITIED BY- US-ID4 - NKS. NEW YORK STATE DEPARTMENT Or TRANW RTATIM. PERIMETER 1311 E OR NEW Y❑RK STATE EEPAR THENT OF EMVM TAL CUW+ EIIVATMN, SWALE NEW VU S MATE SDIL L WATER R;RVATV3N CC[M�97TE E New York State Standards and Specifications Page 3.36 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR PIPE SLOPE DRAIN device when the drainage area is disturbed. A riprap apron shall be installed at all pipe outlet locations where water is being discharged. Construction Specifications 1. The pipe slope drain shall have a slope of 3 percent or steeper. 2. The top of the containment dike over the inlet pipe,and those dikes carrying water to the pipe,shall be at least i one(1)foot higher at all points than the top of the inlet pipe. 3. Corrugated plastic pipe or equivalent shall be used with Definition & Scope watertight connecting bands. A temporary structure placed from the top of a slope to the 4. A flared end section shall be attached to the inlet end of bottom of a slope to convey surface runoff down slopes pipe with a watertight connection. without causing erosion. 5. The soil around and under the pipe and end section Conditions Where Practice Applies shall be hand tamped in 4 in.lifts to the top of the earth dike. Pipe slope drains are used where concentrated flow of sur- face runoff must be conveyed down a slope in order to pre- 6. Where flexible tubing is used,it shall be the same di- vent erosion. The maximum allowable drainage area shall ameter as the inlet pipe and shall be constructed of a be 3.5 acres. durable material with hold down grommets spaced 10 ft.on centers. Design Criteria 7. The flexible tubing shall be securely fastened to the corrugated plastic pipe with metal strapping or water- See Figure 3.15 on page 3.38 for details. tight connecting collars. General 8. The flexible tubing shall be securely anchored to the slope by staking at the grommets provided. Size Pipe/Tubing Di- Maximum Drain- ameter(in.) age Area(Ac.) 9. Where a pipe slope drain outlets into a sediment trap- PSD-12 12 0.5 ping device,it shall discharge at the riser crest or weir elevation. PSD-18 1 18 1.5 10. A riprap apron shall be used at all pipe outlet locations. PSD-21 21 2.5 See Figure 3.15 on page 3.38 . PSD-24 24 3.5 11. Inspection and any needed maintenance shall be per- formed after each storm event. Inlet The minimum height of the containment dike at the en- trance to the pipe slope drain shall be the diameter of the pipe(D)plus 12 inches. Outlet The pipe slope drain shall outlet into a sediment trapping New York State Standards and Specifications Page 3.37 November 2016 For Erosion and Sediment Control Figure 3.15 Pipe Slope Drain Detail NOTE, SYMBOL SIZE DESK TIOM I"S- RSD-P[RE D] .EM„RSI)-1@-F1RE $LOK aRa[w IdI TM IO'O[AN. PIK. �S DJ SO-AAGE INTO A ST48ELIZED VATERCOURSE. SEOWNT TRAPPING DEVICE, OP UNTU A ST"ILLZED APES � � � EARTH CONA,I'�IHEI+IT IIIKE LENGTH AS � NECESSARY TO GU TI-RJ DIKE $TPr 04W PLAOXV 31 FP I/E+ PIPE 4 FJTT[NG ENTR141�E SECTION ' Fl�dtll?' R RRAP SHALL VAYrLRTIW COI�IST OF CONNECTING R'MIN €+'IaId�TER i-i1!aF BAND CUTOFF PLAGEM AS SHO'w'N, VPLLL 6D 3 DEPTH OF .AIPt�CjM FLEXIBLE SLIFE 3X SMALL EDUAL THE OR STIEEPOR PIFIE DI TE$t ANs PJPE. � RMPAP SHALL 'K -A NMI" IF I?qN u TMECNESS. PkO€ILE, RIRRAP APR EIN ELANVIEW �'H[w� LESS THAN �� SLOPE CONSTRUCTION UCTION ELCIFICATIU 1 p. rHr ImE T PIPE ZFb6LL mAVE A 'SLOE Gf TZ CR STEEPER. a TIe Tw or THE EMTM DIKE OVER THE ENJET PINIE AND THE DIKES CARRTING VATER TO THE PIPE SHALL HE AT LEAST I' HIGHER AT .ALL POINTS THAN THE TCIP IF THE INLET PIPE. 3. THE INLET PSI $HALL BE E> UGAILID PJPE V[IH vA1LRIJL, 7 C[1NKCTING BANDS. #. TIIE FLEXIBLE TVDIN5 VALL K THE SAK PTAKTER A4 THE INLET PEPE MI) $Wkk, K EIS 1 RLG T-G EE A DURABLE MATERIAL `KITH HLG-DOVN GROMMETS SPACED AT IV ON CEMTEP. 5. THE FLEXERLE TUMING SHALL RE SECURELY FASTI NENE TO THE CORRUGATEE RIPE VITH METAL STRAPPING IDR VATERTIGHT CONiNECTING MLARS- 6, THE FLEXIBLE TUE[NC} SQL BE SECURELY A►NiEWE TO THE SLI: BY ST AT THE GRC!WTS P VIDEP, T'- A REPRAP APRON SHALL DC PROVIDED AT THE OUTLET- THIS SHALL CCwSE$T OF VDIAmETER STONE PLACED AS SHOWNL IL THE SML AAOitIND AND LRIT[ER twa P c Apa EN izmc.E =ricm &4ALL M HAN11 TAMPED IN 4FLtI'TS TO THE T13 OF EARTH DIKE- 9- F06LCV INSPECTION AND AW NEEDED MAINTEWOCE SHALL K PERrORMED AFTER EACH STORM EVENT. ERAIN,A,GiE AREA MUST NOIT EIVEEE 15 ACRES. AMAPrED PRam nETAILS PMVIDED BY- USDA - NRCS, NEW YORK STATE DEPARTMENT [IF TRANSPORTATION, ���E L��❑ ����� NEW YORK STATE, JSEPAIR7MENT OF E IRON14ENTAL CONSERVATION, `E.'4 YURK STATE 5:11. E +1&tiER WN'SERVAT[014 CUMMITTEE New York State Standards and Specifications Page 3.38 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR ROCK OUTLET PROTECTION must be determined for the design capacity of the pipe. If the tailwater depth is less than half the diameter of the out- let pipe,and the receiving stream is wide enough to accept divergence of the flow,it shall be classified as a Minimum Tailwater Condition;see Figure 3.16 on page 3.42 as an example. If the tailwater depth is greater than half the pipe _ - diameter and the receiving stream will continue to confine the flow,it shall be classified as a Maximum Tailwater Condition;see Figure 3.17 on page 3.43 as an example. Pipes which outlet onto flat areas with no defined channel may be assumed to have a Minimum Tailwater Condition; see Figure 3.16 on page 3.42 as an example. Apron Size Definition & Scope The apron length and width shall be determined from the A permanent section of rock protection placed at the outlet curves according to the tailwater conditions: end of the culverts,conduits,or channels to reduce the Minimum Tailwater—Use Figure 3.16 on page 3.42 depth,velocity,and energy of water,such that the flow will Maximum Tailwater—Use Figure 3.17 on page 3.43 not erode the receiving downstream reach. If the pipe discharges directly into a well defined channel, Conditions Where Practice Applies the apron shall extend across the channel bottom and up the channel banks to an elevation one foot above the maximum This practice applies where discharge velocities and ener- tailwater depth or to the top of the bank,whichever is less. gies at the outlets of culverts,conduits,or channels are suf- ficient to erode the next downstream reach. This applies to: The upstream end of the apron,adjacent to the pipe,shall have a width two(2)times the diameter of the outlet pipe, 1. Culvert outlets of all types. or conform to pipe end section if used. 2. Pipe conduits from all sediment basins,dry storm water Bottom Grade ponds,and permanent type ponds. The outlet protection apron shall be constructed with no 3. New channels constructed as outlets for culverts and slope along its length. There shall be no overfall at the end conduits. of the apron. The elevation of the downstream end of the Design Criteria apron shall be equal to the elevation of the receiving chan- nel or adjacent ground. The design of rock outlet protection depends entirely on the Alignment location. Pipe outlet at the top of cuts or on slopes steeper than 10 percent,cannot be protected by rock aprons or The outlet protection apron shall be located so that there are riprap sections due to re-concentration of flows and high no bends in the horizontal alignment. velocities encountered after the flow leaves the apron. Materials Many counties and state agencies have regulations and de- sign procedures already established for dimensions,type The outlet protection may be done using rock riprap,grout- and size of materials,and locations where outlet protection ed riprap,or gabions. Outlets constructed on the bank of a is required. Where these requirements exist,they shall be stream or wetland shall not use grouted rip-rap,gabions or followed. concrete. Tailwatcr Depth Riprap shall be composed of a well-graded mixture of rock size so that 50 percent of the pieces,by weight,shall be The depth of tailwater immediately below the pipe outlet larger than the d50 size determined by using the charts. A New York State Standards and Specifications Page 3.39 November 2016 For Erosion and Sediment Control well-graded mixture,as used herein,is defined as a mixture Gabions composed primarily of larger rock sizes,but with a suffi- cient mixture of other sizes to fill the smaller voids between Gabions shall be made of hexagonal triple twist mesh with the rocks. The diameter of the largest rock size in such a heavily galvanized steel wire. The maximum linear dimen- mixture shall be 1.5 times the d5o size. sion of the mesh opening shall not exceed 4'/2 inches and the area of the mesh opening shall not exceed 10 square Thickness inches. The minimum thickness of the riprap layer shall be 1.5 Gabions shall be fabricated in such a manner that the sides, times the maximum rock diameter for d50 of 15 inches or ends,and lid can be assembled at the construction site into a less;and 1.2 times the maximum rock size for d50 greater rectangular basket of the specified sizes. Gabions shall be than 15 inches. The following chart lists some examples: of single unit construction and shall be installed according to manufacturer's recommendations. Minimum Dso dmax Blanket Thick- The area on which the gabion is to be installed shall be (inches) (inches) ncss(inches) graded as shown on the drawings. Foundation conditions 4 6 9 shall be the same as for placing rock riprap,and filter cloth shall be placed under all gabions. Where necessary,key,or 6 9 14 tie,the structure into the bank to prevent undermining of the 9 14 20 main gabion structure. 12 18 27 Maintenance 15 22 32 Once a riprap outlet has been installed,the maintenance 18 27 32 needs are very low. It should be inspected after high flows for evidence of scour beneath the riprap or for dislodged 21 32 38 rocks. Repairs should be made immediately. 24 36 43 Desi2n Procedure Rock Quality 1. Investigate the downstream channel to assure that nonerosive velocities can be maintained. Rock for riprap shall consist of field rock or rough unhewn quarry rock. The rock shall be hard and angular and of a 2. Determine the tailwater condition at the outlet to estab- quality that will not disintegrate on exposure to water or lish which curve to use. weathering. The specific gravity of the individual rocks shall be at least 2.5. 3. Use the appropriate chart with the design discharge to determine the riprap size and apron length required. It Filter is noted that references to pipe diameters in the charts are based on full flow. For other than full pipe flow, A filter is a layer of material placed between the riprap and the parameters of depth of flow and velocity must be the underlying soil surface to prevent soil movement into used to adjust the design discharges. and through the riprap. Riprap shall have a filter placed under it in all cases. 4. Calculate apron width at the downstream end if a flare section is to be employed. A filter can be of two general forms: a gravel layer or a plastic filter cloth. The plastic filter cloth can be woven or Design Examples are demonstrated in Appendix B. non-woven monofilament yarns,and shall meet these base requirements:thickness 20-60 mils,grab strength 90-120 Construction Specifications lbs;and shall conform to ASTM D-1777 and ASTM D- 1682. 1. The subgrade for the filter,riprap,or gabion shall be prepared to the required lines and grades. Any fill re- Gravel filter blanket,when used,shall be designed by com- quired in the subgrade shall be compacted to a density paring particle sizes of the overlying material and the base of approximately that of the surrounding undisturbed material. Design criteria are available in Standard and material. Specification for Anchored Slope and Channel Stabilization on page 4.7. 2. The rock or gravel shall conform to the specified grad- New York State Standards and Specifications Page 3.40 November 2016 For Erosion and Sediment Control ing limits when installed respectively in the riprap or filter. 3. Filter cloth shall be protected from punching,cutting, or tearing. Any damage other than an occasional small hole shall be repaired by placing another piece of cloth over the damaged part or by completely replacing the cloth. All overlaps,whether for repairs or for joining two pieces of cloth shall be a minimum of one foot. 4. Rock for the riprap or gabion outlets may be placed by equipment. Both shall each be constructed to the full course thickness in one operation and in such a manner as to avoid displacement of underlying materials. The rock for riprap or gabion outlets shall be delivered and placed in a manner that will ensure that it is reasonably homogenous with the smaller rocks and spalls filling the voids between the larger rocks. Riprap shall be placed in a manner to prevent damage to the filter blan- ket or filter cloth. Hand placement will be required to the extent necessary to prevent damage to the perma- nent works. New York State Standards and Specifications Page 3.41 November 2016 For Erosion and Sediment Control No ong OWN ---------------- ■■g—agrE■aiiign_ --- _____ _ _ � _ _ _ - - -. - 3.��.4a�a�:.a■aaaa®a■■areas was_ �- --------- fi!2!2!=f! 'i...i E•.i.ii. i 7.i.i.HN: i � E.....i i..E...�.. 911111116 7 r7.i,.....E'...111111111110..k11. �. ik'.E...-....■ E...i.�i.iE...�i .fk°.i 7i i..ME.Eli E..f47 �.,`..E.i E..iE■ - ■.a.�a..l...�a.■ mil.■.�.k..■........■ ■! 'is..al....■ ■....■..l....l..■ r,7i`7■7.:..U.....l� . 11.!■�...�.■ i■�i■ii■i■Ili■■i■ 7on."NAM■i■ 611 shines Us h*1>�1■■■ltt■■■�■ sVL■■■It■ as■All ■1 _ a. x�aswsAM.ra.a.a.az■ _ .sa®a■■a■ea■aa.a z-- ae �e�as.`■iauae -- - ---_-- _ _ _.SERE C'3.iJ0 9.63 a 1-S Lj7 G = -3 Ci �a3ae% - 3� �.i�■ - - _- Zmal ati--------------- =_- _ == - 1t ------------- -- __ .....i......�p� ....�....l.ilW.■ ■r■2111 fr9{1. .1.a....MEl...■ -.1.SLM . a ME L ■-------------------------------- RAI Figure 3.17 Outlet Protection Design—Maximum Tailwater Condition Chart (Design of Outlet Protection from a Round Pipe Flowing Full, Maximum Tailwater Condition: Tw > 0.5Do) (USDA -NRCs) d M Flo prap$Ire,Deer kn o 0 Y _ -ti i ce® to ,\� T—E -L { a • a a a -� . • �y�viz � -, . � r• �� M r � � - - fir, •�' � fy 4 4 2 _ LI LL * ; h10 Pa Z 2 � C3 + 1 •# o . ' . E * b o� LP 4 E { e v {k - U Z � NJ It u J .,jL LLI ti New York State Standards and Specifications Page 3.43 November 2016 For Erosion and Sediment Control Figure 3.18 Riprap Outlet Protection Detail (1) A- YMBL.. Wfia PROFILE 4 Dl CHAR❑E TO UNCONFINED SECTION (FLARED OUTLET) (MINIMUM TAtILWATER CONDITI❑N) w A, p L L o _I RLSER IliAINVIE1�+ A----I 6MI41M DISCH, NO ❑`1+'ERFALL EXISTING 00 P1PE STABILIZED _d ' CHANNEL 3' M9I K FADED ALLRL LA T L MTE<R OR. FILTER c:," o-riq NL I E, APNN @ ZE,n GRADE SIDE SLI1PE 24l PROFILE VIES VAR I L 5. #' Lr 1A/2 1 I r SEE RIPRAP STAA uLc's AM+D SPECIrtCA MN GRADED A GC,RE TE FILTER OR FILTER CLOTH CS SECTION A- i -k� PIPIPIAP STANDARDS AND SPE CI F ICATIGNS 14MMU--M TAILwATER CONDITIONS ADAPTED FROM DETAILS PROVIDED BY, USIA — NRCS.. RIPRAP ❑U T L L I NEW Y❑RC STATE DEPARTMENT III TRANSPORTATION, ��❑�E�TI� NEW Tfikx STATE DEPARTFIENT IMF ENv1R�Ik+ttrlENTAL COrSCFtv�T ICNj NEW TORK STATE SAIL IL WATER CCNSER2VATI❑N COMMITTEE EXAMPLE New York State Standards and Specifications Page 3.44 November 2016 For Erosion and Sediment Control Figure 3.19 Riprap Outlet Protection Detail (2) SYMBOL No OVERFALI. SLOPE = G/ AmE AS F AR t1LJTL.-I t =0% Nj I L: DISCHARGE TO CONFINED CHANNEL oil SECTION APRON LENGTH PLAN VIE TUP OF CHANNEL 6'M N, _ ' S DOWNSTREAM NEL WERT 'MIN. GRADED A0GRE—DATE � ['MIN. F10CP OR r]LTER C'. -.TH, F'k::; I: I. VIP �1! MINIMUM DEPTH OF REP'RAP = MAXIMUM DEPTH OF FLOW 4C17VNSTREAM NORMAL DEPTH DR M,ARGE 5E PTHr WHICHEVER ]5 GREA TER5. —,!I, SLOPE TO VARY FROM 21 AT FILTER CLON M GRAND PIPE 13UTLET TO EXISTING AGGREGATE FILTER CWANNEL SLOPE AT END OF WIDTH OF H❑TTI1 TO VARY I.YARIE5 APR❑Nr FROM 1/2 PIPE DIAMETER AT PIPE OUTLET TO EXISTING CHANNEL BOTTOM AT CND or ApRoN. ADAPTED FRM DETAILS PMVIDED By, USDA - NRCS, RIPRAP OUTLET NEW YOkK STATE DEPAR 1 MEN T L* iRANwuxrATXW, NEW YrRK STATE DEPAkTHENT [IF ENVIRONMENTAL CONSERVATION, PR❑TACT ION NEW YORK STATE SOIL & WATER CG NSERVATION CDHMFTTCE E: A MPL E New York State Standards and Specifications Page 3.45 November 2016 For Erosion and Sediment Control Figure 3.20 Riprap Outlet Protection Detail (3) =06 DISC HAKE TG �id2 SEMI-CONFINED SECT10m P9 X" TAILWATF-R C❑NDI T IIIIAI) w/2 g�j LO _II PLAN.VIEb, -'-S; R MIN. DEPTH DISCHARGE OR TAl'LVATER DEPTH, WHIGNEVIE S GREATEN DEPTH DICTATED BY _ CHANNEL SE 1]I1N Ar END or ArPON �dI-ea) ICI S=04— � 6� [�w. 3` MIN. ❑Rr4 D AGGREGATE FILTER OR FILTER CLOT- - PRO F I LE VIE' GRADED Aw CR GATE — GRADCD AGGREGATE FILTER OR FILTER CLOTH FILTER OR FILTER CLOTH SE❑T IOIH A,-A SECTION B-B (AT END OF CULVER', (AT END OF APRON) KIM P?axIPIUM TAILVATER WNDITIONS ADAPTED FROM DETAILS PROV30ED BY, USDA - NKS. RIPRAP OUTLET NEW Y®RK STATE XPARTMENT [IF TRANSF0 `TATIu-bI, �F��T��TIQ NEW YORK STATE DEPAR'TIENT W ENV=NHENTAL C[ 4S?F?VATI0N, NEW YURK STATE SL]IE L WATER CONSERVATION COMMITTEE EXAMPLE November 2016 Page 3.46 New York State Standards and Specifica- For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR STORM DRAIN DIVERSION 3. Delay completion of the permanent storm drain out- fall and temporarily divert storm flow into a sedi- ment basin or trap. Earth dike, swale or design di- version is used, depending on the drainage area, to direct flow into a sediment basin or trap. The basin or trap should be constructed to one side of the pro- posed permanent storm drain location whenever possible. 4. Installation of a stormwater management basin early in the construction sequence. Install temporary measures to allow use of this site as a sediment ba- sin. Since these structures are designed to receive storm drain outfalls, diversion should not be neces- sary. _ Completion and Disposition Definition & Scope When the areas contributing sediment to the system have been stabilized,procedures can be taken to re- The temporary redirection of a storm drain line or outfall store the system to its planned use. channel so that it may discharge into a sediment trapping device in order to prevent sediment laden water from en- The following removal and restoration procedure tering a watercourse,public or private property through a is recommended: storm drain system.This could either be above ground or an underground conveyance system to convey sediment 1. Flush the storm drain system to remove any accumu- laden water to a sediment trapping device. lated sediment. Conditions Where Practice Applies 2. Remove the sediment control devices, such as traps, basins,dikes,swales,etc. One of the following practices or procedures shall be used 3. For sites where an inlet was modified,brick and grout whenever the off-site drainage area is less than 50 percent shut the temporary pipe stub and open the permanent of the on-site drainage area to that system. A special ex- outfall pipe. ception may be given,at the discretion of the local plan approval agency,where site conditions make this proce- 4. Establish permanent stabilized outfall channel as noted dure impossible. on the plans. 5. Restore the area to grades shown on the plan and stabi- Method of Temporary Diversion lize with vegetative measures. 1. Construction of a sediment trap or basin below a 6. For basins that will be incorporated into stormwater permanent storm drain outfall. Temporarily diverts management facilities,remove the accumulated sedi- storm flow into the basin or trap constructed below ment,construct the stormwater facility as designed, permanent outfall channel. and seed all disturbed areas to permanent vegetation. 2. In-line diversion of storm drain at an inlet or man- hole,achieved by installing a pipe stub in the side of a manhole or inlet and temporarily blocking the per- manent outfall pipe from that structure. A tempo- rary outfall ditch or pipe may be used to convey storm flow from the stub to a sediment trap or basin. This method may be used just above a permanent outfall or prior to connecting into an existing storm drain system. New York State Standards and Specifications Page 3.47 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR SUBSURFACE DRAIN storm drainage systems or foundation drains.Regulatory restrictions may apply if wetlands are present. An outlet for the drainage system shall be available,either by gravity flow or by pumping. The outlet shall be ade- quate for the quantity of water to be discharged without causing damage above or below the point of discharge and shall comply with all state and local laws. Design Criteria The design and installation shall be based on adequate sur- veys and on-site soils investigations. Required Capacity of Drains Definition & Scope The required capacity shall be determined by one or more A pennanent conduit,such as tile,pipe,or tubing,installed of the following: beneath the ground surface,which intercepts,collects,and/ 1. Where sub-surface drainage is to be uniform over an or conveys drainage water to serve one or more of the fol- area through a systematic pattern of drains,a drainage lowing purposes: coefficient of 1 inch to be removed in 24 hours shall be 1. Improve the environment for vegetative growth by used; see Drain Chart,Figure 3.21 on page 3.51. regulating the water table and groundwater flow. 2. Where sub-surface drainage is to be by a random inter- ceptor system,a minimum inflow rate of 0.5 cfs per 2. Intercept and prevent water movement into a wet area. 1,000 feet of line shall be used to determine the re- 3. Relieve artesian pressures. quired capacity. If actual field tests and measurements of flow amounts are available,they may be used for 4. Remove surface runoff. determining capacity. 5. Provide internal drainage of slopes to improve their For interceptor subsurface drains on sloping land, in- stability and reduce erosion. crease the inflow rate as follows: 6. Provide internal drainage behind bulkheads,retaining Land Slope Increase Inflow Rate By walls,etc. 2-5 percent 10 percent 7. Replace existing subsurface drains that are interrupted 5-12 percent 20 percent or destroyed by construction operations. Over 12 percent 30 percent 8. Provide subsurface drainage for dry storm water man- agement structures. 3. Additional design capacity must be provided if surface 9. Improve dewatering of sediment in sediment basins. water is allowed to enter the system. (See Standard and Specification for Sediment Basins in Size of Subsurface Drain Section 5). The size of subsurface drains shall be determined from the Conditions Where Practice Applies drain chart found on Figures 3.21 on page 3.51. All subsur- face drains shall have a nominal diameter,which equals or Subsurface drains are used in areas having a high water exceeds four(4)inches. table or where subsurface drainage is required. The soil shall have enough depth and permeability to permit installa- tion of an effective system. This standard does not apply to November 2016 Page 3.48 New York State Standards and Specifica- For Erosion and Sediment Control Depth and Spacing most seepage strata. Behind bulkheads and retaining walls, it shall go to within twelve inches of the top of the structure. The minimum depth of cover of subsurface drains shall be This standard does not cover the design of filter materials 24 inches where possible. The minimum depth of cover where needed. may be reduced to 15 inches where it is not possible to at- tain the 24 inch depth and where the drain is not subject to Materials used for envelopes shall not contain materials equipment loading or frost action. Roots from some types which will cause an accumulation of sediment in the con- of vegetation can plug drains,as the drains get closer to the duit or render the envelope unsuitable for bedding of the surface. conduit. Envelope materials shall consist of either filter cloth or sand/gravel material,which shall pass a 1 '/z inch The spacing of drain laterals will be dependent on the per- sieve,90 to 100 percent shall pass a 3/4 inch sieve,and not meability of the soil,the depth of installation of the drains more than 10 percent shall pass a No. 60 sieve. and degree of drainage required. Generally,drains installed 36 inches deep and spaced 50 feet center-to-center will be Filter cloth envelope can be either woven or non-woven adequate. For more specific information,see the New York monofilament yarns and shall have a sieve opening ranging Drainage Guide(USDA-NRCS). from 40 to 80. The envelope shall be placed in such a man- ner that once the conduit is installed,it shall completely Minimum Velocity and Grade encase the conduit. The minimum grade for subsurface drains shall be 0.10 The conduit shall be placed and bedded in a sand/gravel percent. Where surface water enters the system a velocity envelope. A minimum of three inches depth of envelope of not less than 2 feet per second shall be used to establish materials shall be placed on the bottom of a conventional the minimum grades. Provisions shall be made for prevent- trench. The conduit shall be placed on this and the trench ing debris or sediment from entering the system by means completely filled with envelope material to minimum depth of filters or collection and periodic removal of sediment of 3 inches above the conduit. from installed traps. Soft or yielding soils under the drain shall be stabilized Materials for Subsurface Drains where required and lines protected from settlement by add- ing gravel or other suitable material to the trench,by plac- Acceptable subsurface drain materials include perforated, ing the conduit on plank or other rigid support,or by using continuous closed joint conduits of polyethylene plastic, long sections of perforated or watertight pipe with adequate concrete,corrugated metal,polyvinyl chloride,and clay tile. strength to ensure satisfactory subsurface drain perfor- mance. The conduit shall meet strength and durability requirements of the site. Use of Heavy Duty Corrugated Plastic Drainage Tubing Loading Heavy duty corrugated drainage tubing shall be specified where rocky or gravelly soils are expected to be encoun- The allowable loads on subsurface drain conduits shall be tered during installation operations. The quality of tubing based on the trench and bedding conditions specified for the will also be specified when cover over this tubing is ex- job. A factor of safety of not less than 1.5 shall be used in pected to exceed 24 inches for 4,5,6,or 8 inch tubing. computing the maximum allowable depth of cover for a Larger size tubing designs will be handled on an individual particular type of conduit. job basis. Envelopes and Envelope Materials Auxiliary Structure and Subsurface Drain Protection Envelopes shall be used around subsurface drains for proper The outlet shall be protected against erosion and undermin- bedding and to provide better flow into the conduit. Not ing of the conduit,against damaging periods of submerg- less than three inches of envelope material shall be used for ence,and against entry of rodents or other animals into the sand/gravel envelopes. Where necessary to improve the subsurface drain. An animal guard shall be installed on the characteristics of flow of groundwater into the conduit, outlet end of the pipe. A swinging animal guard shall be more envelope material may be required. used if surface water enters the pipe. Where county regulations do not allow sand/gravel enve- A continuous 10-foot section of corrugated metal,cast iron, lopes,but require a special type and size of envelope mate- polyvinyl chloride,or steel pipe without perforations shall rial,they shall be followed. be used at the outlet end of the line and shall outlet 1.0 foot Envelope material shall be placed to the height of the upper- above the normal elevation of low flow in the outlet ditch or New York State Standards and Specifications Page 3.49 November 2016 For Erosion and Sediment Control above mean high ride in tidal areas. No envelope material shall be used around the 10-foot section of pipe. Two- thirds of the pipe shall be buried in the ditch bank and the cantilevered section shall extend to a point above the toe of the ditch side slope. If not possible,the side slope shall be protected from erosion. Conduits under roadways and embankments shall be water- tight and designed to exclude debris and prevent sediment from entering the conduit. Lines flowing under pressure shall be designed to withstand the resulting pressures and velocity of flow. Surface waterways shall be used where feasible. The upper end of each subsurface drain line shall be capped with a right fitting cap of the same material as the conduit or other durable material unless connected to a structure. Construction Specifications 1. Deformed,warped,or otherwise damaged pipe or tubing shall not be used. 2. All subsurface drains shall be laid to a uniform line and covered with envelope material. The pipe or tubing shall be laid with the perforations down and oriented symmetrically about the vertical centerline. Connec- tions will be made with manufactured appurtenances comparable in strength with the specified pipe or tub- ing unless otherwise specified. The method of place- ment and bedding shall be as specified on the drawing. 3. Envelope material shall consist of filter cloth or a sand/ gravel(which shall pass the 1 '/2 inch sieve,90 to 100 percent shall pass%inch sieve,and not more than 10 percent shall pass the No.60 sieve). 4. The upper end of each subsurface drain line shall be capped with a tight fittings cap of the same material as the conduit or other durable material unless connected to a structure. 5. A continuous 10-foot section of corrugated metal,cast iron,polyvinyl chloride,or steel pipe without perfora- tions shall be used at the outlet end of the line. No en- velope material shall be used around the 10-foot sec- tion of the pipe. An animal guard shall be installed on the outlet end of the pipe. 6. Earth backfill material shall be placed in the trench in such a manner that displacement of the drain will not occur. 7. Where surface water is entering the system,the pipe outlet section of the system shall contain a swing type trash and animal guard. November 2016 Page 3.50 New York State Standards and Specifica- For Erosion and Sediment Control ■i■11■Mi■M N ME�i I1M ME■�A■■M!� moll 1�■11■�all■■ P. ■F-AP MEW 2 WINNOW ■■■1� ■�� ■���II� �■■�■�■III P,rA■Nlow M■M- ■Ian nKNEWI■■FARM ■ � PPQ ■�fly ■■�� ■11�! ��� ����I owns sago■milli STANDARD AND SPECIFICATIONS FOR WATER BAR Slope(%) Spacing(ft.) <5 125 5 TO 10 100 10 TO 20 75 20 TO 35 50 >35 25 �1 5. The positive grade of the water bar shall not exceed _ 2%.A crossing angle of approximately 60 degrees is preferred. Definition & Scope 6. Once diverted,water must be conveyed to a stable sys- tem(i.e.vegetated swale or storm sewer system).Wa- A permanent or temporary ridge,ridge and channel,a struc- ter bars should have stable,unrestricted outlets,either tural channel,or flow deflector,constructed diagonally natural or constructed. across a sloping road or utility right-of-way that is subject to erosion to limit the accumulation of erosive velocity of See Figure 3.22 on page 3.53 for details. water by diverting surface runoff at pre-designed intervals. Conditions Where Practice Applies Where runoff protection is needed to prevent erosion from increased concentrated flow on narrow,steep access roads, driveways,and entrance ways to lot parcels as well as util- ity access right-of-ways generally up to 100 feet in width Design Criteria Design computations are not required. 1. The design height shall be minimum of 12 inches measured from channel bottom to ridge top. 2. The side slopes shall be 2:1 or flatter,a minimum of 4:1 where vehicles cross. 3. The base width of the ridge shall be six feet minimum. 4. The spacing of the water bars shall be as follows(Site spacing may need to be adjusted for field conditions to use the most suitable areas for water disposal): November 2016 Page 3.52 New York State Standards and Specifica- For Erosion and Sediment Control Figure 3.22 Water Bar Detail E:ARTNEN °' ' DL RIDGE VARIES lE' SLOPE MIN. Er - � CROSS SECTION Width us es NET TO SCALE J� * * WATER BA -k i ■ , • a 9�.. a .r +a + ■ +b flow Or ' S-ABLE OUTLET ++ � 1i ���� . * 4 4 �4 k i 4 CONSTRUCTION SPECIFICATIONS L INSTALL THE WATER 13AR AS SOON AS THE RIGHT OF WAY IS CLEARED AND ❑RADEO- 2. O'SK EIR STRIP THE SOD FROM THE BASE FOR THE CONSTRUCTED RInCE BEFORE PLAEM FILL. 1 TRACK THE RIDGE TII COMPACT IT TO THE DESIGN CROSS SECTION.. 4. THE L ESTRICTED OUTLET SHALL DE LOCATED ION AN UNDISTURBED AREA- FIELD SP14CIING WILL BE ADJUSTE10 TO, [USE THE MOST STADLE OUTLET AREAS. OUTLET PROTECTION WILL BE PROVIDED WHEN NATURAL AREAS ARE NET ADEOIATE. 5° VCHTC: F rRn niwo SHALL BE STABILIZED WITH GRAVEL- EXPOSED AREAS SHALL BE SEEDED A 14D MULCHED WITHIN 2 DAYS- 6- PERIODICALLY INSPECT VATER BARS FUR EROSION PAM1AGE AND SEDIMENT. CHECK QLJTLE=T AREAS AND FAKE REPAIRS AS NEEDED TO RESTORE aPERATI❑N_ ALMA PTED Fib DETAILS PRDVI MED 1'Yi USDA - NRC , NEV YURK STATE DEPARTMENT of TRANS TArlaN, '�T�� ��,� rNL'�' IL:KK STATE OEP►A'TW—NT OF ENVUZONmEr0m- CDNSEiRvA:TIDN, NEV WORK STATE SOIL. 9 WATER CO ERVATLION CUKMITTEL New York State Standards and Specifications Page 3.53 November 2016 For Erosion and Sediment Control SECTION 4 EROSION CONTROL - PART 2 SOIL STABILIZATION CONTENTS Page Scopeand Discussion........................................................................................................................................................4.1 Principles of Bioteclmical Practices ..................................................................................................................................4.1 PlanningConsiderations ...................................................................................................................................................4.3 PlantMaterials ..................................................................................................................................................................4.3 AnchoredStabilization Matting ........................................................................................................................................4.5 Armored Slope and Channel Stabilization ........................................................................................................................4.7 BranchPacking ...............................................................................................................................................................4.15 BrushLayer.....................................................................................................................................................................4.17 BrushMattress ................................................................................................................................................................4.19 FertilizerApplication ......................................................................................................................................................4.21 FiberRoll ........................................................................................................................................................................4.22 Landgrading.....................................................................................................................................................................4.24 LimeApplication ............................................................................................................................................................4.29 LiveCrib Wall ................................................................................................................................................................4.30 LiveFascines...................................................................................................................................................................4.32 LiveStakes ......................................................................................................................................................................4.34 LooseStabilization Blankets ...........................................................................................................................................4.37 Mulching .........................................................................................................................................................................4.39 Pennanent Construction Area Planting ...........................................................................................................................4.42 RecreationArea Seeding..................................................................................................................................................4.45 RetainingWalls................................................................................................................................................................4.48 SoilRestoration ...............................................................................................................................................................4.52 StabilizationWith Sod ....................................................................................................................................................4.54 SurfaceRoughening ........................................................................................................................................................4.56 TemporaryConstruction Area Seeding ...........................................................................................................................4.58 Topsoiling .......................................................................................................................................................................4.59 TreeRevetment ...............................................................................................................................................................4.61 Trees,Shrubs, and Vines .................................................................................................................................................4.63 VegetatedRock Gabions .................................................................................................................................................4.66 Vegetating Sand and Gravel Borrow Areas ....................................................................................................................4.68 VegetatingSand Dunes and Tidal Banks ........................................................................................................................4.70 VegetatingWaterways ....................................................................................................................................................4.78 Section prepared by: Donald W.Lake Jr.,PE,CPESC,CPSWQ Former State Conservation Engineer USDA—Natural Resources Conservation Service Syracuse,New York Adjunct Assistant Professor State University of New York,College of Environmental Science and Forestry List of Tables and Figures Table Title Page 4.1 Riprap Gradations.................................................................................................................................4.12 4.2 Guide to Mulch Materials,Rates,and Uses.........................................................................................4.40 4.3 Mulch Anchoring Guide ......................................................................................................................4.41 4.4 Permanent Critical Area Planting Mixture Recommendations ............................................................4.44 4.5 Recreation Turfgrass Seed Mixture......................................................................................................4.46 4.6 Soil Restoration Requirements ............................................................................................................4.53 4.7 Topsoil Application Depth ..................................................................................................................4.60 4.8 Size and Weight of Earth Ball Required to Transplant Wild Stock.....................................................4.65 4.9 Vegetative Treatment Potential for Eroding Tidal Shorelines .............................................................4.73 4.10 Maximum Permissible Velocities for Selected Seed Mixtures.............................................................4.79 Fi ure Title Page 4.1 Angles of Repose of Riprap Stones .......................................................................................................4.9 4.2 Typical Riprap Slope Protection Detail .................................................................................................4.9 4.3 Riprap Streambank Protection..............................................................................................................4.13 4.4 Channel Stabilization Methods ............................................................................................................4.14 4.5 Branch Packing ....................................................................................................................................4.16 4.6 Brush Layer .........................................................................................................................................4.18 4.7 Brush Mattress .....................................................................................................................................4.20 4.8 Fiber Roll.............................................................................................................................................4.23 4.9 Typical Section of Serrated Cut Slope .................................................................................................4.26 4.10 Landgrading.........................................................................................................................................4.27 4.11 Landgrading-Construction Specifications..........................................................................................4.28 4.12 Live Cribwall.......................................................................................................................................4.31 4.13 Live Fascine ........................................................................................................................................4.33 4.14 Live Stake.............................................................................................................................................4.35 4.15 Live Stake Construction Specifications ...............................................................................................4.36 4.16 Typical Retaining Wall Examples .......................................................................................................4.50 4.17 Typical Segmented Retaining Wall Example ......................................................................................4.51 4.18 Surface Roughening ............................................................................................................................4.57 4.19 Tree Revetment....................................................................................................................................4.62 4.20 Vegetated Rock Gabions .....................................................................................................................4.67 4.21 Combination of Sand Fence and Vegetation for Dune Building .........................................................4.72 4.22 Typical Cross-Section Created by a Combination of Sand Fence and Vegetation...............................4.72 4.23 American Beachgrass Information Sheet ............................................................................................4.74 4.24 Cordgrass Information Sheet ...............................................................................................................4.75 4.25 Rill Maintenance Measures..................................................................................................................4.80 EROSION CONTROL - PART 2 SOIL STABILIZATION Scope and Discussion Principles of Biotechnical Practices Soil stabilization is the second step in controlling erosion on a construction site or a disturbed area.Erosion is the The implementation of Biotechnical practices is the gradual wearing away of the land surface as a result of specialized use of woody plant materials to stabilize soil uncontrolled wind and water energy.Sedimentation is the enhance structural practices,and provide added support to result of transport and delivery of eroded particles, habitat. One of the factors that affects erosion is vegetative deposited at some point.Erosion and sediment control is a cover.The more cover soil has,the more protected it is complex interaction of soils,engineering water from the attacking forces of rainfall and runoff. Also management,agronomic,and horticultural practices. working to hold the soil in place is the root mass that Decisions for resolving erosion conditions,both on the site vegetation produces. Biotechnical measures generally and within the upper watershed,are formulated based on combine basic engineering principles with plant science to surface and subsurface water,soil material,climatic create a system of stability and resource management for conditions,and anticipated land use.Creating a stable slope critical areas such as streambanks,roadside slopes,and is necessary prior to vegetating. Sloughing and slumping large exposed areas. These systems may combine with impede establishment of a uniform protective cover. structural measures to effect a strengthening of the soil Stabilizing onsite surfaces can be done with vegetation in structure and improve vegetative cover to resist surface the form of various seed mixes and mulch,land shaping, erosion. and using woody plants specifically selected for site specific applications,also known as a bio-technical There are many advantages to Biotechnical practices: stabilization approach. • they are often less expensive to install General planning considerations for vegetating a steep slope will include evaluating the soil.Factors such as soil texture ' they do not require specialized skills to install and steepness affect the stability of the slope.Texture also . generally,heavy equipment is not required influences the permeability and water holding capacity of the soil.Many slopes are stripped of their topsoil during the . they are environmentally compatible since the design construction phase,leaving an infertile,compacted soil selects natural and native plant materials surface,void of valuable organic matter.Topsoil must be reapplied.Overly compacted soil must be decompacted • they provide a natural aesthetic appearance with appropriate equipment. Soil pH and nutrient level are determined by obtaining a representative soil sample for • they provide wildlife habitat and cover and provide a analysis from an accredited lab.Appropriate plant material food source to many land and aquatic species is designed and selected to meet the final slope and soil . they mitigate thermal impacts to structural stream conditions for the site. These same concerns and practices stabilization practices such as rock riprap and retaining also apply to flatter slopes and level areas. walls by providing shade When specifying a fertilizer mix for an area,design the . they can be self repairing during and after stress appropriate proportions to meet the nutrients needs for the specific site.Always apply as closely as possible the On the other hand,there are some disadvantages to these required amount of fertilizer to meet the needs for the site measures: soils.Adding surplus nitrogen may cause pollution of drinking water and saltwater ecosystems.Excessive • requires planning to obtain sources of plant phosphorus may accelerate the aging process of freshwater materials ecosystems.Excessive amounts of Nitrogen(N)and . higher risk due to less control with vegetation Potassium Oxide(K20)may result in`burning'the grass and killing it.All fertilizer applications will be in compared to structural practices accordance with the Nutrient Runoff Law—ECL Article . require higher maintenance attention 17,Title 21,January 1,2012. • need an establishment period • more sensitive to seasonal changes and seasonal New York State Standards and Specifications Page 4.1 November 2016 For Erosion and Sediment Control restrictions on planting may apply The vegetation also tends to prevent(surface) erosion The use of Biotechnical practices is actually an old by. technology.These techniques have been practiced for 1. Binding and restraining soil particles in place, centuries in Europe. The Natural Resource Conservation Service used and promoted this technology in the 1940's in 2. Filtering soil particles from runoff, Vermont on the Winooski River and also in New York on Buffalo Creek,where plant materials(willows)were used 3. Absorb raindrop energy prior to impact, in combination with rock riprap,concrete slabs,pinned 4. Retarding velocity of runoff,and rock,and cellular modules to halt streambank erosion. 5. Maintaining infiltration. These biotechnical approaches have been"rediscovered" As the stability improves,native vegetation will volunteer, primarily due to their cost effectiveness over more traditional structural measures(hard armor)and for their helping to blend the site into the surroundings. environmental compatibility,aesthetics,and wildlife benefits. There are many areas in towns and counties in There are many techniques used in biotechnical work. New York that experience erosion on streambanks or Some of the most common are: sloughs on roadside slopes that could be controlled with biotechnical protection measures. The low cost and ease Vegetated Rock Gabions—This is a combination of of installation is very attractive to units of government vegetation and rock gabions generally used for slope and highway departments looking to maximize their stabilization.Live branch cuttings are layered through the budget dollars. rock gabion structure to anchor in select earthfill.The cuttings protrude beyond the face of the gabion.The gabion Generally a biotechnical slope protection system consists standard is covered in the"Standard Specifications for of both a structural or mechanical element and vegetative Retaining Walls". See Figure 4.20 on page 4.67 for details. elements working together to stabilize a site-specific condition. Structural components are employed in such a Live Fascines—This technique uses bundles of branches way to allow establishment of vegetative elements,while which are staked into shallow trenches,then filled with soil. at the same time providing a level of protection for They are oriented along the contour and are placed in stability. The vegetative components are not just multiple rows to help stabilize a slope. See Standard and landscaping plantings for a structural project;they also Specifications for Live Fascines. perform a functional role in preventing erosion by protecting the surface,while also stabilizing soil by Brush Mattress—This method uses hardwood brush preventing shallow mass movements.These practices also layered along a streambank as a mattress and anchored in provide a food source to both land based animals as well place with a grid of stakes and wire. The toe below the as smaller aquatic species along streambank revetments. waterline is anchored by rock. This living blanket acts as a Once established,the plantings provide shade in areas mulch for seedlings and plantings established in the bank. where mitigation of thermal impacts is needed due to It also prevents erosion of sloped surfaces. See Standards hardened structural practices. and Specifications for Brush Mattress. Woody plant materials(usually dormant shrub willow Live Staking—These are large stakes or poles sharpened at branches)are placed into the soil in ways that provide an the bottom end and forced vertically into the soft earth immediate degree of stability to the slope. As the along the waterline,usually about 1 foot apart. Depending branches take root and grow,the slope becomes more on the size of the poles and the composition of the and more resistant to failure by shallow mass movements streambank,machinery may be required to force them into due to: the ground or to prepare holes for planting. The poles will grow forming a very thick barrier to flow. See Figure 4.14 1. Mechanical reinforcement from the root system, and Figure 4.15. 2. Soil moisture reduction through transpiration and plant Brush Layering—This technique is generally used to uptake,and stabilize slope areas above the flow line of streambanks as well as cut and fill slopes. It involves the use of long 3. Buttressing and soil arching action from embedded branches that are placed with cut ends into the slope on stems. bulldozed terraces. The tops protrude outside the finished slope. A layer usually includes three layers of brush separated with a thin(3 in.)layer of soil. On this layer a "lift"of 3-5 feet of soil is placed to form the next terrace and so forth. See Figure 4.6. November 2016 Page 4.2 New York State Standards and Specifications For Erosion and Sediment Control Live Cribwall—This is a combination of vegetation and structural elements generally used along streams where Note:Performing activities within or adjacent to flowing water is a hazard. Layers of logs are alternated wetlands,streams and waterbodies may require with long branches protruding out between them. The logs permits from the New York State Department of are spiked together and anchored into the bank with earthfill Environmental Conservation(NYSDEC)pursuant to behind them to create a wall. The live stems help tie the Article 15(Protection of Waters),Article 24 logs together and screen the wall. See Figure 4.12. (Freshwater Wetlands)and Article 25(Tidal Wetlands) Tree Revetment—This method incorporates entire trees of the Environmental Conservation Law(ECL). (without the root wad)for bank stabilization in areas that Project owners should contact NYSDEC's Regional are eroded or undercut,but not flashy or in need of heavy Division of Environmental Permits early in the site maintenance. Trees are overlapped and anchored to the planning process to discuss the requirements for earth for the purpose of absorbing energy and reducing meeting permit issuance standards.Following the New velocity,capturing sediment,and enhancing conditions York State Standards and Specifications for Erosion for colonization of native species. See Figure 4.19. and Sediment Control may not ensure compliance with the above referenced sections of the ECL. Branchpacldng—This technique alternates live branch cuttings with tamped backfill to repair small,localized slumps and holes in slopes. The alternating layers of Planning Considerations branches and soil are placed between long posts driven in to the ground for support. This method is inappropriate There are many facets that need to be considered for areas larger than 4-feet deep or 6-feet wide. See when designing a biotechnical system for a site: Figure 4.5. Method—What is the appropriate method or practice for Fiber Roll—A fiber roll is a coconut fiber, straw,or the particular problem encountered? excelsior woven roll encased in netting of jute,nylon,or burlap used to dissipate energy along bodies of water and Materials—What type should be selected? How much provide a good medium for the introduction of herbaceous is needed to do the job? Where can they be obtained? vegetation. This technique works best where water levels are relatively constant. The roll is anchored into the bank Schedule—When is the best time to maximize and,after suitable backfill is placed behind the roll, the successful rooting or germination of herbaceous or woody vegetation can be planted. See materials? Figure 4.8. Equipment—Since this process is somewhat labor Properly designed structural measures may be necessary intensive,it is necessary to make sure the proper type to help protect the toe or face of a slope against scour or and amount of tools, such as shovels,pick axe,tile erosion from moving water and against mass-moving of spade,hammers,etc.are available for proper soil. These structures are generally capable of resisting installation of material. much higher lateral earth pressures and higher shear Site characteristics—The need for engineering structures values than vegetation. They can be natural,such as will depend on potential hazards,management of site fieldstone,rock and timbers;or,they can be artificial like water,soil conditions,and site access. Aesthetics and concrete and steel. Some structural measures can be a follow-up maintenance are also important considerations. combination like gabions,which are wire baskets Protection from livestock is mandatory. containing stone. Gabions can be used as retaining walls, grade stabilization structures and slope protection. Many Streambanks—Generally applicable where flows are less of these types of structures can be planted or vegetated than 6 feet per second and the stream bottom is not subject with materials to strengthen the system. to degradation and scour. Protection should be carried to the average high water elevation. Plant Materials Plant materials for biotechnical slope protection may be obtained in two basic ways. One method is to locate stands of appropriate species and obtain easements to harvest materials from these stands for incorporation into the project. Criteria for selecting native species are:easy rooting;long,straight,flexible whips;and plentiful supply near the site. A second method is to grow and harvest materials from New York State Standards and Specifications Page 4.3 November 2016 For Erosion and Sediment Control managed production beds that are maintained for commercial distribution. This allows selection of cultivars that have proven performance records and high survival rates. The most popular materials in use today are the shrub willows. Willows have a tremendous ability to sprout roots and stems when in contact with moist soil. Willows are found growing in all parts of the world,so biotechnical slope protection techniques employ them more than any other group of plants. Two of the tested,proven willow cultivars in the Northeast are: • `Streamco'purple osier willow(Salix purpurea) • Bankers'dwarf willow(Salix cottetii—hybrid) `Streamco' and Bankers'willow are both shrubs. `Streamco' has an ultimate height of 15-20 feet,while Bankers' is limited to 6-8 feet. Commercial and state nurseries in the Northeast are producing supplies of both species. In addition to willows,red osier dogwood and poplars are other groups of plants effective for use in biotechnical systems. Species such as elderberry or forsythia can also be used to add biodiversity to a site. All plant materials should be installed on site within 8 hours of cutting,unless provisions for proper storage are made.Materials should be fresh,dormant,and non- desiccated when installed. November 2016 Page 4.4 New York State Standards and Specifications For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR ANCHORED STABILIZATION MATTING Channel Applications-Anchored stabilization mats,for use in supporting vegetation in flow channels,are generally a -- non-degradable,three dimensional plastic structure which can be filled with soil prior to planting. This structure provides a medium for root growth where the matting and roots become intertwined forming a continuous anchor for the vegetated lining. 1. Channel stabilization shall be based on the tractive force method. 2. For maximum design shear stresses less than 2 pounds per square foot,a temporary or bio-degradable mat may Definition and Scope be used. A temporary or permanent protective covering placed on a 3. The design of the final matting shall be based on the prepared,seeded planting area that is anchored in place by mats ability to resist the tractive shear stress at bank staples or other means to aid in controlling erosion by full flow. absorbing rain splash energy and withstand overland flow as well as provide a microclimate to protect and promote 4. The installation details and procedures shall be seed establishment. included on the site erosion and sediment control plan and will follow manufacturers specifications. Conditions Where Practice Applies Anchored stabilization mats are required for seeded earthen slopes steeper than 3 horizontal to 1 vertical;in vegetated channels where the velocity of the design flow exceeds the allowable velocity for vegetation alone(usually greater than 5 feet per second);on streambanks and shorelines where moving water is likely to erode newly seeded or planted areas;and in areas where wind prevents standard mulching with straw. This standard does not apply to slopes stabilized with sod,rock riprap or hard armor material. Design Criteria Slope Applications-Anchored stabilization mats for use on Construction Specifications slopes are primarily used as mulch blankets where the mesh material is within the blanket or as a netting over previously 1. Prepare soil before installing matting by smoothing the placed mulch. These stabilization mats are NOT effective surface,removing debris and large stone,and applying in preventing slope failures. lime,fertilizer and seed. Refer to manufacturers 1. Required on all slopes steeper than 3:1 installation details. 2. Matting will be designed for proper longevity need and 2. Begin at the top of the slope by anchoring the mat in a 6"deep x 6"wide trench. Backfill and compact the strength based on intended use. trench after stapling. 3. All installation details and directions will be included 3. In channels or swales,begin at the downslope end, on the site erosion and sediment control plan and will anchoring the mat at the bottom and top ends of the follow manufactures specifications. blanket. When another roll is needed,the upslope roll New York State Standards and Specifications Page 4.5 November 2016 For Erosion and Sediment Control should overlay the lower layer,shingle style,so that channel flows do not peel back the material. 4. Roll the mats down a slope with a minimum 4" overlap. Roll center mat in a channel in direction of water flow on bottom of the channel. Do not stretch blankets.Blankets shall have good continuous contact with the underlying soil throughout its entire length. 5. Place mats end over end(shingle style)with a 6" overlap,use a double row of staggered staples 4"apart to secure mats. 6. Full length edge of mats at top of side slopes must be anchored in 6"deep x 6"wide trench;backfill and compact the trench after stapling. 7. Mats on side slopes of a channel must be overlapped 4" over the center mat and stapled. 8. In high flow channel applications,a staple check slot is recommended at 30 to 40 foot intervals. Use a row of staples 4"apart over entire width of the channel. Place a second row 4"below the first row in a staggered pattern. 9. The terminal end of the mats must be anchored in a 6"x6"wide trench. Backfill and compact the trench after stapling. 10. Stapling and anchoring of blanket shall be done in accordance with the manufactures recommendations. Maintenance Blanketed areas shall be inspected weekly and after each runoff event until perennial vegetation is established to a minimum uniform 80%coverage throughout the blanketed area. Damaged or displaced blankets shall be restored or replaced within 2 calendar days. November 2016 Page 4.6 New York State Standards and Specifications For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR ARMORED SLOPE AND CHANNEL STABILIZATION Size—The sizes of stones used for riprap protection are determined by purpose and specific site conditions: T� 1. Slope Stabilization—Riprap stone for slope - ' stabilization not subject to flowing water or wave action shall be sized for the proposed grade. The gradient of the slope to be stabilized shall be less than the natural angle of repose of the stone selected. - - Angles of repose of riprap stones may be estimated x from Figure 4.1. - - Riprap used for surface stabilization of slopes does not - add significant resistance to sliding or slope failure and should not be considered a retaining wall. Slopes Definition & Scope approaching 1.5:1 may require special stability analysis. The inherent stability of the soil must be A permanent layer of stone designed to protect and stabilize satisfactory before riprap is used for surface areas subject to erosion by protecting the soil surface from stabilization. rain splash,sheet flow,rill and gully erosion and channel erosion. It can also be used to improve the stability of soil 2. Channel Stabilization-Design criteria for sizing stone slopes that are subject to seepage or have poor soil for stability of channel side slopes are presented under structure. Channel Stabilization Design Criteria on page 4.10. Conditions Where Practice Applies 2. Outlet Protection—Design criteria for sizing stone and determining dimensions of riprap aprons are presented Riprap is used for cut and fill slopes subject to seepage, in Standards and Specifications for Rock Outlet erosion,or weathering,particularly where conditions Protection on page 3.39. prohibit the establishment of vegetation. Riprap is also used for channel side slopes and bottoms,temporary Filter Blanket—A filter blanket is a layer of material dewatering diversion channels where the flow velocities placed between the riprap and the underlying soil to prevent exceed 6 feet/second,grade sills,on shorelines subject to soil movement into or through the riprap. A suitable filter erosion,and at inlets and outlets to culverts,bridges,slope may consist of a well-graded gravel or sand-gravel layer or drains,grade stabilization structures,and storm drains. a synthetic filter fabric manufactured for this purpose. The design of a gravel filter blanket is based on the ratio of Slope Stabilization Design Criteria particle size in the overlying filter material to that of the base material in accordance with the criteria below. Gradation—Riprap shall be a well-graded mixture with Multiple layers may be designed to affect a proper filter if 50%by weight larger than the specified design size. The necessary. diameter of the largest stone size in such a mixture should be 1.5 times the d50 size with smaller sizes grading down to A gravel filter blanket should have the following 1 inch. The designer should select the size or sizes that relationship for a stable design: equal or exceed that minimum size based on riprap gradations commercially available in the area. d bases Thickness—The minimum layer thickness shall be 1.5 times the maximum stone diameter,but in no case less than 5�d°m� 540 6 inches. Quality—Stone for riprap shall be hard,durable field or and quarry materials. They shall be angular and not subject to d. breaking down when exposed to water or weathering. The d bbw s 40 specific gravity shall be at least 2.5. 70 New York State Standards and Specifications Page 4.7 November 2016 For Erosion and Sediment Control Filter refers to the overlying material while base refers to elevation of the surrounding area. Channels shall be exca- the underlying material. These relationships must hold be- vated sufficiently to allow placement of the riprap in a man- tween the base and filter and the filter and riprap to prevent ner such that the finished inside dimensions and grade of migration of material. In some cases,more than one filter the riprap meet design specifications. may be needed. Each filter layer should be a minimum of 6 inches thick,unless an acceptable filter fabric is used. Sand and gravel filter blanket—Place the filter blanket immediately after the ground foundation is prepared. For A synthetic filter fabric may be used with or in place of gravel,spread filter stone in a uniform layer to the specified gravel filters. The following particle size relationships depth. Where more than one layer of filter material is used, should exist: spread the layers with minimal mixing. 1. Filter fabric covering a base containing 50%or less by Synthetic filter fabric—Place the cloth directly on the pre- weight of fine particles(#200 sieve size): pared foundation. Overlap the edges by at least 2 feet,and space the anchor pins every 3 feet along the overlap. Bury A d,,boar(mm) >I the upper and lower ends of the cloth a minimum of 12 HOS x flber fabric (mm) inches below ground. Take precautions not to damage the cloth by dropping the riprap. If damage occurs,remove the B. total open area of filter fabric should not exceed riprap and repair the sheet by adding another layer of filter 36% fabric with a minimum overlap of 12 inches around the damaged area. Where large stones are to be placed,a 4- 2. Filter fabric covering other soils: inch layer of fine sand or gravel is recommended to protect the filter cloth. Filter fabric is not recommended as a filter A. EOS is no larger than 0.21 mm(#70 sieve size) on slopes steeper than 2 horizontal to 1 vertical. B. total open area of filter fabric should not exceed Stone placement—Placement of the riprap shall follow 10% immediately after placement of the filter. Place riprap so that it forms dense,well-graded mass of stone with a mini- *EOS—Equivalent opening size compared to a U.S.stand- mum of voids. The desired distribution of stones through- ard sieve size. out the mass may be obtained by selective loading at the quarry and controlled dumping during final placement. No filter fabric should have less than 4%open area or an Place riprap to its full thickness in one operation. Do not EOS less than U.S. Standard Sieve#100(0.15 mm). The place riprap by dumping through chutes or other methods permeability of the fabric must be greater than that of the that cause segregation of stone sizes. Be careful not to dis- soil. The fabric may be made of woven or nonwoven mon- lodge the underlying base or filter when placing the stones. ofilament yarns and should meet the following minimum The toe of the riprap shall be keyed into a stable foundation requirements: at its base as shown in Figure 4.2-Typical Riprap Slope Thickness 20-60 mils Protection Detail. The toe should be excavated to a depth of 2.0 feet. The design thickness of the riprap shall extend a grab strength 90-120 lbs. minimum of 3 feet horizontally from the slope. The fin- ished slope should be free of pockets of small stone or clus- conform to ASTM D-1682 or ASTM D-177 ters of large stones. Hand placing may be necessary to achieve proper distribution of stone sizes to produce a rela- Filter blankets should always be provided where seepage is tively smooth,uniform surface. The finished grade of the significant or where flow velocity and duration of flow or riprap should blend with the surrounding area. turbulence may cause underlying soil particles to move Maintenance though the riprap. Riprap shall be inspected periodically for scour or dislodged Construction Specifications stones. Control weed and brush growth as needed. Subgrade Preparation—Prepare the subgrade for riprap and filter to the required lines and grades shown on the plans. Compact any fill required in the subgrade to a densi- ty approximating that of the undisturbed material or overfill depressions with riprap. Remove brush,trees,stumps,and other objectionable material. Cut the subgrade sufficiently deep so that the finished grade of the riprap will be at the November 2016 Page 4.8 New York State Standards and Specifications For Erosion and Sediment Control Figure 4.1 Angles of Repose of Riprap Stones (FHWA) KOL-C N %-1-NL SIZE. 050. rr 43 35 W J � {7 g Z% -L& 31 5 a 1-0 20 40 6G 100 400 600 MEAN STONE SIZE, , rnrr Figure 4.2 Typical Riprap Slope Protection Detail 0 Gravel filter(Or IIICer clothe 16 -� �`r min z' min New York State Standards and Specifications Page 4.9 November 2016 For Erosion and Sediment Control - Construction Specifications r r Riprap—Riprap is the most commonly used material to structurally stabilize a channel. While riprap will provide the structural stabilization necessary,the side slope can be enhanced with vegetative material to slow the velocity of water,filter debris,and enhance habitat. See Principles of Biotechnical Practices on page 4.1,for more information. _ y 1. Side slope—slopes shall be graded to 2:1 or flatter prior to placing bedding,filter fabric,or riprap. 2. Filter—filters should be placed between the base Channel Stabilization Design Criteria material and the riprap and meet the requirements of criteria listed pages 4.7 and 4.8. 1. Since each channel is unique,measures for structural channel stabilization should be installed according to a 3. Gradation—The gradation of the riprap is dependent on design based on specific site conditions. the velocity expected against the bank for the design conditions. See Table 4.1 on page 4.12.Once the 2. The plan and profile of the design reach should velocity is known,gradation can be selected from the approximate a naturally stable channel from the project table for the appropriate class of rock.Note,this table area,based on a stable"reference reach"for the subject was developed for a 2:1 slope;if the slope steepens to channel type. 1.5:1 the gradations should be increased 20%.The riprap should extend 2 feet below the channel bottom 3. Develop designs according to the following principles: and be keyed into the side slope both at the upstream end and downstream end of the proposed work or • Make protective measures compatible with other reach. channel modifications planned or being carried out in the channel reaches. See Figure 4.3 on page 4.13 for details. • Whenever excavation and re-shaping work is proposed within channels,the design should provide Reinforced Concrete-Is often used to armor eroding functional channel dimensions and geometry at each sections of flow channel by constructing walls,bulk heads, section. Work proposed within a stream channel or stabilize bank linings in urban areas for redevelopment may require permits from the NYS DEC and US work. Provide positive drainage behind these structures to Army Corps of Engineers. relieve uplift pressures. • Use the design velocity of the peak discharge of the 10-year storm or bankfull discharge,whichever is less. Structural measures should be capable of withstanding greater flows without serious damage. • Ensure that the channel bottom is stable or 1 7- stabilized by structural means before installing any permanent slope protection. — • Channel stabilization should begin at a stable location and end at a stable point along the bank. • Changes in alignment should not be done without a complete analysis of the environmental and stability effects on the entire system. • Provisions should be made to maintain and improve fish and wildlife habitat.For example,restoring lost vegetation will provide valuable shade,food, or cover. • Ensure that all requirements of state law and all permit requirements of local,state,and federal agencies are met. November 2016 Page 4.10 New York State Standards and Specifications For Erosion and Sediment Control Modular Pre-Cast Units—Interlocking modular precast Grid Pavers—Modular concrete units with or without void units of different sizes,shapes,heights,and depths,have areas can be used to stabilize flow channel. Units with void been developed for a wide variety of applications. They areas can allow the establishment of vegetation. These provide vertical support in tight areas as well as durability. structures may be obtained in a variety of shapes(Figure Many types are available with textured surfaces. They also 4.4)or they may be formed and poured in place. Maintain act as gravity retaining walls. They should be designed and design and installation in accordance with manufacturer's installed in accordance with the manufacturer's instructions. recommendations(Figure 4.4). All areas disturbed by construction should be stabilized as soon as the structural measures are complete. �, . . . „ .IL B IL Revetment—Structural support or armoring to protect an embankment from erosion. Riprap and gabions are commonly used. Also used is a hollow fabric mattress with Maintenance cells that receive a concrete mixture.Any revetment should be installed to a depth below the anticipated channel Check stabilized flow channel sections after every high- degradation and into the channel bed as necessary to water event,and make any needed repairs immediately to provide stability. prevent any further damage or unraveling of the existing work. i IMP. } . - .. 4 e - New York State Standards and Specifications Page 4.11 November 2016 For Erosion and Sediment Control Table 4.1 - Riprap Gradations for Channel Stabilization PERCENT FINER BY WEIGHT D io D 5o D 85 D ioo Wt. do d❑ Wt. do d❑ Wt. do d❑ Wt. do d❑ Obs.) (in.) (in.) (lbs.) (in.) (in.) (lbs.) (in.) (in.) (lbs.) (in.) (in.) I 18 8.5 - 5 5 4 50 10 8 100 13 10 150 15 12 II 18 10 - 17 7 6 170 15 12 340 19 15 500 22 18 III 24 12 2 46 10 8 460 21 17 920 26 21 1400 30 24 IV 36 14 3 150 15 12 1500 30 25 3000 39 32 4500 47 36 V 48 17 4.8 370 20 16 3700 42 34 7400 53 43 11,000 60 49 do=gravel material do =angular rock riprap Wt=weight in pounds November 2016 Page 4.12 New York State Standards and Specifications For Erosion and Sediment Control Figure 4.3 Riprap Channel Stabilization SYMBOL EAXl�4 l L:: �TITI�rI _I DESIGN LAYER THICKNESS FABRIC F ILTEFti� - NORMAL WATER FLOW s r I CHANNEL. BOTTOM R PPAP DESIGN TABLE MALH CLASS THICKNESS LAYLR FU HT DW —VM Dirt ALOO F UN' TRU TID I SPE IFI +ATICJ 1 I. SLOPE SHALL BE GRADED TO Eil OR FLATTER F*I❑fit TO PLACING FILTER, FILTEN FABRIC, OR RIPR.AP. 2. RIPRAP 9I4ALL $E .r ETi TO WAINTAIN A wiroRM GRAdAT[ON. LARGI R STONE SHALL DE PLACED AT THE TUC, 3. ENDS Or THE. RIPPAP SHALL BE 14ETED INTO A STABLE BANK. WHEN TYING INTO 13THER STRUCTURES, LARGER RI PRAP CM BE LAID IN STEPS OR STACKED AS NEEDED TO FIT. STUNL$ LARGER THAN THUSE DESIGNED FOR FLOW SRALsL SE USXD FOR THIS PlURP E_ 4.. REMAINING IyISTURREII AREAS SHALL BE GRADED AND PERMANENTLY SEEDED AND MULCHEQ. AEAPTED FROM Dt TAI-3 PROVIDED NY! USIIA — NRCS, R P PRAP NEW XORK STATE ❑EPAR rMtN'i [IF TRANSPORTATION, �;H�N N L L NEV YEW STATE DiEPARTHENT [IF" ENVIRE]NMENT�+L CONSERVATION, KW MIRK $TATE 3Q!L. s VATER CEINSERVi%T EIN CCMHITTEE STABIL.1ZAT '71N New York State Standards and Specifications Page 4.13 November 2016 For Erosion and Sediment Control Figure 4.4 Channel Stabilization Methods STABLE FILTER h �I P BLOCKS WIDE GRID PAVERS EST, 12D CY ROCK RIPRAP (MEDIUM STONE FILL) , EXISTING CHAT❑CHANNEL � � EXCAVATION ` * 1 LINE ZrMIM. BAC�KFILL + k r CREAL RlI[ CAST MODULAR UbJ]7 S In tari ac king O4flcj,:s ADAPTED FROM DETAILS PR13VIDEII BY- USDA - NRUS, CHANNEL NE'r Y❑aK STATE VEPAWTHENJT OF TRANgPURTATIUN, T #BILI TI�MI NEV `Y❑RK STATE DEPARTMENT I3F DWI NTAL CONSERVATMN, NEW FORK STATE s❑]L L VATER CONSERVATION C13MMITEIE METHOD November 2016 Page 4.14 New York State Standards and Specifications For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR BRANCHPACKING Maintenance Due to the susceptibility of plant materials to the physical constraints of the site,climate conditions,and animal populations,it is necessary to inspect installations frequently. This is especially important during the first year or two of establishment. Plant materials missing or damaged should be replaced as soon as possible. Sloughs or breaks in drainage pattern should be reestablished for the site as quickly as possible to maintain stability. E Definition & Scone Branchpacking consists of alternate layers of live branch cuttings and tamped backfill to repair small,localized slumps and holes in slopes to provide repair to existing slopes that have small slips or slumps by filling in the failed area with plant materials and soil. Conditions Where Practice Applies This is an appropriate technique for repairing slip areas that do not exceed 4 feet deep or 6 feet wide. It should not be used as a slope stability measure if structural embankment support is needed. Design Criteria 1. The live branch cuttings shall be 1/2-2 inches in diameter and long enough to touch the undisturbed soil at the back of the area to be repaired. They should extend 4-6 inches beyond the finished backfill grade. 2. Wooden posts should be used to secure the plant material in place. They should be 6-8 feet long and 3 -4 inches in diameter. If lumber is used,it shall be a minimum standard two by four. 3. Wooden posts shall be driven vertically 3 feet deep and placed in a grid pattern 1 -2 feet apart. 4. Beginning at the bottom of the slip area,4-6 inch layers of live branch cuttings are placed in angled layers, 1.5 to 3 feet apart. Compacted moist soil is placed between the layers(see Figure 4.5). 5. Seasonal planting restriction may have to be considered. New York State Standards and Specifications Page 4.15 November 2016 For Erosion and Sediment Control Figure 4.5 Branchpacking SPACE BRANCH CUTTING LAYER 1.5' 1 U SYMBOL 3` APART <SEE CONTRACT DOCI NTS) .�P SEED OR OTHER EROSION EON r RUL MA I LR I AL }* AS SRECIF rEn IN THE CONTRACT DOCUMENTS BETWEEN EASCINE ROWS SELECT CLEAN FILL.. BRANCH CH TIPS Pi OT RUDE T+T++ 4+ IF RE OLi m E *'+* 4 'SLIGHTLY FRUN F INISHEU UPAUL .} * **}�, LIVE BP�4NCN ` TO '' LAYER ❑F }* �} 4 + CUTTINGS �112' --. e- LIVE BRANCH CUTTINGS �r * • '° f IN DIAMETER) BRw�tH LAID IN A C-RISSCRUSS # CUTTINGS SHALL CONFIGURATION WITH PROTRUDE SLI!CHTL°r BASAL ENDS LOWED FROM BAEKPfLL A THAN GRUVINGS TIPS AND TOUCHING PQST I I/3" X :,� I/e' OR UNDISTURBED SOIL AT 3'-+4' IN DIAMc mt AND V BACK or HOLE TO 8' LONG DRIVEN 30 TO ]' T® 1,5 4' INTO LINDISTURRF_D GROUND CROSS SECTION — NOT TO SCALE' CONSTRUCTION SFEE❑IFICA TI❑N 1. STAPT'ING AT THE LOVEEST' POINT DRIVE THE WOODEN POSTS VERi3LaAL,LY J' 1U 4' INTO THE GROUND. STET THE14 1` TO 1,5' APART. 2, A LAYER OF LIVING BRANCHES 4" TIl 6r THICK IS PLACEII IN THE BDT T❑M OF TtIE Er BETWEEN THE VERTICAL POSTS, THEY SHALL BE PLACED IN A CR[SSCRO!SS CONFIGURATION wITK TmE GROWING 'YIPS GENE ALLY ORIENTED rGWARD THE SLOPE IFAEE, SOME OF THE RAE;AL ENDS DF THE BRANCHES F EACH LAVED SHALL TOUCH THE }SACK Or THE HOLE OR SLOPE. S, EACH LAYER OF BRANCHES SHALL BE INSTALLED WITH THE BASAL ENDS LOWER ---AN THE GROWING TIPS OF THE BRANCHES, 4, THE FINAL INSTALLATI❑N SHALL MATCH THE EXISTING SL❑PE, BRANCHES SHOULD PROTRUDE ❑'NL Y SLIGHTLY FROM THE FILLED FACE. 5, EACH LAYER OF BRANCHES SHALL 9E FOLLOWED D BY A I' LAYER OF SCIL HAND TEED TO ENSURE C T ACT WITH, THE BRANCH CUTTINGS. 6. THE SOIL SHALL BE M❑IST OR MOISTENED TO ENSURE THAT LIVE 13PANC'HES 110 NDT Cq ' OUT. 7. WHFRF SPFETF[FD, I IVF STAKFS SHAiL I BF LAFD IN PLACE OF POSTS. ADAPTED FRUN XTATL,S PI�'Ji "V!DED BY. USDA - h:RC5, NEW YO'RK STATE PEPARTIOENu'. Or TRANSPCRTATIQN, NEW TORK STATE DEPART TENT OF ENVIRENMENTAL CINSERvAT]O% BRANCHPAC rNG NEW Y12RK STATE SOIL 1. 'CATER CONSERVATION COMHITTLL November 2016 Page 4.16 New York State Standards and Specifications For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR BRUSH LAYER enough to contact the back of the bench with the growing tips protruding out of the slope face. Care shall be taken not to severely damage the live branch cuttings during installation. Damaged cuttings will be replaced prior to backfilling. Starting at the toe of the slope,excavate benches along the contour of the slope. The benches shall range from 2 to 3 feet wide and the surface of the bench shall be angled so the front edge is higher than the back of the bench (See Figure 4.6). The benches shall be spaced according to the previous table,Slope Distance Between Layers(ft). Live branch cuttings shall be placed on the bench in a Definition & Scope crisscross or overlapping configuration in layers 3-4 inches thick at the butt ends. Backfill shall be placed on top A brush layer is a horizontal row of live branch cuttings of the live branch cuttings and tamped in 6 inch lifts. Small placed in soil with other similar rows,spaced a specific plate compactors may be used to settle the soil Areas vertical distance apart to stabilize cut and fill slope areas by between the rows of brush layers shall be stabilized by reinforcing the soil with uprooted branch stems,trapping seeding or other appropriate erosion control method. debris on slope,drying excessively wet sites,and redirecting adverse slope seepage by acting as horizontal Maintenance drains. Due to the susceptibility of plant materials to the physical Conditions Where Practice Applies constraints of the site,climate conditions,and animal Generally applicable to stabilize slope areas above the flow populations,it is necessary to inspect installations line of streambanks as well as cut and fill slopes. Brush frequently. This is especially important during the first year layers can be used on slopes up to 2:1 in steepness and 20 or two of establishment. Plant materials missing or damaged should be replaced as soon as possible. Sloughs feet in height. or breaks in drainage pattern should be reestablished for the site as quickly as possible to maintain stability. The brush Design Criteria layer may need to be watered periodically during the first The spacing requirements for brush layer rows is dependent year if installation is done during the summer months. on the slope steepness and moisture content. Spacing shall conform with the following table. Slope Distance Between Layers (feet) Slope Wet Dry Max H :V Slope Slope Slope Length 2 to 2.5:1 3' 3' 15' 2.5 to 3.5:1 3' 4' 15' 3.5 to 4.0:1 4' 5' 25' Brush layer cuttings shall be 1/2 to 2 inches in diameter and be from dormant plants. No leaf buds shall have initiated growth beyond 1/4"and the cambium layer shall be moist,green,and healthy. The cuttings shall be long New York State Standards and Specifications Page 4.17 November 2016 For Erosion and Sediment Control Figure 4.6 Brush Layer EXCAVATED BENCH 'SYMBOL BACKFILL (SEE NOTES 4&5) BL SEE[ OR 07HER EIROSIGH CONTROL MATERIAL BETWEEN R0 (SEE NOTE" 6) +* LIVE BRA CUTINGS F + I BRANCH CUTTINCS 1121 TO Br N DIAMETER BENCH SLOPE IN3TALI_EII TO + * CONTACT BACK C= EXISTING SOIL BENCH 3' TO 4' THICK LAYER OF BRANCHES 2' TO 3` CROSS SECTION OF BRUS HL AYER 04 CUT SLICE NOT Tn &CALE FRONT ❑F TRENCH BACK OF TRENCH BRANCH CUTTINGS INSTALLED T❑ CONTACT BACK OF BENCH BRAKCH CUTrI;NC ARRAN= IN CRISSCROSS FASHI❑N, 3' TO 4' THICK PLd�I� �f'IE#d NOT Ta SCALE CONSTRUCTION SPECIFICATIONS L. BENCH SHALL BE ANGLED 'ED OUTSIEE ED13E I3 HIGWR THAN BACK OF BENCH, LIVE DRANCK CUTTINGS BALL BE PLACED OR THE BENCH IN A CRISSGRQ �' -,R OVERLAP GQNFIE ATIQN, S'' TO 4' THICK AT THE 81)TT ENDS, 3. 15RGVING TIPS SHALL BE ALIGNED OUT OF THE SLOPE FACE :AND SIALIL EXTEND SLIGHTLY BEYONE THE FILL AREA, 4, FILL EACH LDWER EENCH WITH SOUL EXCAVATED FROM THE BENCH: AZOVE, TIP BENCH TC DE RACKFILLED WITH INITIAL EXCAVATIDN, 5. PLACiE BACKFILL ON TOP OF BRANCHES S AND HAND TAMP 141 f' LIFTS TO REIIW E AIR POCKETS. 6. SEED OR OTHER EROSION 'CONTROL MATERIAL SHALL BE USED BETWEEN THE RI IC*S AS STAYED IN THE CONTRACT DOCUMENTS. 7: W4HL AYER BEN C Orr% '%HA[,L BE FROm 31 T4 51 vERTICAL APART, DEPENDING CI N 5L❑PE, AS SHOWN ON THE PLANS MEASMIED BETWEEN FRONT EDGE Of KNCHES. MD4PTEJ) FROK DETAIL'S PROVIDED EYE USDA - NRCS, NEV VIIRK STATE MEPART14ENT OF TRANSPORTATION. NEW TORK STATE bEPARTMENT � ENVERINMENTAL CGNSERVAT30% LAYER � NEV YCRK STATE SM 4. VATER CONSEIRVAT[Ohl CUM HITTEE November 2016 Page 4.18 New York State Standards and Specifications For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR BRUSH MATTRESS Construction Specifications 1. Prepare slope surface by grading to a uniform,smooth surface,clear of obstruction. Slopes should be graded -' before the brush mattress is installed. 2. The fascine toe should be installed first. Then lay brush beginning at the downstream end of the work. The toe below the waterline may be anchored by rock. 3. The butt end of the brush will be placed upstream and plant materials inclined approximately 30 degrees. a 4. The upstream edge of the mattress will be keyed into the slope 2 feet. Stakes will be driven throughout the Definition & Scope mattress on 3-foot centers each way beginning along the toe of the mattress. A mulch or mattress of living brush laid on a slope and fastened down with stakes and wire to protect the soil 5. No.9 wire will be attached to the stakes and tightened surface on slopes from erosive forces through the to secure the mattress. generation of a dense stand of woody vegetation. 6. Slope areas above the mattress will be shaped and Conditions Where Practice Applies seeded. Brush mattresses are used primarily on streambanks where Maintenance the velocity is less than 6 feet per second and excessive streamflow has created erosive conditions. This practice Scheduled inspections the first year are necessary to make can resist temporary inundation,but not scour or sure the anchoring system is sound. Broken wire or missing undercutting. stakes shall be replaced immediately. Any missing toe material shall be replaced. The brush mattress may need to Design Criteria be watered periodically during the first year if installation is done during the summer months. Layer Thickness—The brush shall be a minimum of 3 inches thick(excluding top soil layer). Height—The mattress shall be placed up the bank to the bankfull elevation. The toe of the mattress should be located in a fascine trench. Slope—The maximum slope shall be 1.5:1. Anchoring—The mattress shall be anchored on the slope by a grid of 3-foot stakes driven on 3-foot centers each way. No.9 wire is then wound between the stakes,which are driven to secure the mattress. The upstream edge of the mattress should be keyed into the bank 2 feet. Materials—The plant materials should be willow or dogwood brush placed as shown in Figure 4.7. New York State Standards and Specifications Page 4.19 November 2016 For Erosion and Sediment Control Figure 4.7 Brush Mattress A mINIMUM or 50 BRANCI IC S, V OFF LESS IN DIAMETER. PIP 3 SYMBOL FEET EVENLY DISTRIBUTED FOR FULL WIDTH IF MATTRESS h WOOOEM POSTS PM LIVE STAKE (SAC NOTE 4&5) 19 CiAUQE GALVANIZED WIRE SECURED TO POSTS (SEE NOTE 0 BASAL ENDS FACING DOWN SLR (IN C❑NTAC T WITH FASC INE, IF USED) LIVE FASCINE SEE NOTE 51 TVIIhIE: A WATER PLAN VIEW UUT TO SCALE SAW 1 L/2"x3 1/2' DIAGONALLY TO PRODUCE TWO WOODEN P❑S- POSTS Q 1�2' LUMBER BRUSH LAYER COVERED WITH MIN + POST DETa4TL SELECT CLEAN a' LAYER SEL,EET FILL NOT TO SCALE �[.�AN F[. . ANT] BAND TAF;1; I] L_S' MINIMUy MEAN CATER LEVEL_�* SECTICIN A-A2 CONSTRUCTION SPECIFICATIONS t. LAYERS SHALL BE COMPRISED OF LIFE QUICK-ROOTING SPECIES, SEE COI.17P-A-C— D❑CUMENTS. P— CILL MATTRESS WITH S❑IL AND EVENLY DISTRIBUTE TO APPROXIMATELY AF IN DEPTH AND HAND TAMP. 3- PLACE POSTS EVENLY ❑VEFZ THE GRAVED FACE USING 3" SQUARE SPAJCIwi IF LIVE STAKES ARE SPECIFIED, ALTERNATE EVERY OTHER ON WITH 'THE PnST, 4.. STRETCH 9 GAUGE GALVANIZED WIRE BIAGONALLY FROM ONE POST TO ANOTHER' By TIGHTLY WRAPPING 'FIRE AROUND POSTS, NO CLOSED THAN E,' FROM THE TOP ❑F POST. VLNE SHALL Nal BE ATTACHED TO LIVE STACL�, J F' THL Y ARE SPEEIF It D. PtMJND ',%T AKE ',� T« GJNFFO Xti MA r YP-Lti,ti. 5. LIVE FAS:CINES AND LIVE STAKES ARE INSTALLED WHEN AND WHERE QIRECTFII ON THE PLAN SHEET., kDAPTE;D F RUN XTATLS PRO"v!DE d BY. USDA - K RC 5, NEW YORK STATE PEPAWTIoEN7 Or TRANSPERTATEON. NEW TORN STATE DEPA'RIMENT OF ENVIRENMENTAL CINSERvAT30N, BRUSH MATTRESS NEW WORK 7STATE SOIL :L 'CATER CONSERVATION C❑MHITTEE November 2016 Page 4.20 New York State Standards and Specifications For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR FERTILIZER APPLICATION phosphate(phosphorus,P),and the third is the percent of potash(potassium,K).Other elements are sometimes included and are listed with these three basic components. For example a 40 lb bag of 5-10-5 fertilizer contains 5%of 40 lbs of Nitrogen which equals 2 lbs. There is 10%of 40 lbs of phosphate(phosphorus)which equals 41bs,and there is 5%of potash(potassium),another 2 lbs., for a total of 8 lbs of active fertilizer in the 40 lb bag. The rest is filler to �s aid in spreading the material over the area to be treated. Specify the design fertilizer mix and application rates based on the results of the soil tests. Specifications Definition & Scope 1. In no case shall fertilizer be applied between December The permanent incorporation of fertilizer into the planting 1 and April 1 annually. zone of the soil profile to provide nutrient amendments to 2. Fertilizer shall not be spread within 20 feet of a surface the soil for vigorous support to plant and vegetation growth. water. Conditions Where Practice Applies 3. Any fertilizer falling or spilled into impervious surface areas such as parking lots,roadways,and sidewalks This standard applies to all areas where permanent seeding, should be immediately contained and legally applied or sodding,and plant establishment is required. All placed in an appropriate container. application of fertilizer shall be in accordance with Nutrient Runoff Law-ECL Article 17,Title 21. Phosphorus runoff 4. Incorporate the fertilizer,and lime if specified,into the poses a threat to water quality. Therefore,under New York top 2-4 inches of the topsoil or soil profile. Law,fertilizer containing phosphorus may only be applied 5. When applying fertilizer by hydro seeding care should to lawn or non-agricultural turf when: be taken to apply mix only to seed bed areas at an 1. A soil test indicates that additional phosphorus is appropriate flow rate to prevent erosion and spraying needed for growth of that lawn or non-agricultural turf, onto impervious areas. or 2. The fertilizer is used for newly established lawn or non -agricultural turf during the first growing season. For projects located within watersheds where enhanced phosphorus removal standards are required as part of its post-construction stormwater management plan,use of any fertilizer containing more than 0.67 percent phosphate (P205)content will be done only with a valid soil test demonstrating the need for that formulation. Design Criteria Fertilizer is sold with an analysis printed on the tag or bag shown as three numbers separated by a dash,such as 5-10- 5.The first number is the percent of the total weight of the bag that is nitrogen(N),the second is the percent of New York State Standards and Specifications Page 4.21 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR FIBER ROLL as to lay across the top edge of the roll. 6. Where fiber rolls are used to reduce sheet flow on x slopes they should be at least 12"in diameter and spaced according to the straw bale dike standard for sediment control. Maintenance Due to the susceptibility of plant materials to the physical - T constraints of the site,climate conditions,and animal populations,it is necessary to inspect installations frequently. This is especially important during the first year or two of establishment. Plant materials missing or damaged should be replaced as soon as possible. Sloughs Definition & Scope or breaks in drainage pattern should be reestablished for the site as quickly as possible to maintain stability. A fiber roll is a coir(coconut fiber),straw,or excelsior roll encased in netting of jute,nylon,or burlap to dissipate _ energy along streambanks,channels,and bodies of water and to reduce sheet flow on slopes. Conditions Where Practice Applies Fiber rolls are used where the water surface levels are relatively constant. Artificially controlled streams for _ hydropower are not good candidates for this technique. The rolls provide a good medium for the introduction of herbaceous vegetation. Planting in the fiber roll is e appropriate where the roll will remain continuously wet. Design Criteria r 'd% 1. The roll is placed in a shallow trench dug below baseflow or in a 4 inch trench on the slope contour and anchored by 2"x 2",3-foot long posts driven on each side of the roll(see Figure 4.8). 2. The roll is contained by a 9-gauge non-galvanized wire placed over the roll from post to post. Braided nylon rope(1/8"thick)may be used. 3. The anchor posts shall be spaced laterally 4 feet on center on both sides of the roll and driven down to the top of the roll. 4. Soil is placed behind the roll and planted with suitable herbaceous or woody vegetation. If the roll will be continuously saturated,wetland plants may be planted into voids created in the upper surface of the roll. 5. Where water levels may fall below the bottom edge of the roll,a brush layer of willow should be installed so November 2016 Page 4.22 New York State Standards and Specifications For Erosion and Sediment Control Figure 4.8 Fiber Roll SYMBOL VEGETATIVE PLANTING'S OR ❑Ti.'! �c EROSION CONTROL T E CH.10 DUES WILLOW BRUSH LAYER EROSION 1,'2' TO 2R IN MAMETER CONTROL PROA CT, IF EXCAVATE SHALLOW TRENCH — SPECIFIED HERBACEOUS PLUGS AS SPECIP'IED 9 GCE GALVANIZED WIRE EASEFLOW FIBER ROLL HARE-WOOD POSTS 2' .X 2" X 7 CROSS SECIM NOT TO SCALE CONSTRUCTION SPECIFICATIONS 1, EXCAVATE A SHALLOV TRENCH SLIGHTLY BELOW BASEFLOW OR A A' TRENCH ON SLOK CONT"S. 2, PLACE THE ROLL IN THE TRENCH AND ANCHOR WITH 2- K 2" POSTS PLACED ON BOTH SIDES OF THE ROLL AND SPACED LATERALLY ON 2' TO 4" CENTERS. TRIM THE TOP OF TC E POSTS EVEN VITH THE EDGE OF THE ROLL, IF NECESSARY, 3. NOTCH THE POSTS ANTI TIE TOGE'THCR, ACROSS TIC ROLL, WITH 9 GAUGE GALVANIZED WIRE OR 1!8" DIAMETER 'BRAIDED NYLON ROPE„ 4, PLACE WIL EXCAVATED FROM THE TRENCH BEHIND THE ROLL AND HAND TAMP, PLANT WITH SUITABLE HER SOUS IR WOUDY VEGETATION AS SPECIFIED ELSEWHERE IN TIE CONTRACT D❑CUMENT& VEGETAI']ON SHALL BE PLACED IMMEDIATELY ADJACENT TO THE ROLL TO PROMOTE RIOT GROWTH INTO THE FIBER. HERBACEOUS VEGETATION., IF SHECIrIED. SILkL BE PLANTED INTO 714L FIBER ROLL- AUAPTEQ FROM .IDETAILS PRIOV]oEO BY- USDA - NRCS, NEW YOWK STATE VEp`AR7NENT 13F TRi4HSFOzTATIDN, FIBER NEW YORK STATE DEPARTMENT OF Ef+�1f1ROI+INIENTAL CONSERVATION, NEW YORK STATE SUIL i 'WATER CONSERVATHIN COMMITTEE New York State Standards and Specifications Page 4.23 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR LANDGRADING damage slopes or other graded areas;see standards and specifications for Grassed Waterway,Diversion,or Grade Stabilization Structure. 2. Cut and fill slopes that are to be stabilized with grasses shall not be steeper than 2:1. When slopes exceed 2:1, special design and stabilization consideration are required and shall be adequately shown on the plans. (Note: Where the slope is to be mowed,the slope should be no steeper than 3:1,although 4:1 is preferred because of safety factors related to mowing steep slopes.) 3. Reverse slope benches or diversion shall be provided whenever the vertical interval(height)of any 2:1 slope exceeds 20 feet;for 3:1 slope it shall be increased to 30 Definition & Scope feet and for 4:1 to 40 feet. Benches shall be located to divide the slope face as equally as possible and shall Permanent reshaping of the existing land surface by convey the water to a stable outlet. Soils,seeps,rock grading in accordance with an engineering topographic plan outcrops,etc.,shall also be taken into consideration and specification to provide for erosion control and when designing benches. vegetative establishment on disturbed,reshaped areas. A. Benches shall be a minimum of six feet wide to Design Criteria provide for ease of maintenance. B. Benches shall be designed with a reverse slope of The grading plan should be based upon the incorporation of 6:1 or flatter to the toe of the upper slope and with building designs and street layouts that fit and utilize a minimum of one foot in depth. Bench gradient to existing topography and desirable natural surrounding to the outlet shall be between 2 percent and 3 percent, avoid extreme grade modifications. Information submitted unless accompanied by appropriate design and must provide sufficient topographic surveys and soil computations. investigations to determine limitations that must be imposed on the grading operation related to slope stability,effect on C. The flow length within a bench shall not exceed adjacent properties and drainage patterns,measures for 800 feet unless accompanied by appropriate design drainage and water removal,and vegetative treatment,etc. and computations;see Standard and Specifications Many municipalities and counties have regulations and for Diversion on page 3.9 design procedures already established for land grading and 4. Surface water shall be diverted from the face of all cut cut and fill slopes. Where these requirements exist,they and/or fill slopes by the use of diversions,ditches and shall be followed. swales or conveyed downslope by the use of a designed structure,except where: The plan must show existing and proposed contours of the area(s)to be graded. The plan shall also include practices A. The face of the slope is or shall be stabilized and for erosion control,slope stabilization,safe disposal of the face of all graded slopes shall be protected runoff water and drainage,such as waterways,lined ditches, from surface runoff until they are stabilized. reverse slope benches(include grade and cross section), grade stabilization structures,retaining walls,and surface B. The face of the slope shall not be subject to any and subsurface drains. The plan shall also include phasing concentrated flows of surface water such as from of these practices. The following shall be incorporated into natural drainage ways,graded ditches,downspouts, the plan: etc. 1. Provisions shall be made to safely convey surface C. The face of the slope will be protected by anchored runoff to storm drains,protected outlets,or to stable stabilization matting,sod,gravel,riprap,or other water courses to ensure that surface runoff will not stabilization method. November 2016 Page 4.24 New York State Standards and Specifications For Erosion and Sediment Control 5. Cut slopes occurring in ripable rock shall be serrated as 4. Areas to be filled shall be cleared,grubbed,and shown in Figure 4.9 on page 4.26. The serrations shall stripped of topsoil to remove trees,vegetation,roots,or be made with conventional equipment as the excavation other objectionable material. is made. Each step or serration shall be constructed on the contour and will have steps cut at nominal two-foot 5. Areas that are to be topsoiled shall be scarified to a intervals with nominal three-foot horizontal shelves. minimum depth of four inches prior to placement of These steps will vary depending on the slope ratio or topsoil. the cut slope. The nominal slope line is 1 ''/2: 1. These steps will weather and act to hold moisture,lime, 6. All fills shall be compacted as required to reduce fertilizer,and seed thus producing a much quicker and erosion,slippage,settlement,subsidence,or other longer-lived vegetative cover and better slope related problems. Fill intended to support buildings, stabilization. Overland flow shall be diverted from the structures,and conduits,etc.,shall be compacted in top of all serrated cut slopes and carried to a suitable accordance with local requirements or codes. outlet. 7. All fill shall be placed and compacted in layers not to 6. Subsurface drainage shall be provided where necessary exceed 9 inches in thickness. to intercept seepage that would otherwise adversely affect slope stability or create excessively wet site 8. Except for approved landfills or nonstructural fills,fill conditions. material shall be free of frozen particles,brush,roots, sod,or other foreign objectionable materials that would 7. Slopes shall not be created so close to property lines as interfere with,or prevent,construction of satisfactory to endanger adjoining properties without adequately fills. protecting such properties against sedimentation, erosion,slippage,settlement,subsidence,or other 9. Frozen material or soft,mucky or highly compressible related damages. materials shall not be incorporated into fill slopes or structural fills. 8. Fill material shall be free of brush,rubbish,rocks,logs, stumps,building debris,and other objectionable 10. Fill shall not be placed on saturated or frozen surfaces. material. It should be free of stones over two(2)inches 11. All benches shall be kept free of sediment during all in diameter where compacted by hand or mechanical tampers or over eight(8)inches in diameter where phases of development. compacted by rollers or other equipment. Frozen 12. Seeps or springs encountered during construction shall material shall not be placed in the fill nor shall the fill be handled in accordance with the Standard and material be placed on a frozen foundation. Specification for Subsurface Drain on page 3.48 or 9. Stockpiles,borrow areas,and spoil shall be shown on other approved methods. the plans and shall be subject to the provisions of this 13. All graded areas shall be permanently stabilized Standard and Specifications. immediately following finished grading. 10. All disturbed areas shall be stabilized structurally or 14. Stockpiles,borrow areas,and spoil areas shall be vegetatively in compliance with the Permanent shown on the plans and shall be subject to the Construction Area Planting Standard on page 4.42. provisions of this Standard and Specifications. Construction Specifications See Figures 4.9 and 4.10 for details. 1. All graded or disturbed areas,including slopes,shall be protected during clearing and construction in accordance with the erosion and sediment control plan until they are adequately stabilized. 2. All erosion and sediment control practices and measures shall be constructed,applied and maintained in accordance with the erosion and sediment control plan and these standards. 3. Topsoil required for the establishment of vegetation shall be stockpiled in amount necessary to complete finished grading of all exposed areas. New York State Standards and Specifications Page 4.25 November 2016 For Erosion and Sediment Control Figure 4.9 Typical Section of Serrated Cut Slope r I= 111I , ,._ � � II 111 I NORMIL SLOPC LINE 1.51 OR STEEP&R J Hii III -II AOAP E FROM DETAILS MVIDEo By. us0A NMS, TYPICAL SECTION NEW YURK STATE VEPARTkENT OF TRANSPORTATTUN, [IFSERRATED CUT NEW "YORPM STATE DEPARTMENT (IF E14V],ROKME NT AL MNSERVA710N, NCW VOW STATE SML & 'CATER E❑MSERVATTIN G❑HMITTEE SLOPE November 2016 Page 4.26 New York State Standards and Specifications For Erosion and Sediment Control Figure 4.10 Landgrading SYMBOL DITCH OR a IVE RS1(IN TO IVERT SURFACE FLOW s 4M 4 AL ti � JL i i i REN�G, GRADE 2-3% 3 i i A. -ai A. i 4W aw 4mlh� dhN&I err ,rrr � T NAB€. �II�� III 9"hllhl , $ , f r � � # e r Z,% k F 'k 8 20' 3 30' 4 40' ABAPTED FR❑H I]E7AJL3 PROVIDED NSF• USDA KRIS, NEW YORK TA7E DEPARTMENT OF TRANSPURTAT LQH, L A N DG R A B I N❑ NEV YDRK STATE DEPARTMENT DF DWIRONMENTAL CONSERVATION, ]DETAIL IWEW YIWK STATE SOIL & WATER EINSERVATIOM E❑HHITTE'= New York State Standards and Specifications Page 4.27 November 2016 For Erosion and Sediment Control Figure 4.11 Landgrading - Construction Specifications CONSTRUCTION SPECIFICATIONS I. ALL GRADED OR DISTURBED AREAS INCLUDING SLOPES SKQ-L �E PROTECTED DMING CLEARING AND C❑MSTRUCTIDN IN ACCORDANCE WITH THE APPROVED ERUSI❑N AND SE I13ME NT IyQNT RQI- PLAN HIT IL TIC Y ARE PERMANENTLY STABILIZE M ALL SIE DI MENT CONTROL PRACTICES AND MEASURES SHALL BE CONSTRUCTED. APPLIED AND HAINTAINED IN ACCORDANCE WITH TILE APPMVED ERMIGN AND SEDIMENT C❑RTRML PLAN. 3, TAIL REOU'RED FOR THE ESTABLISHMENT OF VEGETATION SHALL DE STOCKPILED IN A-MOUNT NECESSARY TC1 COMPLETE FINISHED GRADING 1OF ALL EXPOSED AREA& A, AREAS TO BE FILLED SHALL BE CLEARED, GRUBBED, AND STRIPPE E OF TOPSOIL T❑ REMOVE TREES, VEGETATION, ROOTS OR OTHER OBJECTIONABLE MATERIAL. 5. .AREAS WH[UH ARE TO SE 70PS❑LLED SHALL II£ SCARCFIED TO A KINIMUM DEPTH I FOUR INCHES PRIOR TO PLA4 EMENT OF TOP$QCL• 6, ALL FILLS SHALL BE COMPACTED AS PE GUI1RE D TO REDUCE, EIROSIOR, &LIPPAGE, SETTLEMENT, SUBSIDENCE OR OTHER RELATED ','PROBLEM. iFIt L INTENDED TO SUPPORT BUILDINGS, STRUCTURES AND CONOUITS, ETC. SMALL BE COMPACTE11 IN ACCORDANCE WITH LOCAL REQUIREMENTS DR. CODES. 7. ALL FILL SHALL BE PLACED AND COMPACTED IN LAYERS NOT TO EXCEED 9 INCHES IN TH]LKNLSS. S. EXCEPT FOR APPROVED LANDFILLS, FILL MATERIAL SHALL BE FREE OF FROZEN PARTICLES, BRUSH, ROOTS, SI , OR OTHER FOREIGN OR OTHER ❑BJECTI❑NABLE MATERIALS THAT W❑ULD INTERFERE WITH OR PREVENT C❑NSTRUC710N OF SATISFACTORY FILL . 9. FROZEN MATERIALS; OR SIFT, MUCKS OR HIGHLY COMPRESSIBLE MATERIALS SHfALL NOT PE INGIOVORATE D IN E 1LL S 10. FILL SHALL NOT 13E PLACED ON SATURATEU UR FROZEN SURFACES. 11. ALL BENCHES SHALL BE KEPT FREE OP SEDIMENT DURING ALL P wAS.LS OF OEVEL❑PMENT. 1.2. SEEPS OR SPRINGS ENCOUNTERED QURING CONSTRUCTION SHALL. BE HANDLED IN ACCORDANCE WITH THE STMN11000 AND SPi`ClrICATION rOR SUBSURFACE AIN DR OTHER APPROVED METHEIC_ I3. ALL GRADED AREAS SMALL BE PERMANENTLY STABILIZED ]MME D CA rE L Y C OLLOW3iNt. FINISHED CRPOING. 14. STOCKPILES, BORROW AREAS AND SPOIL AREAS SHALL BE SHOWN ON THE PLANS AWN SHALL RE SURjECT TO THE PROVISIONS OF THIS STANDARD AND SPECIFICATI❑N. E rTY R RR SPT[NS. NB ORKTAE DEARTKENT OF TRANS O , L A N DG R A D I N G MEW Y❑RK STATE DEPART14ENT OF E N VIR❑4KENTAL CONSERVATION, PE C 1 F T C A 3 ION NEW FORK STATE SOIL t WATER CONSERVATION COMMITTEE November 2016 Page 4.28 New York State Standards and Specifications For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR LIME APPLICATION The amount of limestone needed can be estimated by using the following table. A soil test is the only way to determine the soil pH. This table is very general,but it is useful for planning. General lime guidelines(at 100%ENV) Initial Sands Sandy Loam and Silty Clay Soil pH Loams LSilt Loams 4.5 2.5 6.0 9.5 13.0 4.6-4.7 2.5 6.0 9.0 12.5 Definition & Scope 4.8-4.9 2.5 5.5 8.5 12.0 5.0-5.1 2.0 5.0 7.5 10.5 Permanent incorporation of agricultural ground limestone within the top 2 to 6 inches of the soil profile to 5.2-5.3 1.5 4.0 6.5 8.5 increase the soil pH from an acidic level to a neutral level to provide an active growth medium for vegetation. 5.4-5.5 1.0 3.0 4.0 6.0 5.6-5.7 1.0 2.0 3.0 4.5 Conditions Where Practice Applies 5.8-5.9 0.7 LS 2.5 3.5 At all locations where a vigorous growth of vegetation is 6.0-6.1 0.6 1.5 2.0 3.0 desired and the soil pH is less than 7.0 or neutral. 6.2-6.3 0.4 1.0 1.5 2.0 Design Criteria 6.4-6.5 0.3 0.7 1.0 1.5 Liming material sold in New York varies considerably in 6.6-6.7 0.2 0.5 0.7 1.0 several ways. The mineral content(calcium and Lime guidelines are in tons per acre and are based on a plow depth of 8.0 magnesium)of the limestone may be high or low and,the inches.Correct rate if plowing to a different depth. fineness or particle sizes vary between suppliers. Two Conversion for small areas: 1 ton/acre=2,000#/43,560 W, 46#/1,000 W types of limestone are sold. The most common is limestone high in calcium. Dolomitic limestone contains magnesium Note:Lime should not be applied within 50 feet of streams (Mg)and calcium(Ca). Limestone sold in NY varies from and wetlands. 0 to 20%Mg while the calcium content of lime vanes from 14.7%to 51.5%. Particle size determines how rapidly the calcium and magnesium will react with the acid in the soil. The finer the particle sizes,the quicker the reaction. When obtaining agricultural limestone,one should state on the specification that the amount should be adjusted to 100%effective neutralizing value(ENV). This is the way to compare materials as it adjusts for the reactive Ca and Mg and the particle size. The ENV is stated as the ratio needed to convert a limestone recommendation to 100% ENV. Thus,if the recommendation is 4 tons/acre of 100% ENV lime and the lime being used had an 80%ENV(1/ ENV= 1.25),4 times 1.25 or 5 tons/acre would be required. New York State Standards and Specifications Page 4.29 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR LIVE CRIB WALL foundation 2'-3'below the ground elevation at the toe of slope with the back of the excavation(to the slope) i slightly deeper than the front. 6. The first course of logs is placed along the front and back of the excavated foundation approximately 4-5 - feet apart and parallel to the slope contour. 7. The next course is placed at right angles on top of the a "�hILprevious course to overhang the front and back of the - r 8� previous logs by 3-6 inches. r 8. Each course is placed in the same manner and fastened �.' A.PL 1 to the preceding course to the desired grade. Definition & Scope 9. Stone fill is placed in the bottom of the structure up to the ground level and up to the base flow in a stream A hollow box-like structure made with an interlocking channel. arrangement of untreated logs or timber members spiked together and anchored into the slope. The structure is filled 10. Once the cribwall structure reaches the existing ground with suitable earthfill materials and layers of live branch elevation,live branch cuttings are placed on the stone cuttings which root inside the structure and extend into the fill parallel with the slope contour. slope. This protects exposed or eroded streambanks from the erosive forces of flowing water and stabilize the toe of 11. The cuttings are then covered with select clean fill with slope to reduce slope steepness. a maximum size of 3 inches and not more than 20 percent passing a 200 sieve size. Conditions Where Practice Applies 12. The live branch cuttings shall be placed at each course Generally applicable where flows are less than 6 feet per followed by the select fill to the top of the structure second and no degradation of the streambed occurs. Can With the growing tips slightly protruding from the reduce steepness and provide stability where space is cribwall face. limited and a vertical structure is needed. It is not intended 13. The plant materials shall be kept in a healthy growing to be used where the integrity of a road or structure is condition by watering. Also see maintenance below. dependent on the cribwall since it is not designed to resist large lateral earth pressures. Maintenance Design Criteria Due to the susceptibility of plant materials to the physical constraints of the site,climate conditions,and animal 1. The vegetated cribwall structure shall be designed to a populations,it is necessary to inspect installations height for its intended purpose. frequently. This is especially important during the first year or two of establishment. Plant materials missing or 2. Live branch cuttings should be 1/2 to 2 inches in damaged should be replaced as soon as possible. Sloughs diameter and long enough to reach from the front of the or breaks in drainage pattern should be reestablished for the structure to the undisturbed soil. site as quickly as possible to maintain stability. Plant 3. The structure will be built with a batter of 1 to 12. materials may need to be watered periodically during the Large spikes or rebar are required to secure the logs or first growing season if installed during summer months. timbers together(10 inches minimum). 4. Only untreated logs or timber shall be used in the cribwall. 5. Installation begins with excavating to a stable November 2016 Page 4.30 New York State Standards and Specifications For Erosion and Sediment Control Figure 4.12 Live Cribwall SYMBOL VF-GC TAT[VIE F'1 ANriNUN UR SOIL DI❑ENGINEER IN SYS GEMS FXCAVATION AS REOUIRED UNDISTURBED SOIL LP + SELECT CLEAN FILL +++ BRANCH CUTTINGS, I/2' TO EXISTING GRADC + + 2' IN DIANIE TER, LUNG _ ENIOUGH TO 'REACH FROM FRONT OF THE S TRU I UM 2' T❑ ❑' T 1 TO THE UNDISTURBED SOIL UNTREATED LOG OR TIMBER ICiH a STONE FrLi ING MEMBERS 4- T10 6- IN DIAMETER SECURED WITH 4' To ` ' l' LARGE SPIKES OR REBARS ER❑gs srclINN SECURE EACH COURSE 713 THE SLI15HTLY PROTRUDING ,� CEDING COS SEE NOTE 1. OWING TIPS SEE CONTRACT EXISTING GRADEANN. DOCLOIENTS FOR HEIGHT UNTREATED LOG OR TIMBER 4' T❑ 5' I1EMBEPS 4+ TO 6' IN DTAM+IETE? FRONT ELE okTMtj CONSTRUCTION SPECIFICAI- IONS L EACH C❑LIRSE SHALL HE SEC UREIM TD THE PRECEDING ❑CAE WITH SPIKES OR RfEBARS, SEE C0NTRACT DOCUMENTS FOR 5]ZE AND LENGTH. 2, RACKFILL IN A14D AROUND TIMBER CRIB WITH RIPER �LJGHT FILL) FROM BOTTOM I]v EXCAVATION TO THE LOWER GROUND LEVEL, OR WHEN IN STREAM CHANNEL UP TO BASEFLIOW, 2. EACH TRANSVERSE LOG C> SE CONTAINS LIVE CUTTINGS FOLLOVED BY A LAYER EW TAMPED BACKFILL. 4, EACH FACE LOG COURSE (FRONT AND REAR), AN® THE AREA BEHIND THE STRUCTURE SHALL HC "`I KF ILLED AND HAND TAMPED. KW YUR4K STATE IDEPARTNGNT OF rRAN1SFURTATION, LIVE Cf�IB ALL NEW 'YIIRK STATE DEPARTMENT [IF E IREI HTAL CDNaRVATI❑Nr NEW YURK STATE UIL %i WATER CMSE VATTUN C❑Hr1ITTEE New York State Standards and Specifications Page 4.31 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR LIVE FASCINES Slope Contour Interval 1:1 3' a� R 1.5:1 3' & - a %L .. 2:1 4' ..' 2.5:1 4' 3:1 5' ti 3.5:1 5' a 4:1 6' - 6:1 8' Definition & Scope The placement of groups or bundles of twigs,whips,or See Figure 4.13 for details. branches in shallow trenches,on the contour,on either cut Construction Specifications or fill slopes. To stabilize slopes by slowing water movement down the slope,increasing infiltration,trapping 1. Fascines shall be 4 inches minimum in diameter. slope sediments,and increasing soil stability with root systems. 2. Prior to placing the fascines,the slope shall be smoothed and graded with obstructions removed. Any Conditions Where Practice Applies structural measures for revetment,drainage,or surface On sloping areas such as road cuts,slumped areas,road Water management will be installed first. fills,gullies,and streambanks subject to erosion,seepage, 3. Working from the bottom of the slope to the top, or weathering,which have a low to medium hazard excavate the fasciae trench. Place fascines in trench potential should slope failure occur. Slopes must be 1:1 or and anchor with stakes spaced at 24 inches. Cover flatter. fascines with soil leaving about 10%exposed to view. Fascines shall be overlapped 12 inches minimum in the Design Criteria trench. Materials—Shall be a native or nursery grown cultivar that 4. Soil shall be worked into the fascine and compacted by is capable of performing the intended function. walking on the fascine being covered. Fascines—Shall be made by forming the bundles 8-15 feet 5. All disturbed areas should be seeded upon completion long,4 inches minimum in diameter,from stems no more of fascine placement. than 1 inch in diameter. Overlap—Fascines should be overlapped at the tapered Maintenance ends a minimum of 1-foot. Regular inspection and maintenance of fasciae installations Vertical Spacing—The spacing of the contours for the should be conducted especially during the first year of fascines is dependent on the degree of erosion or potential establishment. Loose stakes should be reset and settled fill erosion at the site. Factors include slope steepness,soil areas should be brought back to grade. Prompt corrections type,drainage,and existing ground cover. The following is to gullies,sloughs or other evident problems shall be made. a general guide to selecting contour interval: November 2016 Page 4.32 New York State Standards and Specifications For Erosion and Sediment Control Figure 4.13 Live Fascine STACMI" BRAEt. TIPS I AL IN❑ T Vl NE SYMBEIL 4' T❑ I}" DJAML I E^f AND KI NIMU14 LENGTH :IF 8' R L PUIRL D FA4SCINE BUNDLE DE T AIL NOT TO SCALE 5 ❑PE FADE SLIGHTLY EXPOSEC AFTER INSTALL,ATIDN PREPARE TRIENCH SEED CR 1OT"ER ER❑SJ❑N C❑L%TR❑L AND B,ACKFILL MATERIAL AS SPECIFIED IN THE CONTRACT LIVE FASCINE DIJCU ME NTH BE T VEEN F A C E ROWS BUNDLE PU_ST— J 1 1/21U 1/2, 'SAW1 1.2"x3 /P L_UNBER L/2- DIAGONALLY CRU5S SECTI❑N e E TO PRODUCE mof TC �MLE U, TWO PMTS ftj , P❑S T DETAIL NOT TTT C ALE ❑ON T U TI❑N SPECIFICATIONS 1, LIVE iFASCINES SHALL BE PREPARED FROK FRESHLY CUT DDROAN!T PLANTS AND INSTALLED VIT N! B NDUNS [IF THE TIME THE MATERIAL IS HAP'VESTE D. UNLESS PRUIPERLY STORER 2. LIFE FASCINE SHALL BE DBTAyINED FRDH SDURCES APPRGVE D B`+ THE EHGINEiER. Live EASICINES SHALL BE 4' TO W IN O AWIEIi, LENGrH�S MAY VARY TD SUIT CONDITIONS. A5 MINI" LENGTH OF D' IS REQUIRED, 4. TFIL TIPS C'F THE FZANLHES WITHIN THE L1VE FASC[AE SHALL BE 5TAGURE II. 3. LIVE FASCI'4ES SK&LL HE PLACED AS INDICATE❑ IN THE C13NTRACT DUCLIMENTS. fi. BEGINNING AT THE BASE OF THE SLGRE, A TRENCH SHALL HE GUG LARGE ENDUGH TO LUNT1IN THE LIVE FASCINES, THE LIVE FASCINES SHALL BE PLACED JAI THE TRENCH. 'WHERE ENDS MEET IN THE TIRENC I, THE FA$C.INN S SHALL OVERLAP BY 10'. 7. WDOI) POSTS HALL BE INSTALLED FLUSH TO THE TOP CE THE FASSCIHE EVERY 1D' ALOM THE LENGTH [IF THE BUNDLES AS SHOWN ION THE =S:S SECT[❑Ft WHERE SPECIFIED LV& STAK]F69 MAY BE USED IN FLACE W Fo-usr s. D, THE TRENCH SHALL LIFE PACKF LLLED 'KITH MOIST SOLL: MD HAIgD TAMPED, THE TOP OF TIME FASUI E SHALL BE SLIGHTLY EXPI E0 WHEN TIC UCSTALLA-TGN Is CGMPLETE AS SHE ION THE CROSS SECTION 9. SEED OR OTHER E1?QSI[N CONTRUL MATERIAL SHALL BE USED BETWEEN TFE FASCINE RIIVS, AS SPECIFIED IN 7HE CONTRACT I)0CU -NT& 10. LIVE IFASCINE TRENCHES SH&.L BE FROM 3' T❑ 0' APART, ACCORDIN❑ T(I SLUPE AND/DR THE EJUNTRACT DOCUMENTS.. ADAPTED FROM DETAILS PIFWVIDEo BY- USIIA NRES, NEW YT]R:K STATE TIEPAR'THENT 13F TRANSPORTATION. LIVE �� �I� NEW YORK STATE DEPARTMENT OF ENVIRONMENTAL CONSERVATION, iqEw YICft STATE =L & WATM C;15EWArI❑N COMMITTEE New York State Standards and Specifications Page 4.33 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR LIVE STAKES . :, shall extend through the surface of the stone fill. t �ti At least half the length shall be inserted into the soil,below the stone fill. Spacing along the E waterline is usually I foot. B. Minimum 2 to 4 inches and two live buds of the live stake shall be exposed above the stone filling. C. Live stakes shall be cut to a point on the basal end for insertion in the ground. D. Use a dead blow hammer to drive stakes into the ground. The hammer head should be filled with shot or sand. A dibble,iron bar,or similar tool shall be used to make a pilot hole to prevent Definition & Scope damaging the material during installation. A stake or pole fashioned from live woody material to E. Live cuttings shall be inserted by hand into pilot create a living root mat that stabilizes the soil by reinforcing holes. and binding soil particles together and by contributing to the reduction of excess soil moisture. F. When possible,tamp soil around live stakes. Conditions Where Practice Applies G. Care shall be taken not to damage the live stakes during installation. Those damaged at the top Live stakes are an appropriate technique for repair of small during installation shall be trimmed back to earth slips and slumps that are frequently wet and for undamaged condition. stabilizing raw streambanks. This technique is for Maintenance relatively uncomplicated site conditions when construction time is limited and an inexpensive vegetative method for Due to the susceptibility of plant materials to the physical stabilization is derived. It is not intended where structural constraints of the site,climate conditions,and animal integrity is required nor to resist large,lateral earth pressures. populations,it is necessary to inspect installations frequently. This is especially important during the first year Design Criteria or two of establishment. Plant materials missing or damaged should be replaced as soon as possible. Sloughs 1. Live stakes shall be 1 -2 inches in diameter and 2-6 or breaks in drainage pattern should be reestablished for the feet long,depending on site application. site as quickly as possible to maintain stability. Plant materials may need to be watered periodically during the 2. No leaf buds shall have initiated growth beyond 1/4" first growing season if installed during summer months. and the cambium layer shall be moist,green and healthy. 3. All material shall be maintained in a continuously cool, covered,and moist state prior to use and be in good condition when installed. 4. Materials harvested on site shall be installed the same day they are prepared. Nursery grown material shall be maintained in a moist condition until installed. 5. Installation Details A. The lengths of live cuttings/live stakes depends upon the application. If through riprap,the length November 2016 Page 4.34 New York State Standards and Specifications For Erosion and Sediment Control Figure 4.14 Live Stake RAHWULL MINIMUM a TO #' AND TV0 LIVE BUDS SHALL TEE SXPOSEt AROVE TW- STONE r3LL EXISTING STCME EILLLN ] - NE RALF OF THE LENGTH OF THE Lei': LIVE CUTTING/LIVE STAKE --,,, CUTTING/LIVE STAK-L IA EPLOW STREAMBED i LIFE CUTTING OR LIVE STAKE 5 T FILL �RCIOT� 0r LIEF [.-LJIIN(Wl ]VS %FAKE LJ, jf T IMG/LIVE STAKE tJ❑MT PL ANT[LAG CROSS SECTION LIVE SQUARE CUT CUTTING MIMIMIJFI OF TWO 3I DS z'/-- EXPOSED ABOVE GROUND /— 0VC STAwr 3/3 TAP S❑IL ARULI14D CUTTING GIRA"-E i OR LIVE STAR ❑/❑ EXISTING S1311- � II F -171 1 I ANGLE CUT 3D* TO 45` I E4J.LllN GF S� E .7ID LIME STAKE CFI❑S 9 SECTIO N07 TO SCALE MT TO SCALE ADAPTE:P FROM DETAILS PRUVIDEU By- uSt1k - NRCS, LIVE ICU7 T INC;S/ NEV `VDRK STATE QEPARTM ENT rrF TRANSP[RTAT IQw, L I ESTAKES NEW YBAK STATE DEPARTW-NT 10F ENVERLMM�MTAL CONSERVATION. NE%7 YORK STATE SOIL 4. '.LATER EONSERVATEON C❑MHIT TEE PLANTING New York State Standards and Specifications Page 4.35 November 2016 For Erosion and Sediment Control Figure 4.15 Live Stake Construction Specifications 'SYMBOL Q C:/l CONSTRUCTION SPECIFICATIONS 1. CARF SMALL BE TAKEN NOT TO DAMAGE THE L[VE C uT TINGS?LIVE STAKES DUFFING INSTALLATI❑N. THOSE DA14AGIED SHALL BE LEFT IN PLACE AND SUPPLEMENTED WITH AN LN T ACT LIVE UUTTING/L]VE STAKE. 2. THE LENGTHS OF LIVE CUTTINGSYLIVE STAKES DEPENDS UPON THE APPLICATION. THE LENGTH SHALL EXTEND THROUGH THE SURFACE OF THE STONE FILL. AT LEAST HALF THE LENGTH] SHALL BE INSERTED IN TO THE S❑IL, BELOW THE STONE FILL. 3.. A PILOT HOLE IS REDUIRED TO ENSUPE TKOLT THE LIVE GUTTING/LIVE STAKE 1S NOT DAMAGED WHEN DRIVEN THROUGH THE STONE FILLING. ACCESS SH&L HE FADE THROUGH THE USE OF A DIBRI F BAR, IR SIMTI AIR TOOL TO WORK AN OPENING THROUGH THE RIM LAYER- 4. MINIMUM 2' TO 4' AND TWO LIVE BUDS OF THE LIVE CUTTING/LIVE STAKE SHALL_ BE EXPOSED ABOVE THE STONE F I L LINE 5, LIVE GU T'T[N1G� SHALL. RANGE FROm 1./2' TO I" IN `G ANV E R AND K FROM L' 10 4' IN LENGTH, 6. LIFE :STAKES SHALL RA E FROM V TO 4' IN DIAMETER AND BE FROM 5' TG G' IN LENGTH. 7. SEE CONTRACT DOCUMENTS FOR SPECIES, SIZE, SPACINGr L❑CAT[❑Nr AND FINAL DETERMINATION ON USE (IF CUTTING& OR STAKES, R, LIVE CUTTINGS/LIVE STAKES SHALL BE CUT T❑ A POINT ON THE BASAL END FOR I ERTION IN THE IGRlluNM 9, USE A DEAD '4i OV HAMMER TO DRIVIE STAKES INTO THE GROUND. (HAMMER HI A FILLED WITH SHOT OR D,) A IMIILE, IR❑N BAR, OR SIMILAR TOOL SHALL BE USED TO MAKE A PILUT HOLE TO PREVENT DAMAGING THE MATERIAL DURING INSTALLATION. 10. LIVE CUTTENGGS SHALL BE INSERTED BY NANO INTO PILOT HOLES.. 11. '4 NEN POSSIBLE, TAW WIL ARID tIVC CUTTING/LIVE STAKES.. A-DAPTED F'REN DETAILS PRUVIDED By- USDA - NRCS. LIVE CUTTINGS/ NEW YORK STATE DEPARTMENT of TRANSPORTATION, LIVE TE E NEW Y]IRK STATE Or-PARTMEMT OF €NVIRDF&ENTAL CONSERVATION, NEV 'CORK $'TATI SOIL !& WATLT CONSERVATION CUMKITTEE PLANTING PLC. November 2016 Page 4.36 New York State Standards and Specifications For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR LOOSE STABILIZATION BLANKETS Placement:The method of application and depth of compost _ Ic_w depend upon site conditions. Vegetation of the compost ` lk ._ blanket is generally archived by incorporating seed into the compost before it is applied. However,seeding may occur after the application if needed. The compost application rate will be in accordance with the following table. Compost is not recommended for slopes steeper than 2H:1 V. Slopes with problem soils and more runoff will require greater application rates. Compost Application Rates Slope Length(ft) <3H:1V Slopes 3H:1V to 2H:1V Definition and Scope Slopes 20 or less 270 cy/acre 540 cy/acre Blankets of various materials placed pneumatically, (2"Layer) (4"Layer) hydraulically,or other means on a prepared planting area or 405 cy/acre 675 cy/acre a critical area where existing vegetation can remain to 20 to 60 (3"Layer) (5"Layer) reduce rain splash and sheet erosion and promote vegetative stabilization. 540 cy/acre 810 cy/acre 60 to 100 (4"Layer) (6"Layer)* Conditions Where Practice Applies *For slopes between 2H:1V and 1H:1V use this rate with a Loose blankets are an appropriate stabilization practice for max. slope length of 40 ft. any soil surface that is rocky,frozen,flat,or steep. They Construction Specifications can be used on streambanks,road cuts and embankments, and construction site areas where stormwater runoff occurs 1. Compost shall be placed evenly and must provide as sheet flow. They should not be used in areas of 100%soil coverage(no soil visible). On highly concentrated flow. unstable soils,use compost in conjunction with appropriate structural measures. Design Criteria 2. Spread the compost uniformly to the design thickness Compost Blanket by hand or mechanically(e.g.with a manure spreader, front end loader,dozer,pneumatic blower,etc.)and Material:The compost infill shall be well decomposed then track(compact)the compost layer using a (matured at least 3 months),weed-free,organic matter. It bulldozer or other appropriate equipment. shall be aerobically composted,possess no objectionable odors,and contain less than 1%,by dry weight,of man- 3. When using a pneumatic(blower)unit,shoot the made foreign matter. The physical parameters of the compost directly at soil,to provide a tighter interface compost shall meet the standards listed in Table 5.2- between the soil and compost and prevent water from Compost Standards Table. Note:All biosolids composts moving between the two layers. produced in New York State(or approved for importation)must meet NYS DEC's 6 NYCRR Part 360 4. Apply compost layer approximately 3 feet beyond the (Soild Waste Management Facilities)requirements. The top of the slope or overlap it into existing vegetation. Part 360 requirements are equal to or more stringent than 40 CFR Part 503 which ensure safe standards for 5. Follow by seeding or ornamental planting as specified. pathogen reduction and heavy metal content. When 6. When planting immediate grass,wildflower,or legume using compost blankets adjacent to surface waters,the seeding or ornamental planting,use only a well compost should have a low nutrient value. composted product that contains no substances toxic to plants. New York State Standards and Specifications Page 4.37 November 2016 For Erosion and Sediment Control 7. Very coarse composts should be avoided if the slope is should be in accordance with manufacturers to be landscaped or seeded,as it will make planting and recommendations. crop establishment more difficult. Composts containing fibrous particles that range in size produce a Construction Specifications more stable mat. BFMs,FGMs and PSFMs are typically applied in two Hydraulically Applied Blankets stages. Unless specifically recommended to be applied in one application by the manufacturer,the seed mixture and These blankets are formed by mixing different types of soil amendments should be applied first. If the seed is materials with water and are then applied using standard applied at the same time as the hydraulically applied hydroseeding equipment. These blankets should not be blankets,the bonded fibers may keep the seed from making used in areas of concentrated flow such as ditches and sufficient contact with the soil to germinate. After the seed channels. mixture is applied,the hydraulically applied blankets should be sprayed over the area at the required application rate, A. Bonded Fiber Matrix(BFM)-This method makes use according to the manufactures recommendations. of a cross-linked hydrocolloid tackifier to bond thermally processed wood fibers. Application rates vary according to site conditions. For slopes up to 3H:1 V the BFM should be applied at a rate of 3,000 lb/ acre. Steeper slopes may need as much as 4,000 lb/ acre in accordance with the manufacturer's recommendations. BFMs should only be used when no rain is forecast for at least 48 hours following the application. This is to allow the tackifier sufficient time to cure properly. Once properly applied,a BFM is very effective in preventing accelerated erosion. Bonded Fiber Matrix should not be applied between September 30 and April 1 to allow for proper curing of the polymer. B. Flexible Growth Medium(FGM)- This method has the added component of 1/2 inch long,crimped manmade fibers which add a mechanical bond to the chemical bond provided by BFMs. This increases the blanket's resistance to both raindrop impact and erosion due to runoff. Unlike BFMs,a flexible growth medium typically does not require a curing time to be effective. Properly applied,an FGM is also very effective. There is no need to smooth the slope prior to application. In fact some roughening of the surface (either natural or mechanically induced)is preferable. However,large rocks(>9 inches)and existing rills should be removed prior to application. Mixing and application rates should follow manufacturer's recommendations. C. Polymer Stabilized Fiber Matrix(PSFM)-PSFMs make use of a linear soil stabilization tackifier that works directly on soil to maintain soil structure, maintain pore space capacity and flocculate dislodged sediment that will significantly reduce runoff turbidity. PSFMs can be used in re-vegetation applications and for site winterization and/or dormant seeding-fall planting for spring germination-applications. Application rates vary according to site conditions and November 2016 Page 4.38 New York State Standards and Specifications For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR MULCHING :. Remove all undesirable stones and other debris to meet the needs of the anticipated land use and maintenance required. Apply mulch after soil amendments and planting is accomplished or simultaneously if hydroseeding is used. Select appropriate mulch material and application rate or material needs. Hay mulch shall not be used in wetlands or in areas of permanent seeding. Clean straw mulch is preferred alternative in wetland application. Determine local availability. Definition and Scope Select appropriate mulch anchoring material. Applying coarse plant residue or chips,or other suitable NOTE: The best combination for grass/legume materials,to cover the soil surface to provide initial erosion establishment is straw(cereal grain)mulch applied at 2 ton/ control while a seeding or shrub planting is establishing. acre(90 lbs./1000sq.ft.)and anchored with wood fiber Mulch will conserve moisture and modify the surface soil mulch(hydromulch)at 500—750 lbs./acre(11—17 temperature and reduce fluctuation of both. Mulch will lbs./1000 sq.ft.). The wood fiber mulch must be applied prevent soil surface crusting and aid in weed control.Mulch through a hydroseeder immediately after mulching. can also be used alone for temporary stabilization in non- growing months. Use of stone as a mulch could be more permanent and should not be limited to non-growing months. Conditions Where Practice Applies On soils subject to erosion and on new seedings and shrub plantings. Mulch is useful on soils with low infiltration r rates by retarding runoff. y Criteria Site preparation prior to mulching requires the installation of necessary erosion control or water management practices and drainage systems. �- - Slope,grade and smooth the site to fit needs of selected mulch products. New York State Standards and Specifications Page 4.39 November 2016 For Erosion and Sediment Control z 0 CD a Mulch Material Standards CD per 1000 Sq.Ft. per Acre Application Remarks N pp 0 c� Wood chips or Air-dried. Free of 500-900 lbs. 10-20 tons 2-7" Used primarily around shrub and tree shavings objectionable coarse plantings and recreation trails to inhibit material weed competition. Resistant to wind blowing.Decomposes slowly. Wood fiber cellulose Made from natural wood 50 lbs. 2,000 lbs. — Apply with hydromulcher. No tie down . (partly digested usually with green dye required. Less erosion control provided wood fibers) and dispersing agent than 2 tons of hay or straw. Gravel,Crushed Washed; Size 2B or 9 cu.yds. 405 cu.yds. 3" Excellent mulch for short slopes and Stone or Slag 3A-1 1/2" around plants and ornamentals. Use 2B where subject to traffic. (Approximately 2,000 lbs./cu.yd.). Frequently used over n filter fabric for better weed control. Hay or Straw Air-dried; free of 90-100 lbs.2-3 bales 2 tons(100- cover about 90% Use small grain straw where mulch is b undesirable seeds& 120 bales) surface maintained for more than three months. CD coarse materials Subject to wind blowing unless anchored. �� p Most commonly used mulching material. �• Provides the best micro-environment for N germinating seeds. Jute twisted yarn Undyed,unbleached 48"x 50 yds.or 48" Use without additional mulch. Tie down z plain weave. Warp 78 x 75 yds. as per manufacturers specifications. ends/yd.,Weft 41 ends/ Good for center line of concentrated yd.60-90 lbs./roll water flow. x Excelsior wood fiber Interlocking web of 4'x 112.5' or 8' x Use without additional mulch. Excellent omats excelsior fibers with 112.5'. for seeding establishment. Anchor as per o photodegradable plastic manufacturers specifications. netting Approximately 72 lbs./roll for excelsior with plastic on both sides. Use two sided plastic for centerline of waterways. Straw or coconut Photodegradable plastic Most are 6.5 ft.x 3.5 81 rolls — Designed to tolerate higher velocity water fiber,or net on one or two sides ft. flow,centerlines of waterways, 60 sq. combination yds.per roll. n � o w o � Table 4.3 Mulch Anchoring Guide Anchoring Method Kind of Mulch to or Material be Anchored How to Apply After mulching,divide areas into blocks approximately 1 sq. yd.in size. Drive 4-6 pegs per block to within 2"to 3"of soil 1. Peg and Twine Hay or straw surface. Secure mulch to surface by stretching twine between pegs in criss-cross pattern on each block. Secure twine around each peg with 2 or more tight turns. Drive pegs flush with soil. Driving stakes into ground tightens the twine. Staple the light-weight paper,jute,wood fiber,or plastic 2. Mulch netting Hay or straw nettings to soil surface according to manufacturer's recommendations. Should be biodegradable. Most products are not suitable for foot traffic. Apply with hydroseeder immediately after mulching. Use 500 3. Wood cellulose fiber Hay or straw lbs.wood fiber per acre. Some products contain an adhesive material("tackifier"),possibly advantageous. Apply mulch and pull a mulch anchoring tool(blunt,straight 4. Mulch anchoring tool Hay or straw discs)over mulch as near to the contour as possible. Mulch material should be"tucked"into soil surface about 3". Mix and apply polymeric and gum tackifiers according to 5. Tackifier Hay or straw manufacturer's instructions. Avoid application during rain.oA 24-hour curing period and a soil temperature higher than 45 Fahrenheit are required. New York State Standards and Specifications Page 4.41 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR PERMANENT CONSTRUCTION AREA PLANTING ..y ground agricultural limestone to attain a pH of 6.0 in the r. upper 2 inches of soil. If soil must be fertilized before results of a soil test can be obtained to determine fertilizer -� needs,apply commercial fertilizer at 600 lbs.per acre of 5-5 -10 or equivalent. If manure is used,apply a quantity to meet the nutrients of the above fertilizer. This requires an appropriate manure analysis prior to applying to the site. Do not use manure on sites to be planted with birdsfoot - e trefoil or in the path of concentrated water flow. Seed mixtures may vary depending on location within the state and time of seeding. Generally,warm season grasses should only be seeded during early spring,April to May. These grasses are primarily used for vegetating excessively drained sands and gravels. See Standard and Specification Definition & Scope for Sand and Gravel Mine Reclamation. Other grasses may be seeded any time of the year when the soil is not frozen Establishing permanent grasses with other forbs and/or and is workable. When legumes such as birdsfoot trefoil shrubs to provide a minimum 80%perennial vegetative are included, spring seeding is preferred. See Table 4.4, cover on areas disturbed by construction and critical areas "Permanent Construction Area Planting Mixture to reduce erosion and sediment transport. Critical areas Recommendations"for additional seed mixtures. may include but are not limited to steep excavated cut or fill slopes as well as eroding or denuded natural slopes and areas subject to erosion. General Seed Mix: lbs./ Ibs/1000 Variety acre sq.ft. Conditions Where Practice Applies Red Clover' OR Acclaim,Rally, 8� 0.20 This practice applies to all disturbed areas void of,or Red Head II, having insufficient,cover to prevent erosion and sediment Renegade transport. See additional standards for special situations Common white clover' Common 8 0.20 such as sand dunes and sand and gravel pits. PLUS Criteria Creeping Red Fescue Coimnon 20 0.45 All water control measures will be installed as needed prior PLUS to final grading and seedbed preparation. Any severely Smooth Bromegrass 2 0.05 compacted sections will require chiseling or disking to OR Common provide an adequate rooting zone,to a minimum depth of 12",see Soil Restoration Standard. The seedbed must be Ryegrass(perennial) Pennfine/Linn 5 0.10 prepared to allow good soil to seed contact,with the soil not 1 too soft and not too compact. Adequate soil moisture must add inoculant immediately prior to seeding z be present to accomplish this. If surface is powder dry or be 41bs each of Empire and Pardee OR 41bs of sticky wet,postpone operations until moisture changes to a Birdsfoot and 4 Ibs white clover per acre. All seeding rates favorable condition. If seeding is accomplished within 24 1 are given for Pure Live Seed(PLS) hours of final grading,additional scarification is generally not needed,especially on ditch or stream banks. Remove Pure Live Seed,or(PLS)refers to the amount of live seed all stones and other debris from the surface that are greater in a lot of bulk seed. Information on the seed bag label than 4 inches,or that will interfere with future mowing or includes the type of seed,supplier,test date,source of seed, maintenance. purity,and germination. Purity is the percentage of pure Soil amendments should be incorporated into the upper 2 seed. Germination is the percentage of pure seed that will inches of soil when feasible. The soil should be tested to produce normal plants when planted under favorable determine the amounts of amendments needed. Apply conditions. November 2016 Page 4.42 New York State Standards and Specifications For Erosion and Sediment Control To compute Pure Live Seed multiply the"germination percent"times the"purity"and divide that by 100 to get Pure Live Seed. PureI weSeedms)=%Gamfinam X%Purity 100 For example,the PLS for a lot of Kentucky Blue grass with 75%purity and 96%germination would be calculated as follows: (96)x(75)=72%Pure Live Seed 100 For 1 Olbs of PLS from this lot= 10=13 9ft 80%Perennial Vegetative Cover 0.72 Therefore, 13.9 lbs of seed is the actual weight needed to meet IOlbs PSL from this specific seed lot. Time of Seeding: The optimum timing for the general seed mixture is early spring. Permanent seedings may be made any time of year if properly mulched and adequate moisture is provided. Late June through early August is not a good time to seed,but may facilitate covering the land without additional disturbance if construction is completed. Portions of the seeding may fail due to drought and heat. These areas may need reseeding in late summer/fall or the following spring. Method of seeding: Broadcasting,drilling,cultipack type seeding,or hydroseeding are acceptable methods. Proper soil to seed contact is key to successful seedings. Mulching: Mulching is essential to obtain a uniform stand of seeded plants. Optimum benefits of mulching new seedings are obtained with the use of small grain straw 50%Pereninial Vegetative Cover applied at a rate of 2 tons per acre,and anchored with a netting or tackifier. See the Standard and Specifications for Mulching for choices and requirements. Irrigation: Watering may be essential to establish a new seeding when a drought condition occurs shortly after a new seeding emerges. Irrigation is a specialized practice and care must be taken not to exceed the application rate for the soil or subsoil. When disconnecting irrigation pipe,be sure pipes are drained in a safe manor,not creating an erosion concern. New York State Standards and Specifications Page 4.43 November 2016 For Erosion and Sediment Control Table 4.4 Permanent Construction Area Planting Mixture Recommendations Rate in lbs./acre Rate in lbs./ Seed Mixture Variety (PLS) 1,000 ft, Mix#1 Creeping red fescue Ensylva,Pennlawn,Boreal 10 .25 Perennial ryegrass Pennfine,Linn 10 .25 *This mix is used extensively for shaded areas. Mix#2 Switchgrass Shelter,Pathfinder,Trailblazer,or Blackwell 20 .50 *This rate is in pure live seed,this would be an excellent choice along the upland edge of a wetland to filter runoff and pro- vide wildlife benefits. In areas where erosion may be a problem,a companion seeding of sand lovegrass should be added to provide quick cover at a rate of 2 lbs.per acre(0.05 lbs.per 1000 sq.ft.). Mix#3 Switchgrass Shelter,Pathfinder,Trailblazer,or Blackwell 4 .10 Big bluestem Niagara 4 .10 Little bluestem Aldous or Camper 2 .05 Indiangrass Rumsey 4 .10 Coastal pamcgmss Atlantic 2 .05 Sideoats grama El Reno or Trailway 2 .05 Wildflower mix .50 .01 *This mix has been successful on sand and gravel plantings. It is very difficult to seed without a warm season grass seeder such as a Truax seed drill. Broadcasting this seed is very difficult due to the fluffy nature of some of the seed,such as bluestems and indiangrass. Mix#4 Switchgrass Shelter,Pathfinder,Trailblazer,or Blackwell 10 .25 Coastal panicgrass Atlantic 10 .25 *This mix is salt tolerant,a good choice along the upland edge of tidal areas and roadsides. Mix#5 Saltmeadow cordgrass(Spartina patens)--This grass is used for tidal shoreline protection and tidal marsh restoration. It is planted by vegetative stem divisions. 'Cape'American beachgrass can be planted for sand dune stabilization above the saltmeadow cordgrass zone. Mix#6 Creeping red fescue Ensylva,Pennlawn,Boreal 20 .45 Chewings Fescue Common 20 .45 Perennial ryegrass Pennfine,Linn 5 .10 Red Clover Common 10 .45 *General purpose erosion control mix. Not to be used for a turf planting or play grounds. November 2016 Page 4.44 New York State Standards and Specifications For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR RECREATION AREA SEEDING D. Lime to a pH of 6.5. See Lime Application Standard. E. Fertilize as per soil test or,if soil must be fertilized before results of a soil test can be obtained to determine fertilizer needs,apply commercial fertilizer at 850 pounds of 5-5-10 or equivalent per acre(20 lbs/1,000 sq.ft.). See Fertilizer Application Standard. F. Incorporate lime and fertilizer in top 2-4 inches of topsoil. - G. Smooth. Remove sticks,foreign matter,and stones over 1 inch in diameter,from the surface. Firm the Definition & Scope seedbed. Establishing pennanent grasses,legumes,vines,shrubs, 3. Planting trees,or other plants,or selectively reducing stand density and trimming woody plants,to improve an area for Use a cultipacker type seeder if possible. Seed to a depth of recreation. To increase the attractiveness and usefulness of 1/8 to 1/4 inch. If seed is to be broadcast,cultipack or roll recreation areas and to protect the soil and plant resources. after seeding. If hyroseeded,lime and fertilizer may be applied through the seeder,and rolling is not practical. Conditions Where Practice Applies 4. Mulching On any area planned for recreation use,lawns,and areas that will be maintained in a closely mowed condition. Mulch all seedings in accordance with Standard and Specifications for Mulching. Small grain straw is the best Specifications material. ESTABLISHING GRASSES(Turfgrass) 5. Seed Mixtures Select seed mixture for site conditions and intended use The following applies for playgrounds,parks,athletic from Table 4.5. fields,camping areas,picnic areas,passive recreation areas such as lawns,and similar areas. 6. Contact Cornell Cooperative Extension Turf Specialist 1. Time of Planting for suitable varieties. Fall planting is preferred. Seed after August 15. In the Turf-type tall fescues have replaced the old KY31 tall spring,plant until May 15. fescues. New varieties have finer leaves and are the most resistant grass to foot traffic. Do not mix it with fine If seeding is done between May 15 and August 15, textured grasses such as bluegrass and red fescue. irrigation may be necessary to ensure a successful seeding. Common ryegrass and redtop,which are relatively short 2. Site Preparation lived species,provide quick green cover. Improved lawn cultivars of perennial ryegrass provide excellent quality A. Install needed water and erosion control measures turf,but continue to lack winter hardiness. and bring area to be seeded to desired grades. A minimum of 4 in.topsoil is required. Common white clover can be added to mixtures at the rate of 1-21bs/acre to help maintain green color during the dry B. Prepare seedbed by loosening soil to a depth of 4-6 summer period;however,they will not withstand heavy inches and decompacting required areas per Soil traffic. Avoid using around swimming areas as flowers Restoration Standard. attract bees which can be easily stepped on. C. See Standard and Specification of Topsoiling. New York State Standards and Specifications Page 4.45 November 2016 For Erosion and Sediment Control Table 4.5 Recreation Turfgrass Seed Mixture Site-Use Species(%by weight) lbs/1.000 ft2 lbs/acre (PLS) (PLS) Athletic fields and similar areas 80%Hard fescue 2.4-3.2 105-138 20%Perennial ryegrass 0.6-0.8 25-37 3.0-4.0 130-175 OR,for southern and eastern,NY 50%Hard fescue 1.5-2.0 65-88 Sunny Sites 50%perennial ryegrass 1.5-2.0 65-87 3.0-4.0 130-175 (well,moderately well,and somewhat poorly drained OR, 100%Creeping Red Fescue 3.4-4.6 150-200 soils) General recreation areas and lawns(Medium to high maintenance) 65%Creeping red fescue 2.0-2.6 85-114 20%Perennial ryegrass 0.6-0.8 26-35 15%Fine fescue 0.4-0.6 19-26 3.0-4.0 130-175 OR, 100%Creeping red fescue 3.4-4.6 150-200 Sunny Droughty Sites 65%Fine fescue 2.6-3.3 114-143 (general recreation areas and 15%Perennial ryegrass 0.6-0.7 26-33 lawns,low maintenance) 20%Creeping red fescue 0.8-1.0 35-44 (somewhat excessively to excessively drained soils, 4.0-5.0 175-220 excluding Long Island) OR, 100%Creeping red fescue 3.4-4.6 150-200 65%fine fescue 2.6-3.3 114-143 15%perennial ryegrass 0.6-0.7 26-33 20%Creeping red fescue 0.8-1.0 35-44 Shady Dry Sites OR 4.0-5.0 174-220 (well to somewhat poorly 80%blend of shade-tolerant Ceral rye 2.4-3.2 105-138 drained soils) 20%perennial ryegrass 0.6-0.8 25-37 OR 3.0-4.0 130-175 100%Creeping red fescue 3.4-4.6 150-200 70%Creeping red fescue 1.4-2.1 60-91 Shady Wet Sites 30%blend of shade-tolerant Hard fescue 0.6-0.9 25-39 (somewhat poor to poorly OR 2.0-3.0 85-130 drained soils) 100%Chewings fescue 3.4-4.6 150-200 For varieties suitable for specific locations,contact Cornell Cooperative Extension Turf Specialist. Reference: Thum,M.C.,N.W.Hummel,and A.M.Petrovic. Cornell Extension Pub.Info. Bulletin 185 Revised. HomeLawns Establishment and Maintenance. 1994. November 2016 Page 4.46 New York State Standards and Specifications For Erosion and Sediment Control 7. Fertilizing—First Year Apply fertilizer as indicated by the soil test three to four weeks after germination(spring seedlings). If test results have not been obtained,apply 1 pound nitrogen/1,000 square feet using a complete fertilizer with a 2-1-1 or 4-1-3 ratio. Summer and early fall seedings,apply as above unless air temperatures are above 85°F for an extended period. Wait for cooler temperatures to fertilize. Late fall/ winter seedings,fertilize in spring. 8. Restrict Use New seedlings should be protected from use for one full year or a spring and fall growth cycle where possible to allow development of a dense sod with good root structure. MAINTAINING GRASSES 1. Maintain a pH of 6.0-7.0. 2. Fertilize in late May to early June as follows with 5-5- 10 analysis fertilizer at the rate of 5 lbs./1,000 sq.ft. and repeat in late August if sod density is not adequate. Avoid fertilizing when heat is greater than 85°F. Top dress weak sod annually in the spring,but at least once every 2 to 3 years. Fertilize in accordance with soil test analysis,after determining adequate topsoil depth exists. 3. Aerate compacted or heavily used areas,like athletic fields,annually as soon as soil moisture conditions permit. Aerate area six to eight times using a spoon or hollow tine type aerator. Do not use solid spike equipment. 4. Reseed bare and thin areas annually with original seed mix. New York State Standards and Specifications Page 4.47 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR RETAINING WALLS k other methods may be used to meet factor requirements. Sliding—A minimum factor of 2.0 should be maintained �v. against sliding. This factor can be reduced to 1.5 when passive pressures on the front of the wall are ignored. Overturning—A minimum factor of safety of 1.5 should be used as the ratio of the resisting moment(that which tends to keep the wall in place)to the overturning moment. atiP �: l�" A Drainage—Unless adequate provisions are made to control both surface and groundwater behind the retaining wall,a substantial increase in active pressures tending to slide or overturn the wall will result. When backfill is sloped down to a retaining wall,surface drainage should be provided. Drainage systems with adequate outlets should be provided behind retaining walls that are placed in cohesive soils. Definition & Scope Drains should be graded or protected by filters so soil material will not move through the drainfill. A pennanent structural wall constructed and located to Load systems—Several different loads or combination of prevent soil movement by retaining soil in place and loads need to be considered when designing a retaining preventing slope failures and movement of material down wall. The minimum load is the level backfill that the wall is steep slopes. being constructed to retain. Its unit weight will vary Conditions Where Practice Applies depending on its composition. Additional loads such as line loads,surcharge loads,or A retaining wall may be used where site constraints will not slope fills,will add to make the composite design load allow slope shaping and seeding to stabilize an area. Slope system for the wall. areas that demonstrate seepage problems or experience erosive conditions at the toe can utilize retaining walls to Construction Specifications help stabilize these areas. Retaining walls can be built from mortared block or stone,cast-in-place concrete,railroad Concrete Walls ties,gabions,and more recently,precast concrete modular units and segmented walls that form a gravity retaining wall 1. Foundation will be prepared by excavating to the lines (see Figure 4.16 and 4.17). These precast units allow for and grades shown on the drawings and removing all ease and quickness of installation while their granular objectionable material. backfill provides drainage. Selection of materials and type of wall should be based on hazard potential,load 2. Subgrade will be compacted and kept moist at least 2 conditions,soil parameters,groundwater conditions,site hours prior to placement of concrete. constraints,and aesthetics. 3. Steel reinforcing will be in accordance with the Design Criteria schedule on the drawings and kept free of rust,scale,or dirt. The design of any retaining wall structure must address the 4. Exposed edges will be chamfered 3/4 inches. aspects of foundation bearing capacity,sliding,overturning, drainage and loading systems. These are complex systems 5. Drainfill will meet the gradations shown on the that should be designed by a licensed professional drawings. engineer. Bearing Capacity—A minimum factor of safety of 1.5 should be maintained as the ratio of the ultimate bearing capacity to the designed unit loading. Spread footers and November 2016 Page 4.48 New York State Standards and Specifications For Erosion and Sediment Control 6. Weep holes will be provided as drain outlets as shown Gabions on the drawings. 1. Foundation will be prepared by excavating to the lines and grades shown on the drawings. 2. Subgrade will be compacted and leveled to receive first layer of gabions. The first row will be keyed into the existing grade at the toe,a minimum of 1.5 feet. 3. Gabions will be placed according to the manufacturers recommendations. 4. Gabions will be filled with stone or crushed rock from 4 to 8 inches in diameter. 7. Concrete will be poured and cured in accordance with American Concrete Institute(ACI)specifications. Precast Units 1. Foundation will be prepared by excavating to the lines and grades shown on the drawings. 2. Subgrade will be compacted and trimmed to receive the leveling beam. 3. Precast units will be placed in accordance with the Non-Mortared Stone Walls manufacturers recommendation. 1. Foundation will be prepared by excavating to the lines 4. Granular fill placed in the precast bins shall be placed and grade shown on the drawings. in 3-foot lifts,leveled off and compacted with a plate vibrator. 2. Subgrade will be compacted and leveled to receive monolithic stone. First row will be placed 1.0 feet Segmented Walls below design toe elevation. 1. Foundation will be prepared by excavating to the lines 3. Stone will be placed horizontally with long dimension and grades shown on the drawings. parallel to face of wall except at return ends. 2. Sub-grade will be compacted and screeded to form the 4. Maximum of 3 lifts of stone each approximately 2' base for the first course of wall units. thick without pinning. Where stones do not fit in good ontact,pinning with two steel#8 re-bar dowels is 3. Units will be placed in accordance with the required. manufacturers recommendations,with each succeeding lift anchored and pinned as specified. 5. Backside of stone will be filled with a minimum of 2' of#1 and#2 stone between filter fabric against parent 4. Granular fill will be placed behind the segmented wall soil and rock to provide drainage. to provide drainage. It shall be compacted with a plate vibrator. A drainage outlet will be provided as specified on the construction drawings. New York State Standards and Specifications Page 4.49 November 2016 For Erosion and Sediment Control Figure 4.16 Typical Retaining Wall Examples (Schematic only - not to be used for design) 4 T {f V +. Y + V _ r'O r•I dr e � i 4P MMA"A� r r•$. Cost 1n plane C&ncrexe Fk.1 d'P0-.0MDn . + xw■ Ij11 C�3#R'��a 'Liwsn =C t M1 �� r VB Lars■ 04 pLa'a[i9 ! itP#iM11 �itiD�orb& 11110t it OAL Gad,l Ong November 2016 Page 4.50 New York State Standards and Specifications For Erosion and Sediment Control Figure 4.17 Typical Segmented Retaining Wall Example (Schematic only - not to be used for design) YMELL 1421IMPERVI❑US FILL APPROXIMATE E.XCAVATIG-M DRAINAGE AGGREGATE WTHI�K IT WA N PIPE BACKF ILL �P If}RAP f E❑TEXTILE FILTER RII REQUIRED)D _ F ABR f C (OVERUAP " f GEDGR I D 1 'MIM.> DRAIN Ply r (A$ REWIRED) -- RETAINED SOIL GE❑TEXTILE t _ GEt `1D <CDNSL .T WITH FILTERr�': r;z _ ' FNGINEER F'OR TIESI'GN) #6 .+ 1E, TI4I1�K I-EVELIN15 PAD WITH GEOGRID REINFORCEMENT ADAPTED FROH DETAI S PFMVIdED BY- USdik — NRCS, TYPICAL �y NEWY13RK STATE EEPARTHENT DF' TRANSIRGRTATION, {_GMENTED NEW Y$IRIG STATE DEPARTNENT 13F ENVIRONMENTAL C4NSERVATT❑N. NEV 'ORK SATE Sa[L & SEATER CONSERVATION COMMETTEE RE 1 A r NING ' AI I New York State Standards and Specifications Page 4.51 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR SOIL RESTORATION 2. Soil restoration will be completed in accordance with " Table 4.6 on page 4.53. Specification for Full Soil Restoration '",��"� �,'� During periods of relatively low to moderate subsoil moisture,the disturbed subsoils are returned to rough grade and the following Soil Restoration steps applied: 'E r 1. Apply 3 inches of compost over subsoil. The compost '` "•; __ ?+_ i _ shall be well decomposed(matured at least 3 months), weed-free,organic matter. It shall be aerobically composted,possess no objectionable odors,and contain less than 1%,by dry weight,of man-made foreign Fiery - matter. The physical parameters of the compost shall Definition & Scope meet the standards listed in Table 5.2-Compost Standards Table,except for"Particle Size" 100%will The decompaction of areas of a development site or pass the 1/2"sieve. Note:All biosolids compost construction project where soils have been disturbed to produced in New York State(or approved for recover the original properties and porosity of the soil;thus importation)must meet NYS DEC's 6 NYCRR Part providing a sustainable growth medium for vegetation, 360(Solid Waste Management Facilities) reduction of runoff and filtering of pollutants from requirements. The Part 360 requirements are equal stormwater runoff. to or more stringent than 40 CFR Part 503 which ensure safe standards for pathogen reduction and Conditions Where Practice Applies heavy metals content. Soil restoration is to be applied to areas whose heavy construction traffic is done and final stabilization is to - begin. This is generally applied in the cleanup,site , y restoration,and landscaping phase of construction followed by the permanent establishment of an appropriate ground cover to maintain the soil structure. Soil restoration measures should be applied over and adjacent to any runoff reduction practices to achieve design performance. _ F' 2. Till compost into subsoil to a depth of at least 12 inches using a cat-mounted ripper,tractor mounted disc,or tiller,to mix and circulate air and compost into the subsoil. 3. Rock-pick until uplifted stone/rock materials of four inches and larger size are cleaned off the site. 4. Apply topsoil to a depth of 6 inches. 5. Vegetate as required by the seeding plan. Use Design Criteria appropriate ground cover with deep roots to maintain the soil structure. 1. Soil restoration areas will be designated on the plan views of areas to be disturbed. 6. Topsoil may be manufactured as a mixture or a mineral component and organic material such as compost. November 2016 Page 4.52 New York State Standards and Specifications For Erosion and Sediment Control At the end of the project an inspector should be able to push a 3/8"metal bar 12 inches into the soil just with body weight. This should not be performed within the drip line of any existing trees or over utility installations that are within 24 inches of the surface. Maintenance Keep the site free of vehicular and foot traffic or other weight loads. Consider pedestrian footpaths. Table 4.6 Soil Restoration Requirements Type of Soil Disturbance Soil Restoration Requirement Comments/Examples No soil disturbance Restoration not permitted Preservation of Natural Features Minimal soil disturbance Restoration not required Clearing and grubbing HSG A&B HSG C&D Areas where topsoil is stripped only-no Protect area from any ongoing construc- change in grade Apply 6 inches of Aerate* and apply tion activities. topsoil 6 inches of topsoil HSG A&B HSG C&D Areas of cut or fill Aerate* and apply Apply full Soil 6 inches of topsoil Restoration** Heavy traffic areas on site(especially in Apply full Soil Restoration a zone 5-25 feet around buildings but (decompaction and compost enhance- not within a 5 foot perimeter around foundation walls) ment) Keep construction equipment from Areas where Runoff Reduction and/or Restoration not required,but may be crossing these areas. To protect newly Infiltration practices are applied applied to enhance the reduction speci- installed practice from any ongoing fied for appropriate practices. construction activities construct a single phase operation fence area Soil Restoration is required on redevel- Redevelopment projects opment projects in areas where existing impervious area will be converted to pervious area. *Aeration includes the use of machines such as tractor-drawn implements with coulters making a narrow slit in the soil,a roller with many spikes making indentations in the soil,or prongs which function like a mini-subsoiler. **Per"Deep Ripping and De-compaction,DEC 2008". New York State Standards and Specifications Page 4.53 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR STABILIZATION WITH SOD moisture content(excessively dry or wet)may adversely affect its survival. 6. Sod shall be harvested,delivered,and installed within a ` period of 36 hours. Sod not transplanted within this period shall be inspected and approved by the contracting officer or his designated representative prior to its installation. Site Preparation Fertilizer and lime application rates shall be determined by = soil tests. Under unusual circumstances where there is insufficient time for a complete soil test and the contracting Definition & Scope officer agrees,fertilizer and lime materials may be applied in amounts shown in subsection 2 below. Slope land such Stabilizing restored,exposed soil surfaces by establishing as to provide good surface water drainage. Avoid long term stands of grass with sod to reduce damage from depressions or pockets. sediment and runoff to downstream areas and enhance natural beauty. 1. Prior to sodding,the surface shall be smoothed and cleared of all trash,debris,and of all roots,brush,wire, Conditions Where Practice Applies grade stakes and other objects that would interfere with planting,fertilizing or maintenance operations. On exposed soils that have a potential for causing off site 2. The soil should be tested to determine the amounts environmental damage where a quick vegetative cover is of amendments needed. Where the soil is acid or desired. Moisture,either applied or natural,is essential to composed of heavy clays,ground limestone shall be success. spread to raise the pH to 6.5. If the soil must be fertilized before results of a soil test can be obtained to Design Criteria determine fertilizer needs,apply commercial fertilizer at 20 lbs.of 5-5-10(or equivalent)and mix into the top 1. Sod shall be bluegrass or a bluegrass/red fescue 3 inches of soil with the required lime for every 1,000 mixture or a perennial ryegrass for average sites. square feet. Soil should be moist prior to sodding. (CAUTION: Perennial ryegrass has limited cold Arrange for temporary storage of sod to keep it shaded tolerance and may winter kill.) Use turf type cultivars and cool. of tall fescue for shady,droughty,or otherwise more critical areas. For variety selection,contact Cornell Sod Installation Cooperative Extension Turf Specialist. 1. For the operation of laying,tamping,and irrigating for 2. Sod shall be machine cut at a uniform soil thickness of any areas,sod shall be completed within eight hours. 3/4 inch,plus or minus 1/4 inch. Measurement for During periods of excessively high temperature,the thickness shall exclude top growth and thatch. soil shall be lightly moistened immediately prior to laying the sod. 3. Standard size sections of sod shall be strong enough to support their own weight and retain their size and shape 2. The first row of sod shall be laid in a straight line with when suspended vertically from a firm grasp on the subsequent rows placed parallel to,and tightly wedged upper 10 percent of the section. against,each other. Lateral joints shall be staggered to promote more uniform growth and strength. Ensure 4. Sod shall be free of weeds and undesirable coarse that sod is not stretched or overlapped and that all weedy grasses. Wild native or pasture grass sod shall joints are butted tight in order to prevent voids which not be used unless specified. would cause air drying of the roots. On sloping areas where erosion may be a problem,sod shall be laid with 5. Sod shall not be harvested or transplanted when the long edges parallel to the contour and with November 2016 Page 4.54 New York State Standards and Specifications For Erosion and Sediment Control staggered joints. 3. Secure the sod by tamping and pegging,or other approved methods. As sodding is completed in any one section,the entire area shall be rolled or tamped to ensure solid contact of mots with the soil surface. 4. Sod shall be watered immediately after rolling or tamping until the underside of the new sod pad and soil surface below the sod are thoroughly wet. Keep sod moist for at least two weeks. Sod Maintenance 1. In the absence of adequate rainfall,watering shall be performed daily,or as often as deemed necessary by the inspector,during the first week and in sufficient quantities to maintain moist soil to a depth of 4 inches. Watering should be done in the morning. Avoid excessive watering during applications. 2. After the first week,sod shall be watered as necessary to maintain adequate moisture and ensure establishment. 3. The first mowing should not be attempted until sod is firmly rooted. No more than 1/3 of the grass leaf shall be removed by the initial cutting or subsequent cuttings. Grass height shall be maintained between 2 and 3 inches unless otherwise specified. Avoid heavy mowing equipment for several weeks to prevent rutting. 4. If the soil must be fertilized before results of a soil test can be obtained to determine fertilizer needs,apply fertilizer three to four weeks after sodding,at a rate of 1 pound nitrogen/1,000 sq.ft. Use a complete fertilizer with a 2-1-1 ratio. 5. Weed Control: Target herbicides for weeds present. Consult current Cornell Pest Control Recommendations for Commercial Turfgrass Management or consult the local office of Cornell Cooperative Extension. 6. Disease Control: Consult the local office of the Cornell Cooperative Extension. Additional References 1. Home Lawns,Establishment and Maintenance,CCE Information Bulletin 185,Revised November 1994. Cornell University,Ithaca,NY. 2. Installing a Sod Lawn. CCE Suffolk County,NY. Thomas Kowalsick February 1994,Revised January 1999. www.cce.comell.edu/counties/suffolk/grownet New York State Standards and Specifications Page 4.55 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR SURFACE ROUGHENING C. Make the vertical cut distance less than the horizontal distance,and slightly slope the horizontal position of the"step"to the vertical wall. D. Do not make vertical cuts more than 2 feet in soft materials or 3 feet in rocky materials. Grooving uses machinery to create a series of ridges and depressions that run perpendicular to the slope following the contour. Groove using any appropriate implement that can be safely operated on the slope,such as disks,tillers, spring harrows,or the teeth of a front-end loader bucket. Do not make the grooves less than 3 inches deep or more than 15 inches apart. Definition & Scope 2. Fill Slope. No mowing Roughening a bare soil surface whether through creating horizontal grooves across a slope,stair-stepping,or tracking A. Place fill to create slopes with a gradient no steeper with construction equipment to aid the establishment of than 2:1 in lifts 9 inches or less and properly vegetative cover from seed,to reduce runoff velocity and compacted. Ensure the face of the slope consists increase infiltration,and to reduce erosion and provide for of loose,uncompacted fill 4 to 6 inches deep. Use trapping of sediment. grooving as described above to roughen the slope, if necessary. Conditions Where Practice Applies B. Do not back blade or scrape the final slope face. All construction slopes require surface roughening to facilitate stabilization with vegetation,particularly slopes 3. Cuts/Fills, Mowed Maintenance steeper than 3:1. A. Make mowed slopes no steeper than 3:1. Design Criteria B. Roughen these areas to shallow grooves by normal There are many different methods to achieve a roughened tilling,disking,harrowing,or use of cultipacker- soil surface on a slope. No specific design criteria is seeder. Make the final pass of such tillage required. However,the selection of the appropriate method equipment on the contour. depends on the type of slope. Methods include tracking, C. Make grooves at least 1 inch deep and a maximum grooving,and stair-stepping. Steepness,mowing of 10 inches apart. requirements,and/or a cut or fill slope operation are all factors considered in choosing a roughening method. D. Excessive roughness is undesirable where mowing is planned. Construction Specifications Tracking should be used primarily in sandy soils to avoid 1. Cut Slope. No mowing undue compaction of the soil surface. Tracking is generally not as effective as the other roughening methods described. A. Stair-step grade or groove cut slopes with a (It has been used as a method to track down mulch.) gradient steeper than 3:1 (Figure 4.18). Operate tracked machinery up and down the slope to leave horizontal depressions in the soil. Do not back-blade during B. Use stair-step grading on any erodible material soft the final grading operation. enough to be ripped with a bulldozer. Slopes of soft rock with some soil are particularly suited to stair-step grading. November 2016 Page 4.56 New York State Standards and Specifications For Erosion and Sediment Control Figure 4.18 Surface Roughening DEBRIS FROM SLIGPE ABOVE IS CAUGHT BY STEPS DRAINAGE �� 2-3' ,DEPENDING ON rM1ATERIA0 M.FE —j I l ii II! GREATER THAN VERTICAL � II I� i�llll L U I S r k-RS 'WITH DRAINAGE T❑ THE BACK.. AVOID LOW SPOTS. STAIR STEPPING CUT SLOPE GROOVE BY MUM rumows ALA THE cwou k IRREGULARITIES IN THE SOIL SURFACE CATCH RAINWATER � A140 RETAIN LIME. FERTILIZER AND 5 EED. GIB❑❑VING 31 QPE ADIPTEII FROM DETAILS PROVIDE❑ OYf USIA - 1,J1115, SURFACE NE V YURK STAW ®EPAWTKENT OF TRANSPORTATION, NEW YORK STATE DEPARTMENT (IF E14VEROINMENTAL C DNSE R V A T ION. ROUGHENING NEW YMK STATE SOIL L WATER CONSERVATION COMMIT TEE D L I AILS New York State Standards and Specifications Page 4.57 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR TEMPORARY CONSTRUCTION AREA SEEDING Criteria Water management practices must be installed as appropriate for site conditions. The area must be rough 4 graded and slopes physically stable. Large debris and rocks are usually removed. Seedbed must be seeded within 24 hours of disturbance or scarification of the soil surface will be necessary prior to seeding. x Fertilizer or lime are not typically used for temporary d 9..9irIFr�a ie"_ -. seedings. IF: Spring or summer or early fall,then seed the area with ryegrass(annual or perennial)at 30 lbs.per acre Definition & Scope (Approximately 0.7 lb./1000 sq.ft.or use 1 lb./1000 sq.ft.). IF: Late fall or early winter,then seed Certified Providing temporary erosion control protection to disturbed `Aroostook'winter rye(cereal rye)at 100 lbs.per acre(2.5 areas and/or localized critical areas for an interim period by lbs./1000 sq.ft.). covering all bare ground that exists as a result of construction activities or a natural event. Critical areas may Any seeding method may be used that will provide uniform include but are not limited to steep excavated cut or fill application of seed to the area and result in relatively good slopes and any disturbed,denuded natural slopes subject to soil to seed contact. erosion. Mulch the area with hay or straw at 2 tons/acre(approx.90 Conditions Where Practice Applies lbs./1000 sq.ft.or 2 bales). Quality of hay or straw mulch allowable will be determined based on long term use and Temporary seedings may be necessary on construction sites visual concerns. Mulch anchoring will be required where to protect an area,or section,where final grading is wind or areas of concentrated water are of concern. Wood complete,when preparing for winter work shutdown,or to fiber hydromulch or other sprayable products approved for provide cover when permanent seedings are likely to fail erosion control(nylon web or mesh)may be used if applied due to mid-summer heat and drought. The intent is to according to manufacturers' specification. Caution is provide temporary protective cover during temporary advised when using nylon or other synthetic products. They shutdown of construction and/or while waiting for optimal may be difficult to remove prior to final seeding and can be planting time. a hazard to young wildlife species. November 2016 Page 4.58 New York State Standards and Specifications For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR TOPSOILING Site Preparation 1. As needed,install erosion and sediment control practices such as diversions,channels,sediment traps, and stabilizing measures,or maintain if already installed. - 2. Complete rough grading and final grade,allowing for depth of topsoil to be added. 3. Scarify all compact,slowly permeable,medium and - - fine textured subsoil areas. Scarify at approximately right angles to the slope direction in soil areas that are steeper than 5 percent.Areas that have been overly compacted shall be decompacted in accordance with the Soil Restoration Standard. 4. Remove refuse,woody plant parts,stones over 3 inches in diameter,and other litter. Definition & Scope Topsoil Materials Spreading a specified quality and quantity of topsoil 1. Topsoil shall have at least 6 percent by weight of fine materials on graded or constructed subsoil areas to provide textured stable organic material,and no greater than 20 acceptable plant cover growing conditions,thereby percent. Muck soil shall not be considered topsoil. reducing erosion;to reduce irrigation water needs;and to reduce the need for nitrogen fertilizer application. 2. Topsoil shall have not less than 20 percent fine textured material(passing the NO.200 sieve)and not more than Conditions Where Practice Applies 15 percent clay. Topsoil is applied to subsoils that are droughty(low 3. Topsoil treated with soil sterilants or herbicides shall available moisture for plants),stony,slowly permeable, be so identified to the purchaser. salty or extremely acid. It is also used to backfill around 4. Topsoil shall be relatively free of stones over 1 1/2 shrub and tree transplants.This standard does not apply to inches in diameter,trash,noxious weeds such as nut wetland soils. sedge and quackgrass,and will have less than 10 percent gravel. Design Criteria 5. Topsoil containing soluble salts greater than 500 parts 1. Preserve existing topsoil in place where possible, per million shall not be used. thereby reducing the need for added topsoil. 6. Topsoil may be manufactured as a mixture of a mineral 2. Conserve by stockpiling topsoil and friable fine component and organic material such as compost. textured subsoils that must be stripped from the Application and Grading excavated site and applied after final grading where vegetation will be established. Topsoil stockpiles must 1. Topsoil shall be distributed to a uniform depth over the be stabilized. Stockpile surfaces can be stabilized by area. It shall not be placed when it is partly frozen, vegetation,geotextile or plastic covers. This can be muddy,or on frozen slopes or over ice,snow,or aided by orientating the stockpile lengthwise into standing water puddles. prevailing winds. 2. Topsoil placed and graded on slopes steeper than 5 3. Refer to USDA Natural Resource Conservation Service percent shall be promptly fertilized,seeded,mulched, soil surveys or soil interpretation record sheets for and stabilized by"tracking"with suitable equipment. further soil texture information for selecting appropriate design topsoil depths. 3. Apply topsoil in the amounts shown in Table 4.7 below: New York State Standards and Specifications Page 4.59 November 2016 For Erosion and Sediment Control Table 4.7 - Topsoil Application Depth Minimum Site Conditions Intended Use Topsoil Depth 1.Deep sand or Mowed lawn 6 in. loamy sand Tall legumes,unmowed 2 in. Tall grass,unmowed 1 in. 2.Deep sandy Mowed lawn 5 in. loam Tall legumes,unmowed 2 in. Tall grass,unmowed none 3.Six inches or Mowed lawn 4 in. more: silt loam, clay loam,loam, Tall legumes,unmowed 1 in. or silt Tall grass,unmowed 1 in. November 2016 Page 4.60 New York State Standards and Specifications For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR TREE REVETMENT 5. Excavate and backfill as necessary to fit the tree revetment to the site. Maintenance Due to the susceptibility of plant materials to the physical - - constraints of the site,climate conditions,and animal populations,it is necessary to inspect installations frequently. This is especially important during the first year or two of establishment. Plant materials missing or damaged should be replaced as soon as possible. Sloughs or breaks in drainage pattern should be reestablished for the site as quickly as possible to maintain stability. Definition & Scone A tree revetment consists of a tree trunk and branches, without root wad,cabled to an earth anchor,which is buried in the streambank to reduce streambank erosion by absorbing energy and reducing velocity,capturing sediment,and enhancing conditions for planting or colonization of native species. Conditions Where Practice Applies This practice is appropriate for streambanks that are eroded or undercut. It should not be used near bridges or other structures where there is a potential for downstream damage if a revetment dislodges. Their use should be limited to non -flashy streams where the needs for future maintenance are less critical. Design Criteria 1. Trees shall be sound,recently felled spruce or fir of 6" or greater diameter and at least 20 feet in length. 2. Trees are placed initially at the base flow elevation with the butt end upstream. Multiple tree revetments shall be overlapped by 25%of their length,working from downstream to upstream. 3. Each tree shall have their branches trimmed off on the bank side and have two anchors,one near the butt end and the other at 3/4 distance up the trunk. 4. The tree shall be fastened with galvanized cable to the anchors,which will be commercially manufactured earth anchoring systems. The butt end cable shall also be attached to the stem of the next tree at 3/4 the distance from the base,as it is placed to the outside of the previous tree. New York State Standards and Specifications Page 4.61 November 2016 For Erosion and Sediment Control Figure 4.19 Tree Revetment [JVERLA+P ,AD JGIN[NCC REVETMENTS BY 25X OF RREVETRHENT LENGTH SYMBOL AND CABLE REVETMENTS � SHORELINE TOGETHER (TYPICAL) TR _TOP OF STREAM BANK EARTH ;ANCHOR SYSTEM (SEE N❑TES 4 L 5) PLAN VIE1�' NOT To SCALD EXISTING VEGETATION, PLANTINGS, OR SaIL BIOENGENEERINEi SYSTEMS TWO TNIRDIS OF BANK _ SECOND RITW INSTALL TWO HEIGHT COVERED APPLIED IF NEEDED GALVANIZE+ (SEE: NOTE 3> CLAMPS STREAM FORMING i CAELE FLOW EARTH ANCHOR BASEFLOW — SYSTFM (SF= i - N107ES 4 RA%9c TOE — CROSS SECTION CABLE A-17Aui RCD TG ANCHOR AND rOR TRILE C❑NSTRUCTI❑N SPECIFICATI❑NS 1. TREES SHALL BE STRUCTURALLY SOUND, RECENTLY FELLED CONIFERS OF 6' DIAMETER OR GREATER AND AT LEAST 20' IN LENGTH 2. TREES SHALL BE PLACED WITH THE BUTT END ❑F THE STEM PLACED UPSTREAM. TREES SHALL BE OVERLAPPED BY 25% OF THEIR LENGTH 3, EACH TREE SHALL HAVE TWO GALVANIZED CABLES, THE FIRST ATTACHED NEAR THE BUTT END, THE SECOND AT 3/4—TRUNK WITH BOTH ATTACHED TO AN ANCH❑R USING TWO GALVANIZED CLAMPS AT EACH C❑NNECTI❑N. 4.. THE ANCHORS SRHALL BE CAIMMERCEALLY MA4 FA,CTURCD EARTH ANEH❑PINS SYSTEMS AS SPECIFIED IN THE CONTRACT DOCUMENTS. THE ANCHORING SYSTEM SHALL BE INSTALLED AS PER THE MANUFACTUR-ER'S SPEC I F I CAT[ �. 5. GALVANIZED CABLES SHALL BE INSERTED NPOUGH A DPILLEI) 14OLE AND WRAPPED AT FEAST ONE ,AND ONE-HALF TINS ARUMB THE KA3N STEM OF THE TIRLE OR ANCHOR, THEN CLAMPEQ. SEE CONTRACT DOCUMENTS FOR CABLE SIZE. AUWTED FRQN DETArLS PRaVIVED 11Y, kJS`0A - NRIES, NEV YURK STATE DER}APPTMFNT OF TRA1+WORTATTnN, TREE REVETMENT NEW 'DIRK STATE MElPARTMCNT [IF EN�+1 MNMENTAL CONSERVATION, MCV YURK STATE SAIL 'I` WATER CONS ATIIIN COMMITTEE November 2016 Page 4.62 New York State Standards and Specifications For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR TREES, SHRUBS, AND VINES attached to plants,bundles of seedlings,containers, and/or flats. C. Plant Protection u ' e Prior to delivery,the trunk,branches,and foliage of the plants shall be sprayed with non-toxic antidesiccant,applied according to the —- manufacturer's recommendations. This does not Find� a`'"R apply to state nursery seedlings. " D. Planting Time Deciduous trees and shrubs: April 1 to June 1 and -F� October 15 to December 15. Evergreen trees and shrubs: April 1 to June 1 and September 1 to November 15. Definition & Scope Establishing trees,shrubs,and vines or selectively reducing E. Spacing stand density and trimming woody plants to protect the soil Plant all trees and shrubs well back from buildings and plant resources,improve an area for recreation and to allow for mature crown size. The following are increase the attractiveness and usefulness of areas. guides for planning: Conditions Where Practice Applies Large Trees 50-60 feet apart Small Trees 20-30 feet apart On any area planned for recreation or landscape use such as yard areas,leisure areas,picnic areas,and park lands Columnar Species 6-8 feet apart providing outdoor recreational opportunities. Hedges 1-4 feet apart Criteria and Specifications For clumps,plan spacing so mature Shrubs shrubs will be touching or overlap- 1. Planting nursery stock ping by only 1 or 2 feet A. Select species to serve the intended purpose. See F. Site Preparation Appendix G,Table G.1,"Trees Suitable for Landscape and Conservation Plantings in New 1) Individual sites for planting seedlings can be York."Where planting of trees is to be done in prepared by scalping the sod away from a four foot recreation areas,use those species resistant to square area where the seedling is to be planted. compaction listed in Table G.2,"Susceptibility of Tree Species to Compaction"whenever possible. 2) All planting beds shall be cultivated to a depth of 8 inches,or chemically treated for weed control. B. Plant Materials Remove objectionable objects that will interfere with maintenance of site. 1) Plants shall conform to the species,variety,size, number,and conditions as stated in a conservation G. Planting plan or on a plant list shown on landscape 1) Plants shall be located as shown on plans and/or drawings. "American Standard for Nursery drawings and,where necessary,located on the site Stock,"by American Association of Nurserymen, by stakes,flags or other means. shall be used to develop the plant list for landscape drawings and to check quality of plant materials. 2) Prior to planting,remove galvanized wire basket securing root ball,untie and roll down 2) Durable,legible labels with the scientific and burlap covering from around the stem. common name and cultivar shall be securely New York State Standards and Specifications Page 4.63 November 2016 For Erosion and Sediment Control 3) The plants shall be set upright in holes as approximate weight of soil ball that must be moved illustrated in Figure G.1 in Appendix G. with each size plant. 4) All plants shall be thoroughly watered on the D. Plant and maintain as described above for nursery same day of planting. Plants that have settled shall stock. be reset to grade. PRUNING AND THINNING H. Wrapping Use Cleared Width Each Cleared Immediately after planting,wrap deciduous tree I Side of Trail Tread(ft.) Height(ft.) trunks from the bottom to the first limb with a 4 TRAILS inch wide bituminous impregnated,insect resistant Hiking 1 8 tape or paper manufactured for that purpose. Tie with jute(bag strings)at top and bottom.The wrap Bicycle 2 10 should be removed per nursery recommendations. Motorbike 2 10 L Mulching Horse 2 12 Mulch the disturbed area around individual trees X-Country Ski Total: 3-12 121 and shrubs with a 2-3"layer of wood chips. Pull wood chips 1 inch away from the base of shrubs to Snowmobile Total: 6-12 121 avoid fungus development. PICNIC&CAMPING AREAS J. Pruning Campfire/Grill 10 ft.diam. 15 After planting,prune to remove injured twigs and Includes allowance for snow depth and snow load on branches branches. The natural shape of the plant should not be changed. K. Cleanup and Maintenance 1. Pruning 1) After all work is complete,all excess soil,peat A. Remove trees,limbs,and limb stubs to the above moss,debris,etc.,shall be removed from the site. widths and heights specified for the intended use. 2) Water plants two weeks after planting.For two B. Remove dead,diseased,or dying limbs that may years,water plants every two weeks during dry fall. periods,which exceed three weeks without a good soaking rain,or water as needed in accordance C. Do not remove more than one-third of the live with local conditions. Shrubs may require 5 to 10 crown of a tree in a year. gallons and trees,20 to 30 gallons for each D. Cut limbs flush to the branch bark ridge. watering. 3) Remove trunk wrap per nursery E. Use the 3 or 4 cut pruning method on all branches recommendation. over 2 inches in diameter: First cut about one- third the way through the underside of the limb 2. Transplanting"Wild"Stock (about 6-12 inches from the tree trunk). Then (approximately an inch further out)make a second Successful transplanting of wild stock will require cut through the limb from the upper side. When heavy equipment and considerable labor as a large the branch is removed,there is no splintering of the weight of soil must be moved with the roots. main tree trunk. Remove the stub. If the branch is larger than 5-6 inches in diameter,use the four cut A. Select trees and shrubs with good form and full system. Cuts 1 and 2 remain the same and cut 3 crowns. should be from the underside of the limb,on the outside of the branch collar. Cut 4 should be from B. Transplant only when plants are dormant and soil the top and in alignment with the 3rd cut. Cut 3 is moist. Wrap soil ball with burlap to prevent soil should be 1/4 to 1/3 the way through the limb. from separating from roots. This will prevent the bark from peeling down the C. Table 4.8 shows minimum diameter and trunk. Do not paint the cut surface. November 2016 Page 4.64 New York State Standards and Specifications For Erosion and Sediment Control 2. Thinning A. Remove dead,diseased,dying,poorly anchored,or ice damaged trees that pose a hazard to recreationists or that interfere with intended use. B. To maintain grass cover in a wooded area,thin according to formula Dx3 (average diameter of the trunk of overstory trees,in inches,times three—the answer is the spacing between trees to be left,in feet). For example,for trees with average diameter of 6 inches,spacing after thinning should leave trees 18 feet apart on average. Crown cover after thinning should be about 50 percent. C. Selectively thin as needed to favor those trees that are most"resistant"to compaction around their roots. See Table G.2,"Susceptibility of Tree Species to Compaction" in Appendix G. If the soil on the site is naturally well drained,those species in the"intermediate"group may also be favored. Table 4.8 Size and Weight of Earth Ball Required to Transplant Wild Stock Vall!2, Ash, &, I:i� M �.Lt;-) (00*pple,TlimaMic.Vie nun,Dogwao6,etc,) MWMiii1� Up to 6f, Milienum c ;� Bale of Ball #ft. P14 Ball or Full fln hy—i Lbuj CCirpl:2 tlnchr:5 29.1 112 14 88 2 L l 33 1 19 IM 4 Ld 00 1-114 3D 227 5 L 9 L8 1-1/2 22 X2 l& LM -3V4 24 390 1 20 227 2 28 611L L-In 22 A2 3 32 836 1-314 24 3% 3.112 36 L.400 2 U 621 4 42 L.M 2-U2 32 916 3 L. 1CWOu is a dimwkr mcw=mml of wxs at a height of 6 imchts above the ground. New York State Standards and Specifications Page 4.65 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR VEGETATED ROCK GABIONS Construction Specifications 1. Prepare the foundation for the gabions by excavating to the lines and grades shown on the drawings. 2. Subgrade will be compacted and leveled to receive the first layer of gabions. The first row will be keyed into the existing grade at the toe,a minimum of 1.5 feet. 3. Gabions will be placed according to the design and filled with stone or crushed rock from 4-8 inches in diameter.A geotextile should be draped over the basket prior to placement of backfill or plant bedding. 4. Backfill behind with select clean fill and compact by hand tamping,or light mechanical tampers,in 6"lifts. Definition & Scope 5. On top of each row of gabions place 1"of select backfill as a plant bedding prior to placement of plant A combination of vegetation with rock filled gabions used cuttings. for slope stabilization by providing a retaining wall with plant canopy to reduce runoff,temperature,and provide a 6. Place plant cuttings in a tight configuration with stem vegetated cover to hardened surfaces. to stem contact so plants extend beyond the next gabion facing by 1 foot and beyond the back of the wall in Conditions Where Practice Applies contact with native soil. 7. Grade above the final row of plant cuttings with select On steep sloping areas such as road cuts,slumped areas, clean fill to a slope no steeper than 2 horizontal to 1 gully cuts,low fill areas,or areas that are subject to erosion, vertical. seepage and weathering and have a low to medium hazard potential should slope failure occur. Maintenance Design Criteria Regular inspection and maintenance of this system should be conducted especially during the first year of Materials-shall be a native or nursery grown cultivars establishment. Repairs should be made to gabions as capable of performing intended function. The live branch necessary and all settled areas should be brought back to cutting shall be 1/2"to 1"in diameter and long enough for grade. each gabion row to extend the tops a minimum of 1 foot beyond the next upper gabion row and be in contact with the undisturbed soil behind the gabion wall. Spacing-The plant cuttings shall be placed tightly side by side with stem contact with each other on top of each gabion row on a 1"layer of raked backfill. Note: These can be complex systems that should be designed by a licensed professional engineer. November 2016 Page 4.66 New York State Standards and Specifications For Erosion and Sediment Control Figure 4.20 Vegetated Rock Gabions 'SYMBOL P EXCAVATION AS RE❑UIRED VEGETATGVE PLANTINGS OR G'L BIOENG.INE:ERING SYSTEMS LIVE ®RANCH CUTTINGS WITH T❑PS PRDT RUIN[NG BEYOND +- LAA10N FRUNI AND JN •# *• 4P CONTACT WITH UNDISTURBED UND13 TURK D SOIL S❑IL IN 'REAR OF TRENCH * *' �+ + P.V.C. COATED OFF 15ALV, GABION BASKETS *+ + * + + 4. * SELECT CLEAN FILL + . + SELECT CLEAN FILL + (SEE HATE 1) (SEE NOTE 1) *+#f + # EXISTING ##*r} �*+*+ LIVE BRANCH GRADECUTTINGS i/2r TO 2' TO 3' FPOM u Ij IN DIAMETER EXISTING GRADE TQ � BOTTOM DE GABIOF49 mOT TO �SCAL�N CONSTRUCTION SPECIFICATION L. ALL SELECT CLEAN r 1LL FOP GABIONS SHALL DE HAND TAMPED IN 6' LIFT-S. 2. A I I AYF R 1F BACKik ]L L SHALL BE PLACE D ON TOP OF TNE R❑fie' OF GABIONS AND RAKED. THE CHIT T INGS SHALL BE PLACED ON THE BACK-PILL MATERIAL AND ANDTHER 1' LAT`ER OF RACKFILL SHALL BE PLACED ON THE C-UTTINGS BETWEEN THE GABIONS.- 3. CLASS 2. T V PE D OR C. INTERMEDIATE EROSION CONTROL PRODUCT SHALL BE INSTALLED ON THE rRONT INSIDE FACE AND ANY OTHER EXPOSED VEPrICAL SURIFACE OF THE GABIGNS. ADAPTCD FROM DETAILS PROVIDED RYi USDA — NRCS, NEW Y❑RK STATE DEPARTMENT OF TRd+NSPOktATION, VEGETATED ROCK NEW YpRK" STATE DEPARTMENT OF ENVI-RONMENTAL CGNS ERVATJDM ��,�I❑N NEVYDRIe S7ATE S❑]L & WATCR C0NSjEpV�+TIIJT+I Caw�w;TTEE New York State Standards and Specifications Page 4.67 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR VEGETATING SAND AND GRAVEL BORROW AREAS 6.0 using agricultural ground limestone. Fertilize to achieve a moderate level of available phosphorus (P205)and potassium(K20). If the soil must be fertilized before results of a soil test can be obtained to determine fertilizer needs,apply 50 pounds per acre of 1 nitrogen. Incorporation will be accomplished following the seeding. P. 6. Select the appropriate seed mix based on percent fines and time of planting. 7 A A. IF 15 percent fines or less: use the warm season grass mix. If fall planting is necessary,use a temporary cover to allow planting of the warm Definition & Scope season grasses in early spring. Two(2)bushels of oats per acre is suggested as this will winter kill Permanently vegetating inactive borrow areas with and not be competitive when the permanent sustainable herbaceous perennial plants in order to stabilize seeding is made.Another option is small grain the soil,thus preventing wind and water erosion;creating a straw at two(2)tons per acre. Do not use old hay. more aesthetically pleasing view;and enhancing the B. Warm Season Grass Table: wildlife habitat for greater diversity. C. IF greater than 15 percent fines: use a grass/ Condition Where Practice Applies legume mixture,or the warm season grass mix. Sand and gravel borrow areas which have had EITHER the top portion of the soil profile replaced as`topsoil' or Certified Seed overburden with greater than 15 percent fines included,OR Species Variety PLS*/Acre the sand and gravel mined condition remains without (lbs.) `topsoil' being replaced resulting in sand and gravel with less than 15 percent fines. Blackwell, Switchgrass Shelter 2 Design Criteria Pathfinder,or Trailblazer 1. Depending upon the type of unconsolidated material being mined,side slopes shall be graded in accordance Coastal panicgrass Atlantic 2 with the New York State Mined Land Reclamation Law.Minimum requirements are:for fine sand,silt, Big bluestem Niagara 4 clay the slope shall not exceed 2 horizontal to 1 vertical (260);for coarse sand and gravel the slope shall not Aldous or exceed 1.5 horizontal to 1 vertical(330) Little bluestem Camper 4 2. Rocks and other debris shall be removed from the site or buried during grading if allowed. Sand bluestem Goldstrike 2 3. Surface soil layer shall be sampled from 0-6"in depth. Nebraska 27 or Combine about 15 core samples to represent the site Sand lovegrass Bend 2 soil conditions. Analyze to determine pH,P and K. 4. Obtain a larger(5-10 lbs.)soil sample to represent the Total mix(PLS/acre) 16 lbs. surface soil texture. Analyze for percent fines *Pure Live Seed(PLS)=(%germination x°/"purity)/100 (particles less than.074 mm or 200 mesh sieve). 5. Apply soil amendments as indicated by soil chemical Pounds to be seeded=(100 x lbs.of 100%PLS required)/°/" test. The surface to be seeded shall be limed to a pH of PLS of commercial seed being used. November 2016 Page 4.68 New York State Standards and Specifications For Erosion and Sediment Control D. Grass/Legume Table: difficult due to the lightweight and fluffy seed characteristics of some species. Species Variety Pure Live Seed E. Incorporate the soil amendments and seed. Per Acre(Ibs.) Creeping red fes- i. "Tracking"an area is using a bulldozer having cue Common 10 cleats at least 1 inch in depth. Operation of the dozer shall be perpendicular to the contour and Smooth Brome- Common 2 such that the entire area is covered by the tracks. grass Perennial ryegrass Pennfine/Linn 5 OR ii. Pulling a cultipacker over the entire site with the Red clover* Empire plus 8** tines up or no deeper than 1 inch. This option Pardee only works if soil moisture is near field capacity. * legume in seed mixture needs to be inoculated. **41bs.of each is best. 8 lbs.of either one is good. 8. Mulching is essential for immediate erosion control and uniform establishment of cool season grasses and legumes on sands and gravels.Use a heavier rate for OR the grass/legume seedings of 4000 lbs./ac.Use only small grain straw. Mulching of warm season grasses may not be necessary when runoff and sediment Pure Live Seed delivery is not an issue. If erosion control is necessary Species Variety per Acre(Ibs.) for warm season grass sites,mulch with 3000 lbs./ac. of small grain straw(not grass hay). On sites where Flatpea* Lathco 10.0 mulch can be avoided,warm season grasses will Perennial pea* Lancer 2.0 respond favorably. American vetch* Common 10.0 9. Anchor the mulch by using the bulldozer tracking technique. This may be done simultaneously with seed incorporation. Optional anchoring techniques and Hard fescue Common 10.0 materials are available in the Mulching Standard. Total Mix(lbs./acre) 32.0 10. Site protection is necessary to avoid wheel and tire *legume in seed mixture needs to be inoculated. damage. 7. Planting instructions: A. Planting dates are very critical for warm season grasses. Very early spring(March/April)is best. The success rate decreases notably by the end of May. Fall seedings are not recommended. Grass/ legume mixes may be reliably planted from early spring through June 15. Avoid June 16 through August 15. After August 15,seed anytime until ground freezes. B. A temporary cover of 2 bushels of oats may be seeded between August 15 and September 15(oats will winter kill). This works well preparing for early spring seedings. C. Inoculate legume seed immediately prior to actual seeding. Use 4 times the standard agricultural rates. D. The seed mix must be uniformly broadcast. A hydroseeder works well or spread by hand if necessary. The use of spinner type seeders is New York State Standards and Specifications Page 4.69 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR VEGETATING SAND DUNES AND TIDAL BANKS back dune areas. Seed at 10 pounds pure live seed per acre. Refer to Standard and Specifications for Vegetative Stabilization of Sand and Gravel Pits for determining the proper amount of pure live seed. 4) Immediately after planting,a wooden sand fence(snow fence)will be built to protect the beachgrass from vehicle and foot traffic. The fence shall surround the planted area at a distance '- of 15 feet from the planted area. Passageways should be provided to allow pedestrians to cross _ "' _ the planted area at appropriate intervals. Elevated boardwalks,or dune cross-overs,are desirable and Definition & Scone required by DEC on many stretches of coastline. . B. Where sand dunes are strengthened or Establishing and maintaining permanent vegetative cover in reconstructed through sand entrapment,and shore order to provide coastal shoreline protection to stabilize conditions allow for sand deposition,appropriate sand dunes,provide for sand entrapment for dune building, permits for altering shorelines must be obtained and provide for protection of dune vegetation from foot prior to beginning work. traffic and vehicles. Also to stabilize tidal banks and provide for long term protection. 2. Building,Planting,and Maintaining Coastal Sand Dunes Condition Where Practice Applies Dune stabilization work should start as far landward as On any coastal shoreline,including shorelines of the Great possible. Whenever feasible,leave room for two or more Lakes,Lake Champlain,Long Island Sound and the dune lines for a double layer of protection. Dunes grow Atlantic Ocean where vegetation can be expected to toward the sand supply,which is the ocean or the lake. effectively stabilize a site. A. Building the dune: Specifications 1) Vegetatively. 1. Sand dunes Where blowing sand is available,a simple, relatively inexpensive and successful method A. Where stabilization of existing sand dunes and/or exists for building dunes. It consists of planting re-establishment of beachgrass is needed. American beachgrass strips parallel to the 1) Long Island and NYC area,use Certified coastline. As the windblown sand moves off the beach landward,it drops its load of sand, `Cape' American Beachgrass. Planting of frontal beginning the natural cycle of dune growth. dunes should be accomplished by April 30. Refer The plantings will trap most of the windblown s American B Information Sheet for sand,particularly during the growing season specific instructibons.ons. ass when the grass will continue to grow up 2) Lake Champlain and Great Lakes,use the Lake through the newly trapped sand. Champlain strain or species if adequate planting 2) Sand Fences(Snow Fence Material). material is available. Use American beachgrass guidelines for planting. `Cape'will do well but is very aggressive compared with the Lake The use of sand fence is effective and the Champlain strain. Some people consider`Cape' an material is readily available. It may be more invasive plant in these locations. expensive than building dunes vegetatively,but is less expensive than doing it with machinery. 3) `Atlantic' coastal panicgrass is excellent for Normally it is also much faster than with November 2016 Page 4.70 New York State Standards and Specifications For Erosion and Sediment Control vegetation alone. or the area between the fences can be planted. Such a combination can trap most of the wind To form a barrier dune,erect the sand fences in blown sand crossing the dune area and produce parallel lines 30 or 40 feet apart. The fences a much broader based dune than either should be roughly parallel to the water line and approach alone. See Figure 4.22. yet be as nearly as possible at a right angle to the prevailing winds. See Figure 4.21 on page 3. Tidal Streams and Estuaries 4.72. Where this is not possible,erect a single line of fence parallel with the water at least 140 The procedures to determine the effectiveness potential of feet from the MHT line and space 30 foot long stabilization of tidal streams and estuaries are found in perpendicular spurs 40 feet apart along the Table 4.9 on page 4.73. seaward side to trap lateral drift. Plants to be used are as follows: As the fences fill with sand,additional sets of fence can be placed over those filled until the A. Certified`Cape'American beachgrass barrier dune has reached a protective height. B. Certified`Bayshore' smooth cordgrass To widen an old dune,the fencing should be set seaward at a distance of 15 feet from the old C. Certified`Avalon' saltmeadow cordgrass dune base. D. Certified`Atlantic' coastal panicgrass Materials- Use standard 4-foot sand(snow)fence. The 4. Coastal panicgrass is primarily used in freshwater tidal fence should be sound and free of decay, areas above high tide line. Frequently,it is seeded over broken wire,and missing or broken slats. top of saltmeadow cordgrass plantings. 5. Additional Reference Wood posts for fence support should be black locust,red cedar,white cedar,or other wood of "Best of Beach Vegetation"by W.Curtis Sharp. equal life and strength. They do not need to be Reprints from Parks and Recreation Resources. treated. They should be a minimum of 6 ft. 6 Volume 1,Nos. 1,2,4&5,7&8.Published in in.long and a minimum diameter of 3 inches. January,February,May/June,July/August 1982. Standard fence post length is usually 7 ft.-8 ft. and should be used where possible. Four(4)wire ties should be used to fasten the fence to the wood posts. Weave fence between posts so that every other post will have fence on ocean side of posts. Tie wires should be no smaller than 12 gauge galvanized wire. The bottom of the fence should be set about 3 inches into the sand,or a mechanical grader could be used to push some sand against the bottom of fence. 3) Sand fence plus vegetation- The combination of these two approaches is more effective than either one alone. The sand fence should be placed as discussed above. Bands of vegetation should then be planted parallel to the fence on the landward and seaward side. Each bank of vegetation should be about 20 feet wide and placed 10 to 15 feet from the sand fence. As the sand fills between the two fences,additional fence can be erected New York State Standards and Specifications Page 4.71 November 2016 For Erosion and Sediment Control Figure 4.21 Combination of Sand Fence and Vegetation for Dune Building VEGETATION W-f5' L31V- ' ' SAND FENCE _ VEGETATION 20 Figure 4.22 Typical Cross-Section Created by a Combination of Sand Fence and Vegetation FENCE ,-- �WEGETATIQN NEk INSTALLATION SLIME SA ACEUMULATION ,,,-NEW FENCE i I ADDITIONAL SANG ACURLATION NEV IP AliTING COMPLETEO DUNE November 2016 Page 4.72 New York State Standards and Specifications For Erosion and Sediment Control Table 4.9 Vegetative Treatment Potential for Eroding Tidal Shorelines DIREIMUMS FOR USE I. 4;V m3WM INK it Id thq rigid fir Lbr is IW VPZMJ{ca&srl mil,ha.`e tllr 41uL WAJ5in+,M(Lh&hr�poUtiis III IIn al"Lgmi Ale Lk uj Lrw lri ti.FIKgk ry. 2. P Nye IN MrSi-cal C TITzirrbrnj I%MCnb'I(Vrl;,,I JLLIr[e l IIY rai h11i LhE Raw lei ththo.hjual LI7 Ultltl ]. I,h4 CliimuYallvc VcCcLzllvr T'riiarni F`ii14inIIJI ilx I,aiLjhk4 I,},v I&4 by midi eit Lhr WTP Iu rich 4. I f y is Z$at milm,Iht p mgsw l fyr the Aim 40 bt MAhlhzod-Irh'ritpunwe is rM d flnit the rest or ft wt�k need na t-e uteri I r II 1, Wft-UL go-L-F i 51 131K VTF kir dhracIii*t e1.m%h 4 ind cbLoin the dL1IliLLLlr1Ht VTP rar vknah"1.9 C ILA eunudwrirC VT? wih ft Ypplllvr TrLzlnxnl PLACM d 3r•Ylt it 1ht hvnam-ir oui prape SHORB-1KE V4RIASLSS DIR1 ' ON POR USF VTP Tk=Vitruh§rt Trtmmlt'fil Pou LfJ(WTP`j an l rlehd r1 hbki iy%t. 1.porch: Avimirdisivom In Ws thin 0.5 fuu 1.4 l.5 Lim 3.4 3.5 Onj4.9 tr milft of open watrmleid- 0.5 nidle& miller miles Irrkiks 3 miles wed Tm9nindiLuLar Lo IN'! S 7 4 2 $ shire arkid-45 dcgrfei ekh er aide Of frefrpcnd1L1U1;1r 10 2,Cfiartirral itfape of sh*rckim Cmcs Irrcgulrr s=lint Hcadlwd.or irraighl for dislame of 2W t sbtreelioe 00 Whi SiCk 94 phkMing g 3 0 tile. 3- Shor-c I inir on c dl#f i on: Any kM WM W SourLh W SWO rO E4M 149M 14 ZUL Gtrfl:J''jl g"raphit dLitC- IhAd 1n M15 Th Watt tiara LbC OK1 Mhos 1f0M. Mils rcch 1 ID S 3 3 4, Bow WN: ImiLy of N 1-10 por Mom Lb*n 10 1-10 Per Wldmtares %iltt n eeTtAilaral & com- wetk'willo pf4rwwk wmk w4hifn 10 ptr wtek mrrvial bm Indira; 102 mi.of Lain i a mi.. Io} .or wsllfin 100 *"C. of sh"t. dom. kdi.of ih e. 5 2 i 0 muladve Vegcutiut Treurtxnt Po tr`fiel forVsrialrlei I. 2.3&.4 If dull A ewc Li.21 er►h)w.Lhe pouhlw far #r Li Yam' iLt!fiie tau ac lYhd[drYid r.f trt Il.ai Id d IG�YGlil+i�],fp f8 irtp�.Gels. S-'W W&Ioff bewh aboYr GrraftT LharL 10 fL 10 A.Iheu 7 ft. 6 fl.Lhly-I tI Ltu Ih"3 ft. IfYC-1fI1 high Ikk is# t 3 2 3 8 ,.Pwnzitl width of Mort rbarw 20 A. 20 ft.Trite, 15 Ih. 14 ft.rlhru 10 ft Ltai Shan 1(Ffr. Plnnrli.ng Rw in foal 3 3 11 1119am P 7 Del Some grWi-;rlt kmraw#% K&M I JL% 1 ff" skgK Rom M LW Lo Ifx 6 of bank. .H. Bch Vgdbuon Vtgtuimlon bekowLit ofiRW toovtoicionbyelaw we of 9.k*c 9. L)tpih ul mrri as rilcifr(hare I0im. 10 art.it" 3 an. I-n than 3 in fIX4-,r hlAft 144 In Ini;e% 3 7 Cwm"uvt Vitlewillit Trtmemni F�L+ltrlrial W, Va;sbks l-9 I C} raw direr. Vr . otoxg loulmot Plsr Wliul gilt 2 Er me moumim ht.,5 reel oc kul■rye him MLA+ It lilt M 13, flwri6m of um io be wi 4c)C-0ar hulk-. ]I fu dW rIuaI mpm 4q%w 2-3 rase mmurt &tF._l.s�x vaLh kU firm k11A+ap w afbuh 40 33 GOW I R fm to dspar of um by W-3 Lim re—Llle 32 2A Fair laf 33 18 Pam New York State Standards and Specifications Page 4.73 November 2016 For Erosion and Sediment Control Figure 4.23 American Beachgrass Information Sheet (Ammophila breviligulata Fern) Adapted from USDA—NRCS Plant Guide Use: Major use is to stabilize moving sand along the maximum erosion control. On very stable areas where wind Atlantic Sea coast and Great Lakes region. It is the best is not a factor,a spacing of 24"x 24"is suitable. An 18"x species for the initial stabilization of frontal dunes. 18"spacing requires 58,500 culms(3 culms/planting unit) per acre,or 1,350 culms per 1,000 square feet. Useful as an erosion control plant on non-dune areas where soils are very sandy and the site conditions make Beachgrass culms must be planted at least 8"deep. This establishment of seeded species very difficult. Also used on prevents plants from drying out,as well as being blown out soils high in salinity such as industrial waste needing by the wind. A tiling or ditching spade is an excellent tool vegetative cover. for opening the planting hole. A two person crew works best in planting on Description: American beachgrass is a leafy,spreading frontal dunes and i grass with many stems per clump. It may reach a height of loose sandy areas. two to three feet. The seed head is a spike-like panicle, The culms and roots about ten inches long,and appears in late July or August. must be kept cool Leaves are long and narrow,and may become rolled or and moist before folded as it matures. and during planting. Success of planting One outstanding growth characteristic is the strong will increase if the underground stems(rhizomes)that spread beneath the sand stock is dormant or and give rise to many new plants. Its vigorous growth has made very little enables the plant to withstand heavy deposits of sand and growth. the ability to grow up through deposits. Fertilizer properly Adaptation: American beachgrass is native to the mid- applied is the key to Atlantic coastal region from Maine to North Carolina,and good vigorous the Great Lakes region. It will grow on island sites,high in growth,as coastal d sand and/or saline content,provided adequate amounts of sands are rather nitrogen and other nutrients are present. infertile. Fertilize in March or April Varieties: `Cape' is the most recent variety and was with 30 to 40 developed by the Soil Conservation Service at the Cape pounds of inorganic AMERICAN BEACHGRASS May Plant Materials Center,Cape May Court House,N.J. nitrogen per acre until `Hatteras' developed by the Agricultural Experiment desired density is obtained. Station in North Carolina is a variety better adapted to southern climates. Management: Once the stand is well established,the rate of fertilizer applied can be reduced by half,or applied only Source: Both are commercially available vegetatively. when the stand appears to be weakening. Seed not available. Exclude vehicular traffic if possible and provide elevated Establishment: The best time to plant beachgrass is from boardwalks for pedestrians. Pedestrian and vehicular October 1 to April 30. If properly planted,good survival traffic that bends or breaks the culms will seriously damage can be expected at any time during this period,except when the plants and may kill them. Move boardwalks,or dune soil is frozen. Summer plantings are not satisfactory. cross-overs,when beachgrass underneath begins to weaken American beachgrass can be planted either by hand or by and become open,exposing the sand for potential blowing. mechanical equipment designed for this work. The stems of On frontal dunes,any area devoid of protective cover is plants called`culms' are used for planting stock. Two or subject to blowing and eventual ruin. Replanting of three culms are planted per hole. Space plants 18"by 18", beachgrass stands that become open should be an annual unless wind erosion is severe,then reduce spacing to 12"by operating procedure. 12". Stagger the plantings in alternate rows to provide November 2016 Page 4.74 New York State Standards and Specifications For Erosion and Sediment Control Figure 4.24 Cordgrass Information Sheet Smooth Cordgrass (Spartina alterniflora) and Saltmeadow Cordgrass (Spartina patens) Adapted from USDA—NRCS Plant Fact Sheets2 Description: Smooth cordgrass,a long life perennial,is the September and October,are ten to twelve inches long and dominant,most productive marsh plant in the regularly hold twelve to fifteen spikelets,each two to three inches flooded inter-tidal zone along the Atlantic and Gulf coast long. Its primary method of spreading is by vigorous, from Newfoundland to Florida and Texas. Smooth hollow rhizomes. cordgrass grows three to seven feet tall with stems up to 1/2 inch in diameter. The leaves are twelve to twenty inches Saltmeadow cordgrass long,tapering to a point. The seed heads,produced in grows in salt marshes and sandy meadows --— along the Atlantic and Gulf coasts from Quebec to Florida and Texas. It occupies the area immediately above the inter-tidal zone. Mature plants are grayish green, usually one to three feet tall. The leaf sheath is round;the leaf blade is long and narrow,usually rolled inward giving a wiry appearance;the upper side of the leaf is rough. The seed heads produced in October have spikelets that grow almost at right Spartina patens angles to the rachis or main stem. Saltmeadow cordgrass reproduces rapidly by long,scaly,slender rhizomes. Both smooth and saltmeadow cordgrasses are used by waterfowl as a source of food. Saltmeadow cordgrass is also used by muskrats for housing materials. Uses: Because of their adaptation to brackish water, smooth and saltmeadow cordgrasses occur naturally or can be planted to stabilize eroding shorelines. Planted along the shoreline,the cordgrasses absorb the wave energy and collect the sediment brought in by water. As the sediment is dropped,the band of vegetation expands,pushing the mean high tide away form the tow of the bank,thus reducing the potential for continuous erosion. Establishment of Shoreline Plantings: Smooth cordgrass is planted between the mean low water level and the mean Spartina alterni ora high water level. Saltmeadow cordgrass is planted above New York State Standards and Specifications Page 4.75 November 2016 For Erosion and Sediment Control Anticipated Results Fri m Vegetative Treatment (COASTAL PANICGRASS AND/ ��J� ORAMERICANBEACHGRASS) (SALT MEADOW CORDGRASS) _ —KM RION TUXNow rum K" 4ar ci . (SMOOTH CORDGRASS) -71N uE 41THOUr VURTMICH WOM mu TT" RVArKENT ]FrOUFJLT AFTOR TUATiTION TAFATPW J51 !Egli HIM FIDE rr - , JW LOW TIDE nf, BU 1 ' � Tj' iP4UMW MAM M TWiTJW ANTICIPATED RES&T9 FFM 4+ERTATIME TREa.nCeT the smooth cordgrass from mean high water to the toe of the used,performance expectations will be less than with the slope. If the distance from the mean high water to the toe of other two methods. Coastal panicgrass can be planted using the slope exceeds 10 feet,American beachgrass should also method one or be seeded. be planted in the upper part of the slope. Typical plantings consist of one row parallel to the Establishment of Plants: There are three types of plant shoreline. Transplants should be midway between the high materials that can be used for planting along the shoreline. and low tide elevations. Plant spacing within the row will One type is seedlings grown in peat pots. Such plants vary according to the size of the transplant materials being should be about 12 inches tall with 3-5 stems per container used and the rate at which full coverage is desired. One before they are large enough for transplanting. The gallon container stock are generally planted at 5'to 8' container is planted with the root mass. centers and plugs generally on 2'-3'centers. Smooth cordgrass typically produces 8'-10'rhizomes for lateral A second method is to grow the plants in containers which spread in one growing season. If two rows are planted, allow the plants with the root mass to slip out at the time of allow 5'between rows.The spacing to be used is influenced planting. Their size,etc.,are the same as above. The by the severity of the site. On sites that have a potential of advantage of this method is that it eliminates the barrier being washed away,the spacing should be closer. In occasionally created by the peat pots that may produce a protected areas where there is little danger of the planting slight turbulence around the plant and wash it out. being initially destroyed,the spacing can be wider. The hole made in the substrata should fully accommodate the A third type is to harvest culms from natural or cultivated plant roots. Be sure to seal the hole by pressing the soil stands which are then planted directly to the shoreline. If around the roots with your heal. the plants are to be taken from natural stands,they should be growing in sandy substrata. The stands should be open Planting Method/Fertilization: and developing rather than dense and mature. The culms will be ready for digging and transplanting when the top Planting Methods: When planting trade-gallons,transplants growth is six to ten inches tall. Each culm should have a should be planted in a hole. Post-hole diggers,gas drills well developed root. with modified bits,or any other methods of digging are satisfactory. The planting hole should be the same size or Methods one,two and three are equally recommended for only slightly larger than the root-ball and deep enough so smooth cordgrass. Methods one and two are recommended that the top of the root-ball is flush or slightly below for saltmeadow cordgrass. Although method three can be ground. The top of the root-ball should not protrude above November 2016 Page 4.76 New York State Standards and Specifications For Erosion and Sediment Control nor be more than 2"below normal ground. The planting hole should be pinched closed. When using tablets with hole should be tightly closed around the plant to prevent the bare-root plugs,drop the tablet in the planting hole prior to plant from wobbling and plants should remain erect after inserting the plug. planting. Planting should be made between mid Spring and July 1. Planting sites where high wave energy is a problem may The early Spring plantings are more hazardous because of require the addition of a plant anchor. A plant anchor storms and less favorable soil temperatures. Actual dates consists of 1/4'steel re-bar bent into a hook(candy-cane are influenced by location. Late Spring plantings are shape)and pushed down into the soil so that the hook lays preferred. across the root-ball,pinning it to the ground. Anchors are generally about 30"in overall length and will add to the Site Suitability: A high percentage of plantings made on cost of the planting. However,anchors are generally tidal shorelines fail due to shoreline conditions,storms,etc. necessary at unusually problematic sites to prevent plants Most shoreline conditions can be identified and their from washing out. likelihood of contributing to success or failure estimated. They are shown in Table 3.9. When planting bare-root plugs,holes need only be approximately 3"in diameter and deep enough to cover the While the procedure outline in Table 3.9 has been tested roots. Any style of tool that will punch a hole this size such against actual plantings,there is no guarantee the outcome as a dibble bar will work. Cupping the roots of the plug in of the planting will be as the guideline suggests. For hand and pushing down into the mud carefully will also instance,unexpected storms could completely eliminate the work in more fluid soils. There are no plant anchors for value of these guidelines and destroy the planting. plugs,and in practice,plugs should not be used at any site where wave energy is a factor. Management of Established Plantings: Plantings should be monitored frequently each year. Plants destroyed or Fertilization: There is no clear consensus on the washed out should be replanted as quickly as possible. All effectiveness of fertilizer when used in saturated and/or debris washed onto the plantings should be immediately anaerobic soils. However,the additional cost of fertilizer is removed to prevent smothering the plants. a small investment given the overall cost involved in vegetative restoration. Sources: Smooth and saltmeadow cordgrasses are available commercially. Because commercial sources are subject to Slow-release fertilizer tablets are commercially available in change,contact your local USDA Natural Resources a range of weights and analyses. Recommended tablet Conservation Service office for sources closest to you. weight should be between 15 and 25 grams and have a `Bayshore' smooth cordgrass, `Avalon' saltmeadow nitrogen content of not less than 15%and not more than cordgrass,and`Atlantic' coastal panicgrass are 30%. When using tablets with trade-gallon plants,push the recommended varieties for Long Island. tablet into the top 3"of the root-ball immediately prior to or immediately after planting the transplant. The resulting New York State Standards and Specifications Page 4.77 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR VEGETATING WATERWAYS A. Lime to pH 6.5. B. The soil should be tested to determine the amounts of amendments needed. If the soil must be fertilized before results of a soil test can be obtained to determine fertilizer needs,apply commercial fertilizer at 1.0 lbs/1,000 sq.ft.of N, P205,and K20. C. Lime and fertilizer shall be mixed thoroughly into the seedbed during preparation. D. Channels,except for paved section,shall have at Definition & Scone least 4 inches of topsoil. E. Remove stones and other obstructions that will Waterways are a permanently constructed conveyance hinder maintenance. channel,shaped or graded. They are vegetated for the safe transport of excess surface water from construction sites 2. Timing of Seeding. and urban areas without damage from erosion. A. Early spring and late August are best. Conditions Where Practice Applies B. Temporary cover to protect from erosion is This standard applies to vegetating waterways and similar recommended during periods when seedings may water carrying structures. fail. Supplemental measures may be required with this practice. 3. Seed Mixtures: These may include: subsurface drainage to permit the growth of suitable vegetation and to eliminate wet spots;a Mixtures Rate per Rate per 1,000 section stabilized with asphalt,stone,or other suitable Acre(lbs) sq.ft.(lbs) means;or additional storm drains to handle snowmelt or storm runoff. A. White clover or Ladino clover' 8 0.20 Retardance factors for determining waterway dimensions are shown in Table 3.1 on page 3.10 and"Maximum Smooth bromegrass 20 0.45 Permissible Velocities for Selected Grass and Legume Creeping red fescue2 2 0.05 Mixtures"(See Table 4.10 on page 4.79). Total 30 0.70 Design Criteria OR Waterways or outlets shall be protected against erosion by B. Smooth bromegass3 25 0.60 vegetative means as soon after construction as practical. Vegetation must be well established before diversions or Creeping red fescue 20 0.50 other channels are outletted into them. Consideration Perennial ryegrass 10 0.20 should be given to the use of turf reinforcement mats, excelsior matting,other rolled erosion control products,or Total 55 1.30 sodding of channels to provide erosion protection as soon 1 Inoculate with appropriate inoculum immediately prior to seeding. Ladi- after construction as possible. It is strongly recommended no or birdsfoot trefoil may be substituted for common white clover and that the center line of the waterway be protected with one of seeded at the same rate. the above materials to avoid center gullies and to protect 2 Perennial ryegrass may be substituted for the creeping red fescue but seedlings from erosion before establishment. increase seeding rate to 5 lbs/acre(0.1 lb/1,000 sq.ft). 3 Use this mixture in areas which are mowed frequently. Common white I. Liming,fertilizing,and seedbed preparation. clover may be added if desired and seeded at 8 lbs/acre(0.21b/1,000 sq. ft.) November 2016 Page 4.78 New York State Standards and Specifications For Erosion and Sediment Control 4. Seeding Waterways shall not be used for roadways. Select the appropriate seed mixture and apply uniformly If rills develop in the centerline of a waterway,prompt over the area. Rolling or cultipacking across the waterway attention is required to avoid the formation of gullies. is desirable. Either stone and/or compacted soil fill with excelsior or filter fabric as necessary may be used during the Waterway centers or crucial areas may be sodded. Refer to establishment phase. See Figure 4.25,Rill Maintenance the standard and specification for Stabilization with Sod. Measures. Spacing between rill maintenance barriers shall Be sure sod is securely anchored using staples or stakes. not exceed 100 feet. 5. Mulching All seeded areas will be mulched. Channels more than 300 feet long,and/or where the slope is 5 percent or more,must have the mulch securely anchored. Refer to the standard and specifications for Mulching for details. 6. Maintenance Fertilize,time,and mow as needed to maintain dense protective vegetative cover. Table 4.10 Maximum Permissible Velocities for Selected Seed Mixtures Permissible Velocity 1 Cover Slope Range 2 (oho) Erosion-resistant Soils Easily Eroded Soils (ft.per sec.) (ft.per sec.) K=0.10-0.35 3 K=0.36-0.80 Smooth Bromegrass 0-5 7 5 Hard Fescue 5-10 6 4 Over 10 5 3 Grass Mixtures 2 0-5 5 4 5-10 4 3 White/Red Clover Alfalfa 4 0-5 3.5 2.5 Red Fescue 'Use velocities exceeding 5 feet per second only where good covers and proper maintenance can be obtained. 2 Do not use on slopes steeper than 10 percent except for vegetated side slopes in combination with a stone,concrete,or highly resistant vegetative center section. 3 K is the soil erodibility factor used in the Revised Universal Soil Loss Equation.Visit Appendix A or consult the appropriate USDA NRCS technical guide for K values for New York State soils. 4 Do not use on slopes steeper than 5 percent except for vegetated side slopes in combination with a stone,concrete,or highly resistant vegetative center section. s Annuals-use on mild slopes or as temporary protection until permanent covers are established. 6 Use on slopes steeper than 5 percent is not recommended. New York State Standards and Specifications Page 4.79 November 2016 For Erosion and Sediment Control Figure 4.25 Rill Maintenance Measures Filter Fabric Fabric Section of A-A A E � Bottom of Channel ti t Compacted A Soil Fill Stone Section of A-A FLOW O=1m Bottom of Channel A November 2016 Page 4.80 New York State Standards and Specifications For Erosion and Sediment Control SECTION 5 SEDIMENT CONTROL CONTENTS Page List of Tables and Figures Scopeand Discussion........................................................................................................................................................5.1 ChemicalTreatment ..........................................................................................................................................................5.1 BufferFilter Strip ..............................................................................................................................................................5.3 CofferdamStructure ..........................................................................................................................................................5.5 CompostFilter Sock..........................................................................................................................................................5.7 DewateringDevice ..........................................................................................................................................................5.10 GeotextileFilter Bag .......................................................................................................................................................5.16 RockDam .......................................................................................................................................................................5.17 SedimentBasin................................................................................................................................................................5.19 SedimentDike .................................................................................................................................................................5.42 SedimentTank-Portable ................................................................................................................................................5.44 SedimentTrap .................................................................................................................................................................5.46 SiltFence ........................................................................................................................................................................5.54 StonnDrain Inlet Protection ...........................................................................................................................................5.57 StrawBale Dike ..............................................................................................................................................................5.63 TurbidityCurtain.............................................................................................................................................................5.65 Section prepared by: Donald W.Lake Jr.,P.E.,CPESC,CPSWQ Former Engineering Specialist New York State Soil&Water Conservation Committee Adjunct Assistant Professor State University of New York,College of Environmental Science and Forestry List of Tables and Figures Table Title Page 5.1 Compost Sock Fabric Minimum Specifications Table ..........................................................................5.8 5.2 Compost Standards Table.......................................................................................................................5.8 Figure Title Page 5.1 Buffer Filter Strip...................................................................................................................................5.4 5.2 Compost Filter Sock...............................................................................................................................5.9 5.3 Skimmer Orifice Design Chart.............................................................................................................5.11 5.4 Skimmer Dewatering Device................................................................................................................5.12 5.5 Riser Pipe Dewatering Device..............................................................................................................5.14 5.6 Riser Pipe Dewatering Device Construction Notes..............................................................................5.15 5.7 Rock Dam.............................................................................................................................................5.18 5.8 Pipe Spillway Design...........................................................................................................................5.26 5.9 Sediment Basin ....................................................................................................................................5.27 5.10 Riser Inflow Chart ...............................................................................................................................5.28 5.11 Pipe Flow Chart;"n"=0.025 ..............................................................................................................5.29 5.12 Pipe Flow Chart;"n"=0.013 ..............................................................................................................5.30 5.13 Concentric Trash Rack and Anti-Vortex Device .................................................................................5.31 5.14 Concentric Trash Rack and Anti-Vortex Device Table .......................................................................5.32 5.15 Riser Base Detail .................................................................................................................................5.33 5.16 Anti-Seep Collar Design......................................................................................................................5.34 5.17 Anti-Seep Collar Design Charts ..........................................................................................................5.35 5.18 Anti-Seep Collar ..................................................................................................................................5.36 5.19 Design Data for Earth Spillways .........................................................................................................5.37 5.20 Design Table for Vegetated Earth Spillways in Erosion Resistant Soils..............................................5.38 5.21 Design Table for Vegetated Spillways Excavated in Very Erodible Soils ..........................................5.39 5.22 Sediment Basin Baffle Details .............................................................................................................5.41 5.23 Sediment Dike .....................................................................................................................................5.43 5.24 Portable Sediment Tank ......................................................................................................................5.45 5.25 Pipe Outlet Sediment Trap: ST-I .........................................................................................................5.49 5.26 Pipe Outlet Sediment Trap: ST-1 -Construction Specifications .........................................................5.50 5.27 Stone Outlet Sediment Trap: ST-II ......................................................................................................5.51 5.28 Compost Sock Sediment Trap: ST-III..................................................................................................5.52 5.29 Optional Sediment Trap Dewatering Devices .....................................................................................5.53 5.30 Reinforced Silt Fence ..........................................................................................................................5.56 5.31 Excavated Drop Inlet Protection..........................................................................................................5.60 5.32 Fabric Drop Inlet Protection ................................................................................................................5.61 5.33 Stone&Block Drop Inlet Protection...................................................................................................5.62 5.34 Straw Bale Dike ...................................................................................................................................5.64 5.35 Turbidity Curtain .................................................................................................................................5.66 SEDIMENT CONTROL Scope and Discussion upslope areas away from disturbed areas. Sediment control is the second component in the site 2. Employ natural vegetative buffers or artificial mats to management plan after erosion control.Primary emphasis assist in sediment capture in sheet flow areas. should be placed on erosion control first which combines 3. Control concentrated flow to minimize additional runoff control and soil stabilization to minimize soil erosion that could overwhelm a practice. erosion. Sediment control practices are then integrated into the plan to further reduce the migration of eroded soil both 4. Stabilize all sediment control systems as soon as they on and off site. are installed so they do not contribute sediment to site runoff. The majority of sediment control practices utilize settling to capture sediment within a storage volume where it can be 5. Remove all practices after use and stabilize the contained and managed.These practices include sediment regraded areas immediately. basins,sediment traps and dikes,rock dams,water Sediment accumulated in the sediment control practices structures,silt fence,turbidity curtains,straw bale dikes, must be removed when the sediment has filled the and portable settling tanks.There is also a group of designated storage volume for the practice.The material practices that rely on both filtering and settling to capture must be disposed of in a manner that stabilizes it on the sediment.These practices include storm drain inlet construction site.These details,as well as the frequency of protection structures,geotextile filter bags,compost tubes, inspection,sequences of installation and removal,and an and buffer filter strips.In addition,the use of chemical inspection checklist shall be included in the Stormwater polymer substances is a process that may,with NYSDEC Pollution Prevention Plan for the site. approval,be used on sites where disturbed clay soils remain in suspension. Chemical Treatment It is important that these sediment control practices be designed,constructed and installed in accordance with the Precipitation of sediment is enhanced with the use of criteria contained in these standards.For these practices to specific chemical flocculants that can be applied to a effectively remove sediment from turbid water,the sediment basin in liquid,powder,or solid form.Flocculants volumes,dimensions,and appropriate attributes of these include polyacrylimide,aluminum sulfate(alum),and individual practices must be maintained.This includes the polyaluminum chloride. calculated relationships of dimensions to respective - drainage areas,length to width ratios,and frequency of ' inspection and maintenance. Note:Performing activities within or adjacent to wetlands,streams and waterbodies may require permits from the New York State Department of S Environmental Conservation(NYSDEC)pursuant to Article 15(Protection of Waters),Article 24 (Freshwater Wetlands)and Article 25(Tidal Wetlands) of the Environmental Conservation Law(ECL). Project owners should contact NYSDEC's Regional Division of Environmental Permits early in the site planning process to discuss the requirements for meeting permit issuance standards.Following the New York State Standards and Specifications for Erosion and Sediment Control may not ensure compliance with Polymer flocculation shall only be used for dispersive soil- the above referenced sections of the ECL. water mixtures that do not respond to normal settling times when allowed to set in sediment traps and basins,i.e.less than 7 days.Controlled application takes place in a To assist with the success of these sediment control sediment basin or trap with anionic polyelectrolytes in the practices,apply the following concepts for the practice form of liquid,powder,or solid form,such as design and location: polyacrylimide,aluminum sulfate,chitosan lactate,or chitosan acetate. Cationic polyelectrolytes have a greater 1. Keep the clean water clean by diverting runoff from toxicity to fish and other aquatic organisms than anionic New York State Standards and Specifications Page 5.1 November 2016 For Erosion and Sediment Control polyelectrolytes because they bind to the gills of fish resulting in respiratory failure(Pitt 2003). Chemical treatment shall not be substituted for proper planning,phasing,sequencing,and the design of appropriate erosion and sediment control practices. Vm No polymer application shall take place without written approval from NYSDEC. Field tests must be conducted on the proposed site at the design basin locations with the tributary soils to establish polymer dosing rates and verify settling performance. Treated water discharged from sediment basins with polymer treatment will be tested to determine that any residual polymer meets the standards set by NYSDEC. Polymer flocculation systems require daily inspection. November 2016 Page 5.2 New York State Standards and Specifications For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR BUFFER FILTER STRIP Land Slope(%) Minimum Filter i Strip Width(ft.) Y <10 50 20 60 30 85 40 105 50 125 60 145 70 165 Definition & Scope 3. The minimum buffer filter strip width to protect paved areas during construction is 20 feet. A temporary/pernianent well vegetated grassed area below a disturbed area that can be used to remove sediment from Maintenance runoff prior to it reaching surface waters or other designated areas of concern,such as parking lots and road pavement. If at any time the width of the buffer filter strip has been reduced by sediment deposition to half its original width or Condition Where Practice Applies concentrated flow has developed,suitable additional prac- tices should be installed. The erosion and sediment control This practice is effective when the flow is in the form of plan shall include these details. sheet flow and the vegetative cover is established prior to disturbance. Surface water must be protected from sedi- ment-laden runoff until buffer filter strip vegetation is es- tablished,and then the proposed disturbance can be under- taken. This practice is effective when the flow is in the form of sheet flow(maximum of 150 feet). Design Criteria 1. The vegetation should be a well established perennial grass. Wooded and brushy areas are not acceptable for purposes of sediment removal. 2. The minimum buffer filter strip width for stream pro- tection shall be in accordance with the following table: New York State Standards and Specifications Page 5.3 November 2016 For Erosion and Sediment Control Figure 5.1 Buffer Filter Strip ':]1]TH R❑Aar CITY SLURE R13AD SIDE DITCFI FILL EDGE' OF CONSTRLC IC% DISTLRBANCE - STROP APPTIED FROM DETAILS PIR13VIDED BTF PENNSTLVAhEA DE13ARTMENT BUFFER FILTER OF EW1ROWENTAL MTECT IEft STRIP November 2016 Page 5.4 New York State Standards and Specifications For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR COFFERDAM STRUCTURES the work area to manage seepage. 5. The ends of the water structures shall be anchored on �.� the stream banks or shorelines at an elevation at least above the top of the structure. . - Structural Component Dams 1. These structures shall be sized and installed in accord- ance with the manufacturers recommendations. 2. The foundation area for the placement of the structural steel framing and the impervious fabric membrane shall be as directed by the manufacturer or by qualified per- sonnel. 3. Dewatering the interior of the coffer dam will be done Definition & Scope in a manner that does not disturb the foundation area of the structural frame. A temporary barrier placed at a worksite to prevent water from flooding the work area so that construction can take 4. A minimum of 2 feet of freeboard shall be provided place without discharging sediment into the water resource. above the expected high water elevation. Condition Where Practice Applies Earthen Coffer Dams Temporary coffer dams are used to separate streams,rivers, 1. The earthen coffer dam shall be constructed of fill ma- terial that will preclude the transmission of water lakes,and other sources of surface water from adjacent lo- through the dam,or contain an impermeable core. cations where soil disturbances are undertaken to complete construction. These barriers can be constructed of manu- 2. The minimum top width shall be 8 feet with 2:1 side factured components such as geotextile/plastic tubes filled slopes,and compacted in 9 inch lifts with a minimum with water,portable dams formed by metal framing with a of 4 passes of construction equipment. geo-membrane,or conventionally constructed earth and stone dike systems. 3. The outside slope shall be covered with a 1 foot layer of rock riprap over a graded stone bedding or geotextile Design Criteria to prevent erosion of soil material into water. An alter- native method is to cover the outside slope with an an- The maximum height for this application is 10 feet. No chored plastic cover with a minimum thickness of 20 construction activity shall commence in the area of the cof- mil ferdam until it is completed and stabilized. 4. Interior work will be conducted in a manner that will Water Filled Structures not disturb or undermine the earthen coffer dam or its foundation. 1. These structures shall be sized and installed according to the manufacturers recommendations. Inspection and Maintenance 2. Adequate freeboard must be provided to prevent flota- 1. All cofferdams will be inspected daily to assure proper tion during high water events and periods of below performance and stability as vibration from construc- freezing temperatures. tion equipment can cause disturbance of the structures. 3. The foundation shall be prepared to provide full bottom 2 Particular attention should be given to the foundation contact prior to filling. support system at perimeter of structural component 4. An interior dewatering system shall be designed within dams. Any undermined or settled areas shall be re- stored immediately. New York State Standards and Specifications Page 5.5 November 2016 For Erosion and Sediment Control 3. Any holes,leaks,or torn areas in the geo-membranes or fabric shall be repaired immediately. 4. Any shifting,movement,or settling of the coffer dam shall be addressed immediately to protect workers in the construction area. 5. Inspect the interior dewatering system and ensure that the system is discharging clean water,or is being pumped to appropriate sediment control facility prior to returning to the water resource. 6. Repair or replace any loss of rock riprap or fill that may occur and assure the top of the coffer dam is level with- out any low spots due to settling. 7. Upon completion of the construction work,remove all excess material,accumulated sediment and debris from the work area,and remove the cofferdam in accordance with the site stabilization plan. November 2016 Page 5.6 New York State Standards and Specifications For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR COMPOST FILTER SOCK that 8"diameter socks may be used for residential lots to control areas less than 0.25 acres. 3. The flat dimension of the sock shall be at least 1.5 times the nominal diameter. 4. The Maximum Slope Length(in feet)above a compost _ filter sock shall not exceed the following limits: t - Slope Dia.(in.) 2 5 10 20 25 33 50 8 225* 200 100 50 20 — — 12 250 225 125 65 50 40 25 18 275 250 150 70 55 45 30 24 350 275 200 130 100 60 35 32 450 325 275 150 120 75 50 Definition & Scope *Length in feet A temporary sediment control practice composed of a de- gradable geotextile mesh tube filled with compost filter media to filter sediment and other pollutants associated with - construction activity to prevent their migration offsite. Condition Where Practice Applies Compost filter socks can be used in many construction site applications where erosion will occur in the form of sheet - erosion and there is no concentration of water flowing to the sock.In areas with steep slopes and/or rocky terrain,soil conditions must be such that good continuous contact be- tween the sock and the soil is maintained throughout its 5. The compost infill shall be well decomposed(matured length.For use on impervious surfaces such as road pave- at least 3 months),weed-free,organic matter. It shall ment or parking areas,proper anchorage must be provided be aerobically composted,possess no objectionable to prevent shifting of the sock or separation of the contact odors,and contain less than 1%,by dry weight,of man- between the sock and the pavement.Compost filter socks made foreign matter. The physical parameters of the are utilized both at the site perimeter as well as within the compost shall meet the standards listed in Table 5.2- construction areas.These socks may be filled after place- Compost Standards Table. Note:All biosolids compost ment by blowing compost into the tube pneumatically,or produced in New York State(or approved for im- filled at a staging location and moved into its designed loca- portation)must meet NYS DEC's 6 NYCRR Part tion. 360(Solid Waste Management Facilities)require- ments. The Part 360 requirements are equal to or Design Criteria more stringent than 40 CFR Part 503 which ensure safe standards for pathogen reduction and heavy 1. Compost filter socks will be placed on the contour with metals content. When using compost filter socks both terminal ends of the sock extended 8 feet upslope adjacent to surface water,the compost should have at a 45 degree angle to prevent bypass flow. a low nutrient value. 2. Diameters designed for use shall be 12"—32"except 6. The compost filter sock fabric material shall meet the New York State Standards and Specifications Page 5.7 November 2016 For Erosion and Sediment Control 7. Compost filter socks shall be anchored in earth with 2" 3. Socks shall be inspected weekly and after each runoff x 2"wooden stakes driven 12"into the soil on 10 foot event.Damaged socks shall be repaired in the manner centers on the centerline of the sock. On uneven ter- required by the manufacturer or replaced within 24 rain,effective ground contact can be enhanced by the placement of a fillet of filter media on the disturbed hours of inspection notification. area side of the compost sock. 4. Biodegradable filter socks shall be replaced after 6 8. All specific construction details and material specifica- months;photodegradable filter socks after 1 year.Poly- tions shall appear on the erosion and sediment control propylene socks shall be replaced according to the constructions drawings when compost filter socks are manufacturer's recommendations. included in the plan. 5. Upon stabilization of the area contributory to the sock, Maintenance stakes shall be removed.The sock may be left in place and vegetated or removed in accordance with the stabi- 1. Traffic shall not be permitted to cross filter socks. lization plan.For removal the mesh can be cut and the compost spread as an additional mulch to act as a soil 2. Accumulated sediment shall be removed when it reach- supplement. es half the above ground height of the sock and dis- posed of in accordance with the plan. Table 5.1 - Compost Sock Fabric Minimum Specifications Table Multi-Filament Heavy Duty Multi- Material Type 3 mil HDPE 5 mil HDPE 5 mil HDPE Polypropylene Filament Polypropylene (MFPP) (HDMFPP) Material Character- Photodegrada- Photodegrada- Biodegradable Photodegrada- Photodegradable istics ble ble ble 12" 12" 12 12" Sock Diameters 12" 181, 181, 18, 181, 181, 24" 24" 24" 24" 32" 32" 32" 32" Mesh Opening 3/8" 3/8" 3/8" 3/8" 1/81, Tensile Strength 26 psi 26 psi 44 psi 202 psi Ultraviolet Stability 100%at 1000 %Original Strength 23%at 1000 hr. 23%at 1000 hr. hr. 100%at 1000 hr. (ASTM G155) Minimum Functional 6 months 9 months 6 months 1 year 2 years Longevity Table 5.2 - Compost Standards Table Organic matter 25%- 100%(dry weight) content Organic portion Fibrous and elongated pH 6.0—8.0 Moisture content 30%-60% Particle size 100%passing a 1"screen and 10-50%passing a 3/8"screen Soluble salt concentration 5.0 dS/m(mmhos/cm)maximum November 2016 Page 5.8 New York State Standards and Specifications For Erosion and Sediment Control Figure 5.2 Compost Filter Sock ❑"XE WOODEN STARES PLACED 10' C.C. COWOST F-_T ER SOCK BLGWN/PLACED FILTER MEDIA U;:: � UREF� DI$TURRED AREA klllvl, SECTION VIE� EXISTTNG CONT URS DISTURBED AREA z � I 2"x2" WOODEN STAKES PLACED 10' D.C. ONDISTURBED C JMP13ST F[L 1 F R S❑EK AREA PLAN VIES,+ COMPOST FILTER ADAPTED FREM DETAILS PROM DE a Vi IF]L TRCXX D CK New York State Standards and Specifications Page 5.9 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR DEWATERING DEVICE 5. The orifice plate will be at the"T"intersection of the perforated skimmer section with the non-perforated - extension arm. -` Riser-Pipe Device 1. The riser-pipe device is constructed as a fined rigid structure with a larger diameter pipe as the vertical riser connected to a smaller diameter horizontal pipe barrel. 2. The joint of these two conduits will be anchored by means of a concrete block or welded steel plate to pre- vent flotation. 3. The riser will be perforated above the bottom of the dewatering zone elevation and wrapped with a geotex- tile filter fabric to filter out sediment. Definition & Scope 4. The filter fabric shall be covered with stone graded as An appurtenance to a sediment trapping structure such as a NYSDOT#1,#2,or a blend of both,to protect the fab- basin or trap that allows sediment laden water to pond al- ric from deterioration. lowing sediment to settle out while removing relatively 5. An orifice plate shall be placed in the riser at the bot- clean water to a suitable,stable outlet. tom of the dewatering zone elevation to control the dewatering rate. Condition Where Practice Applies Dcwatering Drawdown Dewatering devices are appropriate where the discharge from a trap or basin will be by gravity flow through a riser As a minimum,sediment traps and basins should have their and pipe outlet system. The skimmer dewatering device is temporary storage dewatered over a 48 hour period to max- the preferred option. A fixed pipe dewatering device,con- imize sediment retention. If the soils disturbed within the figured as a perforated vertical riser surrounded by filter drainage area will have 60%-80%fines the settling time fabric and stone material is an alternate option for small should be increased to 4 days. Soils containing greater than structures. 80%fines will need longer settling times but in no case longer than 7 days to maintain the hydraulic performance of Design Criteria the basin for recurring runoff events. Skimmer Device 1. Skimmer orifices may be sized by using the design chart shown in Figure 5.3 on page 5.11. 1. Skimmers must be designed so as to float just beneath 2 Riser-pipe orifice sizes may be approximated by the the water surface to remove the least sediment laden following formula: water effectively. 2. Skimmer shall be constructed with a 4 foot long flexi- A _ rfs x 2hD3 ble pipe elbow to allow for vertical movement of the ° T x C x 20,428 skimmer for its designated range of operation. Where: 3. The designer will provide a table that shows all re- quired dimensions for the skimmer. An example of Ao=Areas of the dewatering orifice(ft2) this table is shown in Figure 5.4 on page 5.12. See As=Surface area of the basin/trap(ft) design example in Appendix B. h=head of water above the orifice(ft) 4. The skimmer will be provided with vertical travel Cd=0.6(contraction coefficient of an orifice) guides and a resting stone pad set at the appropriate design elevation. T=Detention time needed to dewater basin(48 hours minimum) November 2016 Page 5.10 New York State Standards and Specifica- For Erosion and Sediment Control Therefore,the minimum A.formula for 48 hrs.reduces to: Maintenance � A.=.4,x 2k 1. Dewatering devices shall be inspected weekly and after each runoff event. Material Specifications 2. Filter fabric or media will be replaced as needed. 1. Skimmer Devices-These devices shall be constructed 3. Any malfunctioning skimmer or its components shall with Schedule 40 PVC pipe with diameters of 4 to 6 be repaired or replaced within 24 hours of inspection inches. The flexible arm shall be equal diameter of non notification. -perforated,corrugated,plastic tubing. 4. Sediment shall be removed from the system when it 2. Riser-pipe Devices-These devices shall be constructed reaches the level marked in a sediment cleanout stake of Schedule 40 PVC if plastic pipe is used or galva- or the top of the skimmer landing area. nized corrugated steel or aluminum pipe. The mini- mum diameter shall be 6 inches if the device is used in 5. The structure shall only be removed when the tributary conjunction with another permanent riser. All perfora- area has been properly stabilized. tions will be at the interior of the corrugations. Figure 5.3 - Skimmer Orifice Design Chart M. —2d -D1 6lkS1aWYATfR 10AILCA'wtUNE 1h F *Figure adapted from Penn State Agricultural and Biological Fact Sheet F-253 Notes: 1. Figure 5.3 is for use in designing the orifice plate for the skimmer shown in Figure 5.4. It assumes 3"to 5"head (depending upon the size of the skimmer). The required head for use of Figure 5.3 varies as follows:For a skimmer with a dewatering tube<2 1/2"diameter,use a 2"head. For a 3"diameter tube,use a 2.5"head;4"tube,use 3.3" head,5"tube use 4"head,and 6"diameter tube use 5"head. 2. Find the vertical line representing the basin's dewatering zone volume. At the intersection of the vertical line with the desired dewatering time,read horizontally to the left to find the required skimmer orifice diameter. New York State Standards and Specifications Page 5.11 November 2016 For Erosion and Sediment Control Figure 5.4 Skimmer Dewatering Device PVC VENT FIRE ARhA .SEMFLY GORE RAILS PERSPECTIVE VIEW PVGIELEWM PVC VEP47? � S�CHEOL&F-40 PVC PIPE T( WATER SURFACE PVC E140 CAP ORIFICE PLATE 40 PVUPIPE SEDIMENT LI-EVAT ION FLEXIBLE MCBE LANCIRM ti DEVICE FRONT VE END VIEW �. *Figure adapted from Penn State Agricultural and Biological Fact Sheet F-253 Top of Land- Flexible Water Sur- Flexible Hose Arm Arm Dia. Orifice ing Device Hose Basin No. face Eleva- Attachment Length* (ft.) (in.) Size** (in.) Elevation Length tion(ft.) (ft.) (in.) Elevation(ft.) *Minimum Arm length=Full design storage depth x 1.414(for 45 degree angle) **Must be equal to or less than arm diameter November 2016 Page 5.12 New York State Standards and Specifica- For Erosion and Sediment Control Skimmer Construction Notes 1. Pipe flotation section shall be solvent welded to ensure an airtight assembly. The contractor is required to con- duct a test to check for leaks prior to installation. 2. Skimmer section shall have 12 rows of 1/2"diameter holes, 1 1/4" on center. If additional filtration is nec- essary,the filtering media shall consist of a Type GD-Il geotextile fabric wrapped around the perforated portion of the skimmer and attached with plastic snap ties, bands,etc. 3. Flexible pipe shall be inserted into solid pipe and fas- tened with 2#8 wood screws. 4. At a minimum,the structure shall be inspected after each rain and repairs made as needed. If vandalism is a problem,more frequent inspection may be necessary. 5. Construction operations shall be carried out in such a manner that erosion and water pollution are minimized. 6. The structure shall only be removed when the contrib- uting drainage area has been properly stabilized. Materials (Note:materials for a 4"diameter arm assembly) 1. Solid Pipe-4"Schedule 40 PVC 2. Perforated Pipe-4"Schedule 40 PVC 3. 90'Tee(1 each)-4"Schedule 40 PVC 4. 90'Elbow(4 each)-4"Schedule 40 PVC 5. Cap(2 each)-4"Schedule 40 PVC,solid 6. Flexible pipe-4"Corrugated Plastic Tubing(non- perforated) New York State Standards and Specifications Page 5.13 November 2016 For Erosion and Sediment Control Figure 5.5 Riser Pipe Dewatering Device Y ,,'B11L OPTIENAL< SEDIMENT BASIN DL WA TER1NG DEVICE - I WITH 6` MIN- PERFORATED RISER CAP END UNLESS EOUAL TO ❑R GREATER Y I EL-E1f, OF TOP OF FILL ANT TEX PRIMARY RISER GREET DEVICE V PERFORATIONS MIFF. 6' RISER INAMET'ER P FILTER' CLOTH OVER WIRE RZSH APPROXIMATE ORIFICE PLATE LOCATION MIN- 6* DIA NYS DOT #2 STUNE PIPE CORE CONTIRLPOUS BAND BArRE-L_ RISER BASE BASE L L P* A T_ ( /4.) PERFORATIONS OR SLITS WM.JST NOT SIM D#EA BE MADE ANT LOWER THA" -ra' ABOVE TIP OF HORIZONTAL. ourrALL BARREL, PERF❑RATIE14S - 6' SPACIN❑ HORIZ04—AL +VERTICAL LOCATED IN CONCAVE. OPTIONAL SEDIMENT BASIN DEWATE INN DEVICE IT PO4D EMBANKMENT 6' if 2' DIAM. ROD BOLTED OR 'DEL OE'D TO RISEN B MIN.. D3AME TER PERFORATED PIPE VRAPPED WITH FILTER CLOTH. FIIFL IVMIN, LAYER* MYS DOLT 02 STDNE 1 'MIN, LAYER MrYS DBT 162 $TQNE - AP E 'WELDED OR CE14ENTED ,JOINT of Pik (WITH ADAPTER IF NECESSARY) ADAPTED FROM DETAILS PRBV3 GEa Bwi USDA - INRCS, RISER PIPE RKTEENTOFENVIRONMENTAL131- C3NEV YO STATE STATE TK DERVA7[QN, DEWATERINE NF V YORIC STATE SOIL 6 VATEP CONSEI?vATTEN CONMIrTEE I)EVTCE: November 2016 Page 5.14 New York State Standards and Specifica- For Erosion and Sediment Control Figure 5.6 Riser Pipe Dewatering Device Construction Notes Riser Pipe Construction Notes 7. The riser shall be wrapped with a Type GD-11 geotex- tile fabric. The fabric shall extend 6inches above the 1. Standpipe and connector pipe shall be a minimum of 6 highest hole and 6"below the lowest hole. Where ends inches diameter. of fabric come together,they shall be overlapped,fold- ed and stapled to prevent bypass. 2. Metal pipe may be galvanized steel or aluminum;plas- tic pipe may be Schedule 40 PVC or HDPP. 8. Straps or connecting bands shall be used to hold the fabric and wire mesh(as needed)in place. They shall 3. Construction operations shall be carried out in such a be placed at the top and bottom of the cloth. manner that erosion and water pollution are minimized. 9. The standpipe shall be anchored with either concrete 4. The structure shall only be removed when the contrib- base or steel plate base to prevent flotation. Concrete uting drainage area has been properly stabilized. bases shall be 12 inches thick with the standpipe em- bedded nine inches. Steel plate bases will be 1/4 inch 5. All pipe connections shall be watertight.The lower minimum thickness attached to the standpipe by a con- portion of the standpipe,at a point above the barrel tinuous weld around the bottom to form a watertight connection,shall be fitted with an internal orifice plate connection. The plate shall have 2.5 feet of stone, sized to release the volume of the basin no sooner than gravel or tampered earth placed on it. 48 hours. 10. The perforated standpipe shall be surrounded by 6. The top 2/3 of the standpipe shall be perforated with 1 NYSDOT#1 or#2 stone or a blend of both to protect inch diameter hole or slit spaced 6 inches vertically and the filter fabric. horizontally and placed in the concave portion of the pipe. No holes will be allowed within 6 inches inches of the horizontal connector pipe. New York State Standards and Specifications Page 5.15 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR GEOTEXTILE FILTER BAG Materials and Installation 1. The geotextile material will have the following attrib- utes: r Minimum Grab Tensile Strength 200 lbs. Minimum Grab Tensile Elongation 50% Minimum Trapezoid Tear Strength 80 lbs. Mullen Burst Strength 380 psi Minimum Puncture Strength 130 lbs Definition & Scope Apparent Opening Size 40-80 US sieve A temporary portable device through which sediment laden Minimum UV Resistance 70% water is pumped to trap and retain sediment prior to its dis- Minimum Flow Thru Rate 70 gpm/sq ft charge to drainageways or off-site. Condition Where Practice Applies 2. The bag shall be sewn with a double needle machine using high strength thread,double stitched"Joe"type On sites where space is limited such as urban construction capable of minimum roll strength of 1001bs/inch or linear projects(e.g.roads and utility work)where rights- (ASTM D4884). of-way are limited and larger de-silting practices are im- practical. 3. The geotextile filter bag shall have an opening large enough to accommodate a 4 inch diameter discharge Design Criteria hose with an attached strap to tie off the bag to the hose to prevent back flow. 1. Location-The portable filter bag should be located to 4. The geotextile shall be placed on a gravel bed 2 inches minimize interference with construction activities and thick,a straw mat 4 inches thick,or a vegetated filter pedestrian traffic. It should also be placed in a location strip to allow water to flow out of the bag in all direc- that is vegetated,relatively level,and provides for ease tions. of access by heavy equipment,cleanout,disposal of trapped sediment,and proper release of filtered water. Maintenance The filter bag shall also be placed at least 50 feet from 1. The geotextile filter bag is considered full when re- all wetlands,streams or other surface waters. maining bag flow area has been reduced by 75%. At 2. Size-Geotextile filter bag shall be sized in accordance this point,it should be replaced with a new bag. with the manufacturers recommendations based on the 2 Disposal may be accomplished by removing the bag to pump discharge rate. an appropriate designated upland area,cut open,re- move the geotextile for disposal,and spread sediment contents and seeded and mulched according to the veg- etative plan. November 2016 Page 5.16 New York State Standards and Specifica- For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR ROCK DAM Dam Section: Top Width 5 feet minimum @ crest Side Slopes 2:1 upstream slope 3:1 downstream slope Height 6'max to spillway crest Length of Crest: The crest length should be designed to carry the 10 yr.peak runoff with a maximum flow depth of 1 foot and 1 foot of freeboard. Rock at the abutments should extend at least 2 feet above the spillway and be at least 2 feet thick. These rock abut- Definition & Scope ments should extend at least one foot above the downstream slope to prevent abutment scour. A rock apron at least 1.5 A rock embankment located to capture and retain sediment feet thick should extend downstream from the toe of the on the construction site and prevent sedimentation in offsite dam a distance equal to the height of the dam to protect the water bodies. outlet area from scour. Rock Fill: The rock fill should be well graded,hard, Conditions Where Practice Applies erosion resistant stone with a minimum d50 size of 9 inches. A"key trench"lined with geotextile filter fabric should be The rock dam may be used instead of the standard sediment installed in the soil foundation under the rock fill. The filter basin with barrel and riser. The rock dam is preferred when fabric must extend from the key trench to the downstream it is difficult to construct a stable,earthen embankment and edge of the apron and abutments to prevent soil movement rock materials are readily available. The site should be ac- and piping under the dam. cessible for periodic sediment removal. This rock dam shall The upstream face of the dam should be covered with a fine not be located in a perennial stream. The top of the dam sashed gravel(NYS-DOT#1 or#lA gravel,crushed stone will serve as the overflow outlet. The inside of the dam will or equal)a minimum 3 feet thick to reduce the drainage be faced with smaller stone to reduce the rate of seepage so a sediment pool forms during runoff events. rate. Trapping Efficiency: To obtain maximum trapping effi- Desi2n Criteria ciency,design for a long detention period. Usually a mini- mum of eight(8)hours before the basin is completely Drainage Area: The drainage area for this off stream drained. Maximize the length of travel of sediment laden structure is limited to 50 acres. water from the inlet to the drain for a minimum length to width ratio of 2 to 1 or greater. Achieve a surface area Location: The location of the dam should: equal to 0.01 acres per cfs(inflow)based on the 10-year storm. See Figure 5.7 on page 5.18 for details. • provide a large area to trap sediment • intercept runoff from disturbed areas Maintenance • be accessible to remove sediment • not interfere with construction activities Check the basin area after each rainfall event. Remove sed- iment and restore original volume when sediment accumu- Storage Volume: The storage volume behind the dam lates to one-half the design volume. Check the structure for shall be at least 3,600 cubic feet per acre of drainage area to erosion,piping,and rock displacement after each significant the dam. This volume is measured one foot below the crest event and replace immediately. of the dam. Remove the structure and any sediment immediately after the construction area has been permanently stabilized. All water should be removed from the basin prior to the remov- al of the rock dam. Sediment should be placed in designat- ed disposal areas and not allowed to flow into streams or drainage ways during structure removal. New York State Standards and Specifications Page 5.17 November 2016 For Erosion and Sediment Control Figure 5.7 Rock Dam FLOW IL SYMBOL CREST p an, � E 3 '� ll 1 i Ek'FI�tiX. �dYS Ta❑T 2'�I' L4 � H �.� al ST❑NE KEY TRENCH�� FILTER FABRIC ROCK SIZE - of 9' ABUTMENT ABUTMENT NUT TO SCALE 2.01 CREST ALENGTH V ARIIES.T 2.01 KEY TRENCH AND A FILTER FABRIC NOT TO SCALE CONSTRUCTION SPECIFICATIDNS L. i -= AREA LIMIER THE ROCK DAM SHALL B 'C'LEiAREB AND STRIPPED ❑F R[1❑T5 AND OTF�EIR Q>�jEGTjQNAjLE MATERIA- THE RIF:SERVOIR SHALL BE CLEARED ASNEE DE D T❑ FACILITATE SEDIMENT REMOVAL 2: d ImE NSI❑NS SHOWN ARE ?4]N]RUMe TRENCH SHALL BE E x v AVATEI) FROM AHU IMLMT TO Aj0jTIMLN1 UN I RL DAM QLN iLR1-JNL. F LL_ r -k i ARRIC HALL CL PL AGED FROM UPSTREAM EDGE OF KEY]RE.NCH TO Q4J WNS T REAM E BGE OF APRON. U❑INTS WILL LAP A KINIOUM OF I FT:. WITH UPSTREAM STRIP ON TOP. 3, CONSTRUCT THE RUCK EMBAWIMENT TO THE DIMENSIONS SHOWN ON THE DRAW[N5, ROCK ABI1TIMENTS SHALL BE MAINTAINED 2 FT. ABOVE THE (SST, 4. TFLE ROCK DA1`d RE, :siahlSTRUCTED PRIQV I LI C_L.I= ]N[, I`HE BASIN AREA. STAIJILIZIL ALL D1S r UR BE D AREAS, EXC E H T THE BASIN AREA, VI T H TEMPICIPARY SEEDINCL S, FENCES AND WARNING SIGNS SHOULD 9E PLACED AS APPROPRIATE. MAXIMUM DRAINAGE #READ 5B ACJYES ADAPTED Elul DETAILS PRO1r'lMED BYo USDA - NRCS, NEW MURK STATE QEPARTMENT QF TRAN�PURIATIIDW NEW YORK STATE JEPARIMENT 13F :ENVTR❑P4MENTAL C NISI`RVATION, ROCK ]DAM NFV YTIRK STATE SDr[, � VATFR CENSIERVATION COMMETTEE November 2016 Page 5.18 New York State Standards and Specifica- For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR SEDIMENT BASIN Design Criteria Compliance with Laws and Regulations Design and construction shall comply with state and local laws,ordinances,rules and regulations,including permits. Location-Maximum Drainage Area=50 acres The sediment basin should be located to obtain the maxi- mum storage benefit from the terrain and for ease of cleanout of the trapped sediment. It should be located to z minimize interference with construction activities and con- struction of utilities. Whenever possible,sediment basins Definition & Scope should be located so that storm drains may outfall or be diverted into the basin. Do not locate basins in perennial A temporary basin with a barrier or dam constructed across streams. a drainage way or at other suitable locations to intercept sediment-laden runoff and reduce the amount of sediment Size and Shape of the Basin leaving the disturbed area in order to protect drainageways, properties,and rights-of--way below the sediment basin. The sediment basin will contain two separate zones.The lowest zone is the sediment storage zone.This zone is sized Conditions Where Practice Applies for a volume equal to 1,000 cubic feet per disturbed acre over the course of the life of the project,contributing to the A sediment basin is appropriate where physical site condi- basin as measured from the bottom of the basin to the bot- tions or land ownership restrictions preclude the installation tom of the dewatering zone.It shall have a minimum depth of other control measures to adequately control runoff,ero- of 1 foot.Layered above this zone is the dewatering zone. sion,and sedimentation. However,it is required that other This zone is sized for a minimum volume equal to 3,600 erosion control measures be used with the sediment basin. cubic feet per each acre draining to the basin.This volume The basin may be used below construction operations which is temporarily stored between the sediment storage zone and expose critical areas to soil erosion. The basin shall be the crest of the principal spillway. This zone should be a maintained until the disturbed area is protected against ero- minimum of 3 feet deep. See Figures 5.8 and 5.9 on pages sion by permanent stabilization. 5.26 and 5.27.This 3,600 cubic feet per acre is equivalent to one inch of sediment per acre of drainage area. The en- This standard applies to the installation of temporary sedi- tire drainage area is used for this computation,rather than ment basins on sites where:(a)failure of the structure the disturbed area above,to maximize trapping efficiency. would not result in loss of life,damage to homes or build- The length to width ratio shall be 2:1 or greater,where ings,or interruption of use or service of public roads or length is the distance between the inlet and outlet.A wedge utilities;(b)the drainage area does not exceed 50 acres;and shape shall be used with the inlet located at the narrow end. (c)the basin is to be removed within 36 months after the See Figure 5.22 on page 5.41. beginning of construction of the basin. Surface Area Permanent(to function more than 36 months)sediment basins,or structures that temporarily function as a sediment Research studies(Barfield and Clar 1985;Pitt,2003)indi- basin but are intended for use as a permanent pool shall be cate that the following relationship between surface area classified as permanent structures and shall conform to cri- and peak inflow rate gives a trapping efficiency of 75%for teria appropriate for permanent structures. These structures silt loam soils,and greater than 90%for loamy sand soils: shall be designed and constructed to conform to NRCS Standard And Specification No. 378 for Ponds in the Na- A=0.01 Qp or,A=0.015x D.A.(whichever is greater) tional Handbook of Conservation Practices and the New York State Department of Environmental Conservation, where, "Guidelines for the Design of Dams." New York State Standards and Specifications Page 5.19 November 2016 For Erosion and Sediment Control A=the basin surface area,acres,measured at the service B. Watertight riser and barrel assembly: The riser spillway crest;and and all pipe connections shall be completely water- tight except for the inlet opening at the top,or a Qp=the peak inflow rate for the design storm. (The mini- dewatering opening.There shall not be other holes, mum design storm will be a 10 year,24 hour storm under leaks,rips,or perforations in the structure. construction conditions). C. Dewatering the basin: D.A. =contributing drainage area. - 1) Preferred Method-The preferred method for Sediment basins shall be cleaned out when the sediment dewatering sediment basins is by using surface storage zone volume described above is reduced by 50 per- skimmers to decant the cleaner top surface water cent,except in no case shall the sediment level be permitted from the basin as the sediment settles out. See De- to build up higher than one foot below the bottom of the watering Device Standard,page 5.10. dewatering zone. At this elevation,cleanout shall be per- formed to restore the original design volume to the sedi- 2) Alternative Method—A fixed vertical riser pipe ment storage zone. configured with perforations and filter fabric with a cone of pea gravel or small crushed stone is an The elevation corresponding to the maximum allowable alternative option for use.See Figure 5.5 on page sediment level shall be determined and shall be stated in the 5.14. design data as a distance below the top of the riser and shall be clearly marked on the riser. The sediment basin dewatering system shall be designed to release the dewatering zone volume The basin dimensions necessary to obtain the required basin between 2 to 7 days in watersheds not impaired by volume as stated above shall be clearly shown on the plans sediment,and 4-7 days in sediment impaired wa- to facilitate plan review,construction,and inspection. tersheds(check the NYSDEC Waterbody Invento- ry/Priority Waterbody List-h1WIL Spillway Design www.dec.ny.i!ov/chemical/36730.html,to see if Runoff shall be computed by standard accepted hydrologic your site is in an impaired watershed).The design methods noted previously in this book of standards.Runoff performance range will depend on the percent of computations shall be based upon the worst soil cover silt and clay in the soils tributary to the basin.If conditions expected to prevail in the contributing drain- the performance of the basin does not meet water age area during the anticipated effective life of the struc- quality objectives after 7 days,chemical treatment ture. The combined capacities of the principal and may be necessary. emergency spillway shall be sufficient to pass the peak rate of runoff from a ten(10)year frequency,24 hour duration D. Anti-vortex device and trash rack: storm. An anti-vortex device and trash rack shall be se- t. Principal spillway: A spillway consisting of a vertical curely installed on top of the riser and shall be the pipe or box type riser joined(watertight connection)to concentric type as shown in Figure 5.13 and 5.14 a pipe(barrel)which shall extend through the embank- on pages 5.31 and 5.32. ment and outlet beyond the downstream toe of the fill. The minimum capacity of the principal spillway shall E. Base: be 0.2 cfs per acre of drainage area when the water surface is at the emergency spillway crest elevation. The riser shall have a base attached with awater- For those basins with no emergency spillway,the prin- tight connection and shall have sufficient weight to cipal spillway shall have the capacity to handle the prevent flotation of the riser. Two approved bases peak flow from aten-year frequency rainfall event. for risers ten feet or less in height are: 1)a con- The minimum size of the barrel shall be 8 inches in crete base 18 in.thick with the riser embedded 9 diameter. See Figures 5.10,5.11 and 5.12 on pages in.in the base,and 2)a'/4"minimum thickness 5.28,5.29,and 5.30 for principal spillway sizes and steel plate attached to the riser by a continuous capacities. weld around the circumference of the riser to form a watertight connection. The plate shall have 2.5 A. Crest elevation: When used in combination with feet of stone,gravel,or compacted earth placed on an emergency spillway,the crest elevation of the it to prevent flotation. In either case,each side of riser shall be a minimum one foot below the eleva- the square base shall be twice the riser diameter. tion of the control section of the emergency spill- way. For risers greater than ten feet high,computations November 2016 Page 5.20 New York State Standards and Specifica- For Erosion and Sediment Control shall be made to design a base which will prevent discharge occurs at the property line,drainage flotation. The minimum factor of safety shall be easements will be obtained in accordance with 1.20(Downward forces= 1.20 x upward forces). local ordinances. Adequate notes and references See Figure 5.15 on page 5.33 for details. will be shown on the erosion and sediment control plan. F. Anti-Seep Collars: Anti-seep collars shall be installed around all conduits through earth fills of Protection against scour at the discharge end of the impoundment structures according to the follow- pipe spillway shall be provided. Measures may ing criteria: include basin,riprap,revetment,excavated plunge pools,or other approved methods. See Standard 1) Collars shall be placed to increase the seepage and Specification for Rock Outlet Protection,Sec- length along the conduit by a minimum of 15 tion 3,page 3.39. percent of the pipe length located within the satu- ration zone. 2. Emergency pillwas: The entire flow area of the emergency spillway shall be constructed in undisturbed 2) Collar spacing shall be between 5 and 14 ground(not fill). The emergency spillway cross- times the vertical projection of each collar. section shall be trapezoidal with a minimum bottom width of eight feet. This spillway channel shall have a 3) All collars shall be placed within the satura- straight control section of at least 20 feet in length;and tion zone. a straight outlet section for a minimum distance equal to 25 feet. 4) The assumed normal saturation zone(phreatic line)shall be determined by projecting a line at a A. Cil aci : The minimum capacity of the emergen- slope of 4 horizontal to 1 vertical from the point cy spillway shall be that required to pass the peak where the normal water(riser crest)elevation rate of runoff from the 10 year 24-hour frequency touches the upstream slope of the fill to a point storm,less any reduction due to flow in the pipe where this line intersects the invert of the pipe spillway. Emergency spillway dimensions may be conduit. All fill located within this line may be determined by using the method described in Fig- assumed as saturated. ure 5.19 on page 5.37 and the Design Tables in Figures 5.20 and 5.21 on pages 5.38 and 5.39. 2(N)(P)=IAS(I,) N=(0.475)(4)1 P B. Velocities: The velocity of flow in the exit chan- nel shall not exceed 5 feet per second for vegetated When anti-seep collars are used,the equation for channels. For channels with erosion protection revised seepage length becomes: other than vegetation,velocities shall be within the non-erosive range for the type of protection used. Where: Ls=Saturated length is length,in feet, C. Erosion Protection: Erosion protection shall be of pipe between riser and intersection of provided for by vegetation as prescribed in this phreatic line and pipe invert. publication or by other suitable means such as riprap,asphalt or concrete. N=number of anti-seep collars. D. Freeboard: Freeboard is the difference between P=vertical projection of collar from the design high water elevation in the emergency pipe,in feet. spillway and the top of the settled embankment. If there is no emergency spillway,it is the difference 5) All anti-seep collars and their connections between the water surface elevation required to shall be watertight. See Figures 5.16 and 5.17 on pass the design flow through the pipe and the top pages 5.34 and 5.35 for anti-seep collar design of the settled embankment. Freeboard shall be at and Figure 5.18 on page 5.36 for construction least one foot. details. Seepage diaphragms may be used in lieu of anti-seep collars.They shall be designed in Embankment Cross-Section accordance to USDA NRCS Pond Standard 378. 1. The maximum height of dam= 15 feet (measured from G. Outlet: An outlet shall be provided,including a the low point of original ground at the downstream toe means of conveying the discharge in an erosion to the top of the dam). free manner to an existing stable channel. Where 2 Minimum top width of dam= 10 feet. New York State Standards and Specifications Page 5.21 November 2016 For Erosion and Sediment Control 3. Side slopes shall be 2.5 to 1 or flatter. Chemical treatment shall not be substituted for proper erosion and sediment control.To reduce the need for Entrance of Runoff into Basin flocculants,proper controls include planning,phasing, sequencing and practice design in accordance to NY Points of entrance of surface runoff into excavated sedi- Standards. Chemical applications shall not be applied ment basins shall be protected to prevent erosion. Consid- without written approval from the NYSDEC. erable care should be given to the major points of inflow into basins. In many cases the difference in elevation of Safety the inflow and the bottom of the basin is considerable,thus creating a potential for severe gullying and sediment gen- Sediment basins are attractive to children and can be very eration. Often a riprap drop at major points of inflow dangerous. Local ordinances and regulations must be ad- would eliminate gullying and sediment generation. hered to regarding health and safety. The developer or owner shall check with local building officials on applicable Diversions,grade stabilization structures or other water safety requirements. If fencing of sediment basins is re- control devices shall be installed as necessary to ensure quired,the location of and type of fence shall be shown on direction of runoff and protect points of entry into the ba- the plans. sin. Points of entry should be located so as to ensure max- imum travel distance of entering runoff to point of exit(the Construction Specifications riser)from the basin. Disposal Site Preparation Areas under the embankment shall be cleared,grubbed,and The sediment basin plans shall indicate the method(s)of stripped of topsoil to remove trees,vegetation,roots,or disposing of the sediment removed from the basin. The other objectionable material. In order to facilitate cleanout sediment shall be placed in such a manner that it will not and restoration,the pool area(measured at the top of the erode from the site. The sediment shall not be deposited pipe spillway)will be cleared of all brush,trees,and other downstream from the basin,adjacent to a stream or flood- objectionable materials. plain. Disposal sites will be covered by an approved sedi- ment control plan. Cutoff-Trench The sediment basins plans shall also show the method of A cutoff trench shall be excavated along the centerline of disposing of the sediment basin after the drainage area is earth fill embankments. The minimum depth shall be two stabilized,and shall include the stabilization of the sedi- feet. The cutoff trench shall extend up both abutments to ment basin site. Water contained within the storage areas the riser crest elevation. The minimum bottom width shall shall be removed from the basin by pumping,cutting the be four feet,but wide enough to permit operation of excava- top of the riser,or other appropriate method prior to re- tion and compaction equipment. The side slopes shall be no moving or breaching the embankment. Sediment shall not steeper than 1:1. Compaction requirements shall be the be allowed to flush into a stream or drainageway. same as those for embankment. The trench shall be de- Chemical Treatment watered during the back filling/compaction operations. Embankment Precipitation of sediment is enhanced with the use of specific chemical flocculants that can be applied to the The fill material shall be taken from approved areas shown sediment basin in liquid,powder,or solid form. on the plans. It shall be clean mineral soil free of roots, Flocculants include anionic polyelectrolytes such as woody vegetation,oversized stones,rocks,or other objec- polyacrylimides,aluminum sulfate(alum),polyaluminum tionable material.Relatively pervious materials such as chloride and chitosan.Cationic polyelectrolytes have a sand or gravel(Unified Soil Classes GW,GP,SW&SP) greater toxicity to fish and other aquatic organisms than shall not be placed in the embankment. Areas on which fill anionic polyelectrolytes because they bind to the gills of is to be placed shall be scarified prior to placement of fill. fish resulting in respiratory failure(Pitt,2003). The fill material shall contain sufficient moisture so that it can be formed by hand into a ball without crumbling. If water can be squeezed out of a ball,it is too wet for proper compaction. Fill material shall be placed in six to eight- inch thick continuous layers over the entire length of the fill. Compaction shall be obtained by routing and hauling the construction equipment over the fill so that the entire surface of each layer of the fill is traversed by at least one November 2016 Page 5.22 New York State Standards and Specifica- For Erosion and Sediment Control wheel or tread track of the equipment or by the use of a Maintenance compactor. The embankment shall be constructed to an elevation 10 percent higher than the design height to allow 1. Repair all damages caused by soil erosion and con- for settlement. struction equipment at or before the end of each work- ing day. Pipe Spillway 2. Sediment shall be removed from the basin when it reaches the specified depth for cleanout noted on the The riser shall be securely attached to the barrel or barrel plans which will not exceed 50%of the capacity of the stub by welding the full circumference making a watertight sediment storage zone. This sediment shall be placed structural connection. The barrel stub must be attached to in such a manner that it will not erode from the site. the riser at the same percent(angle)of grade as the outlet The sediment shall not be deposited downstream from conduit. The connection between the riser and the riser the embankment,adjacent to a stream or floodplain. base shall be watertight. All connections between barrel sections must be achieved by approved watertight bank Final Disposal assemblies. The barrel and riser shall be placed on a firm, smooth foundation of impervious soil. Pervious materials When temporary structures have served their intended pur- such as sand,gravel,or crushed stone shall not be used as pose and the contributing drainage area has been properly backfill around the pipe or anti-seep collars. The fill mate- stabilized,the embankment and resulting sediment deposits rial around the pipe spillway shall be placed in four-inch are to be leveled or otherwise disposed of in accordance layers and compacted under and around the pipe to at least with the approved sediment control plan. The proposed use the same density as the adjacent embankment. of a sediment basin site will often dictate final disposition of the basin and any sediment contained therein. If the site A minimum depth of two feet of hand compacted backfill is scheduled for future construction,then the basin material shall be placed over the pipe spillway before crossing it and trapped sediments must be removed,safely disposed of, with construction equipment. Steel base plates on risers and backfilled with a structural fill. When the basin area is shall have at least 2 '/2 feet of compacted earth,stone,or to remain open space,the pond may be pumped dry,graded, gravel placed over it to prevent flotation. and backfilled. Emergency Spillway Information to be Submitted The emergency spillway shall be installed in undisturbed Sediment basin designs and construction plans submitted ground. The achievement of planned elevations,grades, for review to a local municipality,New York State DEC, design width,entrance and exit channel slopes are critical New York City DEP,Soil and Water Conservation District, to the successful operation of the emergency spillway and or other agency shall include the following: must be constructed within a tolerance of+/-0.2 feet. 1. Specific location of the basin. Vegetative Treatment 2. Plan view of the storage basin and emergency spillway, Stabilize the embankment and emergency spillway in ac- showing existing and proposed contours. cordance with the appropriate vegetative standard and specification immediately following construction. In no 3. Cross section of dam,principal spillway,emergency case shall the embankment remain unstabilized for more spillway,and profile of emergency spillway. than three(3)days. 4. Details of pipe connections,riser to pipe connections, Erosion and Pollution Control riser base,anti-seep control,trash rack cleanout eleva- tion,and anti-vortex device. Construction operations shall be carried out in such a man- 5. Runoff calculations for 1 and 10-year frequency ner that erosion and water pollution will be minimized. storms,if required. State and local laws shall be complied with concerning pollution abatement. 6. Storage Computations Safety A. Zones total required State and local requirements shall be met concerning fenc- B. Zones total Available ing and signs,warning the public of hazards of soft sedi- ment and floodwater. C. Elevation of sediment at which cleanout shall be required;also stated as a distance from the riser New York State Standards and Specifications Page 5.23 November 2016 For Erosion and Sediment Control TEMPORARY SEDIMENT BASIN DESIGN DATA SHEET Computed by Date Checked by Date Project Basin# Location Total Area draining to basin(<50 Ac.) Acres BASIN SIZE DESIGN 1. Sediment storage zone volume = 1,000 cu.ft.x number of disturbed acres= cu.ft., Top of Zone Elev. 2. Dewatering zone volume =3,600 cu.ft.x number of drainage area acres= cu.ft.,Top of Zone Elev. 3. Length to width ratio= 4. A. Cleanout at 50%of sediment storage zone volume,Elev. B. Distance below top of riser feet 5. Minimum surface area is larger of 0.01 Q(lo) or, 0.015 DA= use acres DESIGN OF SPILLWAYS & ELEVATIONS Runoff 6. QP(io)= cfs (Attach runoff computation sheets) Pipe Spillway(Qp,) 7. Min.pipe spillway cap., Q, =0.2 x Drainage Area,acres= cfs Note: If there is no emergency spillway,then required Q,=QP(io) = cfs. 8. H,head= ft. Barrel length= ft 9. Barrel:Diam. inches; Q,=(Q) x(cor.fac.) = cfs. 10. Riser:Diam. inches; Length ft.;h= ft. Crest Elev. 11. Trash Rack:Diameter= inches; H,height= inches Emergency Spillway Design 12. Emergency Spillway Flow,Qe,=QP-QpS= - = cfs. 13. Width ft.; HP ft Crest elevation ;Design High Water Elev. Entrance channel slope % ;Top of Dam Elev. Exit channel slope % ANTI-SEEP COLLAR/SEEPAGE DIAPHRAGM DESIGN Collars: 14. y= ft.; z= :1; pipe slope= %,L,= ft. Use collars, - inches square; projection= ft. Diaphragms: # width ft. height ft. DEWATERING ORIFICE SIZING (Determined from the Dewatering Device Standard) 15. Dewatering orifice diameter= inches. Skimmer or Riser (check one) 16. Design dewatering time days(Min.2 days required) November 2016 Page 5.24 New York State Standards and Specifica- For Erosion and Sediment Control TEMPORARY SEDIMENT BASIN DESIGN DATA SHEET INSTRUCTIONS FOR USE OF FORM 1. Minimum required sediment storage zone volume is 13. Use appropriate tables to obtain values of HP,bottom 1,000 cubic feet per acre from each disturbed acre width,and actual Qe,. If no emergency spillway is to within the total drainage area.Minimum required be used,so state,giving reason(s). dewatering zone volume is 3,600 cubic feet per total area draining to the basin. 14. See Anti-Seep Collar/Seepage Diaphragm Design(see figures 5.16,5.17 and 5.18 on pages 5.34,5.35 and 2. The volume of a naturally shaped basin(no excavation 5.36). in basin)may be approximated by the formula.V= (0.4)(A)(d),where V is in cubic feet,A is the surface 15. Fill in design elevations. The emergency spillway crest area of the basin,in square feet,and d is the maximum must be set no closer to riser crest than value of h, depth of the basin,in feet. Volume may be computed which causes pipe spillway to carry the minimum, from contour information or other suitable methods. required Q. Therefore,the elevation difference between spillways shall be equal to the value of h,or 3. If volume of basin is not adequate for required storage, one foot,whichever is greater. Design high water is excavate to obtain the required zone volumes. the elevation of the emergency spillway crest plus the value of HP,or if there is no emergency spillway,it is 4. The minimum surface area of the basin pool at the the elevation of the riser crest plus h required to handle storage volume elevation will be the larger of the two the 10-year storm. Minimum top of dam elevation elevations shown. requires 1.0 ft.of freeboard above design high water. 5. Use of the NRCC hydrologic data at www.precip.net To use charts for pipe spillway design: with an appropriate hydrologic model,is the preferred process for runoff computation. Runoff curve numbers 1. Enter chart,Figures 5.11 or 5.12 on pages 5.29 and will be computed for the drainage area that reflects the 5.30 with H and required discharge. maximum construction condition. 2. Find diameter of pipe conduit that provides equal or 6. Required minimum discharge from pipe spillway greater discharge equals 0.2 cfs/ac.times total drainage area. (This is equivalent to a uniform runoff of 5 in.per 24 hours). 3. Enter chart,Figure 5.10 on page 5.28 with actual pipe The pipe shall be designed to carry QP if site conditions discharge.Read across to select smallest riser that preclude installation of an emergency spillway to provides discharge within weir flow portion of raring protect the structure. curve.Read down to find corresponding h required. This h must be 1 foot or less. 7. Determine value of"H"from field conditions;"H"is the interval between the centerline of the outlet pipe and the emergency spillway crest,or if there is no emergency spillway,to the design high water. 8. See Pipe Flow Charts,Figures 5.11 and 5.12 on pages 5.29 and 5.30. 9. See Riser Inflow Curves,Figure 5.10 on page 5.28. 10. Compute the orifice size required to dewater the basin over a minimum 48 hour period. See the Dewatering Device Standard on page 5.10. 11. See Trash Rack and Anti-Vortex Device Design, Figures 5.13 and 5.14 on pages 5.31 and 5.32. 12. Compute Q,,by subtracting actual flow carried by the pipe spillway from the total inflow,QP. New York State Standards and Specifications Page 5.25 November 2016 For Erosion and Sediment Control Figure 5.8 Pipe Spillway Design R 4 Ms � w z 1' il F TO*" 4.TEIDf Z36 5. ADAPTED FROM DETAILS PROVIDED BYE USDA - NRES, NEW VURK STALE EEPARTKENT CF TRANSPURTATION, PIPE SPILLWAY NEV "YORK STATE DEPARTMENT (IF E)VIRDINME ITAL C(INSERVATMN, ]DESIGN NEW Y09K STATE SOIL L WATER CONSERVATIEN C13KM "VET November 2016 Page 5.26 New York State Standards and Specifica- For Erosion and Sediment Control Figure 5.9 Sediment Basin �YMB❑L OFF-DAM EMERCENCY TOP W-LDTH SPILLWAT CREST I— I ELEV+ FLOOD POOL—+ TOP ELEV.: CREST ELE V_ — — — 7FREE MI5 1.C�IIEIhi. DIAM. or �T�111 =III=III=11 [-��IIN. ,- Ill�lll=III= III=�=—lll- � INVERTII-III-111�111=111�--IJI�III III III �I ELE�E. [SE, I III=lII—III III—III—III—I ELEV.ANTI-FLOTATION r -` 2.0'MIN. BLOCK C1JTOFt II=1 I III [][AM. DF PRINCIPAL ANTI-SEEP LENGTHSPILLWAY BARREL. A4� STABILIZED WI DT1H s OUTLET PRIKCIPA PpnFILE NOT Tp SCALI MAXIMUM DRAIN04A AREA ACRES ELEVATION OF B❑TT014 WIDTH FLUOR POOL 1_ TOP OF DAM I LEVEL = r � FREEBOARD CARD I.OrMIN, EL LV. APPR❑ACHS■ — FLOW 0,% ' ll� CHANNEL � -III Sa III-11 ?� T SE�TIaN =If—III���� -��glll=�-�-III_. -111=1'11-11=11 1�III-II_III w- 711 BERM LEVEL SECTION EX17 SEC ::L,— L"O'MINIMUH EMBANKHEJNT PROFILE ALE]HQ C W PILLVA" I,SIa NOT TO SCALE CHE PGEMC Y' SPILLWAY PLAN y1E I �j BST TI1w1 L+IZ�Tw I r�]N. NU1 10 SCALL 1 1!— IIi1 1=11=ff I CROs+s SECTION AT t`mjL �.E! x a NOT TO SCALE ADAPTED FROM DEIA1L S PROV I QE® BY- USDA - Hl ?CS, NCV YOWK STA7E MEPAR'THENT of TUN5PORTATION, SEDIMENT BASIN NEW YORI[ STATE IDEPA12TIWCNT OF EiNVEROWMENTAL CONSERVATION, DETAILS NEW TMK STATE SOIL & SEATER COMSERVATION COMNITT`EE New York State Standards and Specifications Page 5.27 November 2016 For Erosion and Sediment Control i ■u WIso bib a an M■■■■di H11r1r� ��Ltil�I fA mmorbow somm mm.mm mmorrimm E: imp aid1f .O ONE Fit ' ��' �■■�r��l�llllr MUNN I arm- noun o Molina HER N U Figure 5.11 Pipe Flow Chart; "n" = 0.025 (USDA -NRCS) n_rt_•. ••n__A rn 7 Fyyyi fjj �r+/� i _� � RE w E i T ii a� +!i f F i i {fi'� ='Q i rz'1#i! rl _PI T* � {R A iF i �,# R P- A �.1-•! _T f _i �-1 a yl I {� 2��__ �+1 4 5y��P■� T R�T•-I� -�I sP� 1F�! �� 11 f-� � e-•RA �7 �T '� M n i Yl rt fi M1 i� �•y y yr � IY r A e•� r7 0%-M� -m� P°qr* * 7 T� M•%�y4•� •4 rt ri 4 VVV M •{� �y y p� y�Y ¢J F N Y i'4!�' !F- _ �4A n•.•n.r r�•. #nx4 M-iM1 ,b M110f +�T �T+! T� � T 3� � _el d vi nY v 8 Min r g y y �rt�N4P� F#@�M M/YiA•e i� �F 14 •*i #.f 9! Rnl-. j � �jRf l ■� -1 .+4 i9 v M-W F*dN PM iM M P.d7 P7�w-M Pti Pk -"• •. i M l y u G �' * X—ri�+rt + .•-a a �9 q n F W a-i R{na t �1 A ./e'h It14 r4 :R•l!• �G 7 p� dYA T'� W'� dY ! I ..n•ems�T !ie!it_i ■ �� {� I. -::I a-F .�.�• a-I �rt!4i�7 A_tr ti A IT A A I� a a•a a r .• e # K I�.a J1 Pt '!iPY q�Yrop i� d +� 8 di 1dt ^R' 'M T IF PL K i PP•�-1 rl�S g U:t i M1 ZZ J4 7 IkIE4Y#i Jl ,+inTP• �•PPq�T.i .fir�##ri�r s.wa�_� d P. �t.; q s #r+ } Alror tn2,.,AP- zIR aYF y19�1�F4w f 14*Fw,let Pt 2!_1 x i■ce M#wiM,Iq.in#te Inn n A,r..Ion, `T1 K4 ggg • rtir oa r.;,roA tir■r-r f bf#ff 'df••.+.# .rv#7ilei ; ;ram �R #�.■�# *r•!## wn.+.Rw IF rY_�! o.,P.Pti a•I rh.•,� � YP f+!� ri n-1•.ei wY,ea I R T f 'fib*A nt:DR4 f*r�l l#�s rs of P,rtry Ir �r4•r Pkr l4 ald's !e w Pi�ri r f f T dp—.%7 �.•i Paw .T. ....•.n �Y F: . '�' s Ir^.4 Ea a�i i■a M1 P- O t t Pr 3,3 Pr rt a 0%PR s.0 P- I.R d-r, dy�ySR d` _F#!ate ri#1_ ..T-RP R*% _ A_a a__ _a_ _ e.•i_ n.y e,y y ri Y y n .:.%.dY� �ri sr ri* rt r#f`P;f; P;#!i* r.•i!�i r: �a fl a o� .ems�� �� _ .. iy4y5• ��rr z Z4 I=2 -� r•r_+ti r°s A AAA 1 PF •T T Yi-4e W it rL 46 1-W� 5f�'•f*# r�a-r••n nt ry a I g! ,C}P- dti ■..P• d5 PY iS e0 2 ■ P4•R R M ¢ _.!•i4 W !� #w Re A 7 rl�P t _ n P•+!f�!•4 r• _I :/r M}¢• .*Ar is •.—_ —— —— 74 F. R 7 tY .,.F6 M' # r r rw I * r5 �•''T�ilF i���� A.0 TTT! • Q.$ � r C Y *^e rGOt_i M1d` NfT �• R # wd• . ,r frb _+r�i .• Fi4 QP- C. .:� �N.y New York State Standards and Specifications Page 5.29 November 2016 For Erosion and Sediment Control Figure 5.12 Pipe Flow Chart; "n" = 0.013 (USDA -NRCS) 1% �A 'M4 w .R.IY � � f � ,A d r H n n �A f pL n 1']n r f f ■r ifl v , Trri. +*A l R. .r■dF. i`~ *wIsi;'ti 3-I�R � # I �9c . . . . . F.Dc . ■ F 'ice i� �etm,�*. ti �d M iY i i r i +dinn� S ■ T T T F- 8 /■!��■�A �a5��� � �aPi a.i•.v.e•1 3 ■ + p6ii31 Fa ,ede�ia ■+•■i.rr�.a}••.1 +y � M 16 F F* M'Ri,••I! ,r-■�,-u F V Q� 8993�•t9 � y..,...b :r.,nnr4 aA:nnn A.A■•smn nI5I�l'6d5 nf7 �rin■irYri X P R may}• ■��•' � $ y d ; f• I•■ i M4 rt 4 r 9 w R w r`S IL ie i �a T �Or r1 i~ �1 i7 !9#F+■YI+q _ � t _ .� . 76 � #�r a■� nd ra 4■ri rl r!A 9-■r9 rl r•1 A 4- ll!! -R,d!R � a,•i r�cr ra r�ti�rt 8 ��y■ .a M Fy � :.1 rl.■,-F.-1 .e■M—wl.i rl #y.`f,yv #.4•nF w F o.n'� n;.�.�+a8 s�■%.i� �y�d■ �i I� �■f 4i � ■ ., Ate■ y L. t. ■ ,a r. per .. R. ,L, ,0iy� �� .o a++s+ wi 416+4 AF1�SL Q�4 Ll4 Tom., +.. - �i "f ii• I' 4% %is*6 1p a ft F,1%r®--1 �'�^ a-, -lea T I a(4+••. _pp_ .. " .. .a.T�.,a` gr+�r*ti ice..,�-+-■ f yam., ►,.,.i•3R �F - f.■ rz ■ rh #r + p p aI�•�� T a �•■��*F, f ,-w,m 8 a ! F O T a.*® w i. �R■. �■Y VY G� $�`��M#� F, ! R dl �A al R R � f T$, $a A el/�4�M it�P•rY� �A;R•M1 F ■ ■. , , 7 a eie s,•e n � pp (p� �¢{y t4 Q a,.rA+T# 1f[% M 00 a,'■r•1 on rl ���,�-, +•■In � ae A e•.. i i November 2016 Page 5.30 New York State Standards and Specifica- For Erosion and Sediment Control Figure 5.13 Concentric Trash Rack and Anti-Vortex Device (USDA -NRCS) �rtrrWM r+rllrr ftJ*4P T" ■sifter (Le rr- a 1,?, aU&M. 9wirH} Lr e : ie4t Lt vu Id.d 1a 6vp a�•r- Ltnd■J 0■e`prnd Iru1a7 L® `r' t�i2ru ■Z Ltm■. Tad Ls t&St C&I"jitt" A A r+.. snail aka" *C"L rlaRt,. r rrwr;Pro ratirt he bis aw.i b■ . ■■■■w. .■..■■■ ti 9ow1 ssed Ft1 anda of tarifu- ZaiLpn& ■rt Sr[c fuLky bC�4; 1 wh4w ctrr4LA4L.td cop la vt Ld ce r 1 I Mow Li irSa ea r rw- t��K ga Ltd R-rra L pip* or f iibr Le bl rd p.. �rti" drat UV tcrtl f-LaL■- F�eJ�ld �s Novii 0' FLA- L) The cr]indrr _Lp6 hil firmv - lstt■na-d! to ch■ R4R 4f 4hil xI1\r- "r ftlWLAI) lwopcYrt a.r Sly skr La# at MA *144# dK WATRIAI� did AAWt rinL�1 ■SLmPAd Lj *Lra" "Lead SUP1499T WhR p3+ Lai L6P i0f f Ltqf- ll�°3�,klt � i:W d-A J l COKE TRIO TWn MU MO AK"- TEA KYLE New York State Standards and Specifications Page 5.31 November 2016 For Erosion and Sediment Control Figure 5.14 Concentric Trash Rack and Anti-Vortex Device Design Table (USDA -NRCS) RI.. C.yhrWer Thwk. Minimum Sim 13[W (ifi- GAU H490 IWp tiA Rar Thir'k,rwss `...._.,._. 12 18 16 6 46 Fxbvr 16 g�, — 15 21 16 7 i*}3cbar 16 P. — 9 V 16 8 66 Rcbar 16 gm, — 21 30 16 11 06 Relpf 16p. �- 24 % 16 13 06 Rtbar 14 ga. — 27 42 1.6 0 "Rdw 14 go. — 42 60 14 19 A Rehm 12&L 0 72 12 21 1 114'PiPC KW I0 grs, — I MEN IMYIM O 6D 90 l 1 tJ7'1 or 8". — i. taxi MW2 k 66 96 10 33 2'pipe or 8.g& 2x2xV16.amgLe whddTfter 2s'2xV4 uglc malt 713 114 LD 39 2 1/27 Idpc or Sm 72'Miser Ste 72'R isff WA19M81C 84 1 W 18 42 2 1jr Pipe to ses.,72- 2 1 a 2 Mx2 1MIA Rlw 2 IM Oxg1e 3y16&M& Nee!The e&&Sa tarsi ring ft cyNnkv{r thm the am baw+eca fim iwide of the cyKader aid the owmi&m4 the r;str i& cqul to or Sma+Uwr tfm the arm irraidrr ft rL=.'Thett(mr,OW WkM Mbk is irwOW for arise vrifh mte p rim November 2016 Page 5.32 New York State Standards and Specifica- For Erosion and Sediment Control Figure 5.15 Riser Base Details ANGL7 Or STUB TO BE SHOWN, ANQLE BASED ON BARREL GRADE — RISER 0 BARREL DRAIN <OPTI❑NAL) 2 KB (MIN.) BARS PLACED AT RIC+HT ANQLES AND PIROJECTING INTO SIDES IF RISER TO HELP — Is" ANCHOR REEF INT11 CONCRETE BASE WIDTH EQUALS 2x DIAMETER OF RISER CONSTRUCTIONSPECIFICATIONS 1, THE COWAETE BASE SHALL BE POURED IN SUCH A MANNER TO INSURE THAT THE CONCRETE FILLS TIME BOTTOM OF THE RISER T❑ THE INVERT ❑F THE OUTLET PIPE TO PREVENT THE RISER FROM FREAKING AWAY FROM THE BASE, e. WITH ALU14INUM OR ALUMINIZED PIPE, THE EMBEDDED SECTION MUST BE PAINTED VITH OHRWATE OR EQUIVALENT. 3. RISER BASE. MAY BE SIZED AS M4PUTED USING FLOATAT10N WITH A FACTOR OF SAFETY OF 1.2. ADAPTED FROM DETAILS PRIIVIDED Dri IlSQA - MRCS, RISER BASE DETAIL NEW YORK STATE` DERAQTPENT OF TRANSPEMTA.TM4, NEV YORK STATE DEPARTMENT JIF ENVIRLINMEHTiaL CONSERVA710N, SEDIMENT BASIN NEW XORK STATC SOIL & WATER C❑NSERVATION CM09TTEE New York State Standards and Specifications Page 5.33 November 2016 For Erosion and Sediment Control Figure 5.16 Anti-Seep Collar Design This procedure provides the anti-seep collar 4d1Mefis1015� Fesr 41.nly Lempo«sy sed i-Ont b*On* t* ire-Crease cht "eptge length by 15% for various pipe slopeA F embankment slopes and riser hm Ighte. The first, step 1rr designing anti-seep collars is to determine t`F�e ler rh e pipe wirhin the saturate4 zone of tb43 em6ankFwnt . 7°hi s can bq done gr,.phically or by [he following equ$tion, assuming that the apstraeam slope of tb4 u-�4nk_m*rat lnG r e RAF the invert of the pipe at its up$trean end. SrF! emban1vmvfit-1nv*.its on the drawing 134Aov: Ls - y (r + 4 ) I + � e ,lloe 2 .-pine al.0pU- Where: LA - leftg Ch of ptp-e �eh t.h* sa t ara ted x one (f t. y . d,i s tame in fee-t f ron upst re m Invert of pipe to highest norm4L I wacer tova1 oxpu .tedd to vtorur diariT1g the life of the rtructure, :suallythe top o f t he rl*ar- x lope of rupstrea.m. eahankment as a ratio of z ft. horizontal to oine ft. vertical. pipe elope - slope of ,pipe In. feat per foot. This procedure i:s bas.L-d on the apprCoxication of the phreat.iC lire as RVioun fin t1u 4rtwing bolowt RISER CREST � ASSUMED -` PF ATTE ALINE E<HBA MENT COLLAR Y LLP�fjj[CTlENN , 46ANKMENT 31iVER'T CR EGTL❑ RIPE DIAMETER LS - ADAPTCL) FIB DETAILS FW9VJ V9 VIV, USDA: - MWS, NrLV V13RM 5TATIE JXPARTHENT OF TRANSPOP10WUN. ANTI—SEEP WEW YORK srA TE MPARTrEINT OF ENv[RONMEMT04- CCwSERVAT PO +. COLLAR DESIGN NEW YCIRK STATE SOIL & VATERk CONSERVArIoN CLIMITTEE November 2016 Page 5.34 New York State Standards and Specifica- For Erosion and Sediment Control Figure 5.17 Anti-Seep Collar Design Charts (USDA -NRCS) Pp B s el MCC ell } 4 2 LLAR PROJECTION, V, FEET � 200 77 100 gn TE This pr& M id low 0 15%imcme in I" lengl h 4+P 1 fbW pop New York State Standards and Specifications Page 5.35 November 2016 For Erosion and Sediment Control Figure 5.18 Anti-Seep Collar TYPICAL ANTI SEEP COLLARS NOT TO SCALE AT LEAST TKE LAST T VC C❑RRUGATtEINS ON EACH CND MUST BE ANGULAR UR FLANGE, , MIN. i�' MIN. IIVS7ALL WITH R CEIRRUCATI❑NS VERTICAL C❑NTINU❑US WELD (FULL CIRCUMFER NLE 801 H SIDES) COLLAR WELDED IN PLACE DN BARREL SECTION 2 PLATES 10 9E PRE-CUT CLAMPED TOGETHER �. CONTINUOUS �'EL 0 (FULL PRE-DRILLED L LABELEDCIRCUMFERENCE 80T11 SLEES) 1"0 TO PAC'_--ATE WATER WELDED FI-ANGE __.,. ASSEMBLY. STAINLESS STEEL NUT L KILT CONNEC7IGN WITH NAMK DEIVEEN PLATES. MULTI-P,j QE COLLAR F®R I-ARQE PIPES USE MASM OR EQUIV, BETWEEN PLATE L FLANGE COLLAR FOR FLANGE J❑INT PIPE ADAPTED rRON DETAILS PROVIDED D)� USDA - NPC , NEW YORK ST&TE DEPARTKERr V TRAMPORTATI❑N, ANTI SEEP COLLAR NEV YORK STATE DEPARTMENT OF EH+�+ TM. CW5ER� AAWK NEW YfPK STATE MIL & VATER CONSEWVAETIM IT7E:E November 2016 Page 5.36 New York State Standards and Specifica- For Erosion and Sediment Control Figure 5.19 Design Data for Earth Spillways LEVEL CONTROL P0 PRE TIQN SECTION CHANNEL ❑UTLET CHANNEL M;�ITROL 5EI~T ICIN OF EMBAIMtMEN7 CATER WWACE PLAMLE-EM18 2ILLMAY TMPr a 2X OR ar 1 I GREATER LEVEL 1_ b �I ERdFiIE LNG SENT L1NF! OF CARTti MrISS SECTION, [F LARTH_SPILL WA t ALL= Al CONTROL.SE-M:1,110 LEf FN n s MANNING S COEFFICIENT OF ROUGHIMIESS. Hp = DIFFERENCE IN EL'EVATI❑N BETWEEN SST OF EARTH SPIL �rY AT THE CONTROL SECTIOPI AND WATER SURFACE IN RESERVOIR, IN b = 130tTOM 'MOTH (IF EARTH SPILLWAY AT THE CONTROL SECTION, IN FEET, Q = TOTAL DISCHARGE, IN cfS. Y. TE WILL TTTNL14cOW ®N Q S CTI , A DESIGN Qr IFC RUE0 TOS3PE ) THAT I� SHQ'r+M a F ATT ST SLOPE �S% IN X, ALLDVABLE FOR C BELOW CONTROL kc r1am X - MINIMIM LENGTH OF CHANNEL BELIJW COMMIL SECTMIMo IN FEET. a = SIDE SLOPE RATIO. NUTES ]) FOR A GIVEN Ho A DECREASE IN THE EMIT SLR FAD M S AS 9EVIE Ii 1HE IA:S❑E DEC E ES SPILL'c AY DISCHARGE BUT INCREASEM+dC+ HE NOT IMI: EASE DISCHARGE. IF AN EXIT SLID ($�TEEPER THAN S IS USED THEN VELOCITY 4Ve) IN TIE Eli T C L WILL INCREASE ACCORDING TO THE F❑LL❑WING RELATIONSHIP- Vr - V 0.3 2) DATA TO RIGHT OF HEAVY VERTICAL LINES ON IIRAVINGS SHOULD BE. USED WITH I�PR❑PORTIONLD OR VE 4 ICSTINNS WILL EXCESS OF EITHER FEC. ADAPTED FROM DETAILS PROVIDED By- ZDA - WES, mEw YORK STATE LEPARTmENT OF TRANSPORTATION, ]DESIGN DATA FOR NEV Y RK STATE DEPARTMENT OF ENVMNMEMAL CONZERVATI11N. EARTH SPILLWAYS NEW VM1RK STATE SAIL. ML WATER CONSERVATION CO MFMITTEC New York State Standards and Specifications Page 5.37 November 2016 For Erosion and Sediment Control Figure 5.20 Design Table for Vegetated Earth Spillways in Erosion Resistant Soils, K=0.1 - 0.35, Side Slopes = 3:1 i€eborle 3i Ra s Bat%-011% rrs t a e t Gi-Ith46T%9-0 5102t 1t rkat 2LDt t Or+ L g# la Him iprupw M&ll fAwm Wtdth F6ee°1� L7 A3,11F.UM Max IMUR w5d%% i Fee% C 3 P#r€€hk Fwreect Feet t*S Pr,r€tnt ?*rc*Fl4 Fact 3.3 12 :1 0 163 2.8 5.2 24 1-2 15 .2.5 Q0 2-L; 5.9 20 1, 14 3. 1 Ia.9 $ . :}_s T.0 32 1.. 20 .312 1 ,0 12 .$1 2.5 ZrO 12 1.94 3.3 17` 3 18 . 70 118 1- 1 2.2 9,IR 22 . 91 4.5 24 732 3_ 1-7.:t €0 .'YO 2,6 C. 1 1. 1� 2. 9 -. 0 $ 1,-0 :a.5 2.11 1 tf 33.0 8.2 I2 a.a 2. 1, 4 0 3.0 1D,7 1$ .96 i 2.45 4.0 24 1, 41 3-3 13.E 20 1119 !a.7 4,s 21 1.30 :2.B 5. 1 0 1.30 2-7 S. 3 32 1.21 2.0 $,.9 12 1. 10 2.B 8, 1 3.0 1.13 3.5 1 9.0 16 .94 2.3 2-*$ 2G 1. 71 3, 1 1I, 24 .65 2.6 3r2 24 758 3.2 14. 1 4 --.7713•f� 2.1 4,5 9 1.4,0 217 4.2 33 1.34 2,9 610 12 1.18 P,-7 4.9 31 -1,21 40 2. 9 7_6 16 1.03 V., S 217 24 1.71 3. 1 0,7 :ao .01 W,6 3.2 20 2, 3.1 11.9 24 .83 140 2. , 3. 2.9 5.3 l 3• ,.7 4.5 40 48 15 1.00 3 _{ 4 20 .98 2.5 3+1 32 1« 3.0 10.4 24 «-99 15Q 1..4 2.7 7 1.57 1-33 _ -q_ 7 1 1.33 2.7 ♦. 50 2.0 15,0 -1 6- r_di 20 1. 2.4 .311 -9-0 34 .94 iB0 2.5 2.15 3.7 44 2.7 3. 9. 12 1«4'7 2.5 P,.7 36 1.71D 2, 5. 2 1. 115 200 3 44 1 _ 37- 17 . 24 1. �$ .� 3.0 6. 2$ ,97 2.4 2.5 4-0 1-'70 2, 1.2 1,00 3 4 pro 2.7 6R 0 ;20 1. 2-0 Z4Ct 2- :24a 2. �2 2.9 7, 20 1.05 � ? 2.4 2•6 215 2.9 12 1. rr 2 2.9 3 1. 2 80 2A 3.6 IB 1_ n3 2,4 �.15 �2 a- 17 November 2016 Page 5.38 New York State Standards and Specifica- For Erosion and Sediment Control Figure 5.21 Design Table for Vegetated Earth Spillways in Very Erodible Soils, K = 0.36 - 0.80, Side Slopes = 3:1 (USDA -NRCS) s har p Slope Range Bottom stage x1hIMU 7 Maxi num Width CPS Percent Percent, Feet Feet 1, 3. 4 4 . 4 12 . 69 . 3„ 4 511� 16 . $01 3. :3 3. a 12 . 80 0 3. 3 4 1 16 . " 0 3. 5 5, � 20 3. 3 3. 3 16 . 79 25 3 IS 4. C 20 . '70 3, 5 4. 24 . P4 313 20 . 78 30 3. 3 4. 0 21 4 . 71 3. 4 4. 1 28 . 55 3. 4 5. 5 32 ' $1 S. 3 3.9 28 z 71 3. 5 5. 2 n8 . 62 3. 3 3. 3 28 . 76 L 3. 4 3.6 Z . 71 3. 4 4. 4 35 .87 3. 4 5.0 40 -84 3. 3 3. 3 . 76 45 3. 4 5,8 35 ■ 72 3. 4 4. 3 40 .67 3. 4 4. 6 44 . 64 3. 3 3. 3 35 3. 3 3.6 4,0 . 71 3. 3 4f3 44 . 813 11. 2 .2 44 . 75 173 3. 3 3- 3 52 . 175 e 3. 1 3. 1 .5B . 78 New York State Standards and Specifications Page 5.39 November 2016 For Erosion and Sediment Control Procedure for Determining or Altering Sediment Basin Shape As specified in the Standard and Specification,the pool area The required basin shape may be obtained by proper site at the elevation of the crest of the principal spillway shall selection,by excavation,or by constructing a baffle in the have a length to width ratio of at least 2.0 to 1. The purpose basin. The purpose of the baffle is to increase the effective of this requirement is to minimize the"short circuiting" flow length from the inflow point to the riser. Baffles(see effect of the sediment laden inflow to the riser and thereby Figure 5.22 on following page)shall be placed midway increase the effectiveness of the sediment basin. The pur- between the inflow point around the end of the baffle to the pose of this procedure is to prescribe the parameters,proce- outflow point. Then: dures,and methods of determining and modifying the shape of the basin. We=A/L,and L:W ratio=LAW, The length of the flow path(L)is the distance from the Three examples are shown on the following page. Note that point of inflow to the riser(outflow point). The point of for the special case in example C the water is allowed to go inflow is the point that the stream enters the normal pool around both ends of the baffle and the effective length,Le= (pool level at the riser crest elevation). The pool area(A)is L, +L2. Otherwise,the length to width ratio computations the area of the normal pool. The effective width(We)is are the same as shown above. This special case procedure found by the equation: for computing Le is allowable only when the two flow paths are equal,i.e.,when L, =Lz. A baffle detail is also shown We=A/L and L:W ratio=L/We in Figure 5.22 on page 5.41. In the event there is more than one inflow point,any inflow point that conveys more than 30 percent of the total peak inflow rate shall meet the length to width ratio criteria. November 2016 Page 5.40 New York State Standards and Specifica- For Erosion and Sediment Control Figure 5.22 Sediment Basin Baffle Details (USDA -NRCS) Sbcamp=1tF.: Plan Vi-ews - not A- .r4 r)�---*- Riser �Gurjaz) 001 yea rotas dlstance from thw Potty# of inflo- around the haflle to tit normla l POW —RI per i 24V jp I Ji sex 3 +f2 xorl pool 1'fl Baffle Detail Shee of 4'x V x 112" exterior Plywood or eg-WIVai-enc. J- Riser crest elegy. #{ ' Pasts-Add- sirs d' square or 5W rdu4d_ .het At j r.as t New York State Standards and Specifications Page 5.41 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR SEDIMENT DIKE 6. The ends of the dike system shall terminate with a 90' return of NYS DOT#IA crushed stone to filter any . J excess flow. 7. The maximum drainage area tributary to this practice shall not exceed 0.5 acres per 100 feet of dike,for slopes less than 10%. For slopes greater than 10%,the drainage area shall be 0.25 acres per 100 feet of dike. 8. The earthen dike shall be seeded and mulched to pre- vent erosion using an annual rye grass mixture at a rate of 1 lb.per 1,000 square feet. Maintenance Definition & Scope 1. No traffic will be allowed on the dike. A temporary earth dike with an excavated trench on the 2. Dike system will be inspected weekly and after each upslope toe placed across a slope to capture sediment laden runoff event. flow from small disturbed drainage areas and allowing sedi- ment to settle out by ponding. 3. Sediment in the system will be removed when the inte- rior trench has filled to 75%capacity. Condition Where Practice Applies 4. Sediment will be disposed of on-site as specified in the This practice can be used on slopes and in areas where it is Erosion and Sediment Control Plan. difficult to place and maintain silt fence. This practice acts as a smaller sediment trap for linear type applications. This 5. Upon stabilization of the tributary drainage area,the practice will handle sheet and rill erosion for small tributary trench will be filled,excess dike fill removed,and the areas. area graded and stabilized in accordance with the Ero- sion and Sediment Control Plan. Design Criteria 1. The earth dike will be a maximum of 2 feet high with a 2 foot top width and 2:1 side slopes. 2. All earth fill will be placed on a stripped foundation, contain no stumps or woody material,and be compact- ed with the weight of the excavator bucket. 3. The interior capture trench will be a minimum 1.5 feet deep,2 feet wide,with 1:1 side slopes and with a near level bottom. In areas where linear slopes exceed 4% the sediment dike system shall be segmented to main- tain capture volume and ponding. 4. The system shall be used with a minimum 5 foot vege- tated buffer on the down slope toe of the dike or an artificial buffer of erosion control matting. 5. The maximum ponding depth behind the dike shall be 1/2 the height of the constructed dike at its lowest ele- vation. November 2016 Page 5.42 New York State Standards and Specifica- For Erosion and Sediment Control Figure 5.23 Sediment Dike ENP❑SEI3 UNDISTURBED S0[L �TABILT2E SOILS "'�'ITH S�C9� Mall] SOIL MULCH OR EROSION CON-ROL MATTING Ex(:E SS MATERIAL FROM EXCAVATION EXISTING GRADE V 1:9" MINIMUM E PAVED AREA CIIRI.IC1�4 F�IF� 1. ALL EARTH FILL VJLL BE PLAE£D EN A STRJP�D FOL14 ATION. E:TMTAIN k® STUMPS OR 'VMDT W[PhhL, P-D K COWACTEI? 'V]Tk THE WEIGMT Or THE E.MEAVATER MKKFT. F. THE SYSTEM THALL BE USED METH A MIDI]" j FWT VEEETATEQ BUFFER IR THE lCww S>`WE HE IF THE DUKE [10 M PRTDF]WIIL b11FFI:R CE EKSIGN CUNTROL WArT]►rj, 5L THE EIS 13r THE CgWE :YSTEN SHALIL TEA} TE %aTH A 90 GE{i12f E RETURN OF 1M MT MIA rRUSHED STM TO FELTER Alff EuCXSS FLOW. 4. THE EMIMM 610E SHALL E 'SEJEIZII AMM HULCHL31 `R] PIV-Vl MT EFMS 114 LMNfm AN ANNUAL RYE URAU MIXTIPF AT A RATE I)r I .jL PER JAW :SOLLW FEET. ADAPTED FROM DETAIL 2 PROVIDED BY- KEN BARBER, BARBER SEDIMENT ENGINEiER]MG New York State Standards and Specifications Page 5.43 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR SEDIMENT TANK - PORTABLE Y Definition & Scope A sediment tank is a compartmented tank or vessel contain- er to which sediment laden water is pumped to trap and retain the sediment prior to releasing the water to drainage- ways,and rights-of-way below the sediment tank site. Conditions Where Practice Applies A sediment tank is to be used on sites where excavations are deep,and space is limited,such as urban construction, where direct discharge of sediment laden water to stream and storm drainage systems is to be avoided. Design Criteria Location The sediment tank shall be located for ease of clean-out and disposal of the trapped sediment,and to minimize the inter- ference with construction activities and pedestrian traffic. Tank Size The following formula should be used in determining the storage volume of the sediment tank;pump discharge (G.P.M.)x 16=Cubic Foot Storage. An example of a typical sediment tank is shown on Figure 5.24 on page 5.45. Other container designs can be used if the storage volume is adequate and approval is obtained from the local approving agency.Commercially manufac- tured tanks are also available. November 2016 Page 5.44 New York State Standards and Specifica- For Erosion and Sediment Control Figure 5.24 Portable Sediment Tank YMEDL 3' DIAM, INTAVE E1VD9 OF BARRELS CuT TO ACT AS a,V r ELS <TYF. FROM SUMP PUMP � A MJRLAP F IL TER 3" DFAM. HOSE TO SUITAKE OUTLET 55 GAL. DRUMS, ❑R GUaLl LEG(npj � A SIMILAR, VELDED END TO END 12'(APRROX-) CIL'E ANDU T SLOT CLIT 110T (IINTERI❑R WALLS ONLY) APPROX. 3.,Y 4 DI AM. OF REL END TO ACT AS BAFFLE 2' x 4' CRAOLiE SECTION A- CONSTRUCTION SPECIFICATIONS 1, CLEAN OUT THE SIE DI MENT TANK WHEN ONE THIRD Q/3) FILLED WITH SILT. 2, STEEL I)RUMS ARE tj$ED AS AN EXAWLE SUE TO TFIEIR READY AVAILABILITY. ANY TANKS MAY BE USED. PRBVIDING THAT THE VOL4.RIE REQUIREMENTS ARE MET 3. ALL SEDIMENT Ca L E❑TEI# IN THE TANK SHAI-L, �E DIVA 1I Er IN A S E D11A NT TRAPPING DEVICE OR AS APPROVED BY THE T F,Cn4; U.S. EEPAR T RENT (IF MIJIL TIRE NATURAL RZSUL►RCES CONSERVATION SERVIC€ PCIR7.ABLE: - `DIME!,'. NEw YORK STATE DEPARTmENT OF ENVIRONMENTAL I={]ZERVATION NEV VERK STATE SOIL 3 V A T EP COME R-VA71IDN C❑HMI TTEE r �¢ New York State Standards and Specifications Page 5.45 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR SEDIMENT TRAP tion during building construction. Locate traps to obtain maximum storage benefit from the terrain and for ease of cleanout and disposal of the trapped sediment. Trap Size The volume of a sediment trap as measured at the elevation z � of the crest of the outlet shall be at least 3,600 cubic feet per 701W- � W ` W acre of drainage area. A minimum length to width ratio of 2:1 should be provided. The volume of a constructed trap shall be calculated using standard mathematical procedures. The volume of a natural sediment trap may be approximat- ed by the equation:Volume(cu.ft.)=0.4 x surface area Em (sq.ft.)x maximum depth(ft.). Trap Cleanout Definition & Scope Sediment shall be removed and the trap restored to the orig- A temporary sediment control device formed by excavation inal dimensions when the sediment has accumulated to '/z of and/or embankment to intercept sediment-laden runoff and the design depth of traps I-II,and 1/3 the depth for trap III. trap the sediment in order to protect drainageways,proper- Sediment removed from the trap shall be deposited in a ties,and rights-of-way below the sediment trap from sedi- protected area and in such a manner that it will not erode. mentation. Embankment Conditions Where Practice Applies All earth embankments for sediment traps shall not exceed five(5)feet in height as measured at the low point of the A sediment trap is usually installed in a drainageway,at a original ground along the centerline of the embankment. storm drain inlet,or other points of collection from a dis- Embankments shall have a minimum four(4)foot wide top turbed area for one construction season. and side slopes of 2:1 or flatter. The embankment shall be compacted by traversing with equipment while it is being Sediment traps should be used to artificially break up the constructed.The embankment shall be stabilized with seed natural drainage area into smaller sections where a larger and mulch as soon as it is completed device(sediment basin)would be less effective. The elevation of the top of any dike directing water to any Design Criteria sediment trap will equal or exceed the maximum height of the outlet structure along the entire length of the trap. If the drainage area to the proposed trap location exceeds 5 acres,or the trap is in place beyond one construction sea- Excavation son,or any of the additional design criteria presented here cannot be met,a full Sediment Basin must be used.See All excavation operations shall be carried out in such a Standard and Specification for Sediment Basin on page manner that erosion and water pollution shall be minimal. 5.19. Excavated portions of sediment traps shall have 1:1 or flat- ter slopes. Drainage Area Outlet The maximum drainage area for all sediment traps shall be 5 acres. The outlet shall be designed,constructed,and maintained in such a manner that sediment does not leave the trap and that Location erosion at or below the outlet does not occur. Sediment traps shall be located so that they can be installed Sediment traps must outlet onto stabilized(preferable un- prior to grading or filling in the drainage area they are to disturbed)ground,into a watercourse,stabilized channel,or protect. Traps must not be located any closer than 20 feet into a storm drain system. Distance between inlet and out- from a proposed building foundation if the trap is to func- let should be maximized to the longest length practicable. November 2016 Page 5.46 New York State Standards and Specifica- For Erosion and Sediment Control All traps must be seeded and mulched immediately after cloth shall cover an area at least six(6)inches above the construction. highest hole and six(6)inches below the lowest hole. The top of the riser pipe shall not be covered with filter cloth. Trap Details Needed on Erosion and Sediment The riser shall have a base with sufficient weight to prevent Control Plans flotation of the riser. Two approved bases are: Each trap shall be delineated on the plans in such a manner 1. A concrete base 12 in.thick with the riser embedded 9 that it will not be confused with any other features. Each in.into the concrete base,or trap on a plan shall indicate all the information necessary to 2 One quarter inch,minimum,thick steel plate attached properly construct and maintain the structure. If the draw- to the riser by a continuous weld around the ings are such that this information cannot be delineated on circumference of the riser to form a watertight the drawings,then a table shall be developed. If a table is connection. The plate shall have 2.5 feet of stone, developed,then each trap on a plan shall have a number and gravel,or earth placed on it to prevent flotation. In the numbers shall be consecutive. either case,each side of the square base measurement The following information shall be shown for each trap in a shall be the riser diameter plus 24 inches. summary table format on the plans. Pipe outlet sediment traps shall be limited to a five(5)acre maximum drainage area. Pipe outlet sediment trap is inter- 1. Trap number changeable in the field with stone outlet provided that these 2. Type of trap sediment traps are constructed in accordance with the detail 3. Drainage area and specifications for that trap. 4. Storage required 5. Storage provided(if applicable) Select pipe diameter from the following table: 6. Outlet length or pipe sizes See details for Pipe Outlet Sediment Trap ST-1 in Figure 7. Storage depth below outlet or cleanout elevation 5.25 and 5.26 on pages 5.49 and 5.50. 8. Embankment height and elevation(if applicable) Optional sediment trap dewatering devices are shown on Type of Sediment Traps Figure 5.29 on Page 5.53. Minimum Sizes There are three(3)specific types of sediment traps which vary according to their function,location,or drainage area. Barrel Diameter' Riser Diameter' Maximum Drain- (in.) (in.) age Area(ac.) 1. Pipe Outlet Sediment Trap IL Stone Outlet Sediment Trap 12 15 1 III. Compost Filter Sock Sediment Trap 15 18 2 L Pipe Outlet Sediment Trap 18 21 3 A Pipe Outlet Sediment Trap consists of a trap formed by 21 24 4 embankment or excavation. The outlet for the trap is 21 27 5 through a perforated riser and a pipe through the embank- ment. The outlet pipe and riser shall be made of steel,cor- 1 Barrel diameter may be same size as riser diameter rugated metal or other suitable material. The top of the embankment shall be at least 1 '/z feet above the crest of the riser. The preferred method of dewatering the sediment trap is by surface skimmer. See Dewatering Device Standard, page 5.10.If the riser alone is used for dewatering,the top 2/3 of the riser shall be perforated with one(1)inch nomi- nal diameter holes or slits spaced six(6)inches vertically and horizontally placed in the concave portion of the corru- gated pipe. No holes or slits will be allowed within six(6)inches of the top of the horizontal barrel. All pipe connections shall be watertight. The riser shall be wrapped with to 1/4 inch hardware cloth wire then wrapped with filter cloth with a sieve size between#40-80 and secured with strapping or connecting band at the top and bottom of the cloth. The New York State Standards and Specifications Page 5.47 November 2016 For Erosion and Sediment Control IL Stone Outlet Sediment Trap Surface runoff can be directed to the trap with standard con- veyance practices.Groundwater or surface ponding in low A Stone Outlet Sediment Trap consists of a trap formed by areas can be pumped into the compost sock sediment trap an embankment or excavation. The outlet of this trap is with appropriate energy dissipation at the pump outlet to over a stone section placed on level ground. The minimum prevent scour. length(feet)of the outlet shall be equal to four(4)times the Design criteria for Compost Sock Sediment Trap drainage area(acres). 1. The maximum drainage area tributary to the trap shall Required storage shall be 3,600 cubic feet per acre of drain- be 5 acres. age area. 2. The minimum settled height above ground shall be 2.0 The outlet crest(top of stone in weir section)shall be level, feet formed by staking 3 compost filter socks in a pyra- at least one(1)foot below top of embankment and no more mid as shown in Figure 5.28 on page 5.52. than one(1)foot above ground beneath the outlet. Stone used in the outlet shall be small riprap(4 in.x 8 in.). To 3. The storage volume provided in the compost sock sedi- provide more efficient trapping effect,a layer of filter cloth ment trap shall be 3,600 cubic feet per tributary drain- should be embedded one(1)foot back into the upstream age acre. face of the outlet stone or a one(1)foot thick layer of two (2)inch or finer aggregate shall be placed on the upstream 4. If necessary,additional storage area can be created by face of the outlet. excavating a sump 1 foot deep beginning at least 5 feet away from the inside sock. Stone Outlet Sediment Traps may be interchangeable in the field with pipe outlet sediment traps provided they are con- 5. All compost filter sock materials,mesh,and compost, structed in accordance with the detail and specifications for will meet the material specifications listed in the Com- those traps. Stone outlet sediment traps shall be limited to a post Filter Sock standard.No spillway is required. five(5)acre maximum drainage area. 6. Compost filter sock sediment traps shall be inspected See details for Stone Outlet Sediment Trap ST-II in Figure weekly and after every rainfall event. Sediment shall be 5.27 on page 5.51 removed when it reaches one third, 1/3,the height of the trap. 7. The maximum limit of use for a compost sock sediment _ trap is one(1)year.The existing trap shall be replaced if there is a need for a trap beyond that time limit. 8. Upon completion of the work,the compost sock sedi- ment trap shall be removed.The compost within the socks may be used during cleanup as a vegetative growth medium in accordance with the site stabiliza- tion plan. III. Compost Sock Sediment Trap A compost sock sediment trap consists of a trap formed by creating an enclosure of geotextile mesh tubes filled with a compost filter media.These traps are used in locations where there is no opportunity to direct runoff into larger , traps or well vegetated areas.This could occur at site en- trances and access points or in tight areas due to construe- - ` tion boundary limits. November 2016 Page 5.48 New York State Standards and Specifica- For Erosion and Sediment Control Figure 5.25 Pipe Outlet Sediment Trap: ST-I SYMBOL 44 �y%V EARTH EF49ANKME T _ EXCAVATE IF NECESSARY OUTLET PREITECTI❑N FOR STURACE 144 ellE RISER EIMWDDED 9' INTO Ny CONCRETE 4y w f EIR 1/4' METAL PLATE WELDED ALL AROUND. DESIGN VOLuwE IS — CUrF T. 4,0'MIN. ALL SLOPES 211 1'6r.MIN. PWGRATED RISER HR FLATTER + 1/4' TH 1/Er HARVARE RIPRAP 5,G'MA X. * * CLEITH VI TH FILTER PROTECT]ON * FABRIC SECURELY 1j) ACCEPTABLE WATER WELD ALL � 10A' TIGHT J13INTS AROUND W=DIAMETER OF RISEN *24r EMBARKMENT SECTION THRU MISER 'SIZES OF PIPE NEEDED, BARREL DIAMETER4 RISER DIAMETERt Ncj rE� C❑NSTR-UCTI❑N SPEcIFIEATION SFOuLa BE 4TrAChEb TO THIS DETAIL TO COMPLETE DESIM MAXIMUM DRAINAGE AREA, 5 ACRES ADAPITED PRmM DETAtL s FRaviI�E O 0 r- ODA — NKS. PIPE OUTLET RWTEEPTC DEPARTMENT R �NEW WOKSIA dARTHENT OF EhrVRONNETAL L� V ATX , SEDIMENT NEV VORX STATE SOIL L WATER UWnCRVATIUN CCwMITTEE TRAP T—I New York State Standards and Specifications Page 5.49 November 2016 For Erosion and Sediment Control Figure 5.26 Pipe Outlet Sediment Trap: ST-I - Construction Specifications SYMBOL 1-INSTRUCTIFIN SPFCTFICATIFINS �i 1. AREA UNDER EMBANKMENT SHALL BE CLEARED, GRUBBED AND STRIPPED OF ANY VEGETATION AND RDOT MAT. THE POOL AREA SHALL BE CLEARED- 2, THE FILL MATERIAL F13R THE EMBANKMENT SHALL 'BE FRFE OF RCUTS OR ❑T4ER WOODY VEGETATI❑N AS WELL AS OVER-SIZED ST❑Nr S, ROCKS, ORGANIC MATERIAL. OR OTHER OBJECTI❑NADLE MATERIAL, THE EFMBANKME y SHALL BE COMPACTED BY TRAVERSING WITH EQUIPMENT WHILE IT IS BEING CONSTRUCTED 3. VOLUME OF SEDIMENT STORAGE SHALL BE '360D CUBIC FEET PER ACRE OF CONTRIBUTORY DRAINAGE, 4, SEDIMENT SHALL BE REMOVED AND TRAP RESTORED TO ITS ORIGINAL DIMENSIONS WHEN THE SI•DIME14T HAS ACCUMULATED TO I/i? THE DE S]UN DEPTH OF THE TRAP, REMOVED SEDIMENT SHALL BE DEPOSITED IN A SUITABLE AREA AND STABILIZED. 5. THE STRUCTURE SHALE K INSPECTED AFTER EACH RAIN AND REPAIRS MADE AS NEEDED. 6. CON97 RUC T ION OPERA i[CIS SHALL DE CARRIED OUT IN SUCH A MANNER THAT EROSION AND SEDIMENT ARE CONTROLLER 7, THE STRUCTURE SHALL K REMI VED AND AREA STABILIZED WHEN T"E DRAINAGE AREA HAS BEEN PROPERLY STABILIZED, $. ALL FILL %OKS SHALL BE all OR FLATTERI CUT SLOPES ill OR FLATTER. 9. ALL PIPE CO EGTI❑NS SHALL BE WA,TERTWHIr. I.D. THE TOP 2/3 OF THE RISER SHALL BE ;PERFORATED WITH ONE (1) INCH DIAMETER RULES OR SLITS SPACED SIX C6T ]INCHES VERTICALLY AND HORIZONTALLY AND PLACED IN THE CONCAVE PORTION OF PIPE. NO HOLES WILL 13E ALLOWED WITHIN SIX (6) INCHES OF THE HORIZONTAL BARREL. 11. THE RISER SHALL BE 'WRAPPED WITH 1/4 TO 1/2 INCH HARDWARE E L❑T H WERE THEN WRAPPED WITH FILTER CLOTH (HAVINC AN EQUIVALENT SIEVE SIZE OF 40-04). THE FILTER CLQTI-I SHALL EXTEND W (r?) INCHLS ADOVE THE HICHEIST HOLE AHII SIX 40 D�IIES BEI, W THE LGVEST HOLE. WHERE ENDS OF THE FILTER CLOTH COME T T`HEF , HEY SHALL BE OVER-LAPPEO, rOLDED AJND STAPLED TO PREVENT BYPASS. 12. S MPS OR CONNECTING BANDS SHALL BE USED TO HOILD THE FILTER CLOTH AND WIRE EABIRIC 1N PLACE. THEY SHALL BE PLACED AT THE 113P AND BOTTOM OF THE CLOTH. 13. FILL MATERIAL AR❑UmD THE PIPE SPILLWAY SMALL BE HAND COS ACTED IN FOUR �4) INCH LAYERS- A MINIMUM OF T+4 FEET OF HAND EIlOP4GTED IkAEFLLL SHALL BE PLACED OVER T[JE: RIPE SPILLWAY I)CrOPE CRDSSING IT WITH! CONSTRUCTION EQUIPMENT, 14. THE, RISER S 4LL BE ANCHORED WLTH EITHER A CONCRETIz BASE OR STEEL PLATE BASE TO PKVENT FLOTATION. FUF? CONCRETE BASE THE DEPTH SHALL 9E TWELVE (I.?) INCHES WITH THE RISER EMBEDDED NINE 9) INCHES, A 114 INCH MINIMUM THICKNESS. STEEL PLATE SHALL BE ATTACKED TO THE RISEN BY A C❑NT[NUIDUS VELA AROUND THE BOTTOM TO FORM A wAT ER T[GmT C❑NNEC T]ON AND THEN PLACE T W❑ FEET UF STONE, GRAVEL, OR TAMPED EARTH ❑N THE PLATE. i�DAPTED FROM DETAILS PROVIDED HYc USDA — MRIS, PIPE OUTLET NEW YCAK STATE QEP'AWTHENT pF TRANSPIRTATI❑NA SEDIMENT TRAP NEV 'YORK STATE DEPARTMENT � ENVIRD�IENTAL CONSERVATION, NEW YMW STATE SOIL L WATER CONSERVATIOM COMMIT TEE T —1 November 2016 Page 5.50 New York State Standards and Specifica- tions For Erosion and Sediment Control Figure 5.27 Stone Outlet Sediment Trap: ST-II IMIK SYMBOL Tf;P OF 1' N. Eh 3ANKMENT r � MAIL. I�R�1LE EICISTING GROUND A--' \ 4F N. Y.S. DOT 'WE I R STINE FLOC+' CPFST `� '� SOT � _ SM�+LL � h�ALL - ;� -- � - 12 STONE h'IPPAP Q[PRAI� SMALL RIPRAP EARTH EXCAVATE FOP ��R� EMPAN'KMENT 4f R.EQUI RED STORAGE 2'APR❑N A w CROSS SECTION A—A 4' UNDISTURBED AREA LIP11❑`, A ONE FOOT LAYER OF N.Y.s_ DOT #2 STONE MAY 13E PLACED ON THE OPSTREAM SIDE OF THE R11PRAP INPLACE OF T1 iE EMBEDDED FILTER GL❑TH. CONSTRUCTION PE IFICAT I ❑ 1 1. AREA UN11E-R EIS IRN4KMENT ALL 13E CLEARED, GRUBBED AND STRIPPED [IF ANY VEGETATION AND R®OT MAT. THE POOL AREA SHALL BE CLEARED. 2. THE FILL MATERIAL FOR THE EMBANKMENT SHALL BE FREE OF P013TS AND OTHER IOODY VEGETATION AS WELL AS OVER—SFZ'D STONIsS, RQCKSr O AN3C MATERIAL OR OTHER OBJECT16RABLE MATERIAL. THE EMBANKMENT SHALL ICE COMPACTED BY TRAVERSING WITH EQU"ENT WHILE IT IS BEING CONSTRUCTED. 3. ALL OUT AND FILL< SLOPES SHALL BE 2-1 OR E LA T T ER. 4. THE ST❑N, LJ 5 F D IN THE OUTLET SHALL DE SHALL RIPRAP 4'—#I' ALCNG VITH A 1' THICKNESS OF 2' AGGREGATE PLANED ON THE UP—GRADE 'SATE ON T-HE SMALL RCPRAP UFO L M OE I DL O FILTER CL07 H Its THE RIP PAP. 5. SEDIMENT SHALL RE REMOVED AND TPO.P RESTORED TO ITS ORIGINAL DIMEN— SIONS WHEN THE. 5EQI6�LN HAS ACCUMULATED TO 112 IHE= DESIGN DEPTH OF THE TRAP, IT SHA—L 9E PLACED ON SITE AND STABILIZED, G. THE 'STRUCTURE SHALL BE INSPECTED AFTER EACH PAIN AND REPAIRS MADE AS NEEDED. 7, CONSTRUCT10N OPERATIONS SHALL BE CARRIED L]UT IN SUCH A KANIER THAT EROSION AND SEDIMENT ARE CONTROLLED. B. THE STRULCTURE SHALL BE REMOVED AND THE AREA STABILIZED WHEN THE DRA LIRAGE AREA HAS BEEN PROPERLY STABILIZED. MAXIMU11 DRAINAGE AREA 5 ACRES A001ED PREIw I'9 TAILS PFWV11IE n BY, u=n . v NRIs; MINE: OUTLET NEW YORK STATE DEPARTMENT OF TRANSPORTATION, NEW Y01RK STATE DEPARTMENT OF CNVERDWEMTAL CN RVAT)UK SEDIMENT TRAP NEW 'YQRK STATE SOIL L WATER r.I 0t'VAT11 N CUOMTTEE T—II New York State Standards and Specifications Page 5.51 November 2016 For Erosion and Sediment Control Figure 5.28 Compost Filter Sock Sediment Trap: ST-III Plan View 12"❑[AMF.rkR SitCK 1. Compost Sock Sediment Trap shall be sized to provide 3,600 cubic feet of storage capacity for acre tributary to the trap. 2. Minimum base width is equivalent to the height. 10"OIAM TER-8W 3. Sediment accumulation shall not exceed 1/3 the total height of the trap. 4. Socks shall be of larger diameter at the base of the trap and decrease in diameter for successive layers as indicated to the left. 24 DRAM ETER,SOCK 5. Ends of the trap shall be a minimum of 1 foot higher in elevation that the mid-section,which shall be located at the point of discharge. Staking Detail I ^P44t*OAROWOM'RTAXFS. MAPPED T{GETF+ER WWH ie GuAoE 1 - 2,;z,o5,Fono woriD sr _tLIr a.c R_MQV179g41gk+ W 'a�S l $� 1I'61110011 *Figures adapted from Filtrexx Specifications: 1. Sock infill and filter media material shall meet the standards of Table 5.1 on page 5.8 . Compost shall meet the com- post filter sock standard of Table 5.2 on page 5.8. 2. Compost sock sediment traps shall not exceed three socks in height and shall be stacked in pyramidal form as shown above. Minimum trap height is one 24 inch diameter sock. Additional storage may be provided by means of an exca- vated sump 12 inches deep extending 1 to 3 feet upslope of the socks along the lower side of the trap. 3. Compost sock sediment traps shall provide 3,600 cubic feet storage capacity with 12 inches of freeboard for each tribu- tary drainage acreage. (See manufacturer for anticipated settlement.) 4. The maximum tributary drainage area is 5.0 acres. Since compost socks are"flow-through,"no spillway is required. 5. Compost sock sediment traps shall be inspected weekly and after each runoff event. Sediment shall be removed when it reaches 1/3 the height of the socks. 6. Photodegradable and biodegradable socks shall not be used for more than 1 year. November 2016 Page 5.52 New York State Standards and Specifica- tions For Erosion and Sediment Control Figure 5.29 Optional Sediment Trap Dewatering Devices for Traps with <5 Acres Drainage Area OPTIONAL SEDIMENT TRAP DEWATERINO SYMBDL DEVICE - I WITH ' PERFORATED RISER r CAP END UNLESS EQUAL TO IR GREATER THAN ELEV.. ❑F' TOP OF FILL ART I-VIIPTEX PRINARY RISER CREST I)EV ICE 1-P PERFORATIONS MIN. 6" RIFE DIAMETER CMR FILM NTH OVER' VIR HESW KYS BUT STOW 6' DID_ PIPE CdlE GWT JS RAND BARREL RISER M1 E BASE PLATE {I/A'3 'P=R FU RAT I DNS ❑R SLITS Ift1ST NOT SIZE- 114,24 BE 'MALE ANY LOWER THAN 6r ABOVE TJP OF HORIZONTAL ❑UTFALL BARREL, PE RFORATIOW - 6* SPACING. HORIZONTAL IL VERTICAL LOCATED IN CONCAVE. OPTIONAL SEDIMENT TRAP DEWATERING DEVICE - II TYPICAL STONE OUTLET 8' MIN, DIA14ETER SEDIMENT TRAP PERFORATED PIPE WRAPPED WITH FILTER , CLOTH, MIX — — L8'M1�1, LAYER NTS DOT 02 STONE. 12*141k LAYER NYS DOT 02 STOKE CAP END OF PIPE OMWTED FROM DETAILS PROVIDE11 EY3 USDA R NRiGS, OPTIONAL SEDIMENT I+E'W YoPx STATE DCPARTd• NT [W TR&NSMRTAT18Nr TRAP E TE I M KV YEW STATEDEPARTMENT EF ENYL►33*CNTAL -COSH ERVArIONr Wv Mk< StATC SOIL & VATER CDNSERVATION CQHMITTEE DEVICES New York State Standards and Specifications Page 5.53 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR SILT FENCE roll down. The area beyond the fence must be undis- ' turbed or stabilized. or 3. The type of silt fence specified for each location on the plan shall not exceed the maximum slope length and JUM maximum fence length requirements shown in the fol- �' lowing table: Slope Length/Fence Length(ft.) t Slope Steepness Standard Reinforced Super <2% <50:1 300/1500 N/A N/A 2-10% 50:1 to 10:1 125/1000 250/2000 300/2500 Definition & Scope 10-20% 10:1 to 5:1 100/750 150/1000 200/1000 20-33% 5:1 to 3:1 60/500 80/750 100/1000 A temporary barrier of geotextile fabric installed on the contours across a slope used to intercept sediment laden 33-50% 3:1 to 2:1 40/250 70/350 1001500 runoff from small drainage areas of disturbed soil by tem- >50% >2:1 20/125 30/175 50/250 porarily ponding the sediment laden runoff allowing settling to occur.The maximum period of use is limited by the ul- Standard Silt Fence(SF)is fabric rolls stapled to wood- traviolet stability of the fabric(approximately one year). en stakes driven 16 inches in the ground. Reinforced Silt Fence(RSF)is fabric placed against Conditions Where Practice Applies welded wire fabric with anchored steel posts driven 16 inches in the ground. A silt fence may be used subject to the following condi- Super Silt Fence(SSF)is fabric placed against chain tions: link fence as support backing with posts driven 3 feet in the ground. 1. Maximum allowable slope length and fence length will not exceed the limits shown in the Design Criteria for 4. Silt fence shall be removed as soon as the disturbed the specific type of silt fence used;and area has achieved final stabilization. 2. Maximum ponding depth of 1.5 feet behind the fence; The silt fence shall be installed in accordance with the ap- and propriate details.Where ends of filter cloth come together, they shall be overlapped,folded and stapled to prevent sedi- 3. Erosion would occur in the form of sheet erosion;and ment bypass.Butt joints are not acceptable.A detail of the silt fence shall be shown on the plan. See Figure 5.30 on 4. There is no concentration of water flowing to the barn- page 5.56 for Reinforced Silt Fence as an example of details er;and to be provided. 5. Soil conditions allow for proper keying of fabric,or other anchorage,to prevent blowouts. Criteria for Silt Fence Materials Design Criteria 1. Silt Fence Fabric: The fabric shall meet the following 1. Design computations are not required for installations specifications unless otherwise approved by the of 1 month or less.Longer installation periods should appropriate erosion and sediment control plan approval be designed for expected runoff. authority. Such approval shall not constitute statewide acceptance. 2. All silt fences shall be placed as close to the disturbed area as possible,but at least 10 feet from the toe of a slope steeper than 3H:IV,to allow for maintenance and November 2016 Page 5.54 New York State Standards and Specifica- tions For Erosion and Sediment Control Super Silt Fence Minimum Fabric Properties Acceptable Test Method Value Grab Tensile Strength(lbs) 110 ASTM D 4632 Elongation at Failure(%) 20 ASTM D 4632 Mullen Burst Strength 300 ASTM D 3786 (PSI) Puncture Strength(lbs) 60 ASTM D 4833 Minimum Trapezoidal 50 ASTM D 4533 Tear Strength(lbs) °`�` . Flow Through Rate(gal/ 25 ASTM D 4491 min/sf) i Equivalent Opening Size 40-80 US Std Sieve ASTM D 4751 Minimum UV Residual 70 ASTM D 4355 - 2. Fence Posts(for fabricated units): The length shall be a minimum of 36 inches long. Wood posts will be of sound quality hardwood with a minimum cross section- al area of 3.5 square inches. Steel posts will be stand- ard T and U section weighing not less than 1.00 pound per linear foot.Posts for super silt fence shall be stand- ard chain link fence posts. 3. Wire Fence for reinforced silt fence: Wire fencing shall be a minimum 14 gage with a maximum 6 in. mesh opening,or as approved. 4. Prefabricated silt fence is acceptable as long as all ma- terial specifications are met. Reinforced Silt Fence ip AS- New York State Standards and Specifications Page 5.55 November 2016 For Erosion and Sediment Control Figure 5.30 Reinforced Silt Fence VOVEN VIRIE FENCE Sym Eel 11 (MIN. t4 Cw4JGE V1 MAX- 6* MESH f—�---■ 10' MAX. E. TO C SPACING) 6' MrN NGTR F-I1FF POSTS v LcIVEN MIN- 16' INTO CP--'4D, HEECHT OF FILTER L8' MIN. -4, * w €- Mi N. PERSPECTIVE VIEW 36' MIN. FENCI WOVEN WIRE .r rNcE CM[It i� GAUGE W1 MAX, 6F MESH SLR#CChIG3 WITH FILTER SLOTHQ'I�L[I+M 'UNDISTURBED GR❑U�-C❑MPACTED EMBEG FILTER CLIFM1N. A M K OF 6' IN' iI NCTI❑N VIEW CONSTRUCTION PE IEI A TIO 'I. WOVEN WIRE FENCE T❑ 13E FASTENED SECURELY TO FENCE POSTS WITH WIRE TIES ®R STAPLES. POSTS &'HALL BE STEEL EITHER 'T' ❑Tt 'U' TYPE OR HARI]VO11D. z. FILTER CL07H TO RE FASTENED SECURELY 70 WOVEN WIRE FENS r WCTH TIES SPACED EVERY 24' AT TOP AND MID SECTION. FENCE SHALL BE WOVEN WIRE, 1�' MAC[[Mkj M MESH OPENING. a WHEN TWO SECTI❑NS OF FILTER CLOTH! ADJOIN EACH OTHER THEY SHALL DE ❑VFE - LAPPED V SIX INCKS AND FULLED, FILTER SLOTH SHALL HE EITHER FILTER X, MIRAF I ]DOX, S TA ICI L INKA T L 40N; OR APPROVED EC3U]VALEN T. 4. PREFABRICATED UN L T S SHALL FEET THE M]4]MUM REQUIREMENTS SHOWN. 5 MAINTENANCE SHALL BE PERFORMED AS MECDEI] AND MATERIAL REMOVED WHEN 'BULGES' TDE vELOP IN THE S[L T FENCE. ADAPTEE FR❑H DETAILS PR❑V.IDED BY-, USDA - NR[S, NEW Y❑RK STATE DEPARTKENT QE TRANSPORTATION, REINFQRIIE'D NEW Y❑RK STATE DEPART14ENT OF ENVIPG4KENTA,L CONSERVATION, ��fi F�IV�� NEW FORK STATE SOIL t WATER CONSERVATION COMHIlIFt November 2016 Page 5.56 New York State Standards and Specifica- tions For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR STORM DRAIN INLET PROTECTION drainage area tributary to the inlet. The crest elevations of these practices shall provide storage and minimize bypass e flow. Type I—Excavated Drop Inlet Protection This practice is generally used during initial overlot grading after the storm drain trunk line is installed. Limit the drainage area to the inlet device to 1 acre. Exca- vated side slopes shall be no steeper than 2:1. The mini- mum depth shall be 1 foot and the maximum depth 2 feet as r .a r,P 1 _ measured from the crest of the inlet structure. Shape the 4. excavated basin to fit conditions with the longest dimension oriented toward the longest inflow area to provide maxi- Definition & Scope mum trap efficiency. The capacity of the excavated basin should be established to contain 900 cubic feet per acre of A temporary barrier with low permeability,installed around disturbed area. Weep holes,protected by fabric and stone, inlets in the form of a fence,berm or excavation around an should be provided for draining the temporary pool. opening,detaining water and thereby reducing the sediment content of sediment laden water by settling thus preventing Inspect and clean the excavated basin after every storm. heavily sediment laden water from entering a storm drain Sediment should be removed when 50 percent of the stor- system. age volume is achieved This material should be incorpo- rated into the site in a stabilized manner. Conditions Where Practice Applies Type II—Fabric Drop Inlet Protection This practice shall be used where the drainage area to an inlet is disturbed,it is not possible to temporarily divert the - a storm drain outfall into a trapping device,and watertight blocking of inlets is not advisable. It is not to be used in place of sediment trapping devices.This practice shall be used with an upstream buffer strip if placed at a storm . drain inlet on a paved surface.It may be used in conjunction p Y J with storm drain diversion to help prevent siltation of pipes _ L installed with low slope angle. Types of Storm Drain Inlet Practices There are five(5)specific types of storm drain inlet protec- tion practices that vary according to their function,location, drainage area,and availability of materials: 1. Excavated Drop Inlet Protection This practice is generally used during final elevation grad- IL Fabric Drop Inlet Protection ing phases after the storm drain system is completed. III. Stone&Block Drop Inlet Protection IV. Paved Surface Inlet Protection Limit the drainage area to 1 acre per inlet device. Land area V. Manufactured Insert Inlet Protection slope immediately surrounding this device should not ex- Desi2n Criteria ceed 1 percent. The maximum height of the fabric above the inlet crest shall not exceed 1.5 feet unless reinforced. Drainage Area—The drainage area for storm drain inlets The top of the barrier should be maintained to allow over- shall not exceed one acre. Erosion control/temporary stabi- flow to drop into the drop inlet and not bypass the inlet to lization measures must be implemented on the disturbed New York State Standards and Specifications Page 5.57 November 2016 For Erosion and Sediment Control unprotected lower areas. Support stakes for fabric shall be materials and any unstable soil and dispose of properly. a minimum of 3 feet long,spaced a maximum 3 feet apart. They should be driven close to the inlet so any overflow Bring the disturbed area to proper grade,smooth,compact drops into the inlet and not on the unprotected soil. Im- and stabilize in a manner appropriate to the site. proved performance and sediment storage volume can be obtained by excavating the area. Type IV—Paved Surface Inlet Protection Inspect the fabric barrier after each rain event and make repairs as needed. Remove sediment from the pool area as necessary with care not to undercut or damage the filter fabric. Upon stabilization of the drainage area,remove all materials and unstable sediment and dispose of properly. Bring the adjacent area of the drop inlet to grade,smooth and compact and stabilize in the appropriate manner to the site. Type III—Stone and Block Drop Inlet Protection This practice is generally used during the initial and inter- mediate overlot grading of a construction site. Limit the drainage area to 1 acre at the drop inlet. The stone barrier should have a minimum height of 1 foot and a maximum height of 2 feet. Do not use mortar. The height should be limited to prevent excess ponding and bypass flow. This practice is generally used after pavement construction has been done while final grading and soil stabilization is Recess the first course of blocks at least 2 inches below the occurring.These practices should be used with upstream crest opening of the storm drain for lateral support. Subse- buffer strips in linear construction applications,and with quent courses can be supported laterally if needed by plac- temporary surface stabilization for overlot areas,to reduce ing a 2x4 inch wood stud through the block openings per- the sediment load at the practice.This practice includes pendicular to the course. The bottom row should have a sand bags,compost filter socks,geo-tubes filled with bal- few blocks oriented so flow can drain through the block to last,and manufactured surface barriers. Pea gravel can also dewater the basin area. be used in conjunction with these practices to improve per- formance. When the inlet is not at a low point,and is off- The stone should be placed just below the top of the blocks set from the pavement or gutter line,protection should be on slopes of 2:1 or flatter. Place hardware cloth of wire selected and installed so that flows are not diverted around mesh with''/2 inch openings over all block openings to hold the inlet. stone in place. As an optional design,the concrete blocks may be omitted and the entire structure constructed of stone,ringing the outlet("doughnut"). The stone should be kept at a 3:1 slope toward the inlet to keep it from being washed into the inlet. A level area 1 foot wide and four inches below the crest will further prevent wash. Stone on the slope toward the inlet ^ - should be at least 3 inches in size for stability and 1 inch or smaller away from the inlet to control flow rate. The eleva- tion of the top of the stone crest must be maintained 6 inch- _ es lower than the ground elevation down slope from the inlet to ensure that all storm flows pass over the stone into the storm drain and not past the structure. Temporary dik- ing should be used as necessary to prevent bypass flow. The barrier should be inspected after each rain event and repairs made where needed. Remove sediment as necessary to provide for accurate storage volume for subsequent rains. Upon stabilization of contributing drainage area,remove all November 2016 Page 5.58 New York State Standards and Specifica- tions For Erosion and Sediment Control The drainage area should be limited to 1 acre at the drain inlet. All practices will be placed at the inlet perimeter or beyond to maximize the flow capacity of the inlet.Practices shall be weighted,braced,tied,or otherwise anchored to prevent movement or shifting of location on paved surfaces. Traffic safety shall be integrated with the use of this prac- tice.All practices should be marked with traffic safety cones as appropriate.Structure height shall not cause flood- ing or by-pass flow that would cause additional erosion. The structure should be inspected after every storm event. Any sediment should be removed and disposed of on the site. Any broken or damaged components should be re- placed. Check all materials for proper anchorage and se- cure as necessary. Type V-Manufactured Insert Inlet Protection The drainage area shall be limited to 1 acre at the drain in- let.All inserts will be installed and anchored in accordance with the manufacturers recommendations and design de- tails.The fabric portion of the structure will equal or exceed the performance standard for the silt fence fabric.The in- serts will be installed to preserve a minimum of 50 percent of the open,unobstructed design flow area of the storm drain inlet opening to maintain capacity for storm events. New York State Standards and Specifications Page 5.59 November 2016 For Erosion and Sediment Control Figure 5.31 Excavated Drop Inlet Protection SYMBOL FLOW zr IFLOW r rr r . r, FLOW EXCAiVATED AREA (ASS REQUIRED} S I'DE SLOPE EXCAVATED II DEPTH MIN. I' TD WEEP HOLES GRAVEL SUPPORTED BY A MAX. 2' SELOV FOR HARDWARE CLOTH TO TOP OF INLET.; DEWATERING + ALLOW DRAINA15E AND RESTRICT SEDIMENT ��— MOVEMENT. CONSTRUCTION PE IPICATIDN M, CLEAR THE AREA OF ALL DEBRIS THAT WILL HINDER EXCAVATIC*L P, GLADE APPROACH TO THE INLET UNIFORMLY AROUND IHE RAS'K 3. WEED HOLES SHALL BE ?R❑TECTEI) BY GRAVCL. 4, UPON STABILIZATIM OF CONTRIBUTING DRAIRAFiE AREA, SEAL WEEP HOLES, FILL EXCAVATION V[TH STADLE S❑IL TO FINAiL GRAiIlEr COMPAC7 IT PROPERLY AND STAI�ILI.ZE VM PERMANENT SEEDING, MAX[MUM DRMNAG+E AREA 1 ACRE ADAFTEn rum DETAILS PROVIDED B1% USDA s NRCS, HE'S Y RR STATE DEPAkTHENT 10F TRANSPORTATION, EXCAVATED DROP NF_V YORK STATE DEPARTMENT OF ENVLROWNTAL LON S ERV T]ON, INLET PROTECTION KEW WORK STALE SJOIL L VATER CONS7ERV kTION C❑HM371EC November 2016 Page 5.60 New York State Standards and Specifica- tions For Erosion and Sediment Control Figure 5.32 Fabric Drop Inlet Protection SYMBOL 8'X4' W10121] FRAMFABRIC TAKE _ 3' MINI 1II� I�1L i, wi=un DROP 'INLET 134lR[E D FABRIC (1Er TH GATE HELa1 GRADE) FRAME I� DRIVE STAKES A MIN, OF 1I° 1. — GATHER EVCE� I I BELOWGR hI]ET AT CDRINE R.S CONSTRUCTION SPECIFILA 1 IUN I. FA13RIC SHALL HAVE AN EQS OF 40-B5. BURLAP MAY BE USED FOR SHEIRT TERM APPLICATIMN& 2. CLIT FABRIC FROM A C❑NTINUELPS. REILL TO ELIMINATE JOINTS. IF JOINTS ARE NEEDED THEY VIL<L. BE GVERLAPPU TO THE NEXT STAKC Z. Hi TElRI SINIMM t ENrj T H� FEET. ❑❑B ❑F! E I +` T. 4. SPACE STAKES EVENLY AROUND INLET 3 FEET APART AND DRIVE A IiIN111 il# LNCME IyEEP, SPAS CPEAi�RR TNAN 3 FEET MAY DE E31 D H �+JTH TF I�SE OP r RE MESH BEHIND iC MTER FABRIC FOR T- S. F IC SHALL, BE EMBEDDED L FOOT NINNUM BEL13W OROUN d AND 1 ACK1-IL LED- IT SHALL BE SECURIEL Y FASTENED TO THE STAKES AND FR r 6r A V x 4' WOOD FRAME SHALL BE C04PLETED AROUND THE CREST [IF THE FABRIC FOR OVER FL❑fir' STABILITY, MAXIMUM DRAINAGE AREA L ACRC -ADAFTEQ FRUM DEIAILS PROVIDED 10Y, 0'S11A — NRr-So FABRIC NEW YORK STATE DEPARIMENT Or TK'AhMP1MTAT91nN. DROP❑P INLET .NEW 'I'ORK STATE CEPARTHEnT OF ENVIROINMENTAL COMISERV TIO", NEW Y❑RK STATE SOIL L WATER CONSERVATION COMMITTEE PROTECTION New York State Standards and Specifications Page 5.61 November 2016 For Erosion and Sediment Control Figure 5.33 Stone & Block Drop Inlet Protection O-WATE;RIN CE'�CRETE BLOCK SY 1B❑L t—G tir- y4WE o o M �- al SLOPE CRAVEL FILTER SI E]NE I BUICK PLAN VIE TEMPORARY SEDIMENT POOL SIREN UEWATERING l"hihT. _ 6, tffirr 111ril V3D D INLET III 5�I'TH 6ATE & SEDIMENT TLMPC NARY STONE- L 14L❑CK DETAIL SEDIN.E SIT POOL WIPE MESH 1gR[K 2,1 SL[]RE� 3-1 SLIDE 413PTII ,L3 214AX. —i FINE GRAVEL FACE (11M THTp SS) 31 STI]W — - 1. LAY ONE BLOCK ON EACH SIDE OF THE STRUCTURE ON ITS SIX FOR DEVATERING- FOUNDATI❑N SHALL III 2 INCRES MINI" BELOW REST 01F INLEI AND BLOCKS SHALL BE PLACED AGAINST INLET FOR SUPPORT. 2. HARDWARE CLOTH OR 1/2' WIRE HESH SHALL BE PLACED OVER BLCICK OPENINGS TO SUPPORT STD 3. USE CLEAR STEW OR 13RAVEL I/Z-3/4 INCH IN 111ANIMER PLACED 2 INCHES BELOW T13P IF BLOCK ON aA 2-1 SLOPE 0R FLAT Tom,. C FOR STONE STOWTURES ONLY, A I FOOT THICK LA'S OF THE FILTER STOW WILL BE PLACED AGAINST THE 3 INCH STONE AS SNOWN ON THE DRAVIHGS. MAXtNUH DRAINAGE AREA 'I ACRE ADAPTED FROM 1METAILS PROVIDED SY1 USDA - HRM, STONE & BLOCK NEW YOW STAIC DEPARTMEHT OF TRMSPMTAT'0N. ❑P INLET NEVY STATEDLPARTKERT OF E�IV'[ rAL WNSE RVATHIN, WIEW YIK STATE SOIL & 'CATER CM*MINATIJON COMMITTEE PR❑7 E C T I D N November 2016 Page 5.62 New York State Standards and Specifica- tions For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR STRAW BALE DIKE 4 quarter of an acre per 100 feet of dike and the length of slope above the dike shall be less than 100 feet. Design Criteria 77 . i _ The above table is adequate,in general,for cone-inch rain- ., fall event. Larger storms could cause failure of this prac- tice. Use of this practice in sensitive areas for longer than - r one month should be specifically designed to store expected runoff. All bales shall be placed on the contour with cut # - edge of bale adhering to the ground. See Figure 5.34 on page 5.64 for details. Definition & Scope A temporary barrier of straw,or similar material,used to intercept sediment laden runoff from small drainage areas of disturbed soil to reduce runoff velocity and effect deposi- tion of the transported sediment load. Straw bale dikes have an estimated design life of three(3)months. Condition Where Practice Applies The straw bale dike is used where: 1. No other practice is feasible. 2. There is no concentration of water in a channel or other drainageway above the barrier. 3. Erosion would occur in the form of sheet erosion. 4. Length of slope above the straw bale dike does not ex- ceed the following limits with the bale placed 10 feet from the toe of the slope: Constructed Percent Slope Slope Length Slope (ft.) 2:1 50 25 3:1 33 50 4:1 25 75 Where slope gradient changes through the drainage area,steepness refers to the steepest slope section con- tributing to the straw bale dike. The practice may also be used for a single family lot if the slope is less than 15 percent. The contributing drainage areas in this instance shall be less than one New York State Standards and Specifications Page 5.63 November 2016 For Erosion and Sediment Control Figure 5.34 Straw Bale Dike SYMBOL FLa'.' II'' 4' ��}E4�TT�GAL FACE I REDDING DETAIL NOT TO SCALE DRAINAGE AREA NO MORE THAN IAA ACRE PER 3.00 FEET Of STRAW BALE DIKE FM SLOPES LESS m4N 25%. ANGLE FIRST STAKE TOWARDS P'REVIERJSLY Lela BALE. FL❑V BOUND BALES P'LAI:ED ON CDNT❑UR. rwr r —` 2 F -BARS, STEEL PICKETS OR 2'X2' S TAKE 5 PLACED I I/Z' TO a' [H GROUND- DRIVE STAKES PLUS w[Tw TOP (IF EALE- ANCH❑RING DETAIL NOT TO SCALE CONSTRUCTION P❑ IFI TI❑N 1. RAL ES SHALL BE PLACED AT THE TOE OF A SLOPE OR ❑N THE CONTOUR AND IN i, RWV w1 TH £NDS TIC 1TLY ADU T T ING THE ADJACENT 8 1%L E S, 2. EACH BALE SMALL HE EMBEDDED 3N THE SDIL A MINIMUM OF (4) D CHES, AND PLACED SO THE BIN❑INGS ARE HIIIRIZ❑NTAL. DALES SHALL- DE SECUKLY ANCHWED IN PLACE BY EITHER TWO STAKES IR IRE-BARS DRIVEN TFIRIO FGH THE BALE. THE FIRST S TAB E IN EACH SALE SHALL BE DRIVEN TOWARD THE PREY[ SLY L.A10 BALE AT AN ANGLE TO FORCE 7-+ BALES TOGETHM STAKES SHALL BE IR'I VEN FLUSH WITH THE BALE- *. INSPE'CTIOrI SHALL B£ EREGUENT AND REPAIR IRE'PLACEmENT SHALL BE MAIX PROMPTLY AS NEEDiEEL S, IIA'LES SHALL BE RENdVED WHER. THEY HAVE SERVEM THEIIR USEFULLNESS SO AS NOT TO BLWK OR IMPEDE STORM FLOW DR DRAINAGE. kDAPTED FR13H DETAILS PR13VIDEII Hof• LPSDA — hRCS, NEW Y❑RK STATE HEPARTHVENT OF TRANSPORTATION, STRAW BAL NEW Y❑RK STATE DEPARTMENT OF DWVIRGNMENTAL CIONSERVATIEN, NEW YORK STATE 5❑]L # VATU CONSUVATIEN C®WHItIEF IDT '+E November 2016 Page 5.64 New York State Standards and Specifica- tions For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR TURBIDITY CURTAIN Construction Specifications The area of proposed installation of the curtain shall be in- spected for obstacles and impediments that could damage - — - the curtain or impair its effectiveness to retain sediment. All materials shall be removed so they cannot enter the wa- terbody. Shallow installations can be made by securing the curtain by staking rather than using a flotation system. Sup- plemental anchors of the turbidity curtain toe shall be used, as needed,depending on water surface disturbances such as boats and wave action by winds. Maintenance Definition & Scope The turbidity curtain shall be inspected daily and repaired or replaced immediately. It is not normally necessary to A temporary flexible,impenetrable barrier used to trap sedi- remove sediment deposited behind the curtain;but,when ment in water bodies. This curtain is weighted at the bot- necessary,removal is usually done by hand prior to removal tom to achieve closure while supported at the top through a of the barrier. All removed silt is stabilized away from the flotation system and used to prevent the migration of silt waterbody. The barrier shall be removed by carefully pull- from a work site in a water environment into the larger ing it toward the construction site to minimize the release of body of water. Top bar float has to support weight of cur- attached sediment. Any floating construction or natural tain material. Bottom anchor has to be flexible so that it debris shall be immediately removed to prevent damage to will lie along the contour of the water body bottom. the curtain. If the curtain is oriented in a manner that faces the prevailing winds,frequent checks of the anchorage shall Condition Where Practice Applies be made. A turbidity curtain is generally used when construction ac- tivity occurs within a waterbody or along its shoreline and is of short duration,generally less than one month. Curtains are used in calm water surfaces and not in areas of flowing water. Turbidity curtains are not to be used across flowing watercourses. Design Criteria The turbidity curtain shall be located beyond the lateral limits of the construction site and firmly anchored in place. The alignment should be set as close to the work area as possible but not so close as to be disturbed by applicable construction equipment. The height of the curtain shall be 20 percent greater than the depth of the water to allow for water level fluctuations. The area that the turbidity curtain protects shall not contain large culverts or drainage areas that if flows occur behind the curtain would cause a breach or lost contact at the bottom surface. If water depths at the design alignment are minimal,the toe can be anchored in place by staking. See Figure 5.35 on page 5.66. New York State Standards and Specifications Page 5.65 November 2016 For Erosion and Sediment Control Figure 5.35 Turbidity Curtain HIGHWAY SURFACE SYMBOL D11,7ANCE NECESSARY TO MANTA[[ STRUCTURAL INTEGR[TX OF CURTAIN VARIES BRIDGE ABUTMENT VARIES ROPE OR CABLE WITH FLOATS FILTER FARR:C WITH FdLDS FOR WATER FLUCTUAT[QN t o - EX[5TING GROU'1D/STREAMBANK �j � W ej COFFER DAM < Py CHAIN OR wEIGHT SEGTICI%� R-B ANCHOR 0� o 7 CONSTRUCTION GRADING LIMIT 3;Lj J kOPE OR CABLE WITH FLOATS 111 HOLM FILTER FABRIC � � Z EDGE Or WATERCOLIRSE L cc LIMIT EIS S70NE PLACEMEN' o , ANCHOR LOCATI❑N 141N, 3' UPLAND OF O.H.W. MARK L& +B I� L 8RIDOGE EXIST, H[CkMWAY COFFER DA 10' MIN. C❑N ST RUCTI❑N !GRADING ! MIT PLAN VIEW 4D.APTED FROM DETAIL'S PROVIDED JOY- USI34 - HRES, NEW YORK STATE ®EFARTKNT OF TRANS PURTAT 1❑N, TURBIDITY ��R T�I�g NEWY❑RK STATE DEPARTMENT OF EI I1RGNMENTAL CONSERVATION, NEW YORK STATE SOIL # VATU CCA+ISMVATL❑N COMMITTEE November 2016 Page 5.66 New York State Standards and Specifica- tions For Erosion and Sediment Control APPENDIX A REVISED UNIVERSAL SOIL LOSS EQUATION (RUSLE) CONTENTS Page List of Tables and Figures Introduction ......................................................................................................................................................................A.1 WhyUse RUSLE? ...........................................................................................................................................................A.1 Soil Erosion Estimates Using Revised Universal Soil Loss Equation For Sheet and Rill Erosion ..................................A.I Step-by-Step,How To Use RUSLE .................................................................................................................................A.2 Examples ..........................................................................................................................................................................A.2 References ......................................................................................................................................................................A.18 Section prepared by: Frederick B.Gaffney,Former Conservation Agronomist USDA Natural Resources Conservation Service, Syracuse,New York and Donald W.Lake Jr.,P.E.,CPESC,CPSWQ Former Engineering Specialist New York State Soil&Water Conservation Committee List of Tables and Figures Table Title Page A.1 Approximated K Values for Some Representative Soils on Construction Sites in New York..............A.6 A.2 Values for Topographic Factor,LS,for High Ratio of Rill to Interrill Erosion'.................................A.I I A.3 Factors for Converting Soil Losses(Air-Dry)from Tons(T)to Cubic Yards(Cu Yds.)....................A.12 A.4 El Values of Certain Key Cities in the New York Area'.....................................................................A.13 A.5 Construction Site Mulching C Factors ...............................................................................................A.14 A.6 Cover Factor C Values for Different Growth Periods for Planted Cover Crops for Erosion Control at Construction Sites .............................................................................................................A.14 A.7 Cover Factor C Values for Established Plants ....................................................................................A.15 A.8 Construction Site P Practice Factors ..................................................................................................A.15 Figure Title Page A.1 Monthly Percent of Annual Erosion Index-New York........................................................................A.4 A.2 Monthly Percent of Annual Erosion Index-Long Island......................................................................A.4 A.3 AVERAGE ANNUAL RAINFALL-RUNOFF EROSIVITY FACTOR(R) for the Northeast.........A.5 REVISED UNIVERSAL SOIL LOSS EQUATION (RUSLE) Introduction benefit of mulch can be predicted by multiplying the above by an appropriate cover or C-value. The benefit of a The science of predicting soil erosion and sediment delivery diversion ditch can be illustrated by comparing the original has continued to be refined to reflect the importance of LS with the shorter slope length LS created when adding different factors on soil erosion and runoff. The Revised this practice. Universal Soil Loss Equation(RUSLE)has improved the effects of soil roughness and the effects of local weather on Equation: A=RK(LS)C P Where: the prediction of soil loss and sediment delivery. A is the computed soil loss per acre per year in units of The importance of estimating erosion and sediment delivery tons. This quantity may be converted to cubic yards by has long been recognized to minimize pollution by using conversion factors shown in Table A.3. sediments and the chemicals carried by soil particles. The R is the rainfall value reflecting the energy factor multiplied visual effects of erosion include rills and gullies along with by the intensity factor. The R-values for each county are sediment blockages found in culverts or drainage ditches. provided in Figure A.3. EI is the abbreviation for energy A well planned,engineered and implemented erosion and intensity and is called the Erosion Index. The energy control and/or water management plan will alleviate many component is related to the size of the raindrops while the concerns about construction site erosion and potential intensity is the maximum intensity for a 30-minute interval pollution. and is measured in inches per hour. EI is frequently Why use RUSLE? illustrated in graphs by showing the percent of EI that occurs within a period of days or months. From the index, RUSLE is a science-based tool that has been improved over one can determine the period when the most intense storms the last several years. RUSLE is a computation method are likely to occur. See Figure A.1 and A.2. which may be used for site evaluation and planning purposes and to aid in the decision process of selecting K is the soil erodibility factor. The value for the subsoil erosion control measures. It provides an estimate of the condition,usually encountered in construction sites,can be severity of erosion. It will also provide quantifiable results determined based on soil texture(relative percent of sand, to substantiate the benefits of planned erosion control silt,and clay)or from most county soil surveys,found in measures,such as the advantage of adding a diversion ditch the table providing Physical and Chemical Properties of or mulch. For example,a diversion may shorten the length Soils. However,K values for subsoils are not always of slope used in calculating a LS factor. Also,the available. If the soil survey does not list a subsoil K for the application of mulch will break raindrop impact and reduce soil series encountered,use the surface K value unless there runoff(See discussion of L,S and C factors). is an obvious change from sand or gravel to silt or clay. Contact the local SWCD or NRCS office for an appropriate This section provides a method to calculate soil loss. K value when in question. Approximated K values for Following the step-by-step procedure will provide estimated some representative soils on construction sites in NY can be erosion in`tons per acre per year',which can be converted found in Table A.1.The most current K values for all New to the more usable measurement,cubic yards of soil. York soils are contained in the USDA-NRCS soil database on their website at:http://websoilsuivev.nres.usda.gov/app/ Other erosion prediction methods such as computer models Web SoilSurvev.aspx. are also available. Examples are the USDA-MRCS RUSLE 2 at http:Hfamo.nserl.ouirdue.edu/msle2 dataweb/ L is the horizontal length of slope measured in feet. It is the RUSLE2 Index.htm and USDA-ARS Water Erosion point of origin where water will begin flowing down the Prediction Project(WEPP)at http://www.as.usda.gov/ slope to the point where concentrated flow begins,such as News/docs.htm?docid=10621. where water flows into a ditch,or deposition occurs and water disperses. S is the slope gradient. Slopes may be uniform,concave(flattening toward the lower end)or Soil Erosion Estimates Using Revised convex(steepening toward the lower end). Table A.2 Universal Soil Loss Equation For Sheet and assumes a uniform slope. If the slope is concave,the LS Rill Erosion factor will be slightly lower. If convex,then the LS will be slightly higher. These factors are interrelated and the LS As mentioned above,soil losses on construction sites can be factor can be obtained from Table A.2. This LS table is predicted by using the Revised Universal Soil Loss specific for construction sites with little or no cover. Equation(RUSLE). The equation is as follows: A=RK(LS)for bare ground conditions of graded areas of C is the factor to reflect the planned cover over the soil construction sites. Referring to the examples above,the surface. Most construction sites are void of vegetation and New York State Standards and Specifications Page A.1 November 2016 For Erosion and Sediment Control therefore would have a value of one(1). On construction The soil is a Schoharie silt loam with a K value of 0.49 in sites where mulch or fabrics are used,the benefit derived both the B and C horizons(The K value is obtained from from intercepting the erosive raindrop impact on the soil Table A.1). The LS value is 3.11 and is obtained from surface is calculated. For example,the value of two tons of Table A.2. straw uniformly covering a slope results in a C-value of 0.1. (see Tables A.5-A.7 at back of this section)Therefore, 1. Compute soil losses from this unprotected surface for a mulching can substantially reduce the predicted soil loss. 12 month period. The average annual rainfall erosion index(R)is 80. P is the factor that represents management operations and R=80 C= 1 support practices on a construction site.Table A.8 lists P K=0.49 factors for surface conditions on construction sites in LS=3.11 (Interpolate between 400' and 600' at 8%) relation to bare soils. A=RK(LS)C=122 T/ac/yr Step-by-Step,How to Use RUSLE 50 ac x 122 Tons/ac/yr =6100 Tons/yr 1. Determine the County. Use Figure A.3 to determine Convert to cu yds: 6100 T/yr x 0.87 cu yds/Y= the R-value. 5307 cu yds/yr 2. Determine the soil erodibility factor based on the soil (0.87 cu yds/T is obtained from Table A.3,silt loam) series or the texture. Determine the appropriate K- value for subsoil by using the estimated K values 2. Compute soil losses from this unprotected surface for a shown in Table A.1. Updated K values can be found 3 month period(June,July,August). This EI value is using web soil survey or by contacting your local obtained as follows: Refer to the erosion index NRCS office. distribution curve applicable to Cortland,New York, Figure A.1. The EI reading for June 1 is 17%and for 3. Measure the horizontal length(plan view)of slope(in September 1 is 76%. The percent of average annual feet)from the top of the slope to the bottom. The index for this period is 76%- 17%or 59%. Since the bottom is either a ditch bank(concentration of water) annual erosion index for this location is 80,the EI or flatter slope where deposition occurs and water value for the 3 month period is 59%of 80 or 47.2. disperses(actual field measurement). 4. Determine the percent slope(actual topographic R=80 C= 1 K=0.49 LS=3.11 measurement). Annual EI(R)=80 3 month EI=47.2 5. Look up LS value in Table A.2. Interpolate if necessary to use the measured length and percent slope A=(EI)K(LS)C=72 Tons/ac/3 mo. obtained by field measurement. 50 ac x 72 Tons/ac/3 mo.=3600 Tons/3 mo. 6. Determine the Cover(C)factor-Most construction sites are void of vegetation and therefore would have a Convert to cu yds: 0.87 cu yds/Tons x 3600 Tons/3 value of one(1). For values of other cover conditions mo.=3132 cu yds/3 mo contact your local SWCD or NRCS office. 3. Compute soil losses for the 1 year out of 5 when the 7. Multiply the R*K*(LS)to obtain soil loss in tons/acre/ rainfall intensity(R)will increase from the normal year. average annual value of 80 to an annual value of 129 8. Convert to cubic yards if desired. Refer to the (the latter value is from Table A.4). conversion factors based on soil texture(Table A.3). R= 129 (Change R from 80 to 129) K=0.49 9. Review the examples that follow for specific field LS=3.11 C= 1 conditions where RUSLE may be useful. A=RK(LS)C Examples The following are examples showing how the Revised A=129 x 0.49 x 3.11 = 197 Tons/ac/yr Universal Soil Loss Equation is used for estimating soil 50ac x 197 Tons/ac/yr=9850 Tons/yr losses: Assume Cortland,New York,as the locale of a construction Convert to cu yds=0.87 cu yds/Tons x 9850 Tons/yr site. The disturbed site is 50 acres in size,with an average =8570 cu yds/yr gradient of 8%and an average slope length of 500 feet. November 2016 Page A.2 New York State Standards and Specifications For Erosion and Sediment Control Examples (continued) A=(EI)K(LS)C=99 Tons/ac/yr 4. Compute soil losses for the 1 year out of 20 when the 50 ac x 99 Tons/ac/yr=4950 Tons/yr rainfall intensity(R)will increase from the average annual R of 80 to an R of 197(the latter value is from Convert to cu yds=0.87 cu yds x 4950 Tons/yr= Table A.4). 4307 cu yds/yr R= 197 (Change R from 80 to 197) Sediment Yield—MUSLE K=0.49 LS=3.11 C=1 The Modified Universal Soil Loss Equation(MUSLE), developed by Williams and Berndt, 1976,can be used to A=RK(LS)C=300 Tons/ac/yr calculate sediment yields from drainage basins to specific locations for selected storm events. 50 ac x 300 Tons/ac/yr = 15,000 Tons/yr The formula is given as: Convert to cu yds=0.87 cu yds/Tons x 15,000 Tons/ yr=13,050 cu yds/yr T=95(V x Qp)0.56 x K x LS x C x P 5. Compute soil losses from the expected magnitude of a Where: single storm that may occur once in 5 years. Looking at Table A.4,the expected magnitude,or EI value,is T=sediment yield per storm event in tons 38. V=volume of runoff per storm event in acre-feet Qp=peak flow per storm event in cubic feet per second EI(R)=38 C= 1 K,LS,C,and P are RUSLE factors K=0.49 LS=3.11 Values for V and Qp are determined from the sites drainage analysis. A=(EI)K(LS)C=38 x 0.49 x 3.11 =58 Tons/ac/yr Example 50 ac x 58 Tons/ac/yr=2900 Tons/yr Compute the sediment yield volume to a basin from a Convert to cu yds=0.87 cu yds/Tons x 1650 Tons/yr drainage area of 10 acres under construction(all disturbed) =2523 cu yds/yr for a 2 inch rainfall. 6. Compute soil losses from the expected magnitude of a The soil(sandy loam)K=0.43,LS=2.34,the volume of single storm that may occur once in 10 years. The EI runoff is 1.5 acre-feet and the peak discharge for the storm value of this storm is 51. (Obtained from Table AA) is 5 cubic feet per second. EI(R)=51 C=1 T=95(1.5x5)0.56(0.43)(2.34)(1)(1) K=0.49 LS=3.11 T=295.4 tons A=(EI)K(LS)C=78 Tons/ac/yr 295.4 tons x 0.70 cy/ton=206.99 cubic yards 50 ac x 78 Tons/ac/yr=3900 Tons/yr Convert to cu yds=0.87 cu yds/Tons x 3900 Tons/yr =3393 cu yds/yr 7. Compute soil losses from the expected magnitude of a single storm that may occur once in 20 years. The EI value of this storm is 65. (Obtained from Table AA) EI(R)=65 C= 1 K=0.49 LS=3.11 New York State Standards and Specifications Page A.3 November 2016 For Erosion and Sediment Control Figure A.1 (USDA -NRCs) Monthly Percent of Annual Erosion Index—New York x k* - z W W - J M Q P W i11 }I 3/1 All Efl EA 711 4A SA Ilit IZA Vk DA TE New York State except Long Island Figure A.2 (USDA -NRCs) Monthly Percent of Annual Erosion Index—Long Island c� z - 9 - GC =•- r l 4 S - - - + J a & 1� - w DATE November 2016 Page A.4 New York State Standards and Specifications For Erosion and Sediment Control 2-9 WrModt oP A=CWI lM NatUr.51 ROBADUrg@* Canls4!rV,3iJO13 .fierI iCle CD CD O C� m AMAGE ANWA -R O" CROSIVITIC FACTOR f* the Northeast d4 WK - _ 95 07, Ra O �• CD ' c AGO led z CD x � CD � C ¢- CD ¢ LSD O � � r CD CDEN 4acibarm4 21rWaraJ Yrclol-mL d'ir 1� � Sd 6 7r9 11k6 131] 4$� Imllu day wop polio: Vim# 1:ko4G 0D2 F - —Tom,.. �---Lg p i 6a.-1 i.. Raps FyL?rnlr .SyFlacuk.r, L■ 3 Mo., hoj*tk]i&:. &Wm-p IFI—I .... Table A.1 Approximated K Values for Some Representative Soils on Construction Sites in New York (These K values and K values for soils not shown in these tables should be verified at the USDA-NRCS website,hilpL websoilsu rvey.nres.usda.t!ov/autn/WebSoilSurvev.asnx.) Depositional Unit Family Texture Class 1 Texture Construction and Representative Series Hoizon Class Erosion Potential Site K Values L Glacial Till SANDY SKELETAL ' Glouster A sl Low .17 B&C vglcs Low SANDY w/PAN Essex A sl Low B gls Low 20 Cx glcs Low COURSE LOAMY w/PAN Empeyville A stl Medium B stsl Medium .17 Bx vstsl Low C vstsl Low Mardin A ch sil Low B ch sil-1 Medium .28 Bx&C v ch 1 Medium Paxton A fsl Medium B gfsl Medium .24 Cx gfsl High Crary A sil Medium B vfsl High .43 IIBx,Cx,C st fsl Medium COARSE LOAMY wBt Madrid A fsl Medium Bt gfsl Medium 28 C gfsl Medium COARSE LOAM,20 TO 40"over BEDROCK Lordstown A ch sil Low B ch sil High C v ch 1 Low .43 R Siltstone or sandstone bedrock 20-40"below surface November 2016 Page A.6 New York State Standards and Specifications For Erosion and Sediment Control Table A.I (cont'd) Approximated K Values for Some Representative Soils on Construction Sites in New York (These K values and K values for soils not shown in these tables should be verified at the USDA-NRCS website, httn://websoilsun,,ey.nres.usda.2ov/ann/WebSoilSun ey.ast)x.) Depositional Unit Family Texture Class i Texture [Site struction and Representative Series Hoizon Class Erosion Potential K Values FINE LOAMY wBt Ontario A I Medium Bt gl Medium .28 C gl Medium Cazenovia A sil High Bt sicl High .43 C gsil Medium Nunda Ap ch sil High B2 ch sil High .49 II132t gcl Medium IIC gl Medium FINE Hornell A sil Medium B sic High C sh sic Medium .43 R Shale bedrock 20-40"below surface Remsen A sicl High Bt c Medium .43 C c High Churchville A sil High Bt sic Medium .49 IIC gl Medium COARSE LOAMY,NO PAN Charlton A fsl Low B fsl High .43 C gfsl Medium Nellis A 1 Medium B 1 High .43 C gl Medium New York State Standards and Specifications Page A.7 November 2016 For Erosion and Sediment Control Table A.I (cont'd) Approximated K Values for Some Representative Soils on Construction Sites in New York (These K values and K values for soils not shown in these tables should be verified at the USDA-NRCS website, http://websoilsuivey.nrus.usda.,2ov/auu/WebSoi]Suivey.ast)x.) Depositional Unit Family Texture Class i Texture Construction and Representative Series Hoizon Class Erosion Potential Site K Values COARSE LOAMY,NO PAN(Cont'd) Pittsfield A 1 Medium B gfsl Low .43 C gfsl High COARSE LOAMY/SAND or SANDY SKELETAL Canton A fsl Medium B fsl Very High .64 IIC vgls Low COARSE SILTY w/PAN Canaseraga A sil High B sil Very High .49 IIBx&C ch High LOAMY SKELETAL Manlius A ch sil Medium B vsh sil Low C fract'd shales Low .28 w/silty fines R Shale bedrock 20-40"below sur- face FINE LOAMY w/PAN Volusia A ch sil Low Bx ch sil High .43 C vch 1 Medium FINE LOAMY,NO PAN Kendaia A sil Medium B gsil Medium .28 C gl Medium November 2016 Page A.8 New York State Standards and Specifications For Erosion and Sediment Control Table A.1 (cont'd) Approximated K Values for Some Representative Soils on Construction Sites in New York (These K values and K values for soils not shown in these tables should be verified at the USDA-NRCS website,httn://websoilsuivey.nms.usda.i!ov/auu/WebSoi]Suivey.asux.) Depositional Unit Family Texture Class i Texture [Site struction and Representative Series Hoizon Class Erosion Potential K Values II. Glacial Outwash and Water Worked Morainic Deposits SANDY SKELETAL Hinckley A gls Low B gls Low .17 C gls Low SANDY Colonic A Ifs Medium B A Low .24 C A Low LOAMY SKELETAL Chenango A gl Low B vgl Low .24 C gls Low FINE LOAMY/SANDY or SANDY SKELETAL Palmyra A gl Medium B gl Low .28 IIC g&s Low LOAMY SKELETAL/CLAYEY Varysburg A gl Low B2t vgl Low II132t sic Medium .28 IIC layered High sic,sil sicl COARSE LOAMY Riverhead A sl Low B sl Low 17 C s w/thin Low layers of g New York State Standards and Specifications Page A.9 November 2016 For Erosion and Sediment Control Table A.I (cont'd) Approximated K Values for Some Representative Soils on Construction Sites in New York (These K values and K values for soils not shown in these tables should be verified at the USDA-NRCS website, http://websoilsuivey.nrus.usda.,2ov/auu/WebSoi]Suivey.asux.) Depositional Unit Family Texture Class H ' izon TextureZ ErosionPotential Construction and Representative Series o Class oena Site K Values IL Glacial Outwash and Water Worked Morainic Deposits(Cont'd) COARSE LOAMY/SANDY or SANDY SKELETAL Haven A 1 High B I High .43 IIC gs Low III. Lacustrine or Stream Terrace Deposits COARSE SILTY Unadilla A sil High B sil Very High .64 C sil Very High COARSE SILTY w/FRAGIPAN Williamson A sil High Bx sil Very High .64 C sil Very High COARSE SILTY/SANDY or SANDY SKELETAL Allard A sil High B sil Very High .64 IIC vgls Low FINE SILTY wBt Collamer A sil High Bt sil High .64 C Layers of Very High sl,vfs FINE Schoharie A sicl High Bt sic Medium .49 C sic High November 2016 Page A.10 New York State Standards and Specifications For Erosion and Sediment Control Table A.1 (cont'd) Approximated K Values for Some Representative Soils on Construction Sites in New York (These K values and K values for soils not shown in these tables should be verified at the USDA-NRCS website,httn://websoilsuivey.nms.usda.i!ov/auu/WebSoi]Suivey.asux.) Depositional Unit Family Texture Class ' Texture Construction and Representative Series Hoizon Class Erosion Potential Site K Values HI. Lacustrine or Stream Terrace Deposits(Con't) VERY FINE Vergennes A c High Bt c Low .49 C c Low SANDY o/CLAYEY Claverack A US Medium B US Low .43 IIC sic High R COARSE LOAMY o/CLAYEY Elmwood A fsl Medium .43 B sl Low C sicl High 1 The thickest B and C horizons in the official series were used in making the K value determinations. 2 Soil texture class abbreviations: Gravel............................g Fine sandy loam..........Al Sandy clay loam.................scl Very coarse sand...............vcos Very fine sandy loam....vfsl Stoney clay loam................stcl Coarse sand.....................cos Gravelly sandy loam.....gs Silty clay.........................sic Sand..............................s Loam.......................g Clay...............................c Fine sand........................A Gravelly loam.............gl Channery.........................ch Very fine sand..................vfs Stoney loam...............stl Shaly..............................sh Loamy coarse sand............lcos Silt..........................si Very channery....................vch Loamy sand....................Is Silt loam...................sil Very shaly........................vsh Loamy fine sand...............lfs Clay loam..................cl Sandy loam.......................sl Silty clay loam.................sisl New York State Standards and Specifications Page A.11 November 2016 For Erosion and Sediment Control Table A.2 (USDA -NRCs) Values for Topographic Factor, LS, for High Ratio of Rill to Interrill Erosion' w CI! dy . c+ wa .,. . c,. . * ear ea a cAs v a¢ � r ^ :K � :tea $ d;� jt;� G Fy CS r r iw e b W; g P% ram+. - CMP 4M 'a _ 064 r.F �p YF 4D #G 43 d•F � i'i 4EF F� W M r �y -0 d0 Q ri ri q+'S VF r~ g 1:'Ei ••z 4 -a 40 4 h .0h Gb d;3 4 fi t �e�i r$ t� 3 0 r- rt i[F # �F r r t [fir q 'M; a P6; CS cti 3 LP fi t C} � ■n lei 4M 4M C 8 C O I r ed Co rS W ko 16� dQ �? 4 $ � 8 -in a 45 1!5 415 2v r5 bn m .r eft F� 1fti ; •� r s-� +e qp i ei qi J 4 Q Y A M 99 TJ ff FL C�L '1 zp -a� Q Y Q V .1R d? 4! F RNJ RrJ C} {rJ 07. T V A F t% ft"t Qk Q g g CP c g o CR 4 g -0 4 4 4 November 2016 Page A.12 New York State Standards and Specifications For Erosion and Sediment Control Table A.3 (USDA -NRCs) Factors for Converting Soil Losses (Air-Dry) from Tons (T) to Cubic Yards (Cu. Yds.) Sands, loamy suds shy loam k-Mulvply sail Losses m T by VO 0 00 Fire sands loam } 11_4 ms.un dy day Wrm ] Sander clay -Midtiply sail lGsses in T by 0.87(851 Silt loam 1 Silly dAy Iwo,Wly Chy ) CLLY laimm MuldFly sail log in T by 1AX(M) X 'The number in parentheses is the air-dry weight of the soil in pounds per cubic foot. The conversion factors were calculated from these air-dry weights using: soil loss(tons)x(2000 lbs/ton)x(fe/dry density lbs)x(cubic yard/27ft3). New York State Standards and Specifications Page A.13 November 2016 For Erosion and Sediment Control Table A.4 E1 Values of Certain Key Cities in the New York Area' a EI Values at Expected Magnitude of a Single Storm 20/o and 5/o Probability Levels EI Value Normally Exceeded Once in— Probability(EI) Location' 20%* 5%** 5 Years 10 Years 20 Years New York Albany 114 159 38 47 56 Binghamton 106 146 36 47 58 Buffalo 96 139 36 49 61 Geneva 106 152 Marcellus 112 167 38 49 62 Rochester 101 151 38 54 75 Salamanca 106 157 32 40 49 Syracuse 129 197 38 51 65 Pennsylvania Erie 181 331 Scranton 140 188 44 53 63 Vermont Burlington 114 178 35 47 58 Connecticut New Haven 222 310 73 96 122 New Jersey Atlantic City 229 311 77 97 117 Marlboro 254 343 85 111 136 Trenton 216 308 76 102 131 Once each five years ** Once each twenty years 'From Agricultural Handbook No. 537 'For additional cities,refer to Agricultural Handbook 537, Tables 17& 18. November 2016 Page A.14 New York State Standards and Specifications For Erosion and Sediment Control Table A.5 Construction Site Mulching C Factors (Data from Wischmeier and Smith 1978, Pitt 2004) Type of Mulch Mulch Rate(tons Land Slope(%) Mulching C Length Limit(ft)' per acre) Factor None 0 all 1.0 n/a Straw or hay,tied down by 1.0 1-5 0.20 200 anchoring and tacking equip- 1.0 6-10 0.20 100 ment 1.5 1-5 0.12 300 1.5 6-10 0.12 150 2.0 1-5 0.06 400 2.0 6-10 0.06 200 2.0 11-15 0.07 150 2.0 16-20 0.11 100 2.0 21-25 0.14 75 2.0 26-33 0.17 50 2.0 34-50 0.20 35 Wood Chips 7 <16 0.08 75 7 16-20 0.08 50 12 <16 0.05 150 12 16-20 0.05 100 12 21-33 0.05 75 25 <16 0.02 200 25 16-20 0.02 150 25 21-33 0.02 100 25 34-50 0.02 75 'Maximum slope lengths for which the specified mulch rate is considered effective.If these limits are exceeded,either a higher application rate or mechanical shortening of the effective slope length is required(such as with terracing). New York State Standards and Specifications Page A.15 November 2016 For Erosion and Sediment Control Table A.6 Cover Factor C Values for Different Growth Periods for Planted Cover Crops for Erosion Control at Construction Sites (Data from Wischmeier and Smith 1978,Pitt 2004) SB Period 1 Period 2 Period 3a Period A Period 3c (seedbed (establishment) (development) (maturing (maturing (maturing prepara- crop) crop) crop) tion) Crop Canopy 1 0-10% 10-50% 50-75% 75-80% 80-90% 90-96% Seeding on topsoil, 0.79 0.62 0.42 0.17 0.11 0.06 without mulch Seeding on a desur- faced area,where residual effects of 1.0 0.75 0.50 0.17 0.11 0.06 prior vegetation are no longer significant Sod 0.01 0.01 0.01 0.01 0.01 0.01 'Percent canopy cover is the percentage of the land surface that would not be hit by directly falling rain drops because the drops would be intercepted by the plant.It is the portion of the soil surface that would be covered by shadows if the sun were directly overhead. Table A.7 Cover Factor C Values for Existing Established Plants (data from NRCS NEH Chapter 3 and Wischmeier and Smith 1978) Percentage of surface covered by residue in contact with the soil Percent Plant 0% 20 40 60 80 95+ Cover' Type C factor for grass,grasslike plants, 0 Grass 0.45 0.20 0.10 0.042 0.013 0.0003 or decaying compacted plant litter C factor for broadleaf herbaceous 0 Weeds 0.45 0.24 0.15 0.091 0.043 0.011 plants(including most weeds with little lateral root networks),or un- decayed residues Tall weeds or short brush with Grass 0.36 0.17 0.09 0.038 0.013 0.003 average drop height of=20inches 25 Weeds 0.36 0.20 0.13 0.083 0.041 0.011 Grass 0.26 0.13 0.07 0.035 0.012 0.003 50 Weeds 0.26 0.16 0.11 0.076 0.039 0.011 Grass 0.17 0.12 0.09 0.068 0.038 0.011 75 Weeds 0.17 0.12 0.09 0.068 0.038 0.011 Mechanically prepared sites,with Not no live vegetation and no topsoil, 0 None 0.94 0.44 0.30 0.20 0.10 and no litter mixed in. given 'Percent cover is the portion of the total area surface that would be hidden from view by canopy if looking straight downward. 2 Drop height is the average fall height of water drops falling from the canopy to the ground. November 2016 Page A.16 New York State Standards and Specifications For Erosion and Sediment Control Table A.8 (USDA-NRCS) Construction Site P Practice Factors Surface Condition P Factor Bare Soil Loose 1.0 Freshly disked or rough irregular surface 0.9 Compact smooth by equipment up and down hill 1.3 Compact smooth by equipment across slope 1.2 Contoured Furrows: Slope(%) Maximum Downslope Length(ft) P Factor 1-2 350 0.6 3-5 250 0.5 6-8 200 0.5 9-12 125 0.6 13-16 75 0.7 17-20 60 0.8 >20 50 0.8 Maximum slope lengths for which the specified mulch rate is considered effective.If these limits are exceeded,either a higher application rate or mechanical shortening of the effective slope length is re- quired(such as with terracing). Source: USDA-MRCS; HDI, 1987;Wischmeier and Smith, 1978 New York State Standards and Specifications Page A.17 November 2016 For Erosion and Sediment Control References 1. Predicting Soil Erosion by Water: A Guide to Conservation Planning With the Revised Universal Soil Loss Equation (RUSLE). USDA-Agricultural Research Service Agric.Hdbk No. 703. Renard,K.G.,G.R.Foster,G.A.Weesies, D.K.McCool,and D.C.Yoder. 1997. 2. (data from Wischmeier and Smith 1978) 3. Construction Site Erosion and Sediment Controls:Planning,Design and Performance.R.Pitt,S. Clark,and D.Lake. 2007. 4. USDA-NRCS,web soil survey database at www.websoilsurvey.sc.egov.usda/App/HomePage.htrn. November 2016 Page A.18 New York State Standards and Specifications For Erosion and Sediment Control APPENDIX B DESIGN EXAMPLES FOR SELECTED EROSION AND SEDIMENT CONTROL PRACTICES CONTENTS Page List of Tables and Figures DeterminingStormwater Runoff......................................................................................................................................B.1 Runoff Control Practices Design Examples .....................................................................................................................B.1 Sediment Storage Volume Design Procedure ..................................................................................................................B.2 Rock Outlet Protection Design Examples ........................................................................................................................B.3 FlowDiffuser Design Examples ......................................................................................................................................BA Cedar Point Section 3 Sediment Basin Design Example .................................................................................................B.6 Section prepared by: Donald W.Lake Jr.,PE,CPESC,CPSWQ Former State Conservation Engineer USDA—Natural Resources Conservation Service Syracuse,New York Adjunct Assistant Professor State University of New York,College of Environmental Science and Forestry List of Tables and Figures Figure Title Page B.1 Flow Diffuser Design Example ............................................................................................................B.5 B.2 NRCC Project Locator Map..................................................................................................................B.7 B.3 NRCC Sediment Basin Location...........................................................................................................B.8 B.4 Cedar Point Google Map Pre-Construction...........................................................................................B.9 B.5 Cedar Point Site Sediment Basin Photograph.....................................................................................B.10 B.6 NRCC Rainfall Text Table..................................................................................................................B.11 B.7 HydroCAD Summary Sheet................................................................................................................B.12 B.8 Cedar Point Sediment Basin Stage-Storage Curve............................................................................B.13 B.9 Temporary Sediment Basin Design Data Sheet...................................................................................B.14 B.10 Temporary Sediment Basin Design Profile Detail..............................................................................B.15 B.11 Temporary Sediment Basin Design Spillway Detail...........................................................................B.16 B.12 Skimmer Orifice Design Chart ...........................................................................................................B.17 B.13 Skimmer Dewatering Device Detail....................................................................................................B.18 APPENDIX B DESIGN EXAMPLES FOR SELECTED EROSION AND SEDIMENT CONTROL PRACTICES Background their website,httu://nrecip.eas.comell.edu/. These data combined with construction site runoff curve numbers are Standard details and drawings for temporary erosion and then used with appropriate software to calculate peak rates sediment control practices have been used since the early of runoff,runoff volumes,and flow durations. 1970's. Many of these details were developed by the United States Department of Agriculture(USDA)Soil A detailed example of this process is presented in the design Conservation Service(SCS),now known as the Natural example for Sediment Basin Design. Resources Conservation Service(MRCS). These details were incorporated into many state design manuals. These Runoff Control Practices Design Examples practices included the following: This method of designing a practice or evaluating the • Earth Dike performance of a proposed practice,is applicable to most of • Construction Ditch the temporary runoff practices. The first example evaluates • Perimeter Dike/Swale the effectiveness of the construction ditch. • Flow Spreader • Pipe Slope Drain Example 1: Case 1 -Construction Ditch A • Straw Bale Dike • Silt Fence Given: What made the use of these details attractive was that they Drainage Area=4.9 acres were sized based upon the drainage area,and no extensive Hydrologic Soil Group=C engineering calculations were needed for design. For Runoff Curve Number—91 (C soil disturbed for example,if we needed to design a construction ditch to construction) control the runoff from 8 acres above a disturbed construction area by sloping the swale at 3 percent,we Slope of Swale=3% would look at page 3.4 and select Ditch B,with a channel Rainfall(P)=2.5 inches(from NRCC)(This represents NY treatment of seed and straw mulch. The Ditch B cross state's average 1-year,24-hour storm) section is a 6-foot bottom width, 1-foot design depth,and 2:1 side slopes. Runoff(Q)= 1.6 inches(from TR55 RCN tables) Time of Concentration for Runoff(T j=6 minute(assumed This selection process is independent of location in New 0.1 hour,the shortest allowed with TR-55) York State as well as the design rainfall amount. As a result,individuals have often wondered what level of From HydroCAD routing: protection is actually being provided. QP=12.2 cfs Site specific practice design depends on a number of variables. These include drainage area,hydrologic soil For Ditch A,the design cross-section shows a bottom width group,cover,topography,rainfall amount,and intensity or of 4 feet.,design depth of 1 foot,and 2:1 side slopes. distribution. Therefore,ditch area=6 ft2 for design depth The following design examples illustrate how these variables can be incorporated into site specific design Compute velocity,V= 1.486( A )2/3 S'/z process. n Wp Where: Determining Stormwater Runoff n=0.040 for vegetated channels Stormwater runoff volumes and peak discharges should be A=6 sq.ft. calculated using current hydrologic data.As noted in Wp=82 ft. (wetted perimeter) Section 1,the hydrologic data published by the Northeast S=.03 ft/ft (slope) Regional Climate Center(NRCC),provides updated rainfall values for a wide range on frequencies and durations on New York State Standards and Specifications Page B.1 November 2016 For Erosion and Sediment Control Therefore,V=1.486 O2/3 (.03)1/2 Rainfall(P)=3.5 inches(NRCC) .04 8.2 Runoff(Q)=2.8 inches (TR55 RCN) = 5 feet per second Assume Time of Concentration for Runoff(T,)=0.1 hour (most conservative value) Select the appropriate stabilization lining. From HydroCAD routing: Since Q=AV, the ditch capacity is Qp = 28.7 cfs Q=(6 ft)(5 ft/sec)=30 cfs or more than twice required From Case 2,Ditch B,we know that the maximum capacity Case 2—Construction Ditch B is 43 cfs with a velocity of 5.37 feet per second. Given: Our conclusions would indicate that Ditch B is adequate for capacity. The velocity is higher and thus a lining should be Drainage Area= 10 acres used to protect the ditch from erosion. Hydrologic Soil Group=C Runoff Curve Number=91 Sediment Storage Volume Design Procedure Slope of Swale=3% Rainfall(P)=2.5 inches Practices such as silt fence,straw bale dikes,earthen berms, Runoff(Q)= 1.6 inches and other slope interupters,are often used on slopes or near the toes of fill slopes to capture sediment laden runoff. Time of Concentration for Runoff(T�)=0.1 These have failed many times in the field due to poor siting, improper installation,lack of maintenance,and little From HydroCAD routing: consideration of the proper use of the practice. QP=25 cfs The following design example shows how careful we need to be in using these practices.We will look at the use of silt For Ditch B,the design cross-section has a 6-foot bottom fence in the following typical situations. width, 1-foot depth,and 2:1 side slopes. Therefore,the area=8 ft2 Case 1 -At the toe of a 3:1 earthfill Computing velocity for a ditch slope of 3%, Given: V=1.486 ( 8 )13 (.03)" Earthfill slope 30 feet high,slope length 95 feet .04 10.47 Hydrologic Soil Group—C The Runoff Curve Number =91 (bare soil) V=(37.15)(.836)(.173)=5.37 ft/sec Typically,the installed height of the silt fence is 30-36". Since: The maximum design sediment depth behind the silt fence is 50%of its height,or 18"maximum. Q=AV, the ditch capacity is Q=(8 ft)(5.37 ft/sec)=43 cfs For this case,the design sediment area is equal to: A=1/2bh Case 3-This site is adjacent to a significant water body in Westchester County. We want to protect the site for the 2- year,24-hour storm. Given: Drainage Area=10 acres 1 T Hydrologic Soil Groupsoils ` =D 3 •.` b = 18 Runoff Curve Number=94,("D"under construction) Slope of Swale=3% *Design sediment storage volume November 2016 Page B.2 New York State Standards and Specifications For Erosion and Sediment Control A= 1/2(15)(4-5') = 3.375 sq.ft.per linear foot Find: Read d50=1.2 and apron length(La)=38 ft. Apron width=diam.+La=5.5 +38=43.5 ft. This equals 337.5 cubic feet per 100 feet of fence. Use:d50= 15",d.�=22",blanket thickness=32" The actual slope surface is approximately 95 feet. For a rainfall of 1 inch on this site,the runoff equals 0.4 inches Example 2: Box Flow(partial)with high tailwater (TR55).The total volume of runoff would equal Given: A box conduit discharging under partial flow 0.4 inches x 9500 sq.ft. = 317 cu.ft. conditions. A concrete box 5.5 ft.x 10 ft.flowing 5.0 ft. 12 inches/ft deep, This example shows that the volume required for a 1-inch Q=600 cfs and tailwater surface is 5 ft.above invert(max. storm is barely provided,but the location of the fence tailwater condition). provides no buffer for material that rolls down the slope nor room for maintenance. The fence should be located at least Since this is not full pipe and does not directly fit the 10 feet from the toe of the slope. nomograph assumptions of Figure 7B.13 substitute depth as the diameter,to find a discharge equal to full pipe flow for Case 2-Determine level of protection for CASE 1 when that diameter,in this case 60 inches. fence is moved 10 feet from the toe of slope. Since,Q=AV and A=7E DZ When the silt fence is moved 10'away from the 3:1 slope, 4 the design area of storage equals, First,compute the actual box culvert velocity for the given 337.5 sq.ft. + 1,500 sq.ft. = 1,837.5 cu.ft.per 100 feet flow conditions: of fence V=(Q/A)=(600/(5)(10))=12 fps Since this is the maximum runoff volume that can be controlled,the runoff depth equates to: Then determine the equivalent flow through a 5 foot diameter pipe using the same velocity as the box culvert as 1,837.5 fe = 0.193 feet = 2.3 inches computed above: 9,500 ftz Q=7LD2 x V=3.14(5f0' x 12 fps=236cfs From TR55 for a runoff Q=2.3 inches,with a Curve 4 4 Number at 91, P,rainfall is found to be 3.2 inches. At the intersection of the curve d=60 in.and Q=236 cfs, Thus,this design configuration can manage to store the read d50=0.4 ft. runoff from a 3.2 inch rainfall event. Then reading the d=60 in.curve,read apron length(La)_ This method can be used to evaluate the positioning of these 40 ft. sediment control practices on the contour to hold sediment Apron width,W=conduit width+(0.4)(Lj= 10+(0.4) close to its source. It allows a designer to evaluate an (40)=26 ft. existing condition,or to select a specific level of protection higher than that which may be provided by the standard Example 3: Open Channel Flow with Discharge to details. Unconfined Section Rock Outlet Protection Design Examples Given: A trapezoidal concrete channel 5 ft.wide with 2:1 (Refer to Rock Outlet Protection Standard on Page 3.40) side slopes is flowing 2 ft.deep,Q= 180 cfs(velocity= 10 fps)and the tailwater surface downstream is 0.8 ft. Example 1: Pipe Flow(full)with discharge to unconfined (minimum tailwater condition). section. Find: Using similar principles as Example 2,compute equivalent discharge for a 2 foot,using depth as a diameter, Given: A circular conduit flowing full. circular pipe flowing full at 10 feet per second. Q=280 cfs,diam.=66 in.,tailwater(surface)is 2 ft.above Velocity: pipe invert(minimum tailwater condition). Q= L Mf x 10 fps=31.4 cfs New York State Standards and Specifications Page B.3 November 2016 For Erosion and Sediment Control 4 length,the diffuser length is: At intersection of the curve,d=24 in.and Q=32 cfs,read d50=0.6ft. W= io = 8.8cfs =35.2ft Then reading the d=24 in.curve,read apron length(La)= QD 0.25 cfs.ft 20 ft. Apron width,W=bottom width of channel+La=5+20= B. Using the standard minimum diffuser cross-section 25 ft. dimensions,solve for the d5o rock size: Example 4: Pipe flow(partial)with discharge to a Assume: 1:1 side slopes,2 ft top width,h=1.0 ft,W=36 ft confined section for: Given: A 48 in.pipe is discharging with a depth of 3 ft. Q__ (h'')(W) Q= 100 cfs,and discharge velocity of 10 fps(established [L/D+2.5 L2]o.5 from partial flow analysis)to a confined trapezoidal channel with a 2 ft.bottom,2:1 side slopes,n=.04,and grade of Where: 0.6%. Calculation of the downstream channel(by Manning's h=ponding depth behind the diffuser Equation)indicates a normal depth of 3.1 ft.and normal W=linear length of diffuser along centerline velocity of 3.9 fps. L=average horizontal flow length through the diffuser Since the receiving channel is confined,the maximum perpendicular to the centerline tailwater condition controls. D=average stone diameter(ft.)in the structure Find: discharge using previous principles: Try a D(00)=0.50 ft(6 inches),from typical cross section,L=3 ft,then, Q= Ljaft2 x 10 fps=71cfs 4 Q= 12" x 36-= 36 = 36 [3/0.5+2.5+(3)2]0.5 (17)0.5 4.18 At the intersection of d=36 in. and Q=71 cfs,read d50= 0.3 ft. Therefore,Q=8.6 cfs,this approximates the 10 year discharge and the design is balanced. Reading the d=36"curve,read apron length(La)=30 ft. Since the maximum flow depth in this reach is 3.1 ft.,that is What if d5o is 0.75 ft.or 9 in.?,then: the minimum depth of riprap to be maintained for the entire Q= 36 = 36 = 9.1 cfs length. [3/0.75+2.5+(3)z]" 3.94 Flow Diffuser Design Examples And this flow exceeds the maximum allowable. Figure B.1 (Refer to Flow Diffuser on Page 3.16) on page B.5 shows the dimensions and details for the final diffuser configuration. The stormwater runoff from a 3.5 acre drainage area is to be discharged offsite through a flow diffuser. The drainage Design Note:Changing the variables of height,side slope, area is upland meadow,pasture and access road. The 10 rock size,and weir length,will result in a change of the year,24 hour rainfall is 3.5 inches. A peak rate of runoff of diffuser discharge. All dimensions need to be balanced so 8.8 cubic feet per second results from a curve number of 80 the diffused flow does not exceed the maximum allowable and a time of concentration of 6 minutes(0.10 hour),using of 0.25 cfs per linear foot of the diffuser. This practice can the HydroCAD computer model. This flow is being be modeled for storage requirements as a pond with a diffused off the right of way to prevent excessive flows constant overflow rate. further down the access road corridor. A. Determine the diffuser length: Since the maximum flow rate from the diffuser onto the vegetated buffer area is 0.25 cfs,per linear foot of weir November 2016 Page B.4 New York State Standards and Specifications For Erosion and Sediment Control Figure B.1 Flow Diffuser Design Example NWE- TYPICAL UZVATE Sew FM AK TO ILLUSTRATE THE OPERATION OF THE FLOV DWRAWt 150 FOOT (H3k) LENGTH A VnZTATEZ MITCH SLIDE SLOPE RECErV]HG loREA DITCH BOTTOM -Cm 20 SL LIPF DRATNAGE FABR M Sob f EXTEND UN>� LEMITS OF FlLL, ON ENDS d' ADDITIONAL BERM HEIGHT AT NITH FNMS OF THE �— ——Ld�— ���� � RM,MVAY PREVENT WASHOJT AT ENDES X � �N, PLANS AREA ''� � �� N DEBRIS COLLECTION 131VERG[ON 5VALE A ExIST 0 PATTERN €'TYP.b ,� FLOW �]��u��a �TI1� � r LCNGTH1 MEASURED HAfERIAL SITE PL#f1 VIEW TO THIS POeNT iYT . F.KH kN4 f _ Fri DRA18WA. �.vrr FABFZC C* kOCK SIZE = C.!5' 1 METING GROIINT F, AVG L-3. STCRuwAtTER mmwa,E FAPRIC CUKVEN(AN:E TO DIFFUSM PM10INC: AREA 5F—LTMR A FLOW DIFFUSER AND DESIGN EXAMPLE New York State Standards and Specifications Page B.5 November 2016 For Erosion and Sediment Control CEDAR POINT SECTION 3 SEDIMENT BASIN DESIGN EXAMPLE Cedar Point is a residential construction project in Cicero, when you toggle down the storm event window.Make sure Onondaga County,New York. Section 3 contains quarter when calculating Tc with HydroCAD that the NRCC 2 year acre lots with residential streets on approximately 20.4 storm value is used for the sheet flow calculation and not acres.A sediment basin will be utilized as a component of the older value.For our example,the 2 year rainfall is 2.37 the erosion and sediment control plan for this project.It will inches and the 10 year rainfall is 3.39 inches. be located at the storm drainage outlet of the project(See Figure B.5).The drainage area to the basin is 14.9 acres. The design results are shown on the following Temporary Sediment Basin Design Data Sheet. The instructions for the The runoff curve number(RCN)used to calculate the use of this form are shown on page 5.25. stormwater runoff for design storms from this drainage area is based on the maximum disturbed construction condition. The outlet for this sediment basin is a skimmer device.It is In this case it means bare soil for all the lot areas and critical to size the orifice so that the appropriate detention impervious surface for the street area.This drainage area time for dewatering is applied to maximize the basin has 1.6 acres of paved roads and gutters;6.4 acres of efficiency.The Dewatering Device standard on page 5.10 exposed soil in Hydrologic Soil Group(HSG)B;and 6.9 sets the criteria for orifice sizing. acres of exposed soil in HSG C.This results in a composite RCN of 90.Based on hydrologic data obtained from the The Cedar Point Section 3 soils contain approximately 45 Northeast Regional Climate Center(NRCC)and using the %fines(less than the#200 sieve size);therefore the storage HydroCAD computer model,the peak discharge for the 10 volume drawdown time should be a minimum of 48 hours. year frequency storm is 39.2 cubic feet per second. See The dewatering volume is calculated to be approximately Figures B.2 to B.7 that show the development of the 54,000 cubic feet.Therefore,from Figure 5.3 on page 5.11 hydrology data.The steps to obtain this data are listed of the Dewatering Device standard,enterthe bottom of the below: chart at 54,000 cubic feet.Travel vertically to the 2 day dewatering time line.Then read across to find the orifice 1. Go to the NRCC website,http://Precit).eas.comell.edu/. diameter at approximately 4.5 inches. 2. Select the tab Data and Products. 3. Use the Google Map to zoom into the project and The arm length for the skimmer is equal to the hypotenuse double click. of a 45 degree right triangle using the full storage depth as 4. From the Products list,select Extreme Precipitation the leg of the triangle(see Figure 5.4 on page 5-12).Our Tables-Text/CSV. full storage depth is 8 feet.Therefore,the length of the 5. At the bottom of the page,set smoothing to No,then skimmer arm is 8 feet x 1.414= 11.3 feet.Use 12.0 feet for click Submit. ease of field construction with a four foot flexible coupling 6. Select Save when asked. to the bottom of the riser(see Figure B.13 on page B.18). 7. Set Save In to your HydroCAD IDF file or your HydroCAD projects folder. The design results are shown on the Temporary Sediment 8. Set the name for this file as NY-Cicero.hci. Basin Design Data Sheet,Figure B.9 on page B.14. 9. Set the file format as"plain text". 10. Click save and close the NRCC site. If you are using a different computer program,import the text files into that program in accordance with the programs protocols.These text files will be converted into rainfall distribution curves for each specific rainfall frequency. 11. Open HydroCAD and click on the calculator icon. 12. Click"Rainfall" 13. Click"Import Events from IDF" 14. Click"Create Mass Curves",then OK. 15. Click"Yes"on popup screen to replace the storm events,and accept. This process imports rainfall values from the 1 year to the 500 year storm.This will be shown on the main screen November 2016 Page B.6 New York State Standards and Specifications For Erosion and Sediment Control Figure B.2 NRCC Project Locator Map Jill � 3 ti r Y 444!ll��T_ a New York State Standards and Specifications Page B.7 November 2016 For Erosion and Sediment Control Figure B.3 NRCC Sediment Basin Location 55 kn Ik f C r, L r S • � � 1 1 r November 2016 Page B.8 New York State Standards and Specifications For Erosion and Sediment Control Figure BA Cedar Point Google Map Pre-Construction t E fi New York State Standards and Specifications Page B.9 November 2016 For Erosion and Sediment Control Figure B.5 Cedar Point Site Sediment Basin Photograph IL Jt- 5r• � T November 2016 Page B.10 New York State Standards and Specifications For Erosion and Sediment Control o CD 0 0 o' x w CD �8dL41 �1�ei1r [.-+rr +41�'rd� n p I EAT Ir, n[II..•Il�ri I 1 5.i w F1r iiF 4dW, i,FqmpwA�.Pi O A LAL L 3.1d i my {ifrrm), YMiwrrla Irrr ,E JIF7.Sy-win Ley-mWmjV1pbM1_5�1°y7•19r ptkn,}`}4i-i mll I--�Fr,i ktr.17y liv.74•41r,a`1ym. .4 a"An±_,• 4w.b1a•drr 1F l,ll_ U. 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LN S I ZE DES]GN 1. SedirnenL slLvW r - 160M euL FR.a number-of tli*1ofW Fms-14a=¢a.h.. Tip Qr7A4w Ekw-, ¢ 1r. Wa° ng rxw volurrm -3,6N cu.ift,x munber of drxinagt arra Um_5�co_IN..Top of Zjxft blek• 3� Lga2ih uo u i&h ratio- 4- A ( onow al jrj,F ursrdirtfflri 2W#W 70M;+ IMP%Llr%. A ,, a B. Diostmx b&w rasp-fit riser ;i.a rta i_ Mtrinrrum i h4C rvea rs larger or o.�D I.Qfi o.,39—or, c1.0 L c,ask ^ ow C .4 acrr' AUean 6. Q�.ic*- 39.2 t:fi (A ruiwiff cnmpuladon sheois) ripe soltwar '1Q,) I. Min 10i9c 11 sag Q. -4.2 JNIWW AFM Ecru-_3 Ch He rrikry ism cumpmocy spite.dMra0red'Q,- 9e Bou3FI EhM. mrhes; Qr.`"IQ} a t�_rac.,�.i cfi. I1); Kit,- �]uW_ '�ircrrlres� l to Ar. —fM,:II-��y i[. i r�57 F1C�'. . [11. TFaA wk-DefMcr- j.—fie,: .h fight- Ll _—inches Cdc }' 1-1[]esllo 11 Fierpnic 'Spitlwex Flow. --9,5 - 'L-_srz:. 13. 10.*b 1? (.; 14. J_j it CICAele iakmi 4101. 0.:1 #ijo High WaLer Fkv. ACVO .e+ Rwow"dhimnel slrpe_ + � s _ * ;Try aftw F.k,,. ANTI UP COLLAWSEEPAGE DI A PI ERAC M DESIGN collom Uxr c IliR� .' el _4oto Kmwb Pe4pnico- lm rAmp1h rnsrrid: wi0d1 rL Irs:i& DEWATERING OR]FICE SIZING (1ketwimcd rrom(he lk-Pax* llcvim"winched) 15. r]�,kaLcri'ik[x�l'i di3mcLer- _ F ie cha, Skimmer ar lkiuT khm:k am) 14. 1�j1p0walaringiimr IL €(h!i►h.'2&LY§Mquilr0d) November 2016 Page B.14 New York State Standards and Specifications For Erosion and Sediment Control o CD 0 0 �. Co _� —arm +.-_- • i . � —q CD CD RL CD j' T FR15E ' I1 METWARD CD ELF-AlJ OOT 3 Y 3 � 37L.5 13AS19 68-1 10m,311 �44 0"• o �T 60, OF R 4 ot1i, �s p I o I d 44Cy a.. -. - .. e e e e _ - �e.� _ it Y �• F — —a_ — - .. CD k u CD N 0 Figure B.11 Temporary Sediment Basin Spillway Detail SYMML OFF-DAM EMERGUCY TIP i MTH SPILLWAY CREST ELEV. !!10r Flea FEM TUP E-LEV. a[rN, [IF cksi �FLv. _SIT IMP=�]R= RISER �ZVER j �=II It:1A_III'Ilk.= EL • , ERT r Il I II I I� Irl 111,Ill I I� 111111 Ial III I U I If=Ilk= IL F-V •r �;=EIS=11 = 1E�I1= ANTI-FLOTAT + 'MINL P. I III I�Lrx Trams . T Ili=111 F,`lrf�F� niAx OF PRiNcjPAL Awl- ER U T14 SPILLWAY ➢A� T IE L €d till]T H r M. allt.LEr eEj1 iCIPjjj, SPILLWAY PRt3FII_E RUT TO SC4LE MAX 1MIA DRAINAGE AREA r !0 J4Gkl::& CLEVAT04 Or IDT W10K ELOD'll FUFIL T13P 13F 1IM FREE119ARil I,OMR ELEV. ' APPIIAL" S_ FLOW BERH LEVEL EECiTr ' °ExIT aTCTl(1N I EKBANKWNT NOT In ICAL-E I. � hIFAGFlJ�"F %F71 L WAT F- V. I; V 1 ` PC1 113 SMILL E i CROSS SECTEM AT C��7 4FET�11�1 NOT TIC SCALE MEw YI VATE DEPARTNUff Of �'r�TATWN. EMMENT BASIN WFV YUM ISTAfir W.POA> rr [jr EkVV1DHHEWrAL RVik'rW% � WW Y� 5TJk7E OR. I. V,4TR CWSERVATIl CQWTTEE November 2016 Page B.16 New York State Standards and Specifications For Erosion and Sediment Control Figure B.12 Skimmer Orifice Design Chart 2 days 4.5 inches - s -++ 3 plays �.� - - 1.000 10,€0 53,640 fe 100.000 1.000.000 BASIN WATER STORAGE VOLUME Ifi New York State Standards and Specifications Page B.17 November 2016 For Erosion and Sediment Control Figure B.13 Skimmer Dewatering Device Detail MAR PIMN" $TAfaDARD C,13INSTRLICTION DIFTAIL skirnmW ` -e r=AdF VAJOE RA" PERSPECTIVE VIEW A( I f- r•�>w ��►+�gilt r�r �� ,5 01A, SUKEOLLE AU �rE ►faf�c lam` r L31 uR:e y 'Mff. F Fll}'111@t } *Wtr NO]L I MIQ 1jFt*OF IMIwrrl",Oyr Mink R-d rhWrs+ld li Wd In 1:11r Ihr, `URL H 3rrup.RM r©p®r Baffin llWdW Arin Arm Chrifice LAOFdIFIG FW.'15id Rose No sw Lmmih nim Sir&A 1}erlEn a AUrrhMeot EWW*Wrl tflM JIM) (ldi+ LlaYi1W LW19W 0xvibuon ' MLwj hq glad 14 Cw p4al Marl ■cm dl.anrsirlr A:ropm,'hAl be aHAclied La 91hip sisdrlmor aFm to fsceliaair acc"!b 1a iM s.ki#xwnrr. nce 1nuMed. Sklmm,nr shalt h*antpected•wvekhy an{t slier fimb ninoff levem A;ly r"ilungdoitlog kkii`i.mr ■hwll 1317 r4�pdiwm j cX rwFiAMR-*d N'ilhllm�?&heiurih or InapOCltdl3. %t Or s*dw 4ol:budidup aro,aild ttw wirrclpal apAwayr*hill Lre ramovW to%,isow iiklrnrrwr[a rips Pond La 1luctuwling wral■r m4 aldcnrr- iedfinaw siball be rerhowed i1rom 1ha hasAn when Il ru&tt -,VW love)5tiirk*d cm Me"dWront c lean-oul stake ar 1he lop of thr larrdlsr.{I derlce. A&LFmi-%iteuM#a Nwhrig ttwa may qm subatllutud Um Lha oub"rr113 November 2016 Page B.18 New York State Standards and Specifications For Erosion and Sediment Control APPENDIX C COST ANALYSIS OF EROSION AND SEDIMENT CONTROL PRACTICES CONTENTS Page List of Tables and Figures AnalyzingBenefits and Costs ..........................................................................................................................................C.1 Ascribing Effects to Treatment Measures.........................................................................................................................C.1 Pricing Treatment Measures and Benefits ........................................................................................................................C.1 Periodof Analysis and Evaluation....................................................................................................................................C.1 Appraisal of Damages and Treatment Costs ....................................................................................................................C.1 TreatmentMeasures .........................................................................................................................................................C.1 Benefit-Cost Analysis ......................................................................................................................................................C.2 Example ...........................................................................................................................................................................C.2 References ........................................................................................................................................................................C.5 Section prepared by: Donald W.Lake Jr.,P.E.,CPESC,CPSWQ Former Engineering Specialist New York State Soil&Water Conservation Committee Adjunct Visiting Professor State University of New York,College of Environmental Science and Forestry List of Tables Table Title Page C.1 Cost Table of Selected Practices...........................................................................................................C.3 C.2 Maintenance Cost As Percentage of Installation Cost ..........................................................................CA COST ANALYSIS OF EROSION AND SEDIMENT CONTROL PRACTICES Analyzing Benefits and Costs normalized prices(based on past prices and trends)should be used for estimating future values(benefits,operations Benefit-Cost analysis is a technique used to determine and maintenance costs and replacement costs)for whether a measure will result in more benefits than it will permanent type measures only. cost. Period of Analysis and Evaluation For the purposes of making a benefit-cost analysis for erosion and sediment control,the time period associated The period of analysis in years should equal the economic with erosion and sedimentation is considered to extend from life(need for a measure)or the physical life of treatment the first disturbance of the land to the time of establishing measures,whichever is less. The benefits considered over effective erosion control. the evaluation period include those accruing over the period. Ascribing Effects to Treatment Measures The annual costs of permanent measures chargeable to the The generally accepted basis for attributing effects of evaluation period include the amortized installation cost and treatment measures on a comparable basis is the"with"and the future annual operation,maintenance,and replacement "without"approach. This approach compares the expected cost necessary to provide the benefits over the evaluation difference in damages between what is expected if no period. The amortization rate should be based on prevailing control is used and what is expected if a measure is local interest rates at the time of installation. installed. The total difference in expected damage is the estimated benefit of the measure. Appraisal of Damages and Treatment Costs Sediment damages may be related to(1)deposition of Many people are affected by the damages resulting from eroded materials on flood plains,in channels,reservoirs, erosion and sedimentation. Also,communities and residences,utilities,and other properties that require the individuals benefit from its prevention,reduction,or removal and disposition of materials,and the repairing of mitigation. damaged facilities and(2)swamping damage which adversely affects existing features or limits potential Costs will be incurred to:(1)install remedial treatment improvement of land caused by a rise in the ground water measures;or(2)correct damages;or(3) a combination of table or by impairing surface drainage. the two. Sediment resulting from construction sites can be deposited Treatment Measures along a stream and cause individual landowners to pay for its removal. Sediment can also destroy aesthetic values of a Treatment measures on developing sites are frequently stream(clean water vs.turbid water)and adversely impact temporary—generally lasting up to one or two construction stream fisheries and micro-organisms. seasons. Benefits and cost for temporary measures can be compared directly using current prices. In municipal and industrial uses where water is pumped directly from a river or reservoir,slugs of sediment Permanent measures are planned to trap sediment and associated with excessive rainfall may pose sever water control erosion and runoff during and beyond the quality problems. Turbidity may be increased,necessitating construction period. The prevention of sediment damages increased treatment,which raises the cost of operations. can be accomplished by either,or both of,two methods: Sediment may also be deposited in storm drains,reducing their ability to control flooding. This increases flood 1. Stabilizing sediment source areas by applying damage and requires the cleanout of sediment from the conservation erosion control measures. storm drain systems. 2. Trapping sediment before it leaves the construction Pricing Treatment Measures and Benefits area(sediment control) Prices applied should reflect values expected to prevail at Erosion control is almost always more effective than the time of occurrence. Current prices are used for sediment control at preventing sediment damage. installation costs of treatment measures. Projected Some of the potential benefits from preventing downstream sediment transport and deposition include: New York State Standards and Specifications Page C.1 November 2016 For Erosion and Sediment Control be reduced 90 percent(P). The cost of the measures would 1. Prevention or reduction in cost of removal and be as follows,(no amortization is required since costs and disposition of sediment from properties. benefits are incurred in a similar one year period): 2. Prevention or reduction in damage to property. 1. Land grading measures.............$2,000 2. Temporary sediment basin.........$3,000 3. Prevention of water quality impairment. 00 Construction Some permanent measures may be retained to provide long- a.b. ConMai Consstenance.........$1, 00 term benefits. c. Restoration...........$500 For example,a sediment basin may be cleaned out after Total Cost(C)............................$5,000 construction is finished and utilized for aesthetics, recreation,fish,or stormwater management. The"without treatment"condition reveals damages in the form of costs to remove sediment. Benefit(costs saved)are Benefits and costs for permanent measures need to be derived by subtracting the sediment removal costs under the converted by discounting and amortizing to average annual "with treatment"condition. figures for comparison. 1. Without treatment condition Benefit-Cost Analysis 8,000 cu.yd.(S)x$2.00/cu.yd.(Y)=$16,000(SxY) A simple equation for determining the benefits of 2. With treatment condition controlling sediment is: a. Costs(C)described above=...............$5,000 B=(SxY)- [C+(SxY)(1.00-P)] b. Removal costs for the 10%of sediment that passes through the control measure(measure is 90% Where: B=Benefits in dollars. effective) S=Cubic yards of sediment expected to move off the (SxY)(1.00-P)=(16,000)(1.00-.90) ...$1,600 site if no control measures are applied.(See Section 3). c. Total Cost=$5,000+$1,600=.......... .$6,600 Y=Cost in dollars per yard to recover and dispose of 3. Benefits sediment that has moved off the site. $16,000—$6,600= .............................$9,400(B) C=Estimated cost of temporary measures to be ($9,400 is money saved by installing sediment installed. (See Cost Tables). treatment) P=Estimated effectiveness of proposed measures Using the formula directly,the computations show the same expressed as a decimal. results: Example B=(SxY)-[c+(SxY)(1.00-P)] This example illustrates the methodology of a benefit-cost B=($8,000 x 2.00)-[($5,000+(8,000 x 2.00)(1.00- analysis: 0.90)] B=($16,000)-($5,000+ 1,600) Given: A construction site of 78 acres,which without erosion or sediment control measures will yield about 5 acre B=($16,000)-($6,600) feet or 8,000 cubic yards of sediment(S)to the lower end of the site. There is a channel with several culverts located B=$9,400 below the site and it is assumed all the sediment would be In this example,the more economical approach would be to deposited in it. It would be necessary to remove all the install treatment measures rather than correct damages at a additional sediment in order to maintain the capacity of the later date. A third alternative would be"do nothing"which channel and avoid increased hazard to flooding. The cost of would result in a higher flood damage hazard that would removing and disposing the sediment is estimated at$2.00 need evaluation under a more sophisticated analytical per cubic yard(Y). model. Also,in this simple example,water quality issues With temporary erosion and sediment control measures, (such as habitat loss)were not included even though including a sediment basin,in place during the one year society,in general,does place a value on such issues. construction period,sediment delivered to the channel will November 2016 Page C.2 New York State Standards and Specifications For Erosion and Sediment Control Table C.l—Cost Table of Selected Practices The cost of implementing erosion and sediment control practices is highly variable and dependent upon many factors including availability and proximity of materials,time of year,prevailing wage rates,and regional cost trends to name a few. It is therefore difficult to develop cost estimates that are applicable statewide and year-round. The cost data contained in this chapter is based on actual bid prices from county and state highway construction projects,and suppliers for the year 2013. The following cost figures for selected practices,are provided to aid project planners in estimating erosion and sediment cost for feasibility studies.Values have been rounded to nearest dollar.The actual dollar amounts are not recommended for use in estimating and bidding construction contracts. It is advisable to check with local suppliers and contractors for this purpose. Erosion and Sediment High Median Control Measures VEGETATIVE MEASURES Temporary Seeding 750/ac. 1,950/ac. 1,050/ac. Permanent Seeding 2,850/ac. 5,000/ac. 3,800/ac. Straw Mulch 1,250/ac. 1,900ac. 1,400/ac. Wood Mulch - 32,000/ac. 32,000/ac. Topsoil Stripping - - 3/cu.yd. Topsoil Spreading - - 38/cu.yd. Sodding - - 23/sq.yd. RECP Netting 8/sq.yd. 10/sq.yd. 9/sq.yd. Tree Protection - - 10/1n.ft. BIOTECHNICAL MEASURES Willow Wattles - - 19/hi.ft. Live Stakes 5.85 9.00 7/ea. Brush Layering - - 15/ln.ft. RUNOFF CONTROL MEASURES Temporary Swale 4/ln.ft. 6/ln.ft. 5/hi.ft. Rock Check Dam 248/ea. 860/ea. 500/ea. Diversion or Grass Channel 12/ln.ft. 23/ln.ft. 19/ln.ft. Riprap Channel 70/cu.yd. 105/cu.yd. 86/cu.yd. Flow Spreader/Diffuser - - 48/ln.ft. Rock Outlet Structure - - 1,900/ea. Turf Reinforcement Mats 25/sq.yd New York State Standards and Specifications Page C.3 November 2016 For Erosion and Sediment Control Table C.l (cont'd) Cost Table for Selected Practices Erosion and Sediment $Low $High $Median Control Measures SEDIMENT CONTROL MEASURES Silt Fence 41n.ft. 10/ln.ft. 6/ln.ft. Straw Bale Dike 6/ln.ft. 10/ln.ft. 8/ln.ft. Stabilized Construction Access - - 57/cu.yd. Temporary Sediment Basin - - 96/cu.yd. Temporary Sediment Trap 1,100/ea. 3,800/ea. 2,900/ea. Temporary Sediment Dike - - 23/ln.ft. Turbidity Curtain 8/sq.yd. 105/sq.yd. 60/sq.yd. Filter Fabric Inlet Protection - - 190/ea. Excavated Drop Inlet Protection - - 950/ea. Temporary Sediment Tank - - 5,000/ea. Block&Gravel Inlet Protection - - 1,000/ea. Compost Filter Sock 50/ln.ft. Geotextile Filter Bag 700/ea. Sediment Basin Skimmer 1,200/ea. Concrete Truck Washout Facility 1,500/ea. Table C.2 Maintenance Cost As Percentage of Installation Cost Item Percentage(%l Seeding 20 Mulch 2 Silt Fence 100 Sediment Trap 30 Sediment Basin 25 Inlet Protection 60 Stabilized Construction Entrance 100 Rock Riprap 10 Grass Channel 10 Temporary Swale 50 Flow Spreader 50 Tree Protection 30 Rock Outlet Structure 20 November 2016 Page CA New York State Standards and Specifications For Erosion and Sediment Control References 1. Soil Conservation Service,USDA. Oct. 1977. National Handbook for Conservation Practices,U.S.Government Printing Office,Washington,D.C. 2. Soil Conservation Service,USDA. July 1984. Engineering Field Manual of Conservation Practices,4th Printing, U.S. Government Printing Office,Washington,D.C. 3. Soil Conservation Service,USDA. Sept. 1987. Drainage Guide for New York State,Syracuse,N.Y. New York State Standards and Specifications Page C.5 November 2016 For Erosion and Sediment Control APPENDIX D EROSION & SEDIMENT CONTROL PLAN FOR SMALL HOMESITE CONSTRUCTION CONTENTS Page List of Figures Definition .........................................................................................................................................................................D.1 Purpose..............................................................................................................................................................................D.1 Criteria..............................................................................................................................................................................D.1 Specifications....................................................................................................................................................................D.1 Small Homesite Minimum Requirements ........................................................................................................................D.1 Small Homesite Examples(with Vegetative Requirements and Compliance Form) .......................................................DA Appendix prepared by: Paula Smith,CPESC,CPSWQ Former Stormwater Management Specialist New York State Department of Environmental Conservation,Region 8 and the NYS DEC General Permits Section Staff,Central Office,Albany List of Figures Figure Title Page D.1 Erosion Control Plan Condition 1 ........................................................................................................D.3 D.2 Erosion Control Plan Condition 2 ........................................................................................................D.5 D.3 Erosion Control Plan Condition 3 ........................................................................................................D.7 DA Erosion Control Plan Condition 4 ........................................................................................................D.9 D.5 Construction Details for Stabilized Construction Entrance and Silt Fence ........................................D.11 D.6 Construction Details for Straw Bale Dike and Rock Check Dam ......................................................D.12 EROSION AND SEDIMENT CONTROL PLAN FOR SMALL HOMESITE CONSTRUCTION Definition to prevent erosion; Small homesite erosion and sediment control plans area • Decompacting and re-vegetating the site as soon aspossible; group of minimum erosion and sediment control practices . Locating soil piles away from roads or waterways; and management techniques that apply to small homesite . Limiting tracking of mud onto streets by requiring construction activity on a single residential lot,in order to allvehicles to use designated access drives; prevent polluted discharge. • Removing sediment carried off-site by vehicles or Purpose storms; • Installing downspout extenders to prevent erosion This appendix lays out a series of minimum requirements from roof runoff;and for erosion and sediment control,and management practices . Maintaining erosion and sediment practices that may be used to meet these requirements.Use of these through sediment removal,structure replacement, templates will help show compliance with the general etc requirements for construction activities that require basic stormwater pollution prevention plans(SWPPP).This Specifications applies to the construction of small homesites. The owner/ developer must complete the relevant conditions(1-4),or Each construction site is different.The owner/developer of small parcel erosion and sediment control plan included in a small construction site may choose and follow one of the this section,and submit the NOI in order to meet four variations of ESC plans included in this section to compliance with the SPDES General Permit for Stormwater develop a SWPPP in compliance with the SPDES Discharges From Construction Activities. Construction Permit For Stormwater Discharges From Construction Activities. However,because of the general Criteria nature of the following conditions,the plans included in this section may not cover all of the resource protection Generally,several types of practices are required on any needs on a particular site,and this form does not exempt one site for effective erosion and sediment control.There an owner from the responsibility of filing an NOI,if are three broad categories of construction-related practices required. for controlling erosion and sediment on small homesite developments: Small Homesite Minimum Requirements: 1. Cover practices prevent erosion by protecting the 1. Stabilized Construction Entrance: soil surface from rainfall and runoff.Prevention of To prevent vehicles and equipment from tracking sediment erosion is the most preferable and cost-effective and mud off-site,a gravel or crushed rock to the restrict approach.These practices include:protection of driveway area and restt rict traffic to this one route. This existing vegetation;temporary covering of exposed soil practice will help keep soil from sticking to tires and stop by mulching,matting,or covering;and permanent site soil from washing off into the street. Carry out periodic stabilization by topsoiling,seeding,and/or sodding. inspections and maintenance including washing,top- 2. Structural Practices are structural controls that dressing with additional stone,reworking,and compaction. either reduce erosion,control runoff,or keep sediment Plan for periodic street cleaning to remove any sediment on the construction site.Examples of these practices that may have been tracked off-site. Remove sediment by include stabilized construction entrances,silt fences, shoveling or sweeping and transport to a suitable disposal sediment traps,berms,and check dams. area where it can be stabilized. 3. Management Measures are construction 2. Stabilization of Denuded Areas: management methods that prevent or reduce erosion potential and ensure the proper functioning of erosion In areas where soil disturbance activity has temporarily or and sediment control practices.Careful construction permanently ceased,the application of soil stabilization management can dramatically reduce the costs measures must be initiated by the end of the next business associated with erosion and sediment problems. day and completed within fourteen(14)days from the date Examples of these management measures include: the current soil disturbance activity ceased. For construction sites that directly discharge to one of the 303 • Preserving existing trees and grass where possible (d)segments listed in the Construction General Permit or is New York State Standards and Specifications Page D.1 November 2016 For Erosion and Sediment Control located in one of the watersheds listed in Appendix C,the dam—if not maintained,high flows could cause erosion application of soil stabilization measures must be initiated around the sides of the structures,adding significant by the end of the next business day and completed within sediment loads downstream. seven(7)days from the date the current soil disturbance activity ceased. 5. Maintenance: Stabilize disturbed areas by implementing soil covering Maintain erosion and sediment control practices through practices(e.g.mulching,matting,sodding).Exposed soils regular inspection.Regular maintenance is extremely are the most prone to erosion from rainfall and runoff. important for the proper operation of structural practices. Vegetation helps protect the soil from these forces and After initial groundbreaking,the responsible contractor provides natural erosion control.Plan construction to limit shall conduct daily maintenance inspections within the the amount of exposed area,and avoid grading activities active work area to ensure practices are being maintained in during the rainy season(November through March)as effective operating conditions at all times. much as possible.Clearing limits should be clearly marked and kept as small as possible.Once construction is 6. Soil Restoration: completed,the site must be permanently stabilized with topsoiling,seeding and plantings,or sodding if needed. Soils that have been disturbed and compacted due to construction activities should be de-compacted to restore 3. Protection of Adjacent Properties: their previous hydrologic condition.This normally involves aeration of small areas for home sites.Large areas should Keep sediment on-site by using structural and source be restored in accordance with the Soil Restoration standard control practices(e.g.vegetative buffer strips,sediment in Section 4 of this book of standards. barriers,soil berms or dikes,etc). See Sections 3,4,or 5 as appropriate.Wherever possible,preserve a buffer of 7. Other Practices: existing vegetation around the site boundary.This will help to decrease runoff velocities and trap sediment suspended in Use additional practices as required by the local plan the runoff.Other structural controls such as filter fence or approval authority to mitigate effects of increased runoff. straw bale barriers should also be used to filter runoff and This may include providing additional controls to a locally trap sediment on-site. protected stream or resource area,protecting riparian corridors(vegetative stream buffers),etc. Individual When excavating basement soils,move the soil to a location homeowners and/or developers are responsible for that is,or will be,vegetated,such as in the backyard or side researching additional requirements related to erosion and yard area.This will increase the distance eroded soil must sediment runoff control established by their local travel,through vegetation,to reach the storm sewer system. jurisdictions. Piles should be situated so that sediment does not run into the street or adjoining yards. Soil piles should be temporarily seeded and circled with silt fence until the soil is either replaced or removed.Backfill basement walls as soon as possible and rough grade the lot.This will eliminate the large soil mounds,which are highly erodible,and prepare the lot for temporary cover.After backfilling,grade or remove excess soil from the site quickly,to eliminate any sediment loss from surplus fill. 4. Concentrated Flow: For constructed drainage ways,or other areas of concentrated flow,install check dams according to the specifications on page E.12 to reduce erosion in the channel. As with other erosion controls,check dams must be inspected regularly. Remove sediment accumulated behind the dam as needed to allow channel to drain through the stone check dam and prevent large flows from carrying sediment over the dam Replace stones as needed to maintain the design cross section of the structures. Sediment removal is crucial to the effectiveness of the November 2016 Page D.2 New York State Standards and Specifications For Erosion and Sediment Control Figure D.} Erosion Control Plan Condition } �� to 0 § a|� a� ■ 4-0 u § § 2 _ . § > d 2 §afps /2 § 2 §E e a2} @� --0 z J r R o _ ee ■ d C©JG CO- �aa§ E\ ■ § a f § § § aka 22� #{ 3 z 2 _ d >K K s azs ee) J}g w j k) §�)% \ _ » ,a. o CL Lj Oil S6§■ 2 | ;% < §� } c d . z j 12 o a § 3 ).d / � ix \ §� § 0. § § / urw \ & LO "}W E/ L k(4z �0 � G � Li � L 0 , � 0 � 0 L) ! 7] ® �ƒ ( aE & E® � ee [ ! § � m-< § § 1> 0 § -C i 0 }( } W 8 \ E0/ C3 W Ld Ld , EE \ 3m - b K K E. % w U e \ E � o e e — - E § , - — J I zc NEvrRK STATE DEPARTMENT OF TRANSPORTATION, EROSION CONTROL NEW�YORK STATE SOIL &WATER�CONSERVATIOON COMMITTEE PLAN CONDITION 1 New York State Standards and Specifications egeOJ November 2016 For Erosion and SeJmetControl Condition 1—Vegetative Requirements & Compliance Form Vegetation Requirements: 1) Site Preparation A. Install needed water and erosion control measures and bring area to be seeded to desired grades using a minimum of 4 in.topsoil. B. Prepare seedbed by loosening soil to a depth of 4-6 inches. C. Lime to a pH of 6.5 D. Fertilize as per soil test or,if fertilizer must be applied before soil test results are received,apply 850 pounds of 5-10-10 or equivalent per acre(20 lbs/1,000 sq.ft.) E. Incorporate lime and fertilizer in top 2-4 inches of topsoil. F. Smooth.Remove all stones over 1 inch in diameter,sticks,and foreign matter from the surface.Firm the seedbed. 2) Planting—Sunny Location. Upon completing soil de-compaction,use a cultipacker type seeder if possible.Seed to a depth of 1/8 to 1/4 inch.If seed is to be broadcast,cultipack or roll after seeding.If hydroseeded,lime and fertilizer may be applied through the seeder and rolling is not practical. Seed using the following mix and rates: Species M by weight) lbs/1,000sci.ft lbs./acre 65%Kentucky bluegrass blend............................................. 2.0-2.6.......................... 85-114 20%perennial ryegrass....................................................... 0.6-0.8.......................... 26-35 15%fine fescue................................................................ 0.4-0.6......................... 19-26 Total............................................................................. 3.0-4.0......................... 13 0-17 5 or, 100%Tall fescue,Turf-type,fine leaf...................................... 3.4-4.6......................... 150-200 3) When using the cultipacker or broadcast seed method,mulch using small gram straw,applied at a rate of 2 tons per acre;and anchor with a netting or tackifier.Hydroseed applications should include mulch,fertilizer and seed. Common white clover can be added to mixtures at the rate of 1-2 lbs/acre to help maintain green color during the dry summer period,however,they will not withstand heavy traffic.Fertilizing First year,(spring seedlings)three to four weeks after germination apply 1 pound nitrogen/1,000 square feet using a complete fertilizer with a 2-1-1 or 4-1-3 ratio or as recommended by soil test results.For summer and early fall seedings,apply as above unless air temperatures are above 85°F for extended period.Wait until heat wave is over to fertilize.For late fall/winter seedings,fertilize in spring.Restrict use—new seedlings should be protected from use for one full year to allow development of a dense sod with good root structure. Certification Statement Please complete and sign this 2-sided document(with Typical Erosion Control Plan)and attach to BLUEPRINTS and SITE PLAN prior to any earth disturbance.These documents must be kept on site and be available for review as requested by any agent of the NYSDEC. This 2-sided form can be used as a basic stormwater pollution prevention plan,but will not exempt a landowner from filing a Notice of Intent. "I hereby certify under penalty of law that I understand and agree to comply with the terms and conditions of the SWPPP and agree to implement any corrective actions identified by the qualified inspectors during a site inspection. I also understand that the owner or operator must comply with the term and conditions of the most current version of the New York State Pollutant Discharge Elimination System (SPDES)general permit for stormwater discharges from construction activities and that is unlawful for any person to cause of contribute to a violation of water quality standards. Furthermore,I am aware that there are significant penalties for submitting false information,that I do not believe to be true,including the possibility of fine and imprisonment for know violations." Builder/Contractor(print) Signature Address November 2016 Page DA New York State Standards and Specifications For Erosion and Sediment Control Figure D.2 Erosion Control Plan Condition 2 4. tW.7 L2 Or {Oi; U.0 d +' pp pp,yy Lpp ❑ H Z �' W is W Vi 3„ aV,�g � ,Ml 7 zW F 6 W 9w. N da°U ❑tU) oc ` 4I a� �` a 2�d c� `81„ LJ NU J I M t7 FaaL ka Uk W-J I 11 > W o w � a N � y� ❑z d W L. J o 0 H ❑#�C "62 O I i : ¢W W OW�u ��L ) L&✓ p F- iL oil y rk CUA0 MLd6L fy U l7 Z H 0 X W W C w I- U a w �- W � i Z a U 03 O A�W 04-' W NF U O < J 4 �U ��oe d l7 < Z 0.+' W❑W U a 0 W ❑ LJ Q A zz z F rZr W O N O _ V W W ~ a a — U M M -W z z a a a NEW YORK STATE DEPARTMENT OF TRANSPORTATION, EROSION CONTROL NEW YORK STATE DEPARTMENT OF ENVIRONMENTAL CONSERVATION, NEW YORK STATE SOIL & WATER CONSERVATION COMMITTEE PLAN CONDITION 2 New York State Standards and Specifications Page D.5 November 2016 For Erosion and Sediment Control Condition 2—Vegetative Requirements & Compliance Form Vegetation Requirements: 1) Site Preparation A. Install needed water and erosion control measures and bring area to be seeded to desired grades using a minimum of 4 in.topsoil. B. Prepare seedbed by loosening soil to a depth of 4-6 inches. C. Lime to a pH of 6.5 D. Fertilize as per soil test or,if fertilizer must be applied before soil test results are received,apply 850 pounds of 5-10-10 or equivalent per acre(20 lbs/1,000 sq.ft.) E. Incorporate lime and fertilizer in top 2-4 inches of topsoil. F. Smooth.Remove all stones over 1 inch in diameter,sticks,and foreign matter from the surface.Firm the seedbed. 2) Planting—Sunny Location. Upon completing soil de-compaction,use a cultipacker type seeder if possible.Seed to a depth of 1/8 to 1/4 inch.If seed is to be broadcast,cultipack or roll after seeding.If hydroseeded,lime and fertilizer may be applied through the seeder and rolling is not practical. Seed using the following mix and rates: Species M by weight) lbs/1,000sci.ft lbs./acre 65%Kentucky bluegrass blend............................................. 2.0-2.6.......................... 85-114 20%perennial ryegrass....................................................... 0.6-0.8.......................... 26-35 15%fine fescue................................................................ 0.4-0.6......................... 19-26 Total............................................................................. 3.0-4.0......................... 13 0-17 5 or, 100%Tall fescue,Turf-type,fine leaf...................................... 3.4-4.6......................... 150-200 3) When using the cultipacker or broadcast seed method,mulch using small grain straw,applied at a rate of 2 tons per acre;and anchor with a netting or tackifier.Hydroseed applications should include mulch,fertilizer and seed. Common white clover can be added to mixtures at the rate of 1-2 lbs/acre to help maintain green color during the dry summer period,however,they will not withstand heavy traffic.Fertilizing First year,(spring seedlings)three to four weeks after germination apply 1 pound nitrogen/1,000 square feet using a complete fertilizer with a 2-1-1 or 4-1-3 ratio or as recommended by soil test results.For summer and early fall seedings,apply as above unless air temperatures are above 85°F for extended period.Wait until heat wave is over to fertilize.For late fall/winter seedings,fertilize in spring.Restrict use—new seedlings should be protected from use for one full year to allow development of a dense sod with good root structure. Certification Statement Please complete and sign this 2-sided document(with Typical Erosion Control Plan)and attach to BLUEPRINTS and SITE PLAN prior to any earth disturbance.These documents must be kept on site and be available for review as requested by any agent of the NYSDEC. This 2-sided form can be used as a basic stormwater pollution prevention plan,but will not exempt a landowner from filing a Notice of Intent. "I hereby certify under penalty of law that I understand and agree to comply with the terms and conditions of the SWPPP and agree to implement any corrective actions identified by the qualified inspectors during a site inspection. I also understand that the owner or operator must comply with the term and conditions of the most current version of the New York State Pollutant Discharge Elimination System (SPDES)general permit for stormwater discharges from construction activities and that is unlawful for any person to cause of contribute to a violation of water quality standards. Furthermore,I am aware that there are significant penalties for submitting false information,that I do not believe to be true,including the possibility of fine and imprisonment for know violations." Builder/Contractor(print) Signature Address November 2016 Page D.6 New York State Standards and Specifications For Erosion and Sediment Control o � 0 0 o' x a z'E MEAN HTGH EROSI❑N CONTROL WATER � � o WATER LINE PLAN LEGEND ¢ SC ;0 m ♦ ♦ i i ♦ PROPERTY LINE CDP¢' i i i ♦ ♦ ♦ V ♦ ♦ ♦ ♦ V i i i i t' �H a ♦ ♦ ♦ ♦, i i ♦, i ♦ i i ♦ a W i i i ♦ ♦ a a ♦ i ♦ i ♦ EXISTING DRAINAGE 100'CRITICAL AREA BUFFER ` ` ` ` ` ` ` FINISHED DRAINAGE (� ��� ♦ ♦ ♦ a i a ♦ ♦ i a ♦ ♦ a i ♦ ♦ a i i i i i ♦ a a i i V a i i i i V i V i i a V i a i LIMITS OF GRADING ♦ ♦ ♦ V a a i i i i i a a i i W V W ♦ V O 141 rn-� a a i i i a a a ♦ ♦ STRAW BALES n Vi D I a i ♦ a I �'•"• O m ■ M-" SILT FENCE r rn Q o Z D ( 1 ) VEGETATION �. �-� SPECIFICATION Q a 0-4 Ptaced on -iTirq TREE PRESERVATION �mz the Contour r)< ZM STOCKPILED SOD_ O 1 \ z;; GRAVEL ' `d G f�12a O d Z I HOUSE 1. On rooderate slo , up to;a 0-1 percent, t fencepes straw 8 o z> GARAGE bales may be used Interchangably. N M z aSlopes exceeding 25 percent w m A shall have slit suppor wed by strawbales for j Use additional practices as 0 lo l / required by the cal plan ` O l approval authority to rdtigate J effects of post constructer STABILIZED runoff. Q r- CONSTRUCTION ENTRANCE Z W H 0 Oz EXISTING CURB AND GUTTER z STREET tj f7 H Q —I Z PROJECT LOCATIONS PROPERTY OWNERi H oZ ANTICIPATED STARTING DATE, CONTRACTORi CD W ANTICIPATED COMPLETION DATE, SOIL TYPE, SLOPEi CD N 0 c, Condition 3—Vegetative Requirements & Compliance Form Vegetation Requirements: 1) Site Preparation A. Install needed water and erosion control measures and bring area to be seeded to desired grades using a minimum of 4 in.topsoil. B. Prepare seedbed by loosening soil to a depth of 4-6 inches. C. Lime to a pH of 6.5 D. Fertilize as per soil test or,if fertilizer must be applied before soil test results are received,apply 850 pounds of 5-10-10 or equivalent per acre(20 lbs/1,000 sq.ft.) E. Incorporate lime and fertilizer in top 2-4 inches of topsoil. F. Smooth.Remove all stones over 1 inch in diameter,sticks,and foreign matter from the surface.Firm the seedbed. 2) Planting—Sunny Location. Upon completing soil de-compaction,use a cultipacker type seeder if possible.Seed to a depth of 1/8 to 1/4 inch.If seed is to be broadcast,cultipack or roll after seeding.If hydroseeded,lime and fertilizer may be applied through the seeder and rolling is not practical. Seed using the following mix and rates: Species M by weight) lbs/1,000sci.ft lbs./acre 65%Kentucky bluegrass blend............................................. 2.0-2.6.......................... 85-114 20%perennial ryegrass....................................................... 0.6-0.8.......................... 26-35 15%fine fescue................................................................ 0.4-0.6......................... 19-26 Total............................................................................. 3.0-4.0......................... 13 0-17 5 or, 100%Tall fescue,Turf-type,fine leaf...................................... 3.4-4.6......................... 150-200 3) When using the cultipacker or broadcast seed method,mulch using small gram straw,applied at a rate of 2 tons per acre;and anchor with a netting or tackifier.Hydroseed applications should include mulch,fertilizer and seed. Common white clover can be added to mixtures at the rate of 1-2 lbs/acre to help maintain green color during the dry summer period,however,they will not withstand heavy traffic.Fertilizing First year,(spring seedlings)three to four weeks after germination apply 1 pound nitrogen/1,000 square feet using a complete fertilizer with a 2-1-1 or 4-1-3 ratio or as recommended by soil test results.For summer and early fall seedings,apply as above unless air temperatures are above 85°F for extended period.Wait until heat wave is over to fertilize.For late fall/winter seedings,fertilize in spring.Restrict use—new seedlings should be protected from use for one full year to allow development of a dense sod with good root structure. Certification Statement Please complete and sign this 2-sided document(with Typical Erosion Control Plan)and attach to BLUEPRINTS and SITE PLAN prior to any earth disturbance.These documents must be kept on site and be available for review as requested by any agent of the NYSDEC. This 2-sided form can be used as a basic stormwater pollution prevention plan,but will not exempt a landowner from filing a Notice of Intent. "I hereby certify under penalty of law that I understand and agree to comply with the terms and conditions of the SWPPP and agree to implement any corrective actions identified by the qualified inspectors during a site inspection. I also understand that the owner or operator must comply with the term and conditions of the most current version of the New York State Pollutant Discharge Elimination System (SPDES)general permit for stormwater discharges from construction activities and that is unlawful for any person to cause of contribute to a violation of water quality standards. Furthermore,I am aware that there are significant penalties for submitting false information,that I do not believe to be true,including the possibility of fine and imprisonment for know violations." Builder/Contractor(print) Signature Address November 2016 Page D.8 New York State Standards and Specifications For Erosion and Sediment Control o � 0 0 o' x v� z C.- CD z'E SENSITIVE AREA - EROSION CONTROL m MUST MAINTAIN A 25' PLAN LEGEND c� v� £o WITH 25X OR = - - _ _ BUFFER BETWEEN CD GREATER SLOPES ANY DISTURBED AREA PROPERTY LINE AND THE TOP OF — EXISTING DRAINAGE CD SLOPES 25% AND ¢ p G7 ... w w w w w w w w FINISHED DRAINAGE W m 4 :. -: :`� + w w GREATER ¢ ad :- + 25'BUFFER w w — — — LD4TS OF GRADING DO m m-i + J� STRAW BALES rD 2. o;0 m + + Placed on I E-W" SILT FENCE �3d w m m the Contour �� p z-0 ( 1 ) VEGETATION SPECIFICATION �'13 TREE PRESERVATION Z z 0 C o '\\ STOCKPD_ED SOIL p z;0- wo i'1 Z-I GAVEL z z p z r 3 I H❑USE ( 1. On moderate slopes, up to e 0 4 percent, sKt fence and straw o z> GARAGE bales may be used Interchangably. j�? shall. have slitefen edince Rixicked by m a straw bales for support p m H J� n 3. Use additional, practices as Z '\ required by the local plan approval authority to mitigate � \ TABILIZED rfunoffs of post construction C �- CONSTRUCTIO ENTRANC Z N H no O Z EXISTING CURB AND GUTTER Z CJ n STREET '-' O i Z PROJECT LOCATION, PROPERTY OWNERi ~ ANTICIPATED STARTING DATES CONTRACTORt o Z �J CD ANTICIPATED COMPLETION DATEi SOIL TYPE, SLOPEt C N 0 c, Condition 4—Vegetative Requirements & Compliance Form Vegetation Requirements: 1) Site Preparation A. Install needed water and erosion control measures and bring area to be seeded to desired grades using a minimum of 4 in.topsoil. B. Prepare seedbed by loosening soil to a depth of 4-6 inches. C. Lime to a pH of 6.5 D. Fertilize as per soil test or,if fertilizer must be applied before soil test results are received,apply 850 pounds of 5-10-10 or equivalent per acre(20 lbs/1,000 sq.ft.) E. Incorporate lime and fertilizer in top 2-4 inches of topsoil. F. Smooth.Remove all stones over 1 inch in diameter,sticks,and foreign matter from the surface.Firm the seedbed. 2) Planting—Sunny Location. Upon completing soil de-compaction,use a cultipacker type seeder if possible.Seed to a depth of 1/8 to 1/4 inch.If seed is to be broadcast,cultipack or roll after seeding.If hydroseeded,lime and fertilizer may be applied through the seeder and rolling is not practical. Seed using the following mix and rates: Species M by weight) lbs/1,000sci.ft lbs./acre 65%Kentucky bluegrass blend............................................. 2.0-2.6.......................... 85-114 20%perennial ryegrass....................................................... 0.6-0.8.......................... 26-35 15%fine fescue................................................................ 0.4-0.6......................... 19-26 Total............................................................................. 3.0-4.0......................... 13 0-17 5 or, 100%Tall fescue,Turf-type,fine leaf...................................... 3.4-4.6......................... 150-200 3) When using the cultipacker or broadcast seed method,mulch using small gram straw,applied at a rate of 2 tons per acre;and anchor with a netting or tackifier.Hydroseed applications should include mulch,fertilizer and seed. Common white clover can be added to mixtures at the rate of 1-2 lbs/acre to help maintain green color during the dry summer period,however,they will not withstand heavy traffic.Fertilizing First year,(spring seedlings)three to four weeks after germination apply 1 pound nitrogen/1,000 square feet using a complete fertilizer with a 2-1-1 or 4-1-3 ratio or as recommended by soil test results.For summer and early fall seedings,apply as above unless air temperatures are above 85°F for extended period.Wait until heat wave is over to fertilize.For late fall/winter seedings,fertilize in spring.Restrict use—new seedlings should be protected from use for one full year to allow development of a dense sod with good root structure. Certification Statement Please complete and sign this 2-sided document(with Typical Erosion Control Plan)and attach to BLUEPRINTS and SITE PLAN prior to any earth disturbance.These documents must be kept on site and be available for review as requested by any agent of the NYSDEC. This 2-sided form can be used as a basic stormwater pollution prevention plan,but will not exempt a landowner from filing a Notice of Intent. "I hereby certify under penalty of law that I understand and agree to comply with the terms and conditions of the SWPPP and agree to implement any corrective actions identified by the qualified inspectors during a site inspection. I also understand that the owner or operator must comply with the term and conditions of the most current version of the New York State Pollutant Discharge Elimination System (SPDES)general permit for stormwater discharges from construction activities and that is unlawful for any person to cause of contribute to a violation of water quality standards. Furthermore,I am aware that there are significant penalties for submitting false information,that I do not believe to be true,including the possibility of fine and imprisonment for know violations." Builder/Contractor(print) Signature Address November 2016 Page D.10 New York State Standards and Specifications For Erosion and Sediment Control o CD 0 0 CD w CD �.. WOVEN W-RE FENCE SYMB❑L SYMEDL CD fM'N 14 GAUGE i„ 50'MIV. _�EXISTING �• s? W/ MAX. 6' MES - PAVEMENT _O' MAX, C. TOC. SPACING) 6'NIN. 0 ¢ 36' MIN. LENGTH FENCE EXISTING� FILTER—f MOUNTABLE BERM CIO POSTS HRIVEN M_N 16' GROUND CLOTH PREFILE c�7I]VAL) CD IN-O GROUND, ow 57M1N C� HEIGH- OF FILTER ]WHIN. ~ P w 16' MIN, EX"STING GROUND �} 6' MIN, O E1f1S7D+IG PAVEMENT 'ERSPECTIVE VIF' V/ PLAN VIEW ]0'MIN, !"r 36' MIN. FENCE POST A� WOVEN WIRE FENCE (MIN, 14 c '/2 GAJGE W/ MAX 6' MES1 �• Y•�• r� SPACING) WITH FILTER CLOTH 25`1IN. ZENSTRUCTI❑N SPECFICATI❑IDS Uo FLOW �• �' UNDISTJRBED GROUND 1. STONE SIZE - USE 1-4 INCH STONE, ER RECLAIMED OR RECYCLED CONCRE-E HZ d COMPACTED SOIL EQUIVALENT. CD EMBED FILTER CLO-H '6'MIN. 2. LENGTH - NOT LESS THAN 50 FEET (EXCEPT ON A SINGLE RESIDENCE LOT WHERE A A MIN. OF 6' 1N GROUND. 30 F017 MINIMUM _ENGTH WOULD APPLY). l 1 rrvv 4• 3. THICKNESS - NO- LESS THAN SIX C6) INCHES. SECTION VEEW 4. WIDTH - -WELVE U) FOOT MINIMUM, BUT NOT LESS THAN THE FULL WIDTH AT C❑N S T R U I S P E ,I F I C A T I❑ S POINTS WHERE =NGRESS OR EGRESS OCCURS. TWEN-Y-FOUR C24) FOOT IF SINGLE ENTRANCE TO SITE. ►� L WOVEN +LIRE =ENCE TJ 3E FASTENED SECUREL" TC FENCE 'OS-S WITH 'WIRE TIES 5. GECTEX71LE - WILL BE PLACED OVER THE ENTIRE AREA PRIDR TO PLACING OF STONE OR STAPLES. POSTS SHALL BE STEEL EITHER "` OR 'U' TY'E ER HAR➢WOOL 6. SURFACE WATER - ALL SURFACE WATER FLOWINS JR DIVERTED TOWARD CDN- 1"r STRUCTION ACCESS SHALL 3E PIPED BENEATH THE ENTRANCE. IF PIPING IS �• 2. FILTER CLOTH TO BE TO BE FASTENED SECURE-Y TD WOVEN WIRE FENCE WITH TIES IMPRACTICAL, A MOUNTABLE BERM WITH 5+1 S_CPES WILL BE PERMITTED. O S?ACED EVER" 24' AT TOP AND MID SECTION. -ENCE SHALL BE 'WOVEN WIRE, 6' MAXIMLM MESH 7ENING. 7. MAINTENANCE - THE ENTRANCE SHALL BE MAINTAINED 1N A CONDITION WHICH WILL PREVENT 7R4C{ING OR FLOWING OF SEDIMENT ONT7 %RLIC RIGHTS-OF-WAY, ALL 3. WHEN TWO SECTIONS OF FILTER CLOTH ADJOIN EAC� OTHER THEY SHALL BE OVER- SEDIMENT SFIL_ED, ➢ROP'ED, WASHED OR TRACKED ONTO PLBLIC RIGHTS-OF-WAY LAPPED BY SIX INCHES AND FOLDED. FILTER CLOT SHALL 3E EITHER ^ILTER X, MUST BE REMOVED IMMEDIATELY. MIRAFI IOI'X, STABILINKA T140N, ER ADPRCVED ERUIVA-ENT. 8. WHEN WASHING IS WCXJIRED, "T SHALL BE DINE ON A AREA STAB:LLZED WITH STOVE 1"r 4. PREFABRICATED UNITS SHA-L BE GEOFAB, ENVIRCFENCE, OR APPROVED EQUIVALENT. ANI WHICH DRAINS INTO AN APPROVED SEDIMENT 'RAPPING DEVICE. 5, MAINTENANCE SHALL BE RAIN.PERFORMED AS NEEDED ANI MATERIAL REMOVED WHEN 4• IC INSPECTION AND NEEDED MAINTENANCE SHALL BE PROVIDED AFTER EACH RAIN. 'BULGES' DIV7LOP IN THE SILT FENCE n ADAPTED FRDM DE-AILS °RCVIDED HY+ usDA - nR�s, STABILIZED ADAPTED FREW EETAILS PROVIDED BY+ USDA - NR"S, NEW YORK STATE DEPARTMENT OF TRANSPQdTAT1ON, NEW aORK STATE DEPARTMENT 0- TRANSPORTATION, S-_T FENCE NEW YORK STATE DEPARTMENT OF ENVIRINNEYTAL CCNSER'JATIOY, CONSTRUCTION NEW YCRK STATE 11EZARTMENT CF ENVIR7NMENTAL CONSERVAT13N. NEW YORK STATE SJUL & WATER CONSERVPT[L.N CCH"ATTCE NEW "ORK STATE SOIL & WATER CONSERVATION C3MMITTEE ACCESS CD wor. CD M� N O C1 z 0 CD cr CD O_ G1 SYMBOL SPACING VARIES SYMBO_ v. DEPENDING [IN FLOW CHANNEL SLOPE X A SAME ELEVATION 4' VERTICAL FACE n CUTOFF TRENCH CREST IIII 1B' WIDE TOE���/SLOP H 24' MAX 6' DEEP E 2 CENTER BEDDING DETAIL PROFILE A NET TO SCALE NOT TO SCALE DRAINAGE AREA NO MORE THAN 1/4 ACRE PER 100 FEET NFILTER 5' OF STRAW BALE DIKE FOR SLOPES LESS THAN 25`/_ F`B IN. �..r __ H (Ft) 9'MIN X SLOPE (FT/FT) ANGLE FIRST STAKE TOWARDS J 1 PREVIOUSLY LAID BALE. FLOWDITCH BOTTOM O CUTOFF TRENCH 2 2 nv BOUND BALES PLACED ►� B DESIGN BOTTOM 1� 1 24' MAX r• ON CONTOUR. G SECTION A-A @ CENTER �q NOT TO SCALZ '��.� 2 RE-BARS, STEEL PICKETS ►� CD - OR 2'X2' STAKES PLACED .� d 1� 1 G. - L 1/2' TO 2' IN GROUND, N FILTER FABRIC 18 - ®RIVE STAKES FLUSH WITH T�' OF BALE, ANC-OR]NG DETAIL SECTION B-B NOT TO SCALE NOT -0 SCA-E C❑NSTRUCTI❑N SPECIFICATI❑NS C❑NSTRUCTION SPECIFICATIONS �D C� 1. STONE WILL BE PLACED ON A FILTER FABRIC FOUNDATION TO THE LINES, 1, BALES SHALL BE PLACED AT THE TOE OF A SLOPE OR ON THE CONTOUR AND IN A �• GRADES AND LOCATIONS SHOWN IN THE PLAN. RGW WITH ENDS TIGHTLY ABUTTING THE ADJACENT BALES. 2, EACH BALE SHALL BE EMBED➢ED IN THE SOIL A M[tiIMUM OF (4) INCHES, AND 2, SET SPACING OF CHECK DAMS 70 ASSUME THAT THE ELEVATIONS OF THE CREST PLACED SO THE BINDINGS ARE HORIZONTAL. A� p OF THE DOWNSTREAM DAM IS AT THE SAME ELEVATION OF THE TOE :IF THE x UPSTREAM DAM, 3, BALES SHALL BE SECURELY ANCHORED IN PLACE BY EITHER TWO STAKES OR IA 3. EXTEND THE STONE A MINIMUM OF 1.5 ;EFT BEYOND THE DITCH BANKS TG RE-BARS DRIVEN THROUGH THE BALE. THE FIRST STAKE IN EACH BALE SHALL F r+ BE DRIVEN TOWARD THE PREVIOUSLY LAID BALE AT AN ANGLE TO FORCE THE .y PREVENT CUTTING AROJN➢ THE DAM BALES TOGETHER, STAKES SHALL BE DRIVEN FLUSH WITH THE BALE. CD 4. PROTECT THE CHANNEL DOWNSTREAM OF THE LOWEST CHECK DAM FROM SCOLR AND EROSION WITH STONE OR LINER AS APPROPRIATE, 4, INSPECTION SHALL BE FREQUENT AND REPAIR REPLACEMENT SHALL BE MADE v PROMPTLY AS NEEDED, p 5, ENSURE THAT CHANNEL APPURTENANCES SUCH AS CULVERT ENTRANCES BELOW 5, BALES SHALL BE REMOVED WHEN THEY HAVE SERVED THEIR USEFULLNESS SO CHECK DAMS ARE NOT SUBJECT TO DAMAGE OR BLOCKAGE FROM DISPLACED STONE, AS NOT TO BLOCK OR IMPEDE STORM FLOW OR DRAINAGE. ¢ MAX-'MUM DRAINAGE AREA 2 ACRES. ADAPTED FROM DETAILS PROVIDED BY- USDA - NRCS, �p ADAPTED FROM DETAILS PROVIDED BY- USDA - NRCS, NEW YORK STATE DEPARTMENT OF TRANSPORTATION, STRAW BALE 0 Y NEW YORK STATE DEPARTMENT OF TRANSPORTATION, CHECK LAM NEV YORK STATE DEPARTMENT O ENVIRONMENTAL'CUNSERVATIUN, DIKE NEW ORK STATE DEPARTMENT OF ENV''RONMENTAL CONSERVATION, NEV YORK STATE SOIL d WATER CONSERVATION COMM[•TEE �p NEW YORK STATE SOIL & WATER CONSERVATION COMMITTEE � n r- v� APPENDIX E EROSION AND SEDIMENT CONTROL PLAN REVIEW CHECKLIST Project Name Site Location Applicant's Name&Address General A narrative statement shall be provided that describes the proposed project nature and purpose;the existing site conditions including topography,vegetation and drainage;adjacent and off-site areas affected by the project;description of the soils on the site and key properties;notations of critical areas such as steep slopes,channels or wetlands;the overall phasing,se- quencing and stabilization plan;total disturbed area and,areas not to be disturbed,and soil restoration plan. L Construction Drawings Are the following items shown on the construction drawings: Yes No 1.Vicinity Map with scale and north arrow 2.Legend,scales,N arrow on plan view 3.Existing and proposed topography shown with contours labeled with spots elevations in critical areas 4. Scope of the plan noted in the Title Block 5.Limits of clearing and grading shown,and methods of spoil disposal 6.Existing vegetation delineated 7. Soil boundaries shown on the existing and proposed plan views 8.Existing drainage patterns, 100 year floodplain and sub-areas shown,runoff outfall locations identified 9.Existing and proposed development facilities/ improvements shown 10.Location of Erosion and Sediment control practices as phased with construction,with dimensions and material specifications 11.Phasing plan with 5 acre threshold limits shown 12. Stockpile locations,staging areas,access points,and concrete trunk washout locations clearly defined 13. Street profiles,utility locations,property boundaries and,easement delineations shown 14. Soil Restoration Plan detailed on the site plan November 2016 Page E.1 New York State Standards and Specifications For Erosion and Sediment Control II. Construction Notes & Details Yes No 1. Specific sequence of operation given for each phase 2.Inspection and maintenance schedule shown for the specific practices 3.Design details show all dimensions and installation details necessary for construction 4.Implementation schedule for E&S practices is provided with removal criteria stated 5. Site pollution and construction waste management plan incorporated in the notes 6. Site Inspections during construction are noted on the drawings and are in accordance with the General Permit for Stormwater Discharges from Construction Activities III. Erosion & Sediment Control Practices A. General Yes No 1.Practice meets purpose and design criteria 2. Standard details and construction notes are provided 3. Special timing of practice noted if applicable 4.Provisions for traffic crossings shown on the drawings where necessary B. Practices Controlling Runoff Yes No 1.Positive drainage is maintained with contributing drainage area shown 2.Flow grades properly stabilized 3.Adequate outlet or discharge condition stabilized 4.Necessary dimensions,gradations,calculations, and materials shown C. Practices Stabilizing Soil Yes No 1. Seeding rates and areas properly shown on the drawings 2.Mulch materials and rates specified on the drawings 3. Sequencing and timing provisions limit soil exposure to 7 to14 days as appropriate New York State Standards and Specifications Page E.2 November 2016 For Erosion and Sediment Control C. Practices Stabilizing Soil (cont'd) Yes No 4.Rolled Erosion Control Products(RECP's) used are specified to location and appropriate weight/tie down 5.All soil seed bed preparation and amendments are specified on the drawings or in the specifications 6.The seeding dates are specified to cover the entire year for both temporary and permanent seedings 7.Maximum created slopes are no steeper than 2 foot horizontal to 1 foot vertical with Cut and Fill slopes shown D. Practices Controlling Sediment Yes No 1. Sediment traps/basins are sized in accordance with criteria 2.The contributing drainage area is shown on the grading plan 3.All scaled dimensions and volumes are shown on the plan 4.Maintenance requirements and clean out elevations established for all sediment control practices(50%capacity) 5.All access points of the project are shown to be stabilized 6. Storm drain inlets adequately protected 7.Buffer filter strips are appropriately sited and installed 7. Silt fences are shown on the contour lines with no more than one quarter acre per 100 foot drainage to it 8.Temporary sediment traps are not being used at locations of future stormwater infiltration facilities 9.Dewatering devices for traps and basins are adequately designed with details shown on the plans 10.Geotextile filter bags are properly sited,sized,and have their maintenance requirements detailed on the drawings 11.Turbidity curtains are properly located with installation, anchoring,and maintenance details shown on the plans November 2016 Page E.3 New York State Standards and Specifications For Erosion and Sediment Control Additional Comments and Notes Plan Reviewed By: Date: New York State Standards and Specifications Page EA November 2016 For Erosion and Sediment Control APPENDIX F CONSTRUCTION SITE INSPECTION AND MAINTENANCE LOG BOOK STATE POLLUTANT DISCHARGE ELIMINATION SYSTEM FOR CONSTRUCTION ACTIVITIES SAMPLE CONSTRUCTION SITE LOG BOOK Table of Contents I. Pre-Construction Meeting Documents a. Preamble to Site Assessment and Inspections b. Pre-Construction Site Assessment Checklist IL Construction Duration Inspections a. Directions b. Modification to the SWPPP November 2016 Page F.1 New York State Standards and Specifications For Erosion and Sediment Control L PRE-CONSTRUCTION MEETING DOCUMENTS Project Name Permit No. Date of Authorization Name of Operator Prime Contractor a. Preamble to Site Assessment and Inspections The Following Information To Be Read By All Person's Involved in The Construction of Stormwater Re- lated Activities: The Operator agrees to have a qualified inspector'conduct an assessment of the site prior to the commence- ment of construction and certify in this inspection report that the appropriate erosion and sediment controls described in the SWPPP have been adequately installed or implemented to ensure overall preparedness of the site for the commencement of construction. Prior to the commencement of construction,the Operator shall certify in this site logbook that the SWPPP has been prepared in accordance with the State's standards and meets all Federal, State and local erosion and sediment control requirements. A preconstruction meeting should be held to review all of the SWPPP requirements with construction personnel. When construction starts, site inspections shall be conducted by the qualified inspector at least every 7 cal- endar days. The Operator shall maintain a record of all inspection reports in this site logbook. The site log- book shall be maintained on site and be made available to the permitting authorities upon request. Prior to filing the Notice of Termination or the end of permit term,the Operator shall have a qualified in- spector perform a final site inspection. The qualified inspector shall certify that the site has undergone final stabilization using either vegetative or structural stabilization methods and that all temporary erosion and sediment controls(such as silt fencing)not needed for long-term erosion control have been removed. In addition,the Operator must identify and certify that all permanent structures described in the SWPPP have been constructed and provide the owner(s)with an operation and maintenance plan that ensures the struc- ture(s) continuously functions as designed. 1 Refer to"Qualified Inspector"inspection requirements in the current SPDES General Permit for Stormwater Discharges from Construction Activity for complete list of inspection requirements. 2"Commencement of construction"means the initial removal of vegetation and disturbance of soils associated with clearing,grading or excavating activities or other construction activities. 3 "Final stabilization"means that all soil-disturbing activities at the site have been completed and a uniform,perennial vegetative cover with a density of eighty(80)percent has been established or equivalent stabilization measures(such as the use of mulches or geotextiles)have been employed on all unpaved areas and areas not covered by permanent struc- tures. November 2016 Page F.2 New York State Standards and Specifications For Erosion and Sediment Control b. Pre-construction Site Assessment Checklist (NOTE: Provide comments below as necessary) 1. Notice of Intent, SWPPP,and Contractors Certification: Yes No NA [] [] [] Has a Notice of Intent been filed with the NYS Department of Conservation? [ ] [] [] Is the SWPPP on-site?Where? [ ] [ ] [] Is the Plan current?What is the latest revision date? [] [] [] Is a copy of the NOI(with brief description)onsite?Where? [] [] []Have all contractors involved with stormwater related activities signed a contractor's certification? 2. Resource Protection Yes No NA [] [] []Are construction limits clearly flagged or fenced? [] [] [] Important trees and associated rooting zones,on-site septic system absorption fields,existing vegetated areas suitable for filter strips,especially in perimeter areas,have been flagged for protection. [] [] [] Creek crossings installed prior to land-disturbing activity,including clearing and blasting. 3. Surface Water Protection Yes No NA [] [] [] Clean stormwater runoff has been diverted from areas to be disturbed. [ ] [ ] [] Bodies of water located either on site or in the vicinity of the site have been identified and protected. [ ] [ ] []Appropriate practices to protect on-site or downstream surface water are installed. [ ] [ ] []Are clearing and grading operations divided into areas<5 acres? 4. Stabilized Construction Access Yes No NA [] [] [] A temporary construction entrance to capture mud and debris from construction vehicles before they enter the public highway has been installed. [ ] [] [] Other access areas(entrances,construction routes,equipment parking areas) are stabilized immediately as work takes place with gravel or other cover. [] [] [] Sediment tracked onto public streets is removed or cleaned on a regular basis. 5. Sediment Controls Yes No NA [] [] [] Silt fence material and installation comply with the standard drawing and specifications. [ ] [ ] [] Silt fences are installed at appropriate spacing intervals [ ] [ ] [] Sediment/detention basin was installed as first land disturbing activity. [ ] [ ] [] Sediment traps and barriers are installed. 6. Pollution Prevention for Waste and Hazardous Materials Yes No NA [] [] [] The Operator or designated representative has been assigned to implement the spill prevention avoidance and response plan. [ ] [] [] The plan is contained in the SWPPP on page [ ] [] []Appropriate materials to control spills are onsite. Where? November 2016 Page F.3 New York State Standards and Specifications For Erosion and Sediment Control II. CONSTRUCTION DURATION INSPECTIONS a. Directions: Inspection Forms will be filled out during the entire construction phase of the project. Required Elements: 1) On a site map, indicate the extent of all disturbed site areas and drainage pathways. Indicate site areas that are expected to undergo initial disturbance or significant site work within the next 14-day period; 2) Indicate on a site map all areas of the site that have undergone temporary or permanent stabilization; 3) Indicate all disturbed site areas that have not undergone active site work during the previous 14-day period; 4) Inspect all sediment control practices and record the approximate degree of sediment accumulation as a percentage of sediment storage volume (for example, 10 percent, 20 percent, 50 percent); 5) Inspect all erosion and sediment control practices and record all maintenance requirements such as verifying the integrity of barrier or diversion systems (earthen berms or silt fencing) and containment systems (sediment basins and sediment traps). Identify any evidence of rill or gully erosion occurring on slopes and any loss of stabilizing vegetation or seeding/mulching. Document any excessive deposition of sediment or ponding water along barrier or diversion systems. Record the depth of sediment within containment structures, any erosion near outlet and overflow structures, and verify the ability of rock filters around perforated riser pipes to pass water; and 6) Immediately report to the Operator any deficiencies that are identified with the implementation of the SWPPP. November 2016 Page FA New York State Standards and Specifications For Erosion and Sediment Control CONSTRUCTION DURATION INSPECTIONS Page 1 of SITE PLAN/SKETCH Inspector (print name) Date of Inspection Qualified Inspector (print name) Qualified Inspector Signature The above signed acknowledges that, to the best of his/her knowledge, all information provided on the forms is accurate and complete. November 2016 Page F.5 New York State Standards and Specifications For Erosion and Sediment Control CONSTRUCTION DURATION INSPECTIONS Page 2 of Maintaining Water Quality Yes No NA [ ] [ ] [] Is there an increase in turbidity causing a substantial visible contrast to natural conditions at the outfalls? [ ] [] [] Is there residue from oil and floating substances,visible oil film, or globules or grease at the outfalls? [] [] [] All disturbance is within the limits of the approved plans. [] [] [] Have receiving lake/bay, stream, and/or wetland been impacted by silt from project? Housekeeping 1. General Site Conditions Yes No NA [] [] [] Is construction site litter, debris and spoils appropriately managed? [] [] [] Are facilities and equipment necessary for implementation of erosion and sediment control in working order and/or properly maintained? [ ] [] [] Is construction impacting the adjacent property? [ ] L] L] Is dust adequately controlled? 2. Temporary Stream Crossing Yes No NA [] [] [] Maximum diameter pipes necessary to span creek without dredging are installed. [ ] [] [] Installed non-woven geotextile fabric beneath approaches. [ ] [] [] Is fill composed of aggregate (no earth or soil)? [ ] [] [] Rock on approaches is clean enough to remove mud from vehicles&prevent sediment from entering stream during high flow. 3. Stabilized Construction Access Yes No NA [ ] [] [] Stone is clean enough to effectively remove mud from vehicles. [ ] [] [] Installed per standards and specifications? [ ] [] [] Does all traffic use the stabilized entrance to enter and leave site? [ ] [] [] Is adequate drainage provided to prevent ponding at entrance? Runoff Control Practices 1. Excavation Dewatering Yes No NA [ ] [] [] Upstream and downstream berms (sandbags, inflatable dams, etc.) are installed per plan. [ ] [] [] Clean water from upstream pool is being pumped to the downstream pool. [ ] [] [] Sediment laden water from work area is being discharged to a silt-trapping device. [ ] [] [] Constructed upstream berm with one-foot minimum freeboard. November 2016 Page F.6 New York State Standards and Specifications For Erosion and Sediment Control CONSTRUCTION DURATION INSPECTIONS Page 3 of Runoff Control Practices (continued) 2. Flow Spreader Yes No NA [] [] [] Installed per plan. [ ] [] [] Constructed on undisturbed soil,not on fill,receiving only clear,non-sediment laden flow. [ ] [] [] Flow sheets out of level spreader without erosion on downstream edge. 3. Interceptor Dikes and Swales Yes No NA [] [] [] Installed per plan with minimum side slopes 2H:1 V or flatter. [] [] [] Stabilized by geotextile fabric, seed, or mulch with no erosion occurring. [] [] [] Sediment-laden runoff directed to sediment trapping structure 4. Stone Check Dam Yes No NA [] [] [] Is channel stable? (flow is not eroding soil underneath or around the structure). [] [] [] Check is in good condition(rocks in place and no permanent pools behind the structure). [] [] [] Has accumulated sediment been removed?. 5. Rock Outlet Protection Yes No NA [] [] [ ] Installed per plan. [] [ ] [ ] Installed concurrently with pipe installation. Soil Stabilization 1. Topsoil and Spoil Stockpiles Yes No NA [] [] [] Stockpiles are stabilized with vegetation and/or mulch. [] [] [] Sediment control is installed at the toe of the slope. 2. Revegetation Yes No NA [] [] [] Temporary seedings and mulch have been applied to idle areas. [] [] [] 4 inches minimum of topsoil has been applied under permanent seedings Sediment Control Practices 1. Silt Fence and Linear Barriers Yes No NA [] [] [] Installed on Contour, 10 feet from toe of slope (not across conveyance channels). [] [] [] Joints constructed by wrapping the two ends together for continuous support. [] [] [] Fabric buried 6 inches minimum. [ ] [] [] Posts are stable, fabric is tight and without rips or frayed areas. Sediment accumulation is % of design capacity. November 2016 Page F.7 New York State Standards and Specifications For Erosion and Sediment Control CONSTRUCTION DURATION INSPECTIONS Page 4 of Sediment Control Practices (continued) 2. Storm Drain Inlet Protection (Use for Stone&Block;Filter Fabric; Curb; or, Excavated; Filter Sock or Manufactured practices) Yes No NA [ ] [] [] Installed concrete blocks lengthwise so open ends face outward,not upward. [ ] [] [] Placed wire screen between No. 3 crushed stone and concrete blocks. [ ] [] [] Drainage area is Iacre or less. [ ] [] [] Excavated area is 900 cubic feet. [ ] [] [] Excavated side slopes should be 2:1. [ ] [] [] 2"x 4" frame is constructed and structurally sound. [ ] [] [] Posts 3-foot maximum spacing between posts. [ ] [] [] Fabric is embedded 1 to 1.5 feet below ground and secured to frame/posts with staples at max fl- inch spacing. [ ] [] [] Posts are stable, fabric is tight and without rips or frayed areas. [ ] [] [] Manufactured insert fabric is free of tears and punctures. [ ] [] [] Filter Sock is not torn or flattened and fill material is contained within the mesh sock. Sediment accumulation % of design capacity. 3. Temporary Sediment Trap Yes No NA [] [] [] Outlet structure is constructed per the approved plan or drawing. [ ] [] [] Geotextile fabric has been placed beneath rock fill. [ ] [] [] Sediment trap slopes and disturbed areas are stabilized. Sediment accumulation is % of design capacity. 4. Temporary Sediment Basin Yes No NA [] [] [] Basin and outlet structure constructed per the approved plan. [] [] [] Basin side slopes are stabilized with seed/mulch. [] [] [] Drainage structure flushed and basin surface restored upon removal of sediment basin facility. [] [] [] Sediment basin dewatering pool is dewatering at appropriate rate. Sediment accumulation is % of design capacity. Note: Not all erosion and sediment control practices are included in this listing. Add additional pages to this list as required by site specific design. All practices shall be maintained in accordance with their respective standards. Construction inspection checklists for post-development stormwater management practices can be found in Appendix F of the New York Stormwater Management Design Manual. November 2016 Page F.8 New York State Standards and Specifications For Erosion and Sediment Control CONSTRUCTION DURATION INSPECTIONS b. Modifications to the SWPPP (To be completed as described below) The Operator shall amend the SWPPP whenever: 1. There is a significant change in design,construction,operation,or maintenance which may have a significant effect on the potential for the discharge of pollutants to the waters of the United States and which has not otherwise been addressed in the SWPPP; or 2. The SWPPP proves to be ineffective in: a. Eliminating or significantly minimizing pollutants from sources identified in the SWPPP and as required by this permit; or b. Achieving the general objectives of controlling pollutants in stormwater discharges from permitted construction activity; and 3. Additionally,the SWPPP shall be amended to identify any new contractor or subcontractor that will implement any measure of the SWPPP. Modification &Reason: November 2016 Page F.9 New York State Standards and Specifications For Erosion and Sediment Control APPENDIX G TREE SPECIES FOR NEW YORK STATE CONTENTS Page List of Tables and Figures Trees Suitable for Landscape and Conservation Plantings in New York .........................................................................G.1 TreePlanting Procedure....................................................................................................................................................G.8 Susceptibility of Tree Species to Compaction .................................................................................................................G.9 Size and Weight of Earth Ball Required to Transplant Wild Stock .................................................................................G.9 List of Tables and Figures Table Title Page G.1 Trees Suitable for Landscape and Conservation Plantings in New York..............................................G.1 G.2 Susceptibility of Tree Species to Compaction ......................................................................................G.9 G.3 Size and Weight of Earth Ball Required to Transplant Wild Stock ......................................................G.9 Fi iffe Title Page G.1 New Tree Planting Procedure ...............................................................................................................G.8 Table G.1 Trees Suitable for Landscape and Conservation Plantings in New York Lit Sa.W Teiti f?.S-*i - Trers Ihar exceed Ihis Flo h+ordaanial bFwKNr4 hcishl al Malwilly. Nir:diurnSinniiTreea f-W 75'k.Trews in Lhj-LhGighr Smau SLUd r=cs f 13•-35'1-Trttt ttlarivelg luw haw omDidmpbloirig �1 mal+�rSlX �P�r�rrlr3lix VAR;(a) ■ warleiars of rhr spry■rc availaW. Py•pyramidal ror various UK$, RID.FOLIrrd E■cwergrcrn UP. IffiR C_Colorful iD[sill Win• wldwope o =JusArm.shiny D=&cidLmut Rom; (x) = buk hAs inter-estrrgg duLr*errri#[jq 4F d=dtr5s€ fir.t"luue nc f"M. v =ui at"I ht'awl FUt.W_fkvwm art rwRir?ul and iii-ibm plirg, f= fitt rtxtumd f g r mgmK s= 'y; SIRS TO L- NCF- u=urwsual shape. gold ■ h+arilly im roars b and I dslorthcasi;tnl moue- I•RU;(r<"F=frurL;srr irricrtesEi ng■r r;ir cdit. raiino LVS;.$S}= leaves have atdrs>,efiwc c4m arr`drur un. w+eL = folr=raMl aF sty wcu to s+amc+what usual shame. poorly drained mails. dry ■ tolerant of sandy, Fraw+elly, eaccu-lveLy WIND,W=suiUb6e Fay'*kx$re*h MW sr x=iq. rained sails. SFW�W■suitable as l win sh—wk tries. at4t=will Wknat ionle sh y siat . f;(K)=Irm oftsn selcoed for street planting— sea=laces wiwh my Wkreec sra pk-cmi7twu. W LJD; Rk=um of'eriri$faxori mid cover to w0d- cilly■lrm lhel wi hliluwl usual city condiim. lift. EESI: 14=!ream F mviding fax4 from frv6I*. FF=usually frec S- LiuvAplihle W&=Wtiof firing*irdfs`-w1rer- a� BARR;(K)=Urns wl1kh 9M be UMd alr a harrier lei -- - — si m traffic. Ha o=ttwral OuLpt of spur gr>awn p[arm. ORN',fX)=goes w•1105rt MIN Value is orrrarnanir]. Di;t broad dfoin("wi&) crtr Wlurnn.ar November 2016 Page G.1 New York State Standards and Specifications For Erosion and Sediment Control � z CD �L LAMA SrMb T tEE$(7$FL.) l�7 SITE TOLEA E --FEA7UgrLS umt.— o1 p'eGm ICxJ4 5cfF= PiWMT WAR FEE QXO`A+U DPW SMJOE Sa Cffv PEST RABIT BAK SLR FRU LWS 41PM%H STM TnL5WFiofIH eEECH.E1UROPMI I& x D.C,d j Py x x x F CD ¢- 04A itA� ¢ I.FIrVER 9u PV x x ¢. DOA&wo BLACK X D.-du x x x x x F x ¢- PMMA CIO OINKOO llu Dcm x F yfy x x x r-I ,BLACIK TUPELO w ojcLd,l x x py x HM;KOft-MNLrr 121Y Ox }[ Ro x n PICKOW.SHAO WUW 12(Y X ox K*w K x F x H€NEYL€]CUST I US X D,c,U x �{ F I3� x x cm VA �• ¢ �.EELKOVA w D0 Sutditt fA Ior Arrm~Eho RoCD h--+ GDZwhm abna N KAr-Q IPAw TREE w1 u'.c,w F Ro x x � f7 pp&-+rLmrD Q LINDC N,LrrTLIE-LEAF 93, x Q.d x x P� x x mTme la L E THEE i Io, 0 s x x xPfiew rAY �d ELF-FbM 1 2Q'° ,X U SO x )t x x x a A� MAPLF-RAW 120 x ox x or x x x OAK_Y*WTE 1� �,� RO.P5 X x F x 7q Abe ROPLAS,HyeAlD 2 w x Id xtrlm X x X PDP�.luq o POPLAR wHiTr= w x Dieu x x X 5 x x x c C �c�pu�us stsa C C4 4.-j SOEET-GUM 125: x D� F Pp• x x CD x f€uKlmrnb;r stynbuftdm c� z CD A,LAWK 3(ZEQ TRUS y7s n.-I y `D L EVER Afi "SPECIE P*PGHr VAR 9XAKQJj UM WET €:ArsHAW SEA 0" PAST MAW WK FLA MU LVS W*M gHbC 2TRf V M.V@AAA OAN � N O_ G1 CEOLM�,EASTERN FIGO Ed x x x E PY x x x JurRAWL& 4'r� • 5!9I?Fkku FII<1,GO.JGLAS "Y x IrA A7 fi P)r x voC_ x FIFL 1WHTE I } rD ON PiF xA w �'h ACM,SUROREAN v 4R' x D d x Syr x dopckm PINE. " .NY x E x Pv x W x � P61M n PINE,EUTRM WtffrE 1 CO-15# x e x, x F%'M PINE,1 W E x � WC CD P1 .pyrrrjlry. �-+ C) SPFVCE,NORWAY 150 x Ell x PY x x we O �� SPR410E,SEMALY X-d O Mad rrnorWs x x '•? SPRUCE,WHITE x E Pf Pk" X x k, CD o ' Thornless,seedless cultivars recommended x z Select male,non-root suckering,disease resistant cultivars �y C Note: It is not recommended to combine Colorado Blue Spruce or any other spruce with Douglas Fir in the same landscape design.Douglas Fir is an alternate host for the Cooley o' ¢ Spruce Gall Aphid. r. o � � o C y MEDMU sizEiD 17tFes 43w-P,sl O — y,TIE TCLE ANICC- RES LI Ew E, . I. 9caoL iS SPEC h! ECIFMPIT VAR FOUAGE COLD WET OW A effy PEbT HAMT WK � "Im Lvs w 5;VEST€I7`44'1L, amFii�N � 3 ALDER E41PaoPi�ow 75' D x xAhA � x >�. + CD ALDERS W-75' x ID4 x 9€ S P.6 M x ¢ ¢ AWAN M. A� CD CIO o ¢. O � � 5Er X x x x r Irnl� � w MGi,EUROPEANBIRO 4#' x Ddu x Go X.1 x F CH ePrwmm pn x x x x x k Pnrmm CD s Pmm ,+ ' �U,d % I�.■dri O CAMIA E. ,wy w x O,-d x wat x,l x F x O M"bomm CF4MEAM l■4®EH W x 0,1x I PM 7R, x C � DOGWOW.FLOWERING 4Cr X C,q�d,l F Hd x Y,u x x x X � �r A�rldr O ELM.SIBERIAN IV x Doi x p x � I ,+e b HAVOTHWH- x r�,e� x s pillis x :x x X X Crate www HORNBEAM.ELMOPEM W x Ing p x X . (a-7mut mar F+DRN��b v.HAIR 4w DA F PY 0 0%s-ya x x c x k' �D C CD N 01 z y CD CD� F rl� d!' 4_FirD VAA P`OLL Lf;�WET DWSHADF 4V-A CRY Pf9r HAW AM FI,FI FRV LVO WVC&1� CM w&OamR Om � N O c JAPANTM PAOO k THEE M x 0 x F RO x x x x x �. MAPU.$MIP'EID 3r x D.Y It x Op x x x rD A1*PwwOwkUM O MOLWAW-ksm.EUNDPFm 45' x D S $ x x x F x 01 S6rfaa IdIP r S � xOAEM w x DA P}fia x x x of M.YwrTE 445' X DA'LIx x RO x M F Mbhmk MACAK�RED n ei t rtfil� 7T DAJ x x Ro x x X k p CkwWOrD Cr Mit ri w DA x x R&A3,o x p 0--w CD C) w x Ckd x d0" O.W so x x x CD x x S 6 lL lL 1L x F x o SORRELTRIEE ?T DEC N P� 14 7L x x b v� V L,LOW,7Ff11 ko w WEEP1ha 4Cr I}•I x S PG x XSLPk fCD �. o of LLO W'.1' HTTE ?V 0 x x up COW"ww InNK"t x � 'Y€tL W x ID,r,d x f4o- �[ x x x �• � a. C4rrJras`:a L,rea � CD a ' Spreads rapidly by root suckers z Spreads rapidly by root suckers,do not plant near Pine Barrens ecosystems CD CD o P71 o C y W WEDFJM QEDTRIEE3 Pf'-75) 0 0 ��-•�IY�T�}L�PI�I�E- .F+E'�L�II — U6Efa��•--� CD p EWE31GREEW=PAS +[; EiY VAn Ft?a A.r;F QQW Yr;7: DFLYWUME SEA CrTY PEST MA T SM FLR FM LVS WIND SME$TRT'WXD PIOAN � ¢- CD AMOAVrAE.AP4ACJWy dQ ]G E,v x 5[ ' x GO we x cn CD v� ¢' ¢ FlLq,MCREAM $ E,d CD err ¢ Fin.VEITCW 75' E,C }i F)r x x Abim voa:rm O oCIO a HEMjDCJK,CAAOLIkA 7F E,d x P'VN x x WrG x 01 7:D� T .r r, PINE. m x x BO Fnrr� y � o NNS,MCM m :E x w ¢ PINE-IRED7W G x x P'Y x we PagE..SCOTCH m x E x x opry x x 10 PINE, $67QNE 35' Exr x Fhys wocx ¢, QQ Pnm umbraCD 'y 1 17 SPRUCE,BLACK 50' E,d X X X Co X WC ~ � � n SPRUCE,BLACK HILLS 75' E,d X X F Co X WC CD CD O b �Q o � C O c� z CD c C.SWLL Slav,-aIEE5OV-M *-Ui'E ToLEfUU%ICE --•FE.STt1RErs- --ts----- rD N ]IXLQdd.us SPELEB HFiGHT wAFS€1X41 GC COLD WU QflY$HAM" VA(;ffV PEST Fw4BYT BnK F`LA WSJ L A 1YN-0 50CE STRT WILD AFIR OR14 � o � eaRC:H.GRAY D x x !* qKr41J A x x popwrokh Wig eLACKHAW w D.C.1 x m Y x x F x vim^'prVadgik- rD GHEAFY.C4ANCLIM 24: x D,1 F Fo x x x F O CF4914pty.WVA -V x 0 x Ra x x F x r Pruma oer■sus COW TREE,AmuR B x wa x x x � Phokx%wKww arnur■r m ¢, CPARLMPLES ITw B x 8 R4 Y,i x x F MAkd a* �, y DOGWOOD.JAf'ANESE 20 x 0,4,1 He X.i x X x � A� FukarTr ms Is:.34 x 15,a x x S fR brr3ny x x x x F x p � D cart■■UL.es RV LABURMJM SCOTCH 317' x D U X U X.CD C La Ll4.il.:J'.JAPANESE TREE 31Y D M x,u x . C MAPL1 MO4[VAN SW 4.Co X X Cur x X x AMr&pWAhArn �+• CDMWNTAIN�AS i,SF� 30, x D x S x x x 4ebui dew o M4f•?+NYELERIRY X, Gir-1 'x x 40w6f :x x x x F x x RFKXXNXMDRON, WAY lz,-3w x E xCD F&*30*V00n RA—UM }� k -SEA A-B 6KZ7HGRK,COMMON 3V x x Fkkea x x CDCD CD �- � � o � � Figure G.1 New Tree Planting Procedure SoUrre; ffrbfin Fug E LM Al IVN� .` f oylFAmeekan Fo ejoyAsiocimiun. 41 The Old terry r . the nErw rnerh wl all UGe*rMN will!MWO in I:KRrjr nr1,ival an6 groMte than llm flld method. Grass[AxnpeIi- tiqn ILrd sod compactI ate two atThe mm(-comm n laO In pw pedcmWnce Thg NOrw 1 BLNXII: Prepare ip plarnJny area 1Ies aittM"diameter of the foa ball or mntalm-r. IDS,s rolcAi er a '4x spades 10 I Find mix the"to o o(a l 12 Incl . OrQa6r- ma[ler [well deconposm can W added. Dig a Wo in ilia-corner to set 1 e try 6o th;pl ahG rM b-111 w M rC5:l.on t6id grour3d Backfill iumr4 lM r"erect., pressZing the so! bqff,ancA packrg 1. MtAnh the renlire prepared area wdh 2 to d I hes od ba rk,wccd ch ps. �� �'•'�d+��i. Iwo$. R�i� �►the af�iiGle'far a��orpilarwal inn. New York State Standards and Specifications Page G.8 November 2016 For Erosion and Sediment Control Table G.2 Susceptibility of Tree Species to Compaction' Resistant: Box elder.................. Acer negundo Willows..................... Salix spp. Green ash................. Fraxinus pennsylvanica Honey locust............... Gleditsia triacanthos Red elm.................... Ulmus rubra Eastern cottonwood....... Populus deltoides Hawthornes............... Crataegus spp. Swamp white oak.......... Quercus bicolor Bur oak.................... Quercus macrocarpa Hophombeam...............Ostrya virginiana Northern white cedar.... Thuja occidentalis Intermediate: Red maple................ Acer rubrum Sweetgum...................Liquidambar styrac flua Silver maple.............. Acer saccharinum Norway maple............. Acer platanoides Hackberry................ Celtis occidentalis Shagbark hickory.......... Carya ovata Black gum............... Nyssa sylvatica London plane.............. Platanus x hybrida Red oak.................. Quercus rubra Pin oak...................... Quercus palustris Basswood................ Tilia americana Susceptible: Sugar maple................ Acer saccharum Austrian Pine............... Pinus nigra White pine.................. Pinus strobus White ash................... Fraxinus americana Blue spruce................. Picea pungens Paper birch................. Betula papyrifera White oak.................. Quercus alba Moutain ash................ Sorbus aucuparia Red pine.................... Pinus resinosa Japanese maple............ Acer palmatum 'If a tree species does not appear on the list,insufficient information is available to rate it for this purpose. Table G.3 Size and Weight of Earth Ball Required to Transplant Wild Stock Shadc Trm SawlL Tfce$&Stnbs (MapLc, Ash,00c, birch,etc_) (Crabeppla,'Tome Le.lfibumLimF w*W.etc.) Mi ni rmv in UP ID 6 ft. h+llnimnm [3ianmler WtIN Iimghl— Nallkrer wei calipul Batt of Ball �ft. Uld Ball of Ball �i� lnetms LLLMJ 12 14 $8 2 12 65 3M 16 LX 3 14 $8 I Is L86 4 16 134 L-114 20 Z27 S 19 L M l An 22 X2 3J4 18 L96 1-V4 24 390 1 2D 227 L I�� 3 32 113,6 1-314 24 3 3-1( is L.400 2 2A 611 4 42 L,897 2-1/2 32 9�6 3 39 L,ADG I Cali per is a diameter measurerneini Cif Utes M a h6ghr of 6 inches bhart ifs graulnd. (American Standards for Nursery Stock) November 2016 Page G.9 New York State Standards and Specifications For Erosion and Sediment Control APPENDIX H GLOSSARY The list of terms that follows is representative of those used by soil conservationists,soil scientists,engineers,developers, contractors,planners,etc. The terms are in common use in conservation matters. ACCESS ROAD-A road or vehicular travel way velocities less than the surrounding flow. constructed to provide needed access to a site. BENCH MARK- ACRE-FOOT-The volume of a substance,such as water, that will cover 1 acre to a depth of 1 foot. (economics)-Data for a specific time period that is used as a base for comparative purposes with comparable data. AESTHETIC VALUE-The increase in value of a property derived from such intangible factors as its inherent (engineering)-A point of reference in elevation surveys. attractiveness,its access to attractive views,or its general appeal to the sense of beauty of the owner or purchaser. BERM-A shelf that breaks the continuity of a slope. AMORTIZATION-To repay a debt in a sequence of BLIND-Placement of loose soil around a tile or conduit to equal payments. Part of each payment is used to pay the prevent damage or misalignment when the trench is interest due at the time it is made,and the balance is applied backfilled. Allows water to flow more freely to the tile. to the reduction of the principal. BLIND DRAIN-A type of drain consisting of an ANGLE OF REPOSE-Angle between the horizontal and excavated trench refilled with pervious materials,such as the maximum slope that a soil assumes through natural coarse sand,gravel or crushed stone,where water percolates processes. through the voids and flows toward an outlet. Often referred to as a French drain because of its initial ANTECEDENT MOISTURE CONDITION(AMC)- development and widespread use in France. The degree of wetness of a watershed at the beginning of a storm. BLIND INLET-Inlet to a drain in which entrance of water is by percolation rather than open flow channels. APRON-A floor or lining to protect a surface from erosion;for example,the pavement below chutes,spillways, BRUSH LAYERING-The embedment of green branches or at the toes of dams. of shrub or tree species,perpendicular to the slope,on successive horizontal rows or contours. ASSESSED VALUE-The value placed on property for taxation purposes. BRUSH-MATTING-A blanket,or covering,of hardwood brush fastened down with stakes and wire. ASSOCIATED COSTS-A term commonly used in water resource development projects. These costs include the a -abbreviation for cubic feet per second. A unit of w value of goods and services needed over and above project Water flow. costs to make the immediate products or services of a project available for use or sale. CAPITAL RECOVERY PERIOD-The period of time required for the net returns from an outlay of capital to BASE FLOW-The stream discharge from groundwater equal the investment. runoff. CAPITALIZED COST-The first cost of an asset plus the BEDDING-The process of laying a drain or other present value of all renewals expected within the planning conduit in its trench and tamping earth around the conduit horizon. to form its bed. The manner of bedding may be specified to CHANNEL-A natural stream that conveys water;a ditch conform to the earth load and conduit strength. or channel excavated for the flow of water. BEDLOAD-The sediment that moves by sliding,rolling, CHANNEL IMPROVEMENT-The improvement of the or bounding on or very near the streambed;sediment moved flow characteristics of a channel by clearing,excavation, mainly by tractive or gravitational forces or both,but at realignment,lining,or other means in order to increase its capacity. Sometimes used to connote channel stabilization. November 2016 Page H.1 New York State Standards and Specifications For Erosion and Sediment Control 2. The summit of a wave or peak of a flood. CHANNEL STABILIZATION-Erosion prevention and stabilization of velocity distribution in a channel using CRITICAL SITE-A sediment producing,highly erodible, jetties,drops,revetments,vegetation,and other measures. or severely eroded area or site. COMPACTION-To unite firmly;the act or process of CRITICAL VELOCITY-Velocity at which a given becoming compact,usually applied in geology to the discharge changes from tranquil to rapid flow;that velocity changing of loose sediments into hard,firm rock. With in open channels for which the specific energy(sum of the respect to construction work with soils,engineering depth and velocity head)is a minimum for a given compaction is any process by which the soil grains are discharge. rearranged to decrease void space and bring them into closer contact with one another,thereby increasing the CROSS-SECTION-A drawing that shows the features weight of solid material per cubic foot. that would be exposed by a vertical cut through a man-made or natural structure or area. CONDUIT-Any channel intended for the conveyance of water,whether open or closed. CROWN(forestry)-The upper part of a tree,including the branches and foliage. CONIFER-A tree belonging to the order of Coniferea, usually evergreen,with cones and needle-shaped or scale- CUBIC FOOT PER SECOND-Rate of fluid flow at like leaves and producing wood known commercially as which 1 cubic foot of fluid passes a measuring point in 1 "soft wood". second.(Abbr.cfs.)(Syn. Second-foot; CUSEC.)See cfs. CONSERVATION-The protection and improvement of CUT-Portion of land surface or area from which earth has natural resources. been removed or will be removed by excavation;the depth below original ground surface to excavated surface. CONSERVATION DISTRICT-A public organization created under state enabling law as a special purpose district CUT-AND-FILL-Process of earth moving by excavating to develop and carry out a program of soil,water,and part of an area and using the excavated material for adjacent related resource conservation,use,and development within embankment or fill areas. its boundaries;usually a subdivision of state government with a local governing body and always with limited CUTOFF- authorities. Often called a soil conservation district or a soil and water conservation district. 1. Wall,collar,or other structure,such as a trench,filled with relatively impervious material intended to reduce CONTOUR- seepage of water through porous strata. 1. An imaginary line on the surface of the earth 2. In river hydraulics,the new and shorter channel formed connecting points of the same elevation. either naturally or artificially when a stream cuts through the neck of a band. 2. A line drawn on a map connecting points of the same elevation. DEBRIS DAM-A barrier built across a stream channel to retain rock,sand,gravel,silt,or other material. CONTOUR INTERVAL-The vertical distance between contour lines. DEBRIS GUARD-Screen or grate at the intake of a channel,draine,or pump structure for the purpose of CONTOUR MAP-A map that shows the shape of the preventing debris from entering. surface features of the ground by the use of contours. DECIDUOUS PLANT-A plant that sheds all of its leaves CONTOUR WATTLING-The packing of lengths of every year at a certain season. bundles of twigs or tree whips into a continuous length, DEGRADATION-To wear down by erosion,especially partially buried across a slope at regular contour intervals through stream action. and supported on the downhill side by stakes. DEPOSIT-Material left in a new position by a natural CREST- transporting agent,such as water,wind,ice,or gravity,or by the activity of man. 1. The top of a dam,dike,spillway,or weir, or other water barrier or control. DESIGN STANDARDS-Standards of construction November 2016 Page H.2 New York State Standards and Specifications For Erosion and Sediment Control governing the size,shape,and relationship of spaces in any given point. The area may be of different sizes for surface structure,which will control soil erosion and sedimentation. runoff,subsurface flow and base flow,but generally the surface runoff area is used as the drainage area. See DESIGN STORM-A given rainfall amount,areal watershed. distribution,and time distribution,used to estimate runoff. The rainfall amount is for a given frequency(25-year,50- DRAINAGE DISTRICT-A cooperative,self-governing year,etc.). public corporation created under state law to finance, construct,operate,and maintain a drainage system DE-SILTING AREA-An area of grass,shrubs,or other involving a group or land holding. vegetation used for inducing deposition of silt and other debris from flowing water,located about a stream,pond, DROP-INLET SPILLWAY-Overfall structure in which field,or other area needing protection from sediment the water drops through a vertical riser connected to a accumulation.See Filter Strip. discharge conduit. DETENTION DAM-A dam constructed for the purpose DROP SPILLWAY-Overfall structure in which the water of temporary storage of stream flow or surface runoff and drops over a vertical wall onto an apron at a lower for releasing the stored water at controlled rates. elevation. DIKE-An embankment to confine or control water, DROP STRUCTURE-A structure for dropping water to a especially one built along the banks of a river to prevent lower level and dissipating surplus energy;a fall. A drop overflow of lowlands;a levee. may be vertical or inclined. DISCHARGE-Rate of flow,specifically fluid flow;a EFFLUENT- volume of fluid passing a point unit time,commonly expressed as cubic feet per second,million gallons per day, 1. The discharge or outflow of water from ground or gallons per minutes,or cubic meters per second. subsurface storage. DISCHARGE FORMULA(hydraulics)-A formula to 2. The fluids discharged from domestic,industrial,and calculate rate of flow of fluid in a conduit or through an municipal waste collection systems or treatment opening. For steady flow discharge,Q=AV,wherein Q is facilities. rate of flow,A is cross sectional area,and V is mean velocity. Common units are: Q=cubic feet per second, ERODIBILITY(OF SOIL)-The'K'value in RUSLE A=square feet,and V=feet per second,respectively. To expresses the average long-term soil and soil profile calculate the mean velocity,V,for uniform flow in pipes or response to the erosive powers of rain storms. open channels,see Manning's formula. EROSION-The wearing away of the land surface by DIVERSION-Channel constructed across the slope for the running water,wind,ice,or other geological agents, purpose of intercepting surface runoff,changing the including such processes as gravitational creep. accustomed course of all or part of the surface water drainage path. See Terrace. a. GULLY EROSION-The erosion process whereby water accumulates in narrow channels DIVERSION TERRACE-Diversions,which differ from and,over short periods,removes the soil from this terraces in that they consist of individually designed narrow area to considerable depths,ranging from 1 channels across a hillside;may be used to protect to 2 feet to as much as 75 to 100 feet. bottomland from hillside runoff or may be needed above a terrace system for protection against runoff from an un- b. RILL EROSION-An erosion process in which terraced area. They may also divert water out of active numerous small channels only a few inches deep gullies,protect farm buildings from runoff,reduce the are formed;occurs mainly on recently cultivated number of waterways,and are sometimes used in soils. See Rill. connection with strip cropping to shorten the length of slope c. SHEET EROSION-The removal of a fairly thin, so that the strips can effectively control erosion. See uniform layer of soil from the land surface by Terrace. runoff water. DRAINAGE-The removal of excess surface water or EROSIVITY(OF SOIL)-The'R'value in RUSLE groundwater from land by means of surface or subsurface expresses the interrelationships of the raindrop energy times drains. DRAINAGE AREA-The area draining into a stream at a November 2016 Page H.3 New York State Standards and Specifications For Erosion and Sediment Control the 30-minute rainfall intensity. average,be equal to or less than a given size or magnitude. EUTROPHICATION-A means of aging lakes whereby FUNCTIONAL PLAN-A plan for one element,or closely aquatic plants are abundant and waters are deficient in related elements of a comprehensive plan,for example, oxygen. The process is usually accelerated by enrichment transportation,recreation,and open spaces.Such plans,of of waters with surface runoff containing nitrogen and necessity,should be closely related to the land use plan. phosphorus. Plans that fall short of considering all elements of a comprehensive plan may be considered as functional plans. EVAPOTRANSPIRATION(ET)-Plant transpiration Thus,resource conservation and development plans and plus evaporation from the soil. Difficult to determine watershed project plans should be considered as functional separately,therefore used together as a unit for study. plans. FALLOW-Cropland plowed,but not seeded during one or GABION-A galvanized wire basket filled with stone used more growing seasons;cropland left idle may be a normal for structural purposes. When fastened together,gabions part of the cropping system for weed control,water are used as retaining walls,revetments,slope protection and conservation,soil conditioning,etc. similar structures. FILTER STRIP-Strip of permanent vegetation designed GRADE STABILIZATION STRUCTURE-A structure to retard flow of runoff water,causing deposition of for the purpose of stabilizing the grade of a gully or other transported material,thereby reducing sediment flow. See watercourse,thereby preventing further head-cutting or Desilting Area. lowering of the channel grade. FINISHED GRADE-The final grade or elevation of the GRASSED WATERWAY-A natural or constructed ground surface conforming to the approved grading plan. waterway,usually broad and shallow,covered with erosion resistant grasses,used to conduct surface water;can reduce FLOOD FRINGE-That portion of the floodplain subject velocity and filter water. only to shallow inundation and low velocity flow of flooding water. GRAVEL ENVELOPE-Selected aggregate placed around the screened pipe section of well casing or a FLOODPLAIN-Normally dry land areas subject to subsurface drain to facilitate the entry of water into the well periodic,temporary inundation by stream flow or tidal or drain. overflow. Land formed by deposition of sediment by water; alluvial land. GRAVEL FILTER-Graded sand and gravel aggregate placed around a drain or well screen to prevent the FLOODPLAIN MANAGEMENT-The wise use of movement of fine materials from the aquifer into the drain floodplains so as to reduce human suffering,property or well. damage,and habitat loss resulting from floods and to lessen the need for expensive flood control structures,such as GRUBBING-The removal of stumps and root material dams and reservoirs. from the soil mantle. FLOODWAY-That portion of the floodplain required to GULLY-A channel or miniature valley cut by store and discharge floodwaters without causing significant concentrated runoff but through which water commonly damaging,or potentially damaging,increases in flood flows only during and immediately after heavy rains or heights and velocities. during the melting of snow. A gully may be dendritic or branching or it may be linear,rather long,narrow,and of FREEBOARD(hydraulics)-Vertical distance between uniform width.The distinction between gully and rill is one the maximum water surface elevation anticipated in design of depth. A gully is sufficiently deep that it would not be and the top of restraining banks or structures provided to obliterated by normal tillage operations,whereas a rill is of prevent overtopping because of unforeseen conditions. lesser depth and would be smothered by ordinary tillage or low impact grading. FREQUENCY-An expression or measure of how often a hydrologic event of given size or magnitude should,on the HARDPAN-A hardened soil layer in the lower A or in the average,be equaled or exceeded.For example,a 50-year B horizon caused by cementation of soil particles with frequency flood should be equaled or exceeded in size,on organic matter,or with materials such as silica, the average,only once in 50 years. In drought or deficiency sesquioxides,or calcium carbonate. The hardness does not studies,it usually defines how many years will,on the November 2016 Page H.4 New York State Standards and Specifications For Erosion and Sediment Control change appreciably with changes in moisture content,and pieces of the hard layer do not slake in water. HYDROLOGIC SOIL GROUP-A group of soils having the same runoff potential under similar storm and cover HIGHWAY EROSION CONTROL-The prevention and conditions. control of erosion in ditches,at cross drains,and on fills and road banks within a highway right-of-way. Includes HYDROLOGY-The science that deals with the vegetative practices and structural practices. occurrence and movement of water in the atmosphere,upon the surface,and beneath the land areas of the earth. HOOD INLET-Entrance to a closed conduit that has been Rainfall intensities,rainfall interception by trees,effects of shaped to induce full flow at minimum water surface crop rotation on runoff,floods,droughts and the flow of elevation. springs and wells,are some of the topics studied by a hydrologist. HORIZONS,MINERAL SOIL- HYDROSEEDING-The dissemination of seed A horizons are surface layers hydraulically in a liquid medium;mulch,lime,and fertilizer B horizons are subsoil horizons '.They are designated can be incorporated into the sprayed mixture. as follows: IMPERVIOUS SOIL-A soil through which water,air • B alone indicates some residual transformation or roots cannot penetrate. No soil is impervious to water or change in place,such as color. and air without significant impact or compaction. • Bt indicates accumulations of translocated clay. IMPOUNDMENT-Generally,an artificial collection or Bx indicates a B horizon with fragipan storage of water,as a reservoir,pit,dugout,sump,etc. characteristics such as firmness,brittleness and high density. INDUSTRIAL PARK-A tract of land,the control and administration of which are vested in a single body,suitable C horizons are substrata layer';they consist of mineral for industrial use because of location,topography,proper material like or unlike the material from which the A& zoning,availability of utilities,and accessibility to B horizons have formed and have been little affected transportation. by soil forming process.They are designated as follows: INFILTRATION-Rainfall minus interception, evaporation,and surface runoff.The part of rainfall that • C alone indicates material like the material from enters the soil. which the A&B horizons have formed. INFILTRATION RATE-A soil characteristic • Cx indicates a C horizon of material like that of determining or describing the maximum rate at which water the A&B horizons but has the firm,brittle and can enter the soil under specified conditions,including the dense characteristics of a fragipan. presence of an excess of water. 'Roman numerals are prefixed to the appropriate horizon INITIAL ABSTRACTION(Ia)-When considering designations such as IIB,IIBt,IIBx,and IIC or IICx when surface runoff,Ia is all the rainfall before runoff begins. it is necessary to number a series of layers of unlike or When considering direct runoff,Ia consists of interception, contrasting material from the surface downward. evaporation and the soil-water storage that must be Claverack is an example in which the A&B horizons exhausted before direct runoff may begin. have formed in sand and the underlying material is contrasting silty clay that is indicated as a IIC horizon. INOCULATION(OF SEEDS)-The addition of nitrogen fixing bacteria(inoculant)to legume seeds or to the soil in HYDRAULIC GRADE LINE-In a closed conduit,a line which the seeds are to be planted;the bacteria take free joining the elevations to which water could stand in risers of nitrogen from the air and make it available to the seeds. vertical pipes connected to the conduit at their lower end INTERCEPTION-Precipitation retained on plant or plant and open at their upper end. In open channel flow,the residue surfaces and finally absorbed,evaporated,or hydraulic grade line is the free water surface. sublimated. That which flows down the plant to the ground HYDROGRAPH-A graph showing stage,flow,velocity, is called"stem flow"and not counted as true interception. or other property of water with respect to time. INTERMITTENT STREAM-A stream,or portion of a stream,that flows only in direct response to precipitation. It HYDROLOGIC SOIL COVER COMPLEX-A receives little or no water from springs and no long term combination of a hydrologic soil group and a type of cover. November 2016 Page H.5 New York State Standards and Specifications For Erosion and Sediment Control continued supply from melting snow or other sources. The other materials,such as sand or paper,on the soil surface. stream,or channel,is dry for some part of the year,usually during the dry months. NETTING-Plastic,paper,cotton,or other material used to hold mulch on the soil surface. ISO-ERODENT VALUE-A term used to correlate areas of equally erosive average annual rainfall. OUTLET-Point of water disposal from a stream,river, lake,tidewater,or artificial drain. LANDSCAPE-All the natural features,such as fields, hills,forests,water,etc.,that distinguish one part of the PARTICLE SIZE CLASSES FOR FAMILY earth's surface from another part,usually that portion of GROUPINGS(as used in the Soil Classification System land or territory which the eye can comprehend in a single of the National Cooperative Soil Survey in the United view,including all of its natural characteristics. States)-Various particle size classes are applied to arbitrary control sections that vary according to the depth of LIME,AGRICULTURAL-A soil amendment consisting the soil,presence or absence of argillic horizons,depth to principally of calcium carbonate,but including magnesium paralithic or lithic contacts,fragipans,horizons. No single carbonate and perhaps other materials,used to furnish set of particle size classes is appropriate as a family calcium and magnesium as essential elements for the grouping for all kinds of soil. The classification tabulated growth of plants and to neutralize soil acidity. below provides a choice of several particle size classes. LINING-A protective covering over all or part of the 1. Sandy-Skeletal-More than 35 percent,by volume, perimeter of a reservoir or a conduit to prevent seepage coarser that 2 millimeters,with enough fines to fill losses,withstand pressure,resist erosion,and reduce interstices larger than 1 millimeter;fraction less than 2 friction or otherwise improve conditions of flow. millimeters is as defined for the sandy class. 2. Loamy-Skeletal-More than 35 percent,by volume, LIVE STAKING-Utilizing vegetative cover for the coarser that 2 millimeters,with enough fines to fill control of erosion and shallow sliding by means of willow interstices larger than 1 millimeter;fraction less than 2 or poplar cuttings that root easily and grow rapidly under millimeters is as defined for loamy classes. certain conditions. 3. Sandy-Sands,except very fine sand,and loamy sands, MANNING'S FORMULA(hydraulics)-A formula used except loamy very fine sand. to predict the velocity of water flow in an open channel or pipeline: 4a. Coarse Loamy-With less than 18 percent clay and more than 15 percent coarser than very fine sand V=[(1.486)(r73)(s'2)]/n (including coarse fragments up to 7.5 centimeters). Where: 4b. Fine-Loamy-With more than 18 percent clay but less V=the mean velocity of flow in feet per second; than 35 percent clay and more than 15 percent coarser than very fine sand(including coarse fragments up to r=the hydraulic radius; 7.5 centimeters). s=the slope of energy gradient or,for assumed 4c. Coarse-Silty-With less than 18 percent clay and less uniform flow,the slope of the channel in feet per foot; than 15 percent coarser than very fine sand(including and coarse fragments up to 7.5 centimeters). n=the roughness coefficient or retardance factor of the channel lining. 4d. Fine-Silty-With more than 18 percent clay and less than 35 percent clay and less than 15 percent coarser than very fine sand(including coarse fragments up to 7.5 centimeters). MUCK SOIL- Sa. Fine-With more than 35 percent clay but less than 60 1. An organic soil in which the organic matter is well percent clay. decomposed(USA usage). 5b. Very-Fine-With more than 60 percent clay. 2. A soil containing 20 to 50 percent organic matter. PEAK FLOW-The maximum instantaneous flow of water MULCH-A natural or artificial layer of plant residue or from a given storm condition at a specific location. November 2016 Page H.6 New York State Standards and Specifications For Erosion and Sediment Control area that is discharged from the area in stream channels. PEAT-Dark brown residual material produced by the Types include surface runoff,groundwater runoff,or partial decomposition and disintegration of plants that grow seepage. in wet places. RUNOFF CURVE NUMBER(CN)-A parameter PERMEABILITY-The quality of a soil horizon that combining the effects of soils,watershed characteristics, enables water or air to move through it. Terms used to and land use. This parameter represents the hydrologic soil describe permeability are as follows:very slow,slow, cover complex of the watershed. moderately slow,moderate,moderately rapid,rapid,and very rapid. RUSLE-Abbreviation for Revised Universal Soil Loss Equation;used to estimate sheet and rill soil loss on pH-A numerical measure of the acidity or alkalinity of a potentially erosive sites. soil;neutral soil has a pH of 7;all pH values below 7 are acid,and all above 7 are alkaline. SCALPING-Removal of sod or other vegetation in spots or strips. PLANNED UNIT DEVELOPMENT-A zoning classification permitting flexibility of site design by SCARIFY-To abrade,scratch,or modify the surface;for combining building types and uses in ways that would be example,to scratch the impervious seed coat of hard seed or prohibited by traditional zoning standards. to break the surface of the soil with a narrow-bladed implement. PLAT OF SURVEY-A scaled drawing identifying a parcel of real estate,prepared by a registered surveyor, SEDIMENT-Solid material,both mineral and organic, including a legal description of the property and the that is in suspension,is being transported,or has been dimensions of the physical improvements. moved from its site of origin by air,water,gravity,or ice and has come to rest on the earth's surface either above or RAINFALL INTENSITY-The rate at which rain is below sea level. falling at any given instant,usually expressed in inches per hour. SEDIMENT BASIN-A basin or pond designed to store a calculated amount of sediment being transported on a site. RECP-Rolled erosion control products.These are manufactured rolls of material used to protect slopes and/or SEDIMENT DISCHARGE-The quantity of sediment, waterways by resisting flow and aiding vegetation. measured in dry weight or by volume,transported through a stream cross-section in a given time. Sediment discharge RETARDANCE(vegetation)-The characteristic of the consists of both suspended load and bedload. vegetative lining of a channel that tends to restrict and impede flow relative to a perfectly smooth channel. SEEDBED-The soil prepared by natural or artificial means to promote the germination of seed and the growth of RETURN FLOW-That portion of the water diverted from seedlings. a stream which finds its way back to the stream channel either as surface or underground flow. SEEPAGE- REVETMENT-Facing of stone or other material,either 1. Water escaping through,or emerging from,the ground permanent or temporary,placed along the edge of a stream along an extensive line or surface,as contrasted with a to stabilize the bank and to protect it from the erosive action spring where the water emerges from a localized spot. of the stream. 2. The process by which water percolates through the soil. RIPARIAN RIGHTS-The rights of an owner whose land abuts water. They differ from state to state and often 3. (percolation)The slow movement of gravitational depend on whether the water is a river,lake or ocean. See water through the soil. Water Rights. RIPRAP-Broken rock,cobbles,or boulders placed on SETTLING BASIN-An enlargement in the channel of earth surfaces,such as the face of a dam or the bank of a a stream to permit the settling of debris carried in stream,for protection against the action of water(waves); suspension. also applied to brush or pole mattresses,or brush and stone, or other similar materials used for soil erosion control. SHRINK-SWELL POTENTIAL-The susceptibility of soil to volume change due to loss or gain in moisture RUNOFF-That portion of the precipitation on a drainage content. November 2016 Page 11.7 New York State Standards and Specifications For Erosion and Sediment Control STATE SOIL AND WATER CONSERVATION SHRUB-A woody perennial plant differing from a COMMITTEE,COMMISSION,OR BOARD-The state perennial herb by its more woody stems and from a tree by agency established by state soil conservation districts, its low stature and habit of branching from the base. There enabling legislation to assist with the administration of the is no definite line between herbs and shrubs or between provisions of the state soil conservation districts law. The shrubs and trees;all possible intergradations occur. official title may vary from the above as new,or amended, state laws are made. SIDE SLOPES(engineering)-The slope of the sides of a canal,dam,or embankment. It is customary to name the STILLING BASIN-An open structure or excavation at horizontal distance first,as 1.5 to 1,or frequently, 1-1/2:1, the foot of an overfall,chute,drop,or spillway to reduce the meaning a horizontal distance of 1.5 feet to 1 foot vertical. energy of the descending stream. SITE ANALYSIS-Evaluation of the qualities and STREAMBANKS-The usual boundaries,not the flood drawbacks of a site by comparison with those aspects of boundaries,of a stream channel. Right and left banks are other comparable sites. named facing downstream. SOIL EROSION AND SEDIMENT CONTROL PLAN- STRATA CAPACITY-The maximum amount of material A plan which fully indicates the necessary land protection a stream is able to transport. and structural measures,including a schedule of the timing of their installation,which will effectively minimize soil STREAM LOAD-Quantity of solid and dissolved erosion and sediment yields. material carried by a stream. See Sediment Load. SOIL STRUCTURE-The arrangement of primary soil STORMWATER MANAGEMENT-Runoff water safely particles into compound particles or clusters that are conveyed or temporarily stored and released at an allowable separated from adjoining aggregates and have properties rate to minimize erosion and flooding. unlike those of an equal mass of unaggregated soil particles. The principal forms of soil structure are:platy(laminated), STRIPPING-Denuding vacant or untouched land of its prismatic(vertical axis of aggregates longer than present vegetative cover and topsoil. horizontal),columnar(prisms with rounded tops),blocky (angular or subangular),and granular. Structureless soils SUBGRADE-The soil prepared and compacted to are:(1)single grain(each grain by itself,as in dune sand), support a structure or a pavement system. or(2)massive(the particles adhering together without any regular cleavage,as in many claypans and hardpans). SUBSOIL-The B horizons of soils with distinct profiles. In soils with weak profile development,the subsoil can be SOIL SURVEY-Survey showing soil type and defined as the soil below the plowed soil(or its equivalent composition. of surface soil),in which roots normally grow. Although a common term,it cannot be defined accurately. SOIL TEXTURE-The relative proportions of the various soil separates in a soil as described by the classes of soil SUMP-Pit,tank,or reservoir in which water is collected texture shown in Figure 1.The textural classes may be for withdrawal or stored. modified by the addition of suitable adjectives when coarse fragments are present in substantial amounts;for example, SUSPENDED LOAD-The fine sediment kept in gravelly silt loam.(For other modifications,see coarse suspension in a stream because the settling velocity is lower fragments).Sand,loamy sand,and sandy loam are further than the upward velocity of the current. subdivided on the basis of the proportions of the various sand separates present. SWALE-A linear,but flattish depression in the ground surface which conveys drainage water but offers no SPILLWAY-An open or closed channel,or both,used to impediment to traffic,as do ditches or gutters. convey excess water from a reservoir. It may contain gates, either manually or automatically controlled,to regulate the TERRACE-An embankment or combination of an discharge of excess water. embankment and channel constructed across a slope to SPOIL-Soil or rock material excavated from a canal, control erosion by diverting or storing surface runoff basin,or similar construction. instead of permitting it to flow uninterrupted down the slope. Terraces or terrace systems may be classified by STAGE(hydraulics)-The variable water surface or the their alignment,gradient,outlet,and cross-section. water surface elevation above any chosen datum. Alignment is parallel or non-parallel. Gradient may be November 2016 Page H.8 New York State Standards and Specifications For Erosion and Sediment Control level,uniformly graded,or variably graded.Grade is often WATER RIGHTS-The legal rights to the use of water. incorporated to permit paralleling the terraces.Outlets may They consist of riparian rights and those acquired by be soil infiltration only,vegetated waterways,tile outlets,or appropriation and prescription. Riparian rights are those combinations of these. Cross-sections may be narrow base, rights to use and control water by virtue of ownership of the broad base,bench,steep backslope,flat channel,or channel. bank or banks. Appropriated rights are those acquired by an individual to the exclusive use of water,based strictly on TIME OF CONCENTRATION-Time required for priority of appropriation and application of the water to water to flow from the most remote point of a watershed,in beneficial use and without limitation of the place of use to a hydraulic sense,to a specific point,usually the outlet. riparian land.Prescribed rights are those to which legal title is acquired by long possession and use without protest of TIMING SCHEDULE-A construction progress schedule other parties. showing the proposed dates of commencement and completion of each of the various subdivisions of work as WATERSHED-The area contributing direct runoff to a shown and called for in the approved plans and stream. Usually it is assumed that base flow in the stream specifications. also comes from the same area. However,the ground water watershed may be larger or smaller. TOPOGRAPHIC MAP-A schematic drawing of prominent landforms indicated by conventional symbols WATERTABLE-The upper surface of groundwater or such as hachures or contour lines. that level below which the soil is saturated with water;locus of points in soil water at which the hydraulic pressure is TOPSOIL-The uppermost layers of soil containing equal to atmospheric pressure. organic material and suited for plant survival and growth. WATERWAY-A natural course or constructed channel TRAP EFFICIENCY-The capability of a reservoir to for the flow of water. trap sediment. WATTLE-A group or bundle of twigs,whips,or witches. TRAVEL TIME-The time for water to travel from one location to another in a watershed. Travel time is a WEEP-HOLES(engineering)-Openings,left in retaining component of time of concentration(Tc). walls,aprons,linings,or foundations to permit drainage and reduce pressure. TRIBUTARY-Secondary,or branch of a stream,drain,or other channel that contributes flow to the primary or main ZONING(rural)-A means by which governmental channel. authority is used to promote the proper use of land under certain circumstances. This power traditionally resides in TRM-Turf reinforcement mat. These are typically non- the state;and the power to regulate land uses by zoning is biodegradable mats with depth,which aid in stabilizing usually delegated to minor units of government,such as waterways by providing strength to vegetative root systems. towns,municipalities,and counties,through an enabling act that specifies powers granted and the conditions under UNIFIED SOIL CLASSIFICATION SYSTEM which these are to be exercised. (engineering)-A classification system based on the identification of soils according to their particle size, ZONING ORDINANCE-The exercise of police power gradation,plasticity index,and liquid unit. for the purpose of carrying out the land use plan of an area. It may also include regulations to effect control of the size UNIT HYDROGRAPH-A discharge hydrograph coming and height of buildings,population density,and use of from one inch of direct runoff distributed uniformly over buildings;for example,residential,commercial,industrial, the watershed,with the direct runoff generated at a uniform etc. rate during the given storm duration. A watershed may have 1-hour,2-hour,etc.unit hydrographs. WATER QUALITY STANDARDS-Minimum requirements of purity of water for various uses;for example,water for agricultural use in irrigation systems should not exceed specific levels of sodium bicarbonates, pH,total dissolved salts,etc. November 2016 Page H.9 New York State Standards and Specifications For Erosion and Sediment Control APPENDIX I DIRECTORIES CONTENTS Page Natural Resources Conservation Service Field Offices in NY..........................................................................................1.1 County Soil&Water Conservation District Offices in NY...............................................................................................I.3 New York State Department of Environmental Conservation Regional Offices,Division of Water................................1.5 New York City Department of Environmental Protection ................................................................................................1.6 U.S.Army Corps of Engineers .........................................................................................................................................I.6 DelawareRiver Basin Commission ..................................................................................................................................I.6 Susquehanna River Basin Commission.............................................................................................................................I.6 RegionalPlanning Councils ..............................................................................................................................................I.6 County Cornell Cooperative Extension Offices in NY .....................................................................................................I.7 Note:These directories are current as of publication date and are subject to change. Natural Resources Conservation Service Field Offices in NY COUNTY OFFICE LOCATION PHONE Albany Troy Service Center,61 State Street,Troy,NY 12180 518-271-1889 Allegany Belmont Service Center,5425 County Road 48,Belmont,NY 14813 585-268-5133 Broome Binghamton Service Center,1163 Upper Front Street,Binghamton,NY 13905 607-723-1384 Cattaraugus Ellicottville Service Center,8 Martha Street,Ellicottville,NY 14731 716-699-2326 Cayuga Auburn Service Center,7413 County House Road,Auburn,NY 13021 315-253-8471 Chautauqua Jamestown Service Center,3542 Turner Road,Jamestown,NY 14701 716-664-2351 Chemung/ Tioga Waverly Service Center,109A Chcmung Street,Waverly,NY 14892 607-565-2106 Chenango Norwich Service Center,99 North Broad Street,Norwich,NY 13815 607-334-3231 Clinton/ Essex Plattsburgh Service Center,6064 State Route 22,Plattsburg,NY 12901 518-561-4616 Columbia/ Greene Ghent Service Center, 1024 State Route 66,Ghent,NY 12075 518-828-4385 Cortland Cortland Service Center,100 Grange Place,Cortland,NY 13045 607-753-0851 Delaware Walton Service Center,44 West Street,Walton,NY 13856 607-865-4005 Dutchess/ Putnam/ Westchester Millbrook Service Center,2715 Route 44,Millbrook,NY 12545 845-677-3952 Erie East Aurora Service Center,50 Commerce Way,East Aurora,NY 14052 716-652-1400 Franklin Malone Service Center,151 Finney Boulevard,Malone,NY 12953 518-483-2850 Fulton/ Hamilton Fultonville Service Center,4001 State Hwy 5S,Fultonville,NY 12072 518-853-4015 Genesee Batavia Service Center,29 Liberty Street,Batavia,NY 14020 585-343-9167 Herkimer Herkimer Service Center,5653 State Route 5,Herkimer,NY 13350 315-866-2520 Jefferson Watertown Service Center,21168 State Route 232,Watertown,NY 13601 315-782-7289 Lewis Lowville Service Center,5274 Outer Stowe Street,Lowville,NY 13367 315-376-3520 Livingston Gcnesco Service Center,11 Megan Drive,Genesco,NY 14454 585-243-0030 Madison Hamilton Service Center,6503 Wes Road,Hamilton,NY 13346 315-684-9076 Monroe Rochester Service Center,1200A Scottsville Rd,Suite 160,Rochester,NY 14624 585-473-3440 Montgomery Fultonville Service Center,4001 ST HWY 5 South,Fultonville,NY 12072 518-853-4015 Nassau/ Suffolk Riverhead Service Center,423 Griffing Avenue,Riverhead,NY 11901 631-727-5666 Niagara Lockport Service Center,4487 Lake Avenue,Lockport,NY 14094 716-433-6703 Oneida Marcy Service Center,9025 State Route 49,Marcy,NY 13403 315-736-3316 Onondaga Lafayette Service Center,US Route 11,Lafayette,NY 13084 315-677-3552 Ontario Canandaigua Service Center,3037 County Road 10,Canandaigua,NY 14424 585-394-0525 Orange/ Rockland Middletown Service Center,225 Dolson Avenue,Middletown,NY 10940 845-343-1872 Orleans Albion Service Center,446 West Avenue,Albion,NY 14411 585-589-5320 Oswego Mexico Service Center,3306 Main Street,Mexico,NY 13114 315-963-0779 Otsego Cooperstown Service Center,967 County Route 33,Cooperstown,NY 13326 607-547-8131 November 2016 Page I.1 New York State Standards and Specifications For Erosion and Sediment Control Natural Resources Conservation Service Field Offices in NY (cont'd) COUNTY OFFICE LOCATION PHONE Rensselaer Troy Service Center,61 State St.,Troy,NY 12180 518-271-1889 St.Lawrence Canton Service Center,1942 Old Dckalb Road,Canton,NY 13617 315-386-2401 Saratoga Ballston Spa Service Center,Municipal Ctr.,50 W High St.,Ballston Spa,NY 12020 518-885-6300 Schenectady/ Schoharic USDA Service Center,108 Holiday Way,Schoharie,NY 12157 518-295-8600 Schuyler/ Tompkins Ithaca Service Center,903 Hanshaw Road,Ithaca,NY 14850 607-257-2737 Seneca Seneca Falls Service Center,12 N Park Street,Seneca Falls,NY 13148 315-568-6346 Steuben Bath Service Center,415 W Morris Street,Bath,NY 14810 607-776-7398 Sullivan/ Ulster Highland Service Center,652 State Route 299,Highland,NY 12528 845-883-7162 Warren/ Washington Greenwich Service Center,2530 State Route 40,Greenwich,NY 12834 518-692-9940 Wayne Lyons Service Center, 10 Leach Road,Lyons,NY 14489 315-946-9912 Wyoming Warsaw Service Center,31 Duncan Street,Warsaw,NY 14569 585-786-3118 Yates Penn Yan Service Center,270 Lake Street,Penn Yan,NY 14527 315-536-4012 New York State Standards and Specifications Page L2 November 2016 For Erosion and Sediment Control County Soil & Water Conservation District Offices in NY COUNTY OFFICE LOCATION PHONE Albany P.O.Box 497,24 Martin Road,Voorheesville,NY 12186 518-765-7923 Allegany 5390 County Rt 48,Lot A,Belmont,NY 14813 585-268-5840 Broome 1163 Upper Front Street,Binghamton,NY 13905 607-724-9268 Cattaraugus P.O.Box 1765,8 Martha St.,Suite 2,Ellicottville,NY 14731 716-699-2326 Cayuga 7413 County House Road,Auburn, NY 13021 315-252-4171 Chautauqua 220 Fluvanna Ave Suite 600,Jamestown,NY 14701 716-664-2351 Chemung 851 Chemung Street,Horseheads,NY 14845 607-739-2009 Chenango 99 North Broad Street,Norwich,NY 13815-1388 607-334-8634 Clinton 6064 Route 22,Suite 1,Plattsburgh,NY 12901 518-561-4616 Columbia 1024 Route 66,Ghent,NY 12075-3200 518-828-4386 Cortland 100 Grange Place,Room 202,Cortland,NY 13045 607-756-5991 Delaware 44 West Street,Suite 1,Walton,NY 13856 607-865-7161 Dutchess 2715 Route 44,Suite 3,Millbrook,NY 12545 845-677-8011 Erie 50 Commerce Way,East Aurora,NY 14052-2185 716-652-8480 Essex Cornell Cooperative Extension,P.O.Box 407,Westport,NY 12993 518-962-8225 Franklin 151 Finney Boulevard,Malone,NY 12953-9622 518-483-4061 Fulton 113 Hales Mills Road Ext.,Johnstown,NY 12095-9742 518-762-0077 Genesee USDA Center,29 Liberty Street,Suite#3,Batavia,NY 14020 585-343-2362 Greene 907 County Office Building,Cairo,NY 12413-2868 518-622-3620 Hamilton P.O.Box 166, 103 County View Dr.,Lake Pleasant,NY 12108-0166 518-548-3991 Herkimer 5653 State Route 5,Herkimer,NY 13350 315-866-2520 Jefferson P.O.Box 139,21168 NYS Rt.232,Watertown,NY 13601 315-782-2749 Lewis 5274 Outer Stowe St.,Suite#1,Lowville,NY 13367 315-376-6122 Livingston 11 Megan Drive,Suite#2,Geneseo,NY 14454 585-243-0043 Madison USDA Service Center,6503 Wes Road,Hamilton,NY 13346 315-824-9849 Monroe 145 Paul Road,Building#5,Rochester,NY 14624 585-753-7380 Montgomery 4001 State Highway 5S,Fultonville,NY 12072-1721 518-853-4015 Nassau 1864 Muttontown Road,Syosset,NY 11791 516-364-5860 New York City 121 Sixth Ave.,Suite 501,New York,NY 10013 212-431-9676 Niagara USDA Service Center,4487 Lake Avenue,Lockport,NY 14094 716-434-4949 Oneida 121 Second Street(315)736-3335,Oriskany,NY 13424 315-736-3334 Onondaga 6680 Onondaga Lake Parkway,Liverpool,NY 13088 315-457-0325 Ontario 480 North Main Street,Canandaigua,NY 14424 585-396-1450 Orange 225 Dolson Avenue,Suite 103,Middletown,NY 10940 845-343-1873 Orleans 446 West Avenue,Albion,NY 14411-1589 585-589-5959 Oswego 3105 State Route 3,Fulton,NY 13069 315-592-9663 Otsego 967 County Highway 33,Cooperstown,NY 13326 607-547-8337 Putnam 841 Fair Street,Carmel,NY 10512 845-878-7918 Rensselaer County Ag.&Life Sciences Building,61 State Street,Troy,NY 12180-3496 518-271-1740 Rockland 50 Sanitorium Road,Building K,Pomona,NY 10970 845-364-2670 Saratoga 50 West High Street,Building#5,Ballston Spa,NY 12020 518-885-6900 November 2016 Page I.3 New York State Standards and Specifications For Erosion and Sediment Control County Soil & Water Conservation District Offices in NY (cont'd) COUNTY OFFICE LOCATION PHONE Schenectady 24 Hetcheltown Road,Glenville,NY 12302 518-399-6980 Schoharic 173 South Grand Street,Suite 3,Cobleskill,NY 12043 518-823-4535 Schuyler 2400 Meads Hill Rd,Watkins Glen,NY 14891 607-535-9650 Seneca 2041 US Route 20,Suite#2,Seneca Falls,NY 13148 315-568-4366 St.Lawrence 1942 Old DeKalb Road,Canton,NY 13617-3134 315-386-3582 Steuben USDA Service Center,415 West Morris Street,Bath,NY 14810 607-776-7398 Suffolk 423 Griffing Avenue,Suite 110,Riverhead,NY 11901 631-852-3285 Sullivan 64 Ferndale-Loomis Road,Liberty,NY 12754 845-292-6552 Tioga 183 Corporate Drive,Owego,NY 13827 607-687-3553 Tompkins 170 Bostwick Road,Ithaca,NY 14850 607-257-2340 Ulster 5 Park Lane,Highland,NY 12528 845-883-7162 Warren 394 Schroon River Road,Warrensburg NY 12885 518-623-3119 Washington USDA Service Center,2530 State Route 40,Greenwich,NY 12834-9627 518-692-9940 Wayne 10 Leach Road,Lyons,NY 14489-9798 315-946-4136 Westchester 148 Martine Avenue,Room 432,White Plains,NY 10601-4704 914-995-4423 Wyoming 31 Duncan Street,Warsaw,NY 14569 585-786-5070 Yates 417 Liberty Street,Suite 1034,Penn Yan,NY 14527 315-536-5188 New York State Standards and Specifications Page L4 November 2016 For Erosion and Sediment Control o — _ ••ram - -- R NYSDEC Division of Water Regional Contacts CD cr 0 etc a"Ma b 8fA[i!o1mt 041efto ,i'(l N DiM Ei!91rdrFt tt11�W Tel � �+173 7b+� �T 6l��1fMPt IE a. 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Tel t'� � T[�1'ry � 11ry�fr rr�lFCD CD iv,49 2 No so t�s c) 1�uYil�lidrElr°!iN 11lLMIMGi `r'WY„ ii111 n � la 1t161+Iq, ^ o � o � _ New York City Department of Environmental Protection East of Hudson Engineering Office,Valhalla 914-773-0343 West of Hudson Engineering Office,Ashokam 845-657-5767 U.S. Army Corps of Engineers Baltimore District 410-962-7608 Buffalo District 716-879-4209 Auburn Field Office 315-255-8090 New York District 212-264-0100 Troy Field Office 518-270-0589 Philadelphia District 215-656-6728 Pittsburgh District 412-395-7154 Delaware River Basin Commission 609-883-9500 Susquehanna River Basin Commission 717-238-0423 Regional Planning Councils Capital District Regional Planning Commission One Park Place,Suite 102,Albany,NY 12205 518-453-0850 Central New York Regional Planning and Development Board 126 N.Salina Street,Suite 200,Syracuse,NY 13202 315-422-8276 Genesee/Finger Lakes Regional Planning Council 50 West Main Street,Suite 8107,Rochester,NY 14614 585-454-0190 Herkimer-Onieda Counties Comprehensive Planning Program 321 Main Street,Utica,NY 13501-1229 315-798-5710 Hudson Valley Regional Council 1010 D Street,New Windsor,NY 12553-8474 845-567-9466 Lake Champlain—Lake George Regional Planning and Development Board P.O.Box 765,310 Canada Street,Lake George,NY 12845 518-668-5773 Mohawk Valley Economic Development District 26 West Main Street,P.O.Box 69,Mohawk,NY 13407-0069 315-866-4671 Southern Tier Central Regional Planning and Development Board 145 Village Square,Painted Post,NY 14870 607-962-5092 Southern Tier East Regional Planning Development Board 375 State Street,Binghamton,NY 13901-2385 607-724-1327 Southern Tier West Regional Planning and Development Board 4039 Route 219,Suite 200,Salamanca,NY 14779 716-945-5301 New York State Standards and Specifications Page L6 November 2016 For Erosion and Sediment Control County Cornell Cooperative Extension Offices in NY COUNTY OFFICE LOCATION PHONE Albany PO Box 497,Voorheesvillc,NY 12186-0497 518-765-3500 Albany Regional 90 State Street,6th Floor,Suite 600,Albany,NY 12207 518-462-2553 Allegany 5435A County Road 48,Belmont,NY 14813 716-268-7644 Broome 840 Upper Front Street,Binghamton,NY 13905-1542 607-772-8953 Cattaraugus 28 Parkside Drive,Suite A,Ellicotvillc,NY 14731 716-699-2377 Cayuga 248 Grant Avenue,Auburn,NY 13021-0167 315-255-1183 Chautauqua 3542 Turner Road,Jamestown,NY 14701-9608 716-664-9502 Chemung 425 Pennsylvania Avenue,Elmira,NY 14904-1793 607-734-4453 Chenango 99 North Broad Street,Norwich,NY 1381.5-1386 607-334-5841 Clinton 6064 Route 22,Plattsburgh,NY 12901-9601 518-561-7450 Columbia 479 NYS Route 66,Hudson,NY 12534-9706 518-828-3346 Cortland 60 Central Avenue,Room 105,Cortland,NY 13045-5590 607-753-5077 Delaware PO Box 184,Hamden,NY 13782-0184 607-865-6531 Dutchess Farm and Home Center,2715 Route 44,Suite 1,Millbrook,NY 12545 845-677-8223 Eric 21 South Grove Street,East Aurora,NY 14052-2398 716-652-5400 Essex PO Box 388,Westport,NY 12993-0388 518-962-4810 Franklin 63 West Main Street,Malone,NY 12953-1817 629-483-7403 Fulton 55 East Main Street,2nd Floor,Suite 210,Johnstown,NY 12095 518-725-6441 Genesee 420 East Main Street,Batavia,NY 14020-2599 716-343-3040 Greene HCR3,Box 906,Cairo,NY 12413-9503 518-622-9820 Hamilton Box 7,NYS Route 8,Piseco,NY 12139 518-548-6191 Herkimer 5657 State Route 5,Herkimer,NY 13350-9721 315-866-7920 Jefferson 223 J.B.Wise Place,Watertown,NY 13601-2597 315-788-8450 Lewis PO Box 72,Lowville,NY 13367 315-376-5270 Livingston 158 South Main Street,Mt.Morris,NY 14510-1595 716-658-3250 Madison PO Box 1209,Morrisville,NY 13408-0640 315-684-3001 Monroe 249 Highland Avenue,Rochester,NY 14620 585 461-1000 Montgomery 55 East Main Street,2nd Floor,Suite 210,Johnstown,NY 12095 518-853-3471 Nassau 1425 Old Country Road,Plainview,NY 11803-5015 516-454-0900 Niagara 4487 Lake Avenue,Lockport,NY 14094 716-433-6731 NYC 16 East 34th Street,8th Floor,NY,NY 10016-4328 212-340-2900 Oneida 121 Second Street,Oriskany,NY 13424-9799 315-736-3394 Onondaga 220 Herald Place,2nd Floor,Syracuse,NY 13202-1045 315-424-9485 Ontario 480 North Main Street,Canandaigua,NY 14424-1099 716-394-3977 Orange 1 Ashley Avenue,Education Ctr.Comm.Campus,Middletown,NY 10940 845-344-1234 Orleans PO Box 150,Albion,NY 14411-0150 716-589-5561 November 2016 Page I.7 New York State Standards and Specifications For Erosion and Sediment Control County Cornell Cooperative Extension Offices in NY (cont'd) COUNTY OFFICE LOCATION PHONE Oswego 3288 Main Street,Mexico,NY 13114-3499 315-963-7286 Otsego 123 Lake Street,Cooperstown,NY 13326 607-547-2536 Putnam 10 Geneva Road,Brewster,NY 10509 845-278-6738 Rensselaer 61 State Street,Ag&Life Science Building,Troy,NY 12180 518-272-4210 Rockland PO Box 1000,Thiells,NY 10984 845-429-7085 St.Lawrence 1894 State Highway 68,Canton,NY 13617-1477 315-379-9192 Saratoga 50 West High Street,Ballston Spa,NY 12020 518-885-8995 Schenectady Schaffer Heights, 107 Nott Terrace,Suite 301,Schenectady,NY 12308 518-372-1622 Schoharie 41 South Grand Street,Cobleskill,NY 12043 518-234-4303 Schuyler 208 Broadway,Montour Falls,NY 14865 607-535-7161 Seneca PO Box 748,Waterloo,NY 13165 315-539-9252 Steuben 3 East Pulteney Square,Bath,NY 14810 607-776-9631 Suffolk 246 Griffing Avenue,Riverhead,NY 11901-3086 631-727-7850 Sullivan 69 Ferndale-Loomis Road,Liberty,NY 12754-2903 845-292-6180 Tioga 56 Main Street,Owego,NY 13827-1588 607-687-4020 Tompkins 615 Willow Avenue,Ithaca,NY 14850-3555 607-272-2292 Ulster 10 Westbrook Lane,Kingston,NY 12401-2928 845-340-3990 Warren 377 Schroon River Rd,Warrensburg,NY 12885-4807 518-623-3291 Washington Lower Main Street,Hudson Falls,NY 12839 518-746-2560 Wayne 1581 NYS Route 88N,Newark,NY 14513-9739 315-331-8415 Westchester 26 Legion Drive,Valhalla,NY 10595 914-285-4630 Wyoming 401 North Main Street,Warsaw,NY 14569 716-786-2251 Yates 110 Court Street,Penn Yan,NY 14527 315-536-5123 New York State Standards and Specifications Page L8 November 2016 For Erosion and Sediment Control I NEW Department of rR Conservation STORMWATER MANAGEMENT DESIGN MANUAL July 31 , 2024 t f y Originally Prepared by: i° Center for Watershed Protection 8391 Main Street s. r� �'� 'N , - __... .-_-•�- I i, Ellicott City, MD 21043 r s six* p Updated by: New York State Department of Environmental Conservation 625 Broadway Albany, NY 12233 .. . _ a. 'BAR •v" �,�� �n� y - Kathy Hochul,Governor Sean Mahar,Interim Commissioner This Page is Left Intentionally Blank NEW Department of PORK STATE Environmental Conservation Acknowledgments The latest revision of the New York State Stormwater Management Design Manual was prepared under a joint effort between the New York State Department of Environmental Conservation (DEC), Environmental Facilities Corporation (EFC) and LaBella Associates. The key individuals from LaBella Associates include: Kelsey Carr, CPMSM, LEED AP BD+C, Senior Civil Engineer Sara Drury, EIT, Civil Engineer Courtney Davis, EIT, Civil Engineer Roger Keating, PE, LEED AP BD+C, Senior Civil Engineer James "Andy" Rymph, RLA, Senior Landscape Architect James Connors, PE, Senior Civil Engineer Linda Stancliffe, RLA, LEED AP, Senior Landscape Architect The key individuals from the DEC include: Carrie Buetow, Environmental Program Specialist, DOW Region 4 David Gasper, PE, Professional Engineer 1 (Environmental), DOW Central Office Luke Scannell, PhD, PE, Professional Engineer 1 (Environmental), DOW Region 8 Ethan Sullivan, Assistant Engineer, DOW Central Office Ryan Waldron, PE, Chief, Metropolitan Compliance Section, DOW Central Office The key individuals from or associated with EFC include: Brian Gyory, RLA, Assistant Project Manager, NYS Environmental Facilities Corporation Joy Kuebler, RLA, ASLA, President and CEO of Joy Kuebler Landscape Architect Tim Toland, RLA, SLINY-ESF Associate Professor, Department of Landscape Architecture Additionally, the Center for Watershed Protection (CWP) reviewed a draft of the updates and provided the DEC with comments prior to the Public Notice. The individuals from CWP include: Greg Hoffman, PE, Director of Stormwater Services Deb Caraco, PE, Senior Water Resources Engineer Acknowledgements&Preface Preface The New York State Stormwater Design Manual is prepared to provide standards for the design of the Stormwater Management Practices (SMPs)to protect the waters of the State of New York from the adverse impacts of urban stormwater runoff. This manual is intended to establish specifications and uniform criteria for the practices that are part of a Stormwater Pollution Prevention Plan (SWPPP). This manual is intended primarily for engineers and other professionals who are engaged in the design of stormwater treatment facilities for new developments. Users are assumed to have a background in hydrology, hydraulics, and runoff and pollutant load computation. It is not intended to be a primer on any of these subjects. The manual may also be used by reviewing authorities to assess the adequacy of SWPPPs. The Technical Standards, consisting of proven technology, are intended to serve as design criteria for the preparation of plans and specifications for Stormwater Management Practices, to suggest limiting values for items upon which an evaluation of such plans and specifications may be made by the reviewing authority, and to establish, as far as practicable, uniformity of practice. The technical standards constitute discharge technology requirements of the Clean Water Act. As statutory requirements and legal authority pertaining to stormwater management are not uniform across the State,and since conditions and administrative procedures and policies also differ, the use of these Standards must be adjusted to these variations. The terms "shall' and "must" are used where the practice is sufficiently standardized to permit specific delineation of requirements or where safeguarding of the public health justifies such definite action. Other terms, such as "should," "recommend," and "preferred," indicate desirable procedures or methods, with deviations subject to individual consideration. Acknowledgements&Preface Table of Contents Chapter 1: Introduction to the Manual.............................................................................................................................1-1 Section 1.1 Purpose of the Manual ................................................................................................................................1-1 Section1.2 How to Use the Manual...............................................................................................................................1-1 Section 1.3 Symbols and Acronyms........................................................................................................................... ...1-4 Chapter 2: Impacts of New Development...................................................................................................... ...............2-1 Section 2.1 Declining Water Quality...............................................................................................................................2-2 Section 2.2 Diminishing Groundwater Recharge and Quality........................................................................................2-5 Section 2.3 Impacts to the Stream Channel...................................................................................................................2-6 Section 2.4 Increased Overbank Flooding.....................................................................................................................2-7 Section2.5 Floodplain Expansion..................................................................................................................................2-9 Section 2.6 Impacts to Aquatic Organisms ....................................................................................................................2-9 Section 2.7 Climate Change Resiliency Planning........................................................................................................2-11 Chapter 3: Stormwater Management Planning...............................................................................................................3-1 Section3.1 Introduction..................................................................................................................................................3-1 Section 3.2 Runoff Reduction Techniques for Stormwater Management......................................................................3-2 Section 3.3 Standard Stormwater Management Practices for Treatment......................................................................3-5 3.3.1 Practice List.......................................................................................................................................................3-5 3.3.2 Criteria for Practice Addition..............................................................................................................................3-7 Section3.4 Quantity Controls.........................................................................................................................................3-7 Section 3.5 Maintenance Requirements ........................................................................................................................3-8 Section 3.6 The Six Step Process for Stormwater Site Planning and Practice Selection..............................................3-9 Chapter 4: Unified Stormwater Sizing Criteria................................................................................................................4-1 Section4.1 Introduction..................................................................................................................................................4-1 Section 4.2 Water Quality Volume (WQv)......................................................................................................................4-2 Section 4.3 Water Quality Volume (WQv) for Enhanced Phosphorus Removal Watersheds ...................................... 4-4 Section 4.4 Runoff Reduction Volume (RRv).................................................................................................................4-4 Section 4.5 Runoff Reduction Volume (RRv) for Enhanced Phosphorus Removal Watersheds. .................................4-5 Section 4.6 Stream Channel Protection Volume Requirements (CPv)..........................................................................4-5 Section 4.7 Overbank Flood Control Criteria (Qp) .........................................................................................................4-6 Section 4.8 Extreme Flood Control Criteria (Q0 ............................................................................................................4-7 Section 4.9 Rainfall Data, Distribution Curves and Hydrologic Modeling ......................................................................4-8 Section 4.10 Alternative Method ....................................................................................................................................4-9 Section 4.11 Conveyance Criteria................................................................................................................................4-10 Section 4.12 Stream Order Identification .....................................................................................................................4-10 Table of Contents TOC-1 Section 4.13 Downstream Analysis..............................................................................................................................4-11 Section 4.14 Stormwater Hotspots...............................................................................................................................4-12 Chapter 5: Runoff Reduction Techniques.......................................................................................................................5-1 Section 5.1 Planning for Runoff Reduction: Preservation of Natural Features and Conservation Design ....................5-1 5.1.1 Preservation of Undisturbed Areas .................................................................................................................. 5-1 5.1.2 Preservation of Buffers......................................................................................................................................5-3 5.1.3 Reduction of Clearing and Grading...................................................................................................................5-5 5.1.4 Locating Development in Less Sensitive Areas................................................................................................5-6 5.1.5 Open Space Design ..........................................................................................................................................5-8 5.1.6 Soil Restoration ...............................................................................................................................................5-10 Section 5.2 Planning for Runoff Reduction: Reduction of Impervious Cover ..............................................................5-14 5.2.1 Roadway Reduction ........................................................................................................................................5-14 5.2.2 Sidewalk Reduction.........................................................................................................................................5-16 5.2.3 Driveway Reduction.........................................................................................................................................5-18 5.2.4 Cul-de-sac Reduction......................................................................................................................................5-19 5.2.5 Building Footprint Reduction ...........................................................................................................................5-21 5.2.6 Parking Area Reduction ..................................................................................................................................5-22 Section 5.3 Runoff Reduction Techniques...................................................................................................................5-25 5.3.1 Conservation of Natural Areas (RR-1) ............................................................................................................5-27 5.3.2 Sheet Flow to Riparian Buffers or Filter Strips (RR-2) ....................................................................................5-31 5.3.3 Tree Planting/Tree Pit/Tree Trench (RR-3).....................................................................................................5-37 5.3.4 Disconnection of Rooftop Runoff(RR-4).........................................................................................................5-46 5.3.5 Vegetated Swale (RR-5) .................................................................................................................................5-51 5.3.6 Rain Gardens (RR-6).......................................................................................................................................5-56 5.3.7 Stormwater Planter(RR-7)..............................................................................................................................5-61 5.3.8 Rainwater Harvesting System (RR-8) .............................................................................................................5-66 5.3.9 Porous Pavement (RR-9)................................................................................................................................5-71 5.3.10 Green Roofs (RR-10) ....................................................................................................................................5-79 5.3.11 Stream Daylighting (RR-11) ..........................................................................................................................5-84 Chapter 6: Standard Stormwater Management Practices..............................................................................................6-1 Section6.1 Stormwater Ponds.......................................................................................................................................6-3 6.1.1 Feasibility...........................................................................................................................................................6-8 6.1.2 Conveyance.......................................................................................................................................................6-8 6.1.3 Pretreatment......................................................................................................................................................6-9 6.1.4 Treatment........................................................................................................................................................6-10 6.1.5 Landscaping ....................................................................................................................................................6-13 Section 6.2 Stormwater Wetlands................................................................................................................................6-18 6.2.1 Feasibility.........................................................................................................................................................6-24 6.2.2 Conveyance.....................................................................................................................................................6-25 Table of Contents TOC-2 6.2.3 Pretreatment....................................................................................................................................................6-25 6.2.4 Treatment........................................................................................................................................................6-27 6.2.5 Landscaping ....................................................................................................................................................6-29 Section 6.3 Stormwater Infiltration Practices ...............................................................................................................6-35 6.3.1 Feasibility.........................................................................................................................................................6-40 6.3.2 Conveyance.....................................................................................................................................................6-42 6.3.3 Pretreatment....................................................................................................................................................6-43 6.3.4 Treatment........................................................................................................................................................6-43 6.3.5 Landscaping ....................................................................................................................................................6-45 Section 6.4 Stormwater Filtering Practices ..................................................................................................................6-50 6.4.1 Feasibility.........................................................................................................................................................6-57 6.4.2 Conveyance.....................................................................................................................................................6-58 6.4.3 Pretreatment....................................................................................................................................................6-58 6.4.4 Treatment........................................................................................................................................................6-60 6.4.5 Landscaping ....................................................................................................................................................6-63 Section 6.5 Open Channel Systems ............................................................................................................................6-70 6.5.1 Feasibility.........................................................................................................................................................6-73 6.5.2 Conveyance.....................................................................................................................................................6-73 6.5.3 Pretreatment....................................................................................................................................................6-73 6.5.4 Treatment........................................................................................................................................................6-74 6.5.5 Landscaping ....................................................................................................................................................6-76 Chapter 7: Stormwater Management Design Examples ................................................................................................7-1 Section 7.1 Sizing Example—Conservation, Bioretention and Wet Pond.....................................................................7-1 Section 7.2 Sizing Example— Filtration Bioretention & Infiltration Basin for Treatment of Stormwater Hotspot.........7-21 Section 7.3 Sizing Example— Dry Swale.....................................................................................................................7-25 Section 7.4 Sizing Example— Multiple Dry Wells in Series .........................................................................................7-31 Chapter 8: Urban Stormwater Management....................................................................................................................8-1 Section 8.1 NYSDOT Urban Roadway Classification ....................................................................................................8-1 Section 8.2 Urban Practice Suitability............................................................................................................................8-2 Section 8.3 Implementation of Urban Stormwater Management Practices ...................................................................8-3 Chapter9: Redevelopment Activity .................................................................................................................................9-1 Section9.1 Introduction..................................................................................................................................................9-1 Section9.2 Scope and Applicability...............................................................................................................................9-1 9.2.1 Sizing Criteria ....................................................................................................................................................9-2 9.2.2 Performance Criteria .........................................................................................................................................9-4 Section 9.3 Water Quality Peak Flow Calculation..........................................................................................................9-4 Section 9.4 Alternative Stormwater Management Practices Proprietary Practices.......................................................9-4 9.4.1 Evaluation of Alternative Practices....................................................................................................................9-4 Table of Contents TOC-3 9.4.2 Recommended Application of Practice .............................................................................................................9-5 9.4.3 Benefits..............................................................................................................................................................9-5 9.4.4 Feasibility/Limitations ........................................................................................................................................9-5 9.4.5 Sizing and Design Guidance.............................................................................................................................9-6 9.4.6 Environmental/Landscape Elements.................................................................................................................9-6 9.4.7 Maintenance......................................................................................................................................................9-6 Chapter 10: Addressing Stormwater Pollutants of Concern.......................................................................................10-1 Section 10.1 Introduction and Overview.......................................................................................................................10-1 10.1.1 Description of Properties of Pollutants of Concern .......................................................................................10-2 10.1.2 Summary of Pollutant Characteristics...........................................................................................................10-3 Section 10.2 Pollutant Removals in Stormwater Management Practices....................................................................10-4 Section 10.3 Recommended SMP Design Modifications to Enhance Pollutant Removal...........................................10-6 10.3.1 Plant Species Selection.................................................................................................................................10-6 10.3.2 Iron-Enhanced Check Dams.........................................................................................................................10-7 10.3.3 Enhanced Bioretention Media.......................................................................................................................10-7 Chapter 11: Planting Guidance for Stormwater Management Practices Facilities...................................................11-1 Section11.1 Introduction..............................................................................................................................................11-1 Section11.2 Landscape Planning................................................................................................................................11-2 Section 11.3 General Plant Considerations .................................................................................................................11-4 11.3.1 Site Constraints.............................................................................................................................................11-4 11.3.2 Confined Sites...............................................................................................................................................11-5 11.3.3 Snow Storage................................................................................................................................................11-5 11.3.4 Water Availability...........................................................................................................................................11-5 11.3.5 Plant Origin....................................................................................................................................................11-5 11.3.6 Planting Location...........................................................................................................................................11-6 11.3.7 Plant Growth Patterns ...................................................................................................................................11-7 11.3.8 Plant Installation Considerations...................................................................................................................11-7 11.3.9 Material Availability........................................................................................................................................11-8 Section 11.4 Practice Specific Plant Considerations ...................................................................................................11-9 11.4.1 Plant Form.....................................................................................................................................................11-9 11.4.2 Plant Installation Categories........................................................................................................................11-10 11.4.3 Plant Scale ..................................................................................................................................................11-10 11.4.4 Rooting Depth..............................................................................................................................................11-11 11.4.5 Rooting Volume...........................................................................................................................................11-11 11.4.6 Inundation Tolerance...................................................................................................................................11-12 11.4.7 Maintenance Requirements ........................................................................................................................11-12 11.4.8 Plant Considerations—Practice Specific Summaries.................................................................................11-12 Section11.5 Plant Maintenance.................................................................................................................................11-26 11.5.1 First Year Maintenance ...............................................................................................................................11-26 Table of Contents TOC-4 11.5.2 Second Year Maintenance..........................................................................................................................11-26 11.5.3 Third Year Maintenance..............................................................................................................................11-26 11.5.4 Long Term Maintenance .............................................................................................................................11-26 11.5.5 Invasive Control...........................................................................................................................................11-27 Chapter 12: Maintenance Guidance...............................................................................................................................12-1 Section12.1 Introduction..............................................................................................................................................12-1 12.1.1 Stormwater Management Practice (SMP) Groups........................................................................................12-1 12.1.2 Maintenance Hierarchy .................................................................................................................................12-2 12.1.3 Level 1, 2 and 3 Inspections..........................................................................................................................12-3 12.1.4 Planning for Stormwater Maintenance..........................................................................................................12-7 Section 12.2 Inspections by SMP Group ...................................................................................................................12-13 12.2.1 Sheet Flow and Disconnection....................................................................................................................12-13 12.2.2 Tree Plantings .............................................................................................................................................12-14 12.2.3 Swales.........................................................................................................................................................12-15 12.2.4 Bioretention .................................................................................................................................................12-16 12.2.5 Rainwater Harvesting ..................................................................................................................................12-18 12.2.6 Porous Pavement........................................................................................................................................12-19 12.2.7 Green Roof..................................................................................................................................................12-20 12.2.8 Ponds and Wetlands ...................................................................................................................................12-21 12.2.9 Infiltration.....................................................................................................................................................12-22 12.2.10 Sand Filters ...............................................................................................................................................12-23 Section 12.3 Diagnostics and Maintenance Measures..............................................................................................12-24 12.3.1 Contributing Drainage Area— Pollutant Sources ........................................................................................12-25 12.3.2 Physical Obstructions..................................................................................................................................12-27 12.3.3 Erosion ........................................................................................................................................................12-29 12.3.4 Departure from Design Dimensions............................................................................................................12-30 12.3.5 Improper Flow Paths ...................................................................................................................................12-31 12.3.6 Sediment Buildup ........................................................................................................................................12-34 12.3.7 Clogging ......................................................................................................................................................12-36 12.3.8 Vegetation ...................................................................................................................................................12-40 12.3.9 Embankment and Overflow Condition.........................................................................................................12-42 12.3.10 Structural Damage.....................................................................................................................................12-44 12.3.11 Pool Stability..............................................................................................................................................12-45 12.3.12 Pool Quality...............................................................................................................................................12-46 Table of Contents TOC-5 Appendix A: NYSDEC Guidelines for Design of Dams................................................................................................ A-1 Appendix B: Water Quality Peak Flow Rate.................................................................................................................. B-1 Appendix C: Miscellaneous Details ............................................................................................................................... C-1 Appendix D: Infiltration Testing Requirements ............................................................................................................ D-1 Appendix E: Plan Review Checklists.............................................................................................................................. E-1 Appendix F: Construction Inspection Checklists.......................................................................................................... F-1 Appendix G: Non-Erosive Velocities of Vegetated Channels...................................................................................... G-1 Appendix H: Cold Climate Sizing Criteria...................................................................................................................... H-1 Appendix I: Geomorphic Assessment............................................................................................................................. 1-1 References Glossary Table of Contents TOC-6 Chapter 1 : Introduction to the Manual Section 1 .1 Purpose of the Manual The purpose of this manual is threefold: 1. To protect the waters of the State of New York from the adverse impacts of urban stormwater runoff 2. To provide design standards on the most effective stormwater management approaches including: Incorporation of runoff reduction achieved by infiltration, groundwater recharge, reuse, recycle, evaporation/evapotranspiration through the use of runoff reduction techniques as a standard practice Design and implementation of standard stormwater management practices (SMPs) Implementation of a good operation, inspection, and maintenance program 3. To improve the quality of runoff reduction techniques and standard SMPs constructed in the State, specifically in regard to their performance, longevity, safety, ease of maintenance, community acceptance and environmental benefit Section 1 .2 How to Use the Manual The New York State Stormwater Management Design Manual provides designers a general overview on how to select, locate, size, and design SMPs at a development site to comply with State stormwater performance standards. The manual also contains appendices with more detailed information on landscaping, SMP construction specifications, step- by-step SMP design examples and other assorted design tools. The manual is organized as follows: Stormwater Design Chapters Chapter 2. Impacts of New Development This Chapter examines the physical, chemical, and biological effects of unmanaged stormwater runoff on the water quality of local streams and waterbodies. This brief overview provides the background for why the stormwater management manual is needed and how the new criteria will help local communities meet water quality standards. Chapter 3. Stormwater Management Planning This Chapter explains the required stormwater management planning process and steps for maintaining preconstruction natural hydrologic conditions of the site by application of environmentally-sound development principles, such as runoff reduction techniques, as well as steps involved in treatment and control of runoff discharges from the site in new development and redevelopment projects. Chapter 4. Unified Stormwater Sizing Criteria This Chapter explains sizing criteria for water quality, runoff reduction, channel protection, overbank flood control, and extreme flood management in the State of New York. The Chapter also outlines the basis for design calculations. Chapter 5. Runoff Reduction Techniques This Chapter provides planning and design criteria on runoff reduction approach and specifications for acceptable runoff reduction practices. This Chapter contains the following sections: Planning for Runoff Reduction Techniques Preservation of Natural Features and Conservation Design Reduction of Impervious Cover Runoff Reduction Techniques Chapter 1: Introduction to the Manual 1 A Chapter 6. Standard Stormwater Management Practices This Chapter presents specific performance criteria and design specifications for the design of the five groups of structural SMPs. Each group of SMPs have six performance criteria: Feasibility Conveyance Pretreatment Treatment Landscaping 6. Maintenance Chapter 7. Stormwater Management Design Examples Design examples are provided to help designers and plan reviewers better understand the design criteria outlined in this manual. The step-by-step design examples demonstrate how the stormwater sizing criteria are applied, and some of the design procedures and performance criteria that should be considered when planning a new stormwater management practice. The following design examples are provided: Conservation, Bioretention and Wet Pond Filtration Bioretention & Infiltration Basin for Treatment of a Stormwater Hotspot Dry Swale 4. Multiple Dry Wells in Series Chapter 8. Urban Stormwater Management This Chapter presents guidance for implementation of runoff reduction techniques and applicable SMPs, in both new development and redevelopment projects located in urban areas. Chapter 9. Redevelopment Activity This Chapter outlines alternative approaches and sizing criteria for addressing stormwater management at projects that include the disturbance and reconstruction of existing impervious surfaces (i.e. redevelopment activity). The approaches set forth in this Chapter comply with the Department's technical standards. Chapter 10.Addressing Stormwater Pollutants of Concern This Chapter presents common pollutants of concern found in stormwater runoff. Common pollutant sources and environmental fate and transport characteristics are provided and an overview of SMP pollutant removal capabilities as well as recommended SMP design modifications to further reduce specific pollutants of concern are discussed. Chapter 11. Planting Guidance for Stormwater Management Practices This Chapter provides guidance for selection of plants for stormwater management practices, in order to maximize the runoff reduction and water quality benefits. Chapter 12. Maintenance Guidance This Chapter provides maintenance guidance for 10 SMP groups that include each of the runoff reduction techniques and standard SMPs included in this Manual. A three-level inspection and maintenance hierarchy is established, with responsibilities and procedures being defined for each level. Recommendations for maintenance planning and budgeting are also included. The Chapter concludes by outlining the key components of Level 1, Level 2 and Level 3 Inspections including diagnostic and repair measures for specific issues. Chapter 1: Introduction to the Manual 1.2 Stormwater Design Appendices The appendices contain the technical information needed to design, landscape and construct an SMP. There are a total of nine appendices: Appendix A. Guidelines for Design of Dams This appendix provides the general guidelines that New York State Department of Environmental Conservation offers the design engineers on the design of dams. These guidelines represent professional judgment and sound engineering practices for small dams. Appendix B. Water Quality Peak Flow Rate This appendix provides step-by-step instructions, including an example, for calculating the water quality peak flow rate for sizing flow-based practices. Appendix C. Miscellaneous Details The designs of various structures previously discussed in the manual are presented in Appendix C. These structures help enhance the performance of stormwater management practices, especially in cold climates. Schematics of structures such as weirs, trash racks, and observation wells are included. Appendix D. Testing Requirements for SMPs This appendix describes required soil testing for both the feasibility and design phases. Appendices E. Plan Review Checklists This appendix provides example checklists that can be used to assist in the stormwater management plan review. Appendices F. Construction Inspection Checklists This appendix provides example checklists that can be used to assist in construction inspection of an SMP. Appendix G. Non-Erosive Velocities of Vegetated Channels This appendix provides data on critical erosive velocities for vegetated channels. Appendix H. Cold Climate Sizing Criteria This appendix supplies guidance on sizing SMPs to account for cold climate conditions that might reduce performance. Sizing example that illustrate how to incorporate cold climate criteria into SMP design are also included. Appendix I. Geomorphic Assessment This appendix provides a description of the Distributed Runoff Control (DRC) methodology to size stormwater practices based on downstream geomorphic characteristics. Chapter 1: Introduction to the Manual 1.3 Section 1 .3 Symbols and Acronyms As an aid to the reader, Table 1.1 outlines the symbols and acronyms that are used throughout the text. In addition, a glossary is provided at the end of this volume that defines the terminology used in the text. Table 1.1 Key Symbols Symbol Definition Symbol Definition %ALT Percent of redevelopment impervious LT total length of underdrain piping area treated by alternative SMP %ICREo Percent reduction in existing disturbed Lu design length of underdrain pipe impervious area %RR Percent of redevelopment impervious M moisture in spring snowpack area treated by runoff reduction technique %SMP Percent of redevelopment impervious MS4 Municipal Separate Storm Sewer System area treated by standard SMP (D porosity n Manning's coefficient A Area N Number of specified object Ab bottom area nDL maximum water retention of drainage layer AC contributing drainage area NOAA National Oceanic and Atmospheric Administration Af area of filter NRCC Northeast Regional Climate Center AcR green roof surface area NRCS Natural Resources Conservation Service total area of new impervious cover for Aic nsM maximum water retention of soil media project site Aimp impervious cover in contributing drainage NYSEFC New York State Environmental Facilities area Corporation AN subcatchment area %PT Percent WQv pretreatment required Ap porous pavement surface area P 90% rainfall depth As sedimentation basin surface area Pi 1-yr 24-hr design storm rainfall depth ASTM American Society for Testing and Pz 2-yr 24-hr design storm rainfall depth Materials AT Surface area of the infiltration trench Pso calculated rainfall value b channel bottom width PW wetted perimeter B maximum basin retention Q runoff BMP best management practice Qf extreme flood storage volume BOD biological oxygen demand Qi peak inflow discharge C number of check dams Qo peak outflow discharge CH check dam height Qp overbank flood control storage volume CN curve number R ratio of contributing area,to porous pavement surface area CNN curve number for subcatchment RES water reservoir for factor of safety CNw weighted curve number RRv runoff reduction volume COD chemical oxygen demand RRvmin minimum runoff reduction volume Cs check dam spacing R5 snowmelt runoff CWP Center for Watershed Protection Rv volumetric runoff coefficient d WQv flow depth S, annual snowfall dio stone/soil particle diameter of which 10% S HSG specific reduction factor of the sample is smaller than Chapter 1: Introduction to the Manual 1-4 Dz 2-yr average flow depth SI stability index db depth of basin SL slope DDL depth of the drainage layer Sp spacing between underdrain pipes df depth of filter t thickness of dry well wall DOT Department of Transportation T travel time through filter strip dp depth of stone Tc time of concentration DP minimum depth of permanent pool tf design filter drain time ds depth of sedimentation chamber Tmax maximum temperature Technical Release No. 20 Project DsM depth of soil media TR-20 Formulation-Hydrology, computer program dt depth of trench TR-55 Technical Release No. 55 Urban Hydrology for Small Watersheds du dwelling units is thickness of stone reservoir E sediment basin efficiency UIC Underground Injection Control ED extended detention USC Unified Soil Classification EPA Environmental Protection Agency (United USDA United States Department of Agriculture States) ET summer evapotranspiration rate V velocity fc soil infiltration rate V10 10-year peak discharge velocity H Inside height of dry well VC channel volume provided h:v ratio of horizontal to vertical V; inside volume of dry well hf average height of ponding Vol Volume HOA homeowner's association Vr volume of runoff I percent impervious cover Vs volume of storage la initial abstraction Vst volume of stone reservoir IC impervious cover Vsys volume of system INF monthly infiltration loss Vt total volume k permeability flow rate Vv volume of voids Ksat saturated hydraulic conductivity VW volume provided per dry well I:w ratio of length to width W width L length WQF water quality peak flow rate Li losses to hauling WQV water quality storage volume Lz losses to sublimation WQ -ED 12-hr or 24-hr extended detention of the water quality volume Ls losses to winter melt Ws particle settling velocity Lp length provided WTop channel top width L, length required Chapter 1: Introduction to the Manual 1 This Page is Left Intentionally Blank NEWYORK Department of p PURTUNITY Environmental Conservation Chapter 2: Impacts of New Development Urban development has a profound influence on the quality of New York's waters. To start, development dramatically alters the local hydrologic cycle (see Figure 2.1). The hydrology of a site changes during the initial clearing and grading that occur during construction. Trees that had intercepted rainfall are removed, and natural depressions that had temporarily ponded water are graded to a uniform slope. The spongy humus layer of the forest floor that had absorbed rainfall is scraped off, eroded or severely compacted. Having lost its natural storage capacity, a cleared and graded site can no longer prevent rainfall from being rapidly converted into stormwater runoff. WATER BALANCE PRE-DEYELOPMENT Canopy POST-DEVELOPMENT r,, Interception +w� Evapo Transpiration transpiratio »� Surface Runoff Surface S" Runoff Z � Interflow Interflow Baeeflow Baatflow Figure 2.1 Water Balance at a Developed and Undeveloped Site (Schueler, 1987) The situation worsens after construction. Rooftops, roads, parking lots, driveways and other impervious surfaces no longer allow rainfall to soak into the ground. Consequently, most rainfall is directly converted into stormwater runoff. This phenomenon is illustrated in Figure 2.2, which shows the increase in the volumetric runoff coefficient (R ) as a function of site imperviousness. The runoff coefficient expresses the fraction of rainfall volume that is converted into stormwater runoff. As can be seen, the volume of stormwater runoff increases sharply with impervious cover. For example, a one- acre parking lot can produce 16 times more stormwater runoff than a one-acre meadow each year(Schueler, 1994). The increase in stormwater runoff can be too much for the existing drainage system to handle. As a result, the drainage system is often "improved"to rapidly collect runoff and quickly convey it away (using curb and gutter, enclosed storm sewers, and lined channels). The stormwater runoff is subsequently discharged to downstream waters, such as streams, reservoirs, lakes or estuaries. Runoff Coefficient (RV) 1 F_ --- — — . M 0.9 0.8 0.7 0.5 N 1 CA � ■ m 0.3 ® J, a 0.2 ®� m 0 0 10 20 30 40 so 60 70 80 90 IOC Watershed Imperviousness ( ) Figure 2.2 Relationship Between Impervious Cover and Runoff Coefficient(Schueler, 1987). Chapter 2: Impacts of New Development 2-1 Section 2.1 Declining Water Quality Impervious surfaces accumulate pollutants deposited from the atmosphere, leaked from vehicles, or windblown in from adjacent areas. During storm events, these pollutants quickly wash off, and are rapidly delivered to downstream waters. Some common pollutants found in urban stormwater runoff are profiled in Table 2.1. Sediment (Suspended Solids) Sources of sediment include washoff of particles that are deposited on impervious surfaces and erosion from streambanks and construction sites. Streambank erosion is a particularly important source of sediment, and some studies suggest that streambank erosion accounts for up to 70% of the sediment load in urban watersheds (Trimble, 1997). Table 2.1 National Median Concentrations for Chemical Constituents in Stormwatel�_­, Constituent Units Concentration Total Suspended Solids' mg/I 54.5 Total Phosphorus' mg/I 0.26 Soluble Phosphorus' mg/I 0.10 Total Nitrogen' mg/I 2.00 Total Kjeldhal Nitrogen' mg/I 1.47 Nitrite and Nitrate' mg/I 0.53 Copper' ug/I 11.1 Lead' ug/I 50.7 Zinc' ug/I 129 BOD' mg/I 11.5 COD' mg/I 44.7 Organic Carboni mg/I 11.9 PAH3 mg/I 3.5* Oil and Grease' mg/I 3.0* Fecal Coliform5cno11/100 15,000* Fecal Strep5 col/ 35,400* 100 ml Chloride(snowmelt)6 mg/I 116 * Represents a Mean Value Source: 1: Pooled NURP/USGS (Smullen and Cave, 1998) 2: Derived from the National Pollutant Removal Database(Winer, 2000) 3: Rabanal and Grizzard 1995 4: Crunki Ito n et a1. (1996) 5: Schueler(1999) 6: Oberts 1994 Both suspended and deposited sediments can have adverse effects on aquatic life in streams, lakes and estuaries. Turbidity resulting from sediment can reduce light penetration for submerged aquatic vegetation critical to estuary health. In addition, the reflected energy from light reflecting off of suspended sediment can increase water temperatures (Kundell and Rasmussen, 1995). Sediment can physically alter habitat by destroying the riffle-pool structure in stream systems and smothering benthic organisms such as clams and mussels. Finally, sediment transports many other pollutants to the water resource. Chapter 2: Impacts of New Development 2_2 Nutrients Runoff from developed land has elevated concentrations of both phosphorus and nitrogen, which can enrich streams, lakes, reservoirs and estuaries. This process is known as eutrophication. Significant sources of nitrogen and phosphorus include fertilizer, atmospheric deposition, animal waste, organic matter, and stream bank erosion. Another nitrogen source is fossil fuel combustion from automobiles, power plants and industry. Data from the upper Midwest suggest that lawns are a significant contributor, with concentrations as much as four times higher than other land uses, such as streets, rooftops, or driveways (Steuer et al., 1997; Waschbusch et al., 2000; Bannerman et al., 1993). Nutrients are of particular concern in lakes and estuaries and are a source of degradation in many of New York's waters. Nitrogen has contributed to hypoxia in the Long Island Sound and is a key pollutant of concern in the New York Harbor and the Peconic Estuary. Phosphorus in runoff has impacted the quality of a number of New York natural lakes, including the Finger Lakes and Lake Champlain, which are susceptible to eutrophication from phosphorus loading. Phosphorus has been identified as a key parameter in the New York City Reservoir system. The New York City DEP developed water quality guidance values for phosphorus for City drinking water reservoirs (NYC DEP, 1999); a source-water phosphorus guidance value of 15 tag/I has been proposed for seven reservoirs (Kensico, Rondout, Ashokan, West Branch, New Croton, Croton Falls, and Cross River) in order to protect them from use-impairment due to eutrophication, with other reservoirs using the State recommended guidance value of 20 tag/I. Organic Carbon Organic matter, washed from impervious surfaces during storms, can present a problem in slower moving downstream waters. Some sources include organic material blown onto the street surface, and attached to sediment from stream banks, or from bare soil. In addition, organic carbon is formed indirectly from algal growth within systems with high nutrient loads. As organic matter decomposes, it can deplete dissolved oxygen in lakes and tidal waters. Declining levels of oxygen in the water can have an adverse impact on aquatic life. An additional concern is the formation of trihalomethane (THM), a carcinogenic disinfection by-product, due to the mixing of chlorine with water high in organic carbon. This is of particular importance in unfiltered water supplies, such as the New York City Reservoir System. Bacteria Bacteria levels in stormwater runoff routinely exceed public health standards for water contact recreation. Some stormwater sources include pet waste and urban wildlife. Other sources in developed land include sanitary and combined sewer overflows, wastewater, and illicit connections to the storm drain system. Bacteria is a leading contaminant in many of New York's waters, and has led to shellfish bed closures in the New York Bight Area, on Long Island, and in the Hudson-Raritan Estuary. In addition, Suffolk, Nassau, and Erie Counties issue periodic bathing-beach advisories each time a significant rainfall event occurs (NRDC, 2000). Hydrocarbons Vehicles leak oil and grease that contain a wide array of hydrocarbon compounds, some of which can be toxic to aquatic life at low concentrations. Sources are automotive, and some areas that produce runoff with high runoff concentrations include gas stations, commuter parking lots, convenience stores, residential parking areas, and streets (Schueler, 1994). Trace Metals Cadmium, copper, lead and zinc are routinely found in stormwater runoff. Many of the sources are automotive. For example, one study suggests that 50% of the copper in Santa Clara, CA comes from brake pads (Woodward-Clyde, 1992). Other sources of metals include paints, road salts, and galvanized pipes. These metals can be toxic to aquatic life at certain concentrations and can also accumulate in the bottom sediments of lakes and estuaries. Specific concerns in aquatic systems include bioaccumulations in fish and macro-invertebrates, and the impact of toxic bottom sediments on bottom-dwelling species. Chapter 2: Impacts of New Development 2-3 Pesticides A modest number of currently used and recently banned insecticides and herbicides have been detected in urban and suburban streamflow at concentrations that approach or exceed toxicity thresholds for aquatic life. Key sources of pesticides include application to urban lawns and highway median and shoulder areas. Chlorides Salts that are applied to roads and parking lots in the winter months appear in stormwater runoff and meltwater at much higher concentrations than many freshwater organisms can tolerate. One study of four Adirondack streams found severe impacts to macroinvertebrate species attributed to chlorides (Demers and Sage, 1990). In addition to the direct toxic effects, chlorides can impact lake systems by altering their mixing cycle. In 1986, incomplete mixing in the Irondequoit Bay was attributed to high salt use in the region (MCEMC, 1987). A primary source of chlorides in New York State, particularly in the State's northern regions, is salt applied to road surfaces as a deicer. Thermal Impacts Runoff from impervious surfaces may increase temperature in receiving waters, adversely impacting aquatic organisms that require cold and cool water conditions (e.g., trout). Data suggest that increasing development can increase stream temperatures by between five- and twelve-degrees Fahrenheit, and that the increase is related to the level of impervious cover in the drainage area (Galli, 1991). Thermal impacts are a serious concern in trout waters, where cold temperatures are critical to species survival. Trash and Debris Considerable quantities of trash and debris are washed through the storm drain networks. The trash and debris accumulate in streams and lakes and detract from their natural beauty. Depending on the type of trash,this material may also lead to increased organic matter or toxic contaminants in water bodies. Snowmelt Concentrations The snow pack can store hydrocarbons, oil and grease, chlorides, sediment, and nutrients. In cold regions, the pollutant load during snowmelt can be significant, and chemical traits of snowmelt change over the course of the melt event. Oberts (1994) studied this phenomenon, and describes four types of snowmelt runoff(Table 2.2). Oberts and others have reported that 90% of the hydrocarbon load from snowmelt occurs during the last 10% of the event. From a practical standpoint, the high hydrocarbon loads experienced toward the end of the season suggest that stormwater management practices should be designed to capture as much of the snowmelt event as possible. Table 2.2 Runoff and Pollutant Characteristics of Snowmelt Stages (Oberts, 1994) Snowmelt Duration/ Runoff Pollutant Characteristics Stage Frequency Volume Pavement Short, but many Acidic, high concentrations of soluble Melt times in winter Low pollutants, chloride, nitrate, lead. Total load is minimal. Roadside Moderate Moderate Moderate concentrations of both Melt soluble and particulate pollutants. Gradual, often Dilute concentrations of soluble Pervious most at end of High pollutants, moderate to high Area Melt concentrations of particulate pollutants, season depending on flow. High concentrations of particulate Rain-on- Short Extreme pollutants, moderate to high Snow Melt concentrations of soluble pollutants. High total load. Chapter 2: Impacts of New Development -4 Section 2.2 Diminishing Groundwater Recharge and Quality The slow infiltration of rainfall through the soil layer is essential for replenishing groundwater. Groundwater is a critical water resource across the State. Not only do many residents depend on groundwater for their drinking water, but the health of many aquatic systems is also dependent on its steady discharge. For example, during periods of dry weather, groundwater sustains flows in streams and helps to maintain the hydrology of non-tidal wetlands. Because development creates impervious surfaces that prevent natural recharge, a net decrease in groundwater recharge rates can be expected in urban watersheds. Thus, during prolonged periods of dry weather, streamflow sharply diminishes. Another source of diminishing baseflow is well drawdowns as populations increase in the watershed. In smaller headwater streams, the decline in stream flow can cause a perennial stream to become seasonally dry. One study in Long Island suggests that the supply of baseflow decreased in some developing watersheds, particularly where the water supply was sewered (Spinello and Simmons, 1992; Figure 2.3). Urban land uses and activities can also degrade groundwater quality, if stormwater runoff is infiltrated without adequate treatment. Certain land uses and activities are known to produce higher loads of metals and toxic chemicals and are designated as stormwaterhotspots. Soluble pollutants, such as chloride, nitrate, copper, dissolved solids and some polycyclic aromatic hydrocarbons (PAH's) can migrate into groundwater and potentially contaminate wells. Stormwater runoff from designated hotspots should never be infiltrated, unless the runoff receives full treatment with another practice. 100 _ ao - 60 40 — -- 1 20 -- r D 1957 1961 1965 1969 1955 1959 1963 1967 Carmans 0 connetquot Massapequa 0 Bellmore Ll Pines Brook Valley Stream Notes: Carrmans and Connetquot: Rural/,suburban, watersheds are unsewered Bellmore and Massapequa: Moderately urbanized, not sewered until 1989 Valley Stream and Pine Brook: Urbanized and densely populated watersheds, sewer systems completed in 1960s 1953.1.964: Period of sanitary sewer construction in eastern Nassau County 1962-1.966. Drought years Figure 2.3 Declining Baseflow in Response to Development Chapter 2: Impacts of New Development 2-5 Section 2.3Impacts to the Stream Cr As pervious meadows and forests are converted into less pervious urban soils, or pavement, both the frequency and magnitude of storm flows increase dramatically. As a result, the bankfull event occurs two to seven times more frequently after development occurs (Leopold, 1994). In addition, the discharge associated with the original bankfull storm event can increase by up to five times (Hollis, 1975). As Figure 2.4 demonstrates, the total flow beyond the "critical erosive velocity" increases substantially after development occurs. The increased energy resulting from these more frequent bankfull flow events results in erosion and enlargement of the stream channel, and consequent habitat degradation. 140 -- Strearnflow —Pre --Past 120 q 16 100 80 60 I) 11 1) 11 I 1 � !a 1 l it i i r cMical l WdWr&Rate) 40 1. r r rt r 'i r 1 i t r i it r l x n i i i i ! r 20 i i Ir i I i i fi D Time Figure 2.4 Increased Frequency of Erosive Flow After Development Channel enlargement in response to watershed development has been observed for decades, with research indicating that the stream channel area expands to between two and five times its original size in response to upland development (Hammer, 1972; Morisawa and LaFlure, 1979; Allen and Narramore, 1985; Booth, 1990). One researcher developed a direct relationship between the level of impervious cover and the "ultimate" channel enlargement, the area a stream will eventually reach overtime (MacRae, 1996; Figure 2.5). 14.UB J 12.00 y =0.0012 +0.0230. + 1 ° 10.00 z 8.00 6.00 ° LU 4.00 a 2.00 ° 0.00 0.1) 10_0 20.0 3n.0 40.0 911.0 611M 7n.n MILD imlierviousness(%) Figure 2.5 Relationship Between Impervious Cover and Channel Enlargement Chapter 2: Impacts of New Development 2-6 Historically, New York has used two-year control (i.e., reduction of the peak flow from the two-year storm to pre-developed levels)to prevent channel erosion, as required in the 1993 SPDES General Permit (GP-93-06). Research suggests that this measure does not adequately protect stream channels (McCuen and Moglen, 1988, MacRae, 1996). Although the peak flow is lower, it is also extended over a longer period of time, thus increasing the duration of erosive flows. In addition, the bankfull flow event actually becomes more frequent after development occurs. Consequently, capturing the two-year event may not address the channel-forming event. This stream channel erosion and expansion, combined with direct impacts to the stream system, act to decrease the habitat quality of the stream. The stream will thus experience the following impacts to habitat(Table 2.3): Decline in stream substrate quality (through sediment deposition and embedding of the substrate) Loss of pool/riffle structure in the stream channel Degradation of stream habitat structure Creation of fish barriers by culverts and other stream crossings (see DEC standard: Stream Crossings: Guidelines and Best Management Practices) Loss of"large woody debris,"which is critical to fish habitat ImpactsTable 2.3 Stream Channel Impact Key Finding Reference Year Habitat Characteristics Interstitial spaces between substrate fill with Embeddedness increasing watershed imperviousness Horner et al. 1996 Important for habitat diversity and Spence et al. 1996 Large Woody Debris anadramous fish. (LWD) Decreased LWD with increases in Booth et al. 1996 imperviousness Altered pool/riffle sequence with Richey 1982 Changes in Stream Features urbanization Loss of habitat diversity Scott et al. 1986 Direct Channel Impacts Reduction in 1 st Order Streams Replaced by storm drains and pipes Dunne and 1972 increases erosion rate downstream Leopold Channelization and hardening Increase instream velocities often leading to Sauer et al. 1983 of stream channels increased erosion rates downstream Metropolitan Fish Blockages Fish blockages caused by bridges and Washington 1989 culverts Council of Governments Section 2.4 Increased Overbank Flooding Flow events that exceed the capacity of the stream channel spill out into the adjacent floodplain. These are termed "overbank" floods and can damage property and downstream structures. While some overbank flooding is inevitable and sometimes desirable, the historical goal of drainage design in New York has been to maintain pre-development peak discharge rates for both the two- and ten-year frequency storm after development, thus keeping the level of overbank flooding the same overtime. This management technique prevents costly damage or maintenance for culverts, drainage structures, and swales. Overbank floods are ranked in terms of their statistical return frequency. For example, a flood that has a 50% chance of occurring in any given year is termed a "2-year" flood. The two-year event is also known as the "bankfull flood," as researchers have demonstrated that most natural stream channels in the State have just enough capacity to handle the two-year flood before spilling out into the floodplain. Although many factors, such as soil moisture, topography, and snowmelt, can influence the magnitude of a particular flood event, designers typically design for the "2-year" storm event. In New York State, the two-year design storm ranges between about 2.0 to 4.0 inches of rain in a 24-hr period. Similarly, a flood that has a 10% chance of occurring in any given year is termed a 10-year flood."A ten-year flood occurs when a Chapter 2: Impacts of New Development 2•7 storm event produces between 3.2 and 6.0 inches of rain in a 24-hr period. Under traditional engineering practice, most channels and storm drains in New York are designed with enough capacity to safely pass the peak discharge from the ten-year design storm. Urban development increases the peak discharge rate associated with a given design storm, because impervious surfaces generate greater runoff volumes and drainage systems deliver it more rapidly to a stream. The change in post- development peak discharge rates that accompany development is profiled in Figure 2.6. Note that this change in hydrology increases not only the magnitude of the peak event, but the total volume of runoff produced. La+ye Higher and More Pre-development Sloan jl$ Rapid Peak Discharge _ post-development 1 � Small f Storm ,f 1,�,/ More Runoff Volume a 1 A, Lower and Less m f Rapid PeakLL f ! f 1 g Higher Baseflaw 1 Gradual 1 w 1 �� �Recession cc ! Vl _ TIME Figure 2.6 Hydrographs Before and After Development Chapter 2: Impacts of New Development 2-8 Section 2.5 Floodplain Expansion In general, floodplains are relatively low areas adjacent to rivers, lakes, and oceans that are periodically inundated. For the purposes of this document, the floodplain is defined as the land area that is subject to inundation from a flood that has a one percent chance of-being equaled or exceeded in any given year. This is typically thought of as the 100-year flood. In New York, a 100-year flood typically occurs after between 5 and 8 inches of rainfall in a 24-hr period (i.e., the 100-year storm). However, snow melt combined with precipitation can also lead to a 100-year flood. These floods can be very destructive and can pose a threat to property and human life. As with overbank floods, development sharply increases the peak discharge rate associated with the 100-year design storm. As a consequence, the elevation of a stream's 100-year floodplain becomes higher and the boundaries of its floodplain expand (see Figure 2.7). In some instances, property and structures that had not previously been subject to flooding are now at risk. Additionally, such a shift in a floodplain's hydrology can degrade wetland and forest habitats. C. RESPONSE OF STREAM GEOMETRY k Floodplain Limit�- PRE-DEVELOPMENT --- 5ummer Low Flow Level tl a c Floodplain Limit P05T-DEVELOPMENT 5ummer Low Flow Level Figure 2.7 Floodplain Expansion with New Development Section 2.6 Impacts to Aquatic Organisms The decline in the physical habitat of the stream, coupled with lower base flows and higher stormwater pollutant loads, has a severe impact on the aquatic community. Research suggests that new development impacts aquatic insects, fish, and amphibians at fairly low levels of imperviousness, usually around 10% impervious cover(Table 2.4). New development appears to cause declining richness (the number of different species in an area or community), diversity (number and relative frequency of different species in an area or community), and abundance (number of individuals in a species). Chapter 2: Impacts of New Development 2- Table 2.4 Research Examining the Relationship of Urbanization to Aquatic Habitat and Organisms JL Watershed Indicator Key Finding Reference Year Location A comparison of three stream types found urban streams had Aquatic insects lowest diversity and richness. Urban streams had substantially Crawford & 1989 North and fish lower EPT scores (22% vs 5% as number of all taxa, 65% vs Lenat Carolina 10% as percent abundance) and IBI scores in the poor range. Insects, fish, Steepest decline of biological functioning after 6% o Horner et Puget Sound habitat, water imperviousness. There was0a steady decline, with approx. 50/o aL 1996 Washington quality of initial biotic integrity at 45/o I. Fish, aquatic A study of five urban streams found that as land use shifted from Masterson insects rural to urban, fish and macroinvertebrate diversity decreased. & 1994 Wisconsin Bannerman Insects, fish, Physical and biological stream indicators declined most rapidly habitat, water during the initial phase of the urbanization process as the May et al. 1997 Washington quality, percentage of total impervious area exceeded the 5-10% range. riparian zone Metropolitan Aquatic insects There was significant decline in the diversity of aquatic insects Washington 1992 Washington, and fish and fish at 10% impervious cover. Council of DC Governments Evaluation of the effects of runoff in urban and non-urban areas Aquatic insects found that native fish and insect species dominated the non- Pitt 1995 California and fish urban portion of the watershed, but native fish accounted for only 7% of the number of species found in urban areas. Wetland Mean annual water fluctuation inversely correlated to plant& plants, amphibian density in urban wetlands. Declines noted beyond Taylor 1993 Seattle amphibians 10% impervious area. Residential urban land use in Cuyahoga watersheds created a significant drop in IBI scores at around 8%, primarily due to Aquatic insects certain stressors that functioned to lower the non-attainment Yoder et. al. 1999 Ohio &fish threshold When watersheds smaller than 100mi2 were analyzed separately, the level of urban land use for a significant drop in IBI scores occurred at around 15%. Aquatic insects All 40 urban sites sampled had fair to very poor index of biotic Yoder 1991 Ohio &fish integrity (IBI) scores, compared to undeveloped reference sites. IBI: Index of Biotic Integrity-A measure of species diversity for fish and macro i nve rte brates EPT: A measure of the richness of three sensitive macro-invertebrates (may flies, caddis flies, and stone flies), used to indicate the ability of a waterbody to support sensitive organisms. Chapter 2: Impacts of New Development 2•10 Section 2.7 Climate Change Resiliency Planning Climate change is expected to cause a range of impacts in New York State, including changes in temperature, precipitation, sea level rise, and frequency of extreme storms. The United Nation's Intergovernmental Panel on Climate Change suggests greenhouse gas emissions from human activities are responsible for accelerating global warming and climate change (Lee et al., 2023). Higher temperatures, more frequent precipitation and severe storms, faster rates of ocean warming, and sea level rise are some of the key physical effects that are impacting communities and ecosystems around the world. New York State is predicted to experience these same challenges from a rapidly changing climate (NYSDEC 2021, NYSERDA 2023) including: Increasing Temperature: Temperatures across NYS are expected to rise, which is further stressed by materials in the built environment that absorb the sun's heat throughout the day (Urban Heat Island effect), drive localized temperatures higher and increase the temperature of stormwater runoff entering heat-vulnerable environments. Increasing Precipitation: The intensity and frequency of precipitation events are projected to increase, resulting in significant increases in stormwater runoff and the potential for stormwater management and conveyance systems to be overwhelmed, leading to exacerbated or new sources of water quality pollution, and more frequent and severe flooding (USEPA 2023). Rising Sea Level: Flooding already impacts parts of the State and is projected to worsen as sea levels rise and inundate low-lying coastal areas during high tides. Shifting Ecology: Studies indicate that regional ecology, including significant and natural communities, will shift with the change in climate. To strengthen New York's resiliency to these risks, the Community Risk and Resiliency Act (CRRA) was adopted. The scale of impacts from climate change will vary across the state, and it is anticipated that climate change will result in chronic erosion, flooding, severe property damage and loss of ecological species. Guidance related to climate resilient SMP design will be made available in a future version of the Design Manual. At this time, the following guidance documents have been issued by the NYSDEC and can be found on their website. They can be used as a reference for the design of climate change mitigation measures: Using Natural Measures to Reduce the Risk of Flooding and Erosion New York State Flood Risk Management Guidance for Implementation of the Community Risk and Resiliency Act New York State Flood Risk Management Guidance for Implementation of the Community Risk and Resiliency Act Estimating Guideline Elevations Tidal Wetlands Guidance: Living Shoreline Techniques in the Marine District of New York State At a minimum, to the extent practicable and where achievable, construction activities and stormwater management within New York State should incorporate green infrastructure concepts to reduce overall stormwater runoff and improve water quality in new construction and redevelopment projects. Infrastructure should be designed and built to account for projected climate change impacts which may occur over their lifespans. This includes incorporating climate projections and adaptation strategies in upfront design and in expected operations and management. Preservation of open space and nature-based solutions should be considered as strategies for reducing peak stormwater discharge and overall climate risk mitigation. Chapter 2: Impacts of New Development 2m 11 The average life span of stormwater management and control structures varies depending on the type and material used but typically ranges anywhere from 20— 100 years. As a result of their long lifespan their design should: Attempt to account for the range of expected climate driven changes to average precipitation and potential peak flows that can be expected over the life of the structure. Should consider the increasing frequency and higher volumes of extreme precipitation events and the likelihood of increased potential for flooding due to climate change. In New York State, precipitation is generally projected to increase over time due to climate change by as much as 20% but will likely vary by region (NYSERDA 2014). Similarly, average flood peak flows are expected to increase by 10 to 20% (NYSDEC 2020). These adjustments should be factored into the design and construction of new stormwater management and control structures to ensure they sufficiently account for the effects of climate change, reducing future flood risk and protecting New York State's water quality. As noted above, while specific climate resilient SMP design will be incorporated into future versions of the design manual, project owners/operators should, at a minimum, begin incorporating climate change mitigation measures wherever possible, including sufficient design capacity for projected increases in precipitation and peak flows, green infrastructure, nature-based solutions, and open space preservation. Designers should document these management and design considerations in the Stormwater Pollution Prevention Plan (SWPPP). References Lee, H., Calvin, K., Dasgupta, D., Krinner, G., Mukherji, A., Thorne, P., Trisos, C., Romero, J., Aldunce, P. and Ruane, A.C., 2023. CLIMATE CHANGE 2023 Synthesis Report Summary for Policymakers. CLIMATE CHANGE 2023 Synthesis Report: Summary for Policymakers. NYSERDA. 2014. Climate Change in New York State: Updating the 2011 ClimAID Climate Risk Information. Supplement to NYSERDA Report 11-18. New York State Energy Research and Development Authority. Albany, New York. 24 pgs. NYSERDA. 2023. New York State Energy Research and Development Authority. Climate Change, November 9, 2023. httos://www.nvserda.nv.ciov/All-Programs/Environmental-Research/Climate-Change- Research. NYSDEC. 2020. New York State Flood Risk Management Guidance for Implementation of the Community Risk and Resiliency Act. New York State Department of Environmental Conservation. Albany, New York. 100 pgs. NYSDEC. 2021. Observed and Projected Climate Change in New York State: An Overview. New York State Department of Environmental Conservation. Albany, New York. 38 pgs. USEPA. 2023. United States Environmental Protection Agency. Climate Adaptation and Stormwater Runoff, November 9, 2023. httr)s://www.er)a.gov/arc-x/climate-adaptation-and-stormwater-runoff. 2-12 Chapter 3: Stormwater Management Planning This Chapter presents a required planning process that must be followed when addressing stormwater management in new development and redevelopment projects. This process is intended to guide the designer through steps that maintain pre-construction (Note: For new development, the pre-construction terminology indicates pre-development or natural conditions) hydrologic conditions of the site by application of environmentally-sound development principles, such as runoff reduction techniques, as well as treatment and control of runoff discharges from the site. Section 3.1 Introduction The increased emphasis on a holistic approach to resource protection, water quality treatment, flow volume control, maintenance cost reduction, and the dynamics of stormwater science has led to several changes in stormwater management. Carrying out stormwater management design standards for the past few years has provided the regulatory agencies, regulated entities, and design community with valuable experiences and a body of knowledge to enhance and improve urban runoff planning, methodologies, and techniques towards implementation of runoff reduction techniques. In the context of stormwater management, the term runoff reduction technique includes a wide array of practices at multiple scales to manage and treat stormwater, maintain and restore natural hydrology and ecological function by infiltration, evapotranspiration, capture and reuse of stormwater, and establishment of natural vegetative features. On a regional scale, runoff reduction techniques are the preservation and restoration of natural landscape features, such as forests, floodplains and wetlands, coupled with policies such as infill and redevelopment that reduce overall imperviousness in a watershed or ecoregion. On the local scale runoff reduction techniques consists of site- and neighborhood-specific practices. Such practices essentially result in runoff reduction and or establishment of habitat areas with significant utilization of soils, vegetation, and engineered media rather than traditional hardscape collection, conveyance and storage structures. Some examples include green roofs, trees and tree boxes, pervious pavement, rain gardens, vegetated swales, planters, reforestation, and protection and enhancement of riparian buffers and floodplains. Planners and designers must address this approach in a six step process that involves site planning and stormwater management practice (SMP) selection to meet the sizing criteria outlined in Chapter 4. The six steps include: Step 1. Site Planning: provide an evaluation of the site's feasibility for implementation of each green infrastructure planning measure, in order to preserve natural resources and reduce impervious cover. Step 2. Calculate Water Quality Volume (WQv) for the site. Step 3.Apply Runoff Reduction techniques and standard SMPs with Runoff Reduction Volume (RRv) capacity to reduce total WQv. If 100% of the required WQv cannot be reduced, provide an evaluation of the site's feasibility for application of each runoff reduction technique and standard SMP with RRv capacity. Step 4. If applicable, calculate the minimum RRv required. Step 5. If applicable, apply standard SMPs to treat the remaining portion of WQv that was not addressed in Step 3 by runoff reduction techniques and standard SMPs with RRv capacity. Step 6.Apply volume and peak rate control practices, where required, to meet quantity control criteria. Refer to Section 3.6 and the flow chart in Figure 3.3, for more detailed information on the six step process. For detailed information on the State Pollutant Discharge Elimination System ("SPDES") General Permit for Stormwater Discharges from Construction Activity, as well as environmental permits under the Uniform Procedures Act (UPA) consult DEC website at http://www.dec.ny.gov/chemical/8468.html. Chapter 3:Stormwater Management Planning 3-1 Section 3.2 Runoff Reduction Techniques for Stormwater Management The runoff reduction approach for stormwater management reduces a site's impact on the aquatic ecosystem through the use of site planning measures, runoff reduction techniques, and certain standard SMPs with RRv capacity. The objective is to replicate pre-development hydrology and provide groundwater recharge by maintaining pre-construction infiltration, peak runoff flow, discharge volume, as well as minimizing concentrated flow by using runoff control techniques to provide treatment in a distributed manner before runoff reaches the collection system. This approach offers a distinct advantage over conventional "hard"stormwater infrastructure by reducing the production of runoff and the need for collection, storage, and treatment. When implemented throughout a development and watershed, runoff reduction techniques can (Coffman, 2002 and USEPA, 2007): Reduce runoff volume, peak flow, and flow duration Slow down the flow to increase time of concentration and promote infiltration and evapotranspiration Improve groundwater recharge Protect downstream water resources, including wetlands Reduce downstream flooding and property damage Reduce incidence of combined sewer overflow (CSOs) Provide water quality improvements/reduced treatment costs Reduce thermal pollution Improve wildlife habitat For the greatest level of success at reducing the negative effects of stormwater, this approach must be incorporated into an iterative site planning and design process. During the iterative site planning and design process, the designer shall try implementing various combinations of runoff reduction techniques (described in this section) and certain standard SMPs with RRv capacity (described in Section 3.3 and Section 3.6) to address stormwater runoff so that the RRv requirement is met. The design and layout of stormwater management features shall be conducted in unison with site planning and runoff reduction objectives. This approach has three primary components that mitigate the effects of stormwater runoff from development: Avoiding the Impacts—Avoid or minimize disturbance by preserving natural features and using conservation design techniques Reducing the Impacts—Reducing the impacts of development by reducing impervious cover Managing the Impacts—Manage the impacts by using natural features and runoff reduction practices to slow down the runoff, promote infiltration and evapo-transpiration, and consequently minimizing the need for the structural"end-of-pipe"practices Runoff reduction techniques are highly effective when used to address stormwater runoff from smaller, more frequent storms. As precipitation size and intensity increase, pervious surfaces become less capable of infiltrating runoff and their peak flow reduction "benefits" diminish. Thus, runoff reduction is not generally sufficient to achieve volume and peak rate control for larger storms. Additional volume and peak rate control practices for meeting quantity control objectives must be documented in the Stormwater Pollution Prevention Plan (SWPPP). Exceptions to Meeting the Runoff Reduction Volume (RRv) Criteria: Although encouraged, meeting the RRv criteria is not required for redevelopment activities that meet the criteria in Chapter 9 of this manual. Meeting the RRv criteria is required for projects over karst geology. However, the use of large infiltration basins must be avoided. A geotechnical assessment is recommended for infiltration and recharge at small scales. For projects that meet the "hotspot" criteria in Section 4.14 of this manual, designers shall use non-infiltration type practices, or two treatment practices in series (i.e. non-infiltration standard SMP/ runoff reduction technique, followed by an infiltration practice) to meet the RRv criteria. Chapter 3:Stormwater Management Planning 3- A summary of the green infrastructure planning measures and runoff reduction techniques covered in this Manual can be found in Table 3.1 and Table 3.2, respectively. The runoff reduction planning measures, presented in Table 3.1, are practices that indirectly result in runoff reduction. The runoff reduction techniques, presented in Table 3.2, are practices for which runoff reduction is quantified. Complete definition, design criteria, and sizing criteria for runoff reduction Techniques are presented in Chapter 5 of this manual. CategoriesTable 3.1 Green Infrastructure Planning General Group Practice Description Preservation of Delineate and protect undisturbed forests, native vegetated areas, riparian Undisturbed Areas corridors,water bodies, wetlands, and natural terrain. Preservation of Delineate and protect naturally vegetated buffers along perennial streams, Buffers rivers, shorelines, and wetlands. Reduction of Clearing Limit clearing and grading to the minimum amount needed for roads, and Grading driveways, foundations, utilities and stormwater management facilities. Preservation Locating Avoid sensitive resource areas such as floodplains, steep slopes, erodible of Natural Development in Less soils, wetlands, mature forests and critical habitats by locating Resources Sensitive Areas development to fit the terrain in areas that will create the least impact. Open Space Design Use clustering, conservation design or open space design to reduce impervious cover, preserve more open space and protect water resources. Restore the original properties and porosity of the soil by deep till and Soil Restoration amendment with compost to reduce the generation of runoff and enhance the runoff reduction performance of practices such as grass channels, filter strips, and tree clusters. Roadway Reduction Minimize roadway widths and lengths, below local requirements, to reduce site impervious area. Sidewalk Reduction Minimize sidewalk lengths and widths, below local requirements, to reduce site impervious area. Driveway Reduction Minimize driveway lengths and widths, below local requirements, to reduce site impervious area. Reduction of Minimize the number of cul-de-sacs and incorporate landscaped areas to Impervious Cul-de-sac Reduction reduce their impervious cover. Cover Building Footprint Reduce the impervious footprint of buildings by using alternate or taller Reduction buildings while maintaining the same floor to area ratio. Reduce imperviousness on parking lots by eliminating unneeded spaces, providing compact car spaces and efficient parking lanes, reducing stall Parking Reduction dimensions below local requirements, using porous pavement surfaces in overflow parking areas, and using multi-storied parking decks where appropriate. Chapter 3:Stormwater Management Planning -3 or Table 3.2 Acceptable Runoff Reduction Techniques Group Practice Description Retain the pre-development hydrologic and water quality characteristics of Conservation of undisturbed natural areas by permanently conserving these areas on a site. Natural Areas(RR-1) Undisturbed natural areas include: forest retention areas; reforestation areas; stream and river corridors; shorelines; wetlands, vernal pools, and associated vegetated buffers; and undisturbed open space. Sheet flow to Riparian Undisturbed natural areas such as forested conservation areas and stream Buffers/Filter Strips buffers or vegetated filter strips and riparian buffers can be used to treat and (RR-2) control stormwater runoff from some areas of a development project. Tree Planting/Tree Plant or conserve trees to reduce stormwater runoff, increase nutrient uptake, Pit/Tree Trench and provide bank stabilization. Trees can be used for applications such as (RR-3) landscaping, stormwater management practice areas, conservation areas and erosion and sediment control. Disconnection of Direct runoff from rooftop areas and upland overland runoff flow to designated Rooftop Runoff pervious areas to reduce runoff volumes and rates. (RR-4) The natural drainage paths, or properly designed vegetated channels, can be Vegetated Swale used instead of constructing underground storm sewers or concrete open (RR-5) channels to increase time of concentration, reduce the peak discharge, and Runoff provide infiltration. Reduction Manage and treat small volumes of stormwater runoff using a conditioned Techniques Rain Garden (RR-6) planting soil bed and planting materials to filter runoff stored within a shallow depression. Small, landscaped stormwater treatment devices that can be designed as Stormwater Planter infiltration or filtering practices. Stormwater planters use soil infiltration and (RR-7) biogeochemical processes to decrease stormwater quantity and improve water quality. Rainwater Harvesting Capture and store stormwater runoff to be used for irrigation systems or filtered System(RR-8) and reused for non-contact activities. Pervious types of pavements that provide an alternative to conventional paved Porous Pavement surfaces, designed to infiltrate rainfall through the surface, thereby reducing (RR-9) stormwater runoff from a site and providing some pollutant uptake in the underlying soils. Capture runoff by a layer of vegetation and soil installed on top of a conventional Green Roof(RR-10) flat or sloped roof. The rooftop vegetation allows evaporation and evapotranspiration processes to reduce volume and discharge rate of runoff entering conveyance system. Stream Daylighting Stream Daylight previously culverted/piped streams to restore natural habitats, (RR-11) better attenuate runoff by increasing the storage size, promoting infiltration, and help reduce pollutant loads. Chapter 3:Stormwater Management Planning 3-4 Section 3.3 Standard Stormwater Management Practices for Treatment This section presents a list of standard stormwater management practices (SMPs) that are acceptable for water quality treatment, data justifying the use of these practices, and the minimum criteria for addition of new practices to the list. The practices on the acceptable list have been selected based on the following criteria: 1. Can capture and treat the full water quality volume (WQv). 2. Are capable of 80% TSS removal and 40% TP removal. 3. Have acceptable longevity in the field. 4. Have a pretreatment device. Standard SMPs are structural practices designed to capture and treat the water quality volume (the portion infeasible to retain on-site using runoff reduction techniques) through one or more pollutant removal pathways. Their performance is documented by removal efficiency of specific pollutants. Standard SMPs are often cited as "end-of-pipe"treatment systems, designed to function as storage or flow-through systems. 3.3.1 Practice List Practices on the acceptable list will be presumed to meet water quality requirements set forth in this manual if designed in accordance with the sizing criteria presented in Chapter 4, constructed in accordance with the performance criteria in Chapter 6, and properly maintained in accordance with the prescribed maintenance criteria presented in Chapter 12. Acceptable practices are divided into five groups, including: Stormwater Ponds: Practices that have either a permanent pool of water or a combination of permanent pool and extended detention capable of treating the WQv. Stormwater Wetlands: Practices that include significant shallow marsh areas and may also incorporate small permanent pools and extended detention storage to achieve the full WQv. Infiltration Practices: Practices that capture and temporarily store the WQv before allowing it to infiltrate into the soil. Filtering Practices: Practices that capture and temporarily store the WQv and pass it through a filter bed of sand, soil, or other acceptable treatment media. Open Channel Practices: Practices explicitly designed to capture and treat the full WQv within dry or wet cells formed by check dams or other means. The following Table provides a summary of the standard SMPs acceptable for water quality treatment. Refer to the Standard SMP Feasibility Matrix and the one-page practice Fact Sheets in Chapter 6, for assistance in selection and suitability of each standard SMP. Chapter 3:Stormwater Management Planning - e e , e • NNW • e e • !� , Group Practice Description Micropool Extended Detention Pond that treats the majority of the water quality volume through extended Pond (P-1) detention and incorporates a micropool at the outlet of the pond to prevent sediment resuspension. Wet Pond (P-2) Pond that provides storage for the entire water quality volume in the permanent Pond pool. Wet Extended Detention Pond Pond that treats a portion of the water quality volume by detaining storm flows (P-3) above a permanent pool for a specified minimum detention time. Multiple Pond System(P-4) A group of ponds that collectively treat the water quality volume. Shallow Wetland (W-1) A wetland that provides water quality treatment entirely in a wet shallow marsh. Extended Detention Wetland A wetland system that provides some fraction of the water quality volume by (W-2) detaining storm flows above the marsh surface. A wetland system that provides a portion of the water quality volume in the Pond/Wetland System(W-3) permanent pool of a wet pond that precedes the marsh for a specified minimum Wetland detention time. A shallow wetland design adapted for the treatment of runoff from small drainage Pocket Wetland (W-4) areas that has variable water levels and relies on groundwater for its permanent pool. Gravel Wetland (W-5) A wetland system filled with crushed stone that allows water quality volume to flow subsurface through the root zone. Infiltration Trench (1-1) An infiltration practice that stores the water quality volume in the void spaces of a gravel trench before it is infiltrated into the ground. Infiltration Basin (1-2) An infiltration practice that stores the water quality volume in a shallow depression, before it is infiltrated it into the ground. Infiltration An infiltration practice that includes a shallow excavation filled with stone or an Dry Well (1-3) underground perforated structure surrounded by stone, that is designed to intercept and temporarily store runoff to promote infiltration into the surrounding native soils. An infiltration practice below grade that stores the water quality volume in pre- Underground Infiltration (1-4) manufactured pipes, vaults or other modular structures, before it is infiltrated into the ground. Surface Sand Filter(F-1) A filtering practice that treats stormwater by settling out larger particles in a sediment chamber, and then filtering stormwater through a sand matrix. Underground Sand Filter(F-2) A filtering practice that treats stormwater as it flows through underground settling and filtering chambers. Perimeter Sand Filter(F-3) A filter that incorporates a sediment chamber and filer bed as parallel vaults Filtering adjacent to a parking lot. Practices A shallow depression that treats stormwater as it flows through a soil matrix and is Filtration Bioretention (F-4) returned to the storm drain system. Infiltration Bioretention (F-5) A shallow depression that treats stormwater as it flows through a soil matrix, before it is infiltrated into the ground. Permeable engineered soil media that is installed along embankments or other Bioslope(F-6) slopes, designed to capture and treat stormwater runoff from adjacent impervious surfaces. Dry Swale(0-1) An open drainage channel or depression explicitly designed to detain and promote Open the filtration of stormwater runoff into the soil media. Channels An open drainage channel or depression designed to retain water or intercept Wet Swale(O-2) groundwater for water quality treatment. Chapter 3:Stormwater Management Planning - 3.3.2 Criteria for Practice Addition The stormwater field is always evolving, and new technologies constantly emerge. The New York State Department of Environmental Conservation supports the development of innovative practices, provided the runoff reduction requirements are met, and allows the use of manufactured systems where specific site conditions demand. However, the Department currently does not have a stormwater management practice verification process in place. Instead, the Department relies on the verification and certification process, being implemented by other regulatory agencies with technical standards similar to those of New York State, to identify the alternative practices that are acceptable for installation in New York State. The goals for performance of practices remain consistent with the performance criteria as stated in Section 3.3 of this Manual. A list of acceptable sources of verification for new stormwater management practices is provided on the Department's website. All proposed alternative stormwater management practices in new construction are considered to be in deviation from State Standards. Such practices must provide a full description to justify the reason(s) for deviation as well as detailed justification on how the proposed practice is equivalent to the standards defined in this Design Manual. In order to be in compliance with the technical standards, projects must meet both required performance and sizing criteria. All proposed alternative practices must at minimum meet the sizing criteria as defined in Chapter 4 of this Design Manual. The equivalency of the performance of the proposed new technologies to the performance criteria required by the State of New York must be verified and certified by one of the sources accepted by the Department and documented in the SWPPP. All design and plan review professionals must adhere to the design parameters that constitute the removal efficiency equivalent to the Department's performance criteria (80% TSS removal and 40% phosphorus removal). Specific requirements for redevelopment applications are addressed in Chapter 9 of this Design Manual. Section 3.4 Quantity Controls Quantity control practices are systems that are primarily designed for channel protection, safe conveyance of the flow, and flood control. Most quantity control facilities are structural systems that provide detention and control discharge rate. Some examples of quantity control practices include detention ponds, underground storage vaults (chambers, large diameter pipe), and blue roofs. Additional standard SMPs can be used to provide quantity control, based on the sizing criteria outlined in Chapter 5 and Chapter 6. Examples of practices that provide quantity control only are presented in Table 3.4. Table 3.4 Stormwater Management Practices for Stormwater Quantity Control Group Practice Description Dry detention basins and dry extended detention basins are surface facilities Dry Detention intended to provide for the temporary storage of stormwater runoff to reduce downstream water quantity impacts. Above ground systems Blue roofs (rooftop detention systems)are constructed by installing slotted Blue Roofs flow restriction devices known as collars or restrictors around the roof drains of flat, structurally sound, waterproof roofs. By this mechanism, stormwater is detained on the roof and the peak rate of discharge is reduced. An underground storage system is a subsurface stormwater system suitable for sites within high-density urban areas. Such systems are designed as an Underground Underground Storage Vaults arched structure, a vault or large diameter pipe and function in both systems (chambers, pipes) permeable and non-permeable soils for subsurface detention of stormwater runoff or infiltration. Chambers, vaults or pipes can decrease the peak flow when used with a controlled flow orifice at the outlet. Chapter 3:Stormwater Management Planning •7 Section 3.5 Maintenance Requirements The responsibility for implementation of long-term operation and maintenance of a post-construction stormwater management practice shall be vested with a responsible party by means of a legally binding and enforceable mechanism, such as a maintenance agreement, deed covenant or other legal measure. This mechanism shall protect the practice from neglect, adverse alteration and/or unauthorized removal. The mechanism and Operation and Maintenance (O&M) plan must be included in the SWPPP. At a minimum, the O&M plan must address each of the following: An owner of a post-construction stormwater management practice (including runoff reduction techniques, standard SMPs, and alternative STO_ MWATER practices), shall erect or post a sign, in the immediate vicinity of each stormwater management practice, except for open channel practices and bioslopes along high-speed limited access highways; or WETPOND roads defined as interstates, freeways and expressways, or principal arterials by the United States Department of Transportation. Materials must conform to local, regulatory and/or funding agency requirements. OPERATION See Figure 3.1 for an example. The sign(s) shall have minimumACCORDANCE _'' MAINTENANCE dimensions of 18 inches by 24 inches and shall have white letters on a NOT BE REMOVED ,. ALTERED. green background and contain the following information: Stormwater Management Practice Figure 3.1 Example Post-Construction (Insert name of practice) Stormwater Management Practice Sign (Insert SPDES Construction Permit#) Practice must be maintained in accordance with Operation & Maintenance plan. THIS SIGN MAY NOT BE REMOVED OR ALTERED. Alternatively, the owner may erect or post one comprehensive sign, in a highly visible area, that lists all stormwater management practices within the project site. The comprehensive sign shall include keyed numbers that correspond to each practice on site. With this approach, additional simplified signs shall be erected at each individual practice; excluding RR-2, RR-3, and RR-4; depicting their keyed number. For any practice or pretreatment device that has unrestricted access to ponded water of 3 ft or more, provide an 18"x12"warning sign per p� Figure 3.2. Materials must conform to local, regulatory and/or funding V Y 1111► R N I N G agency requirements. The sign shall have a white background, a black border and text, and red "Warning"text. Where a practice is enclosed WATER DEPTH = X FT with a fence, the practice shall be considered restricted, and the sign POSSIBLE POLLUTANTS IN WATER not required. SWIMMING,WADING Identification of the entity that will be responsible for long term operation AND SKATING PROHIBITED and maintenance of the stormwater management practices. IL Identification of the mechanism(s) that will be used to ensure long term Figure 3.2 Warning Sign operation and maintenance of the stormwater management practices (Deed covenant, easements/rights-of-way, executed maintenance agreement, etc.). Include a copy of such mechanism. A copy of the site plan identifying all practices locations on site. A copy of the schematics of the practice,with the measurements of design specifications clearly defined. A list of maintenance requirements (already defined in this Design Manual and the additional site-specific requirements), proper frequency, and a maintenance log for tracking and observation. Chapter 3:Stormwater Management Planning -3 Stormwater management using runoff reduction techniques is summarized in the six step process described below, and as shown in the flow chart in Figure 3.3. Designers are required to adhere to the six step process when developing a SWPPP. This includes providing information in the SWPPP, which documents compliance with the required process. For projects with redevelopment activities, see Chapter 9 for Step 3 redevelopment criteria. For urban development and redevelopment projects refer to Chapter 8 for urban design considerations. Step 1:Site Planning Refer to Chapter 5 section 5.1-5.2 Step 2:Determine Water Quality Volume(WQv) Refer to Chapter 4 Section 4.1 Step 3:Runoff Reduction by Applying Runoff Reduction Techniques and SNIPS with RRv Capacity Refer to Chapter 5 Section 5.3 and Chapter 6 Section 6.3-6.5 Is RRv>WQv Are there site limitations tha excuse 100%reduction of WQv 14n Has all neF— �— Has a justification of imperv1 " infeasibility been made directed for those areas not pra directed e= .— Y"es Step 6:Apply volume and peak St rate control practices ep 4:Determine minimum RRv required Refer to Chapter 4 Section 4A-4.6 rdi7 Is RR`,,>Min"RRv<i> 1"zw "i e= Complete Plan Step 5:Apply SV[Ps to address remaining WQv Refer to Chapter 6 Figure 3.3 Stormwater Site Planning and Practice Selection Flow Chart Chapter 3:Stormwater Management Planning 3-9 Step 1: Site Planning In Step 1, the designer uses practices identified in Table 3.1 to protect natural resources and utilize the hydrology of the site before laying out the proposed development. The Preservation of Natural Resources practices (see Table 3.1) include protecting natural areas, avoiding sensitive areas and minimizing grading and soil disturbance. The designer then considers practices to reduce impervious cover when laying out the initial site design. The Reduction of Impervious Cover practices (see Table 3.1) include conservation design and reducing impervious cover in roads, driveways and parking lots. The SWPPP must include an evaluation of all the green infrastructure planning measures as they apply to the site. This evaluation process requires the following measures: Developing a map that identifies natural resource areas and drainage patterns; including but not limited to: o Wetlands (jurisdictional, wetland of special concern) o Waterways (major, perennial, intermittent, springs) o Buffers (stream, wetland, forest, etc.) o Floodplains o Forest, vegetative cover o Critical areas o Topography (contour lines, existing flow paths, steep slopes, etc.) o Soil (hydrologic soil groups, highly erodible soils, etc.) a Bedrock, significant geology features Devising the strategies for protection and enhancement of natural resources o Prior to site layout, preserve natural features (site fingerprinting) o Utilize natural features to preserve the natural hydrology o Maintain natural drainage design points o Maximize retention of forest cover and undisturbed soils o Avoid erodible soils on steep slopes and limit mass grading Reducing the impacts of development by reducing impervious surfaces Demonstrating that all reasonable opportunities for preserving natural conditions of the site are employed to minimize the runoff and maintain the pre-construction hydrology During the planning step, the designer should check with the municipality to determine if there are local laws and ordinances that regulate wetlands, stream buffers, forest or habitat protection, erosion control or grading. If present, the local regulations will determine minimum areas of protection that the designer can then expand upon to maximize runoff reduction objectives. The designer should also consult the municipality for laws relating to conservation or cluster design, roads, driveways and parking lots to determine the level of flexibility in reducing impervious surfaces. This component of the plan must also be clearly addressed in the Erosion and Sediment Control (ESC) Plan (Development of ESC plan is provided in the New York Standards and Specifications for Erosion and Sediment Control). Description and minimum requirements for meeting site planning principles are presented in Chapter 5 of this Manual. Chapter 3:Stormwater Management Planning 3•1 The choices made by the designer should be influenced to some extent by the resource(s) being protected, and the region of New York State where the site is located. The following matrix (Table 3.5) presents some design considerations for six watershed or regional factors in New York: Sensitive Streams: The guidance presented here should apply to all trout waters and Class N waters, and any streams that support high biodiversity and water quality and have a low density of development. Aquifers: In sole source aquifers, special care should be taken to select practices and incorporate design considerations that protect the groundwater quality. The EPA"Map of Sole Source Aquifer Locations" (www.epa.gov) depicts sole source aquifers in the State of New York. Lakes: Lakes are of particular concern in New York, which has many natural lake systems and borders on two Great Lakes. The information in this matrix focuses on phosphorous removal, which is an important concern in most lake systems. It is important to note, however, that many lakes in New York State have other important issues to address. Some lakes, such as Onondaga Lake, have other specific concerns, such as toxics and metals. Each community should also take these goals into consideration when reviewing site plans. Reservoirs: For drinking water reservoirs, and in particular for unfiltered water supplies such as the New York City Reservoir system, turbidity, phosphorous removal, and bacteria are of particular concern. A particular reservoir may have other specific concerns, which should be identified as part of a Source Water Assessment. Estuary/Coastal: In New York State, coastal or estuary areas include the South Shore Estuary Reserve, Peconic Estuary, NY/NJ Harbor, and Hudson River Estuary. In these areas, nitrogen is typically a concern due to potential eutrophication. In addition, bacteria control is important to protect shellfish beds. Chapter 3:Stormwater Management Planning 3-11 Table 3.5 Watershed/Regional Selection Matrix ff SMP Sensitive Stream Aquifer Lakes Reservoir Estuary/Coastal Group Emphasize channel protection. Restrict in-stream practices. Encourage long Ponds May require liner if Encourage the use of detention times to HSG A soils are a large permanent promote bacteria In trout waters, minimize present. Encourage the use pool to improve removal. permanent pool area, of a large sediment and extended detention time Pretreat 100%of WQv permanent pool to phosphorous removal. and encourage shading. from hotspots. improve Provides high nitrogen removal. Require channel phosphorus Promote long protection. Provide a 2' removal. detention times to In flat coastal areas, a separation distance to encourage bacteria water table. removal. pond drain may not be Wetlands Restrict i. stream feasible. practices. Restrict use in trout waters. OK, but provide a Strongly encourage use separation distance to Provide a 100' seasonal high water for groundwater Provide 100' horizontal separation table. recharge. horizontal separation distance from wells distance from public OK. Provides high Infiltration phosphorus or private reservoirs In the sand soils Combine with a and 4'vertical removal. y detention facility to distance from the typical of coastal provide channel water table. Pretreat runoff prior to areas, additional protection. infiltration practices. pretreatment may be required (See Section 6.3.3) Excellent Moderate to high pretreatment for coliform en OK, but designs infiltration or o Combine with a Excellent with a submerged p removal Filtering detention facility to pretreatment for g channel practices. Systems provide channel infiltration or open filter may result in phosphorus igns with a submerged protection. channel practices. release. Moderate to filter bed appear to high coliform have very high nitrogen removal removal Combine with a OK, but hotspot runoff OK. Moderate Open detention facility to must be adequately phosphorous Poor coliform removal Poor coliform removal Channels provide channel pretreated removal. for wet swales. for grass wet swales. protection. Chapter 3:Stormwater Management Planning 3_1 Step 2: Calculate Water Quality Treatment Volume (WQv) In Step 2, the designer calculates the required WQ for the site using the criteria in Chapter 4. Once the preliminary site layout is prepared, impervious areas are defined, and sub-catchments are delineated, the designer should calculate the water quality volume. This initial calculation of WQ may have to be revised after runoff reduction techniques are applied. Step 3: Apply Runoff Reduction Techniques and Standard SMPs with RRv Capacity to Reduce Total WQv In Step 3, the designer experiments with combinations of runoff reduction techniques and standard SMPs with RRv capacity on the site. In each case, the designer estimates the spatial area to be treated by each runoff reduction technique, potentially reducing the required WQv by incorporating runoff reduction techniques or standard SMPs with RR capacity within each drainage area on the site. The runoff reduction techniques are listed in Table 3.6, and are divided into two categories for Area Reduction and Volume Reduction. For each runoff reduction technique, a designer can apply the following percentages of WQv towards meeting the RRv sizing criteria, provided the design of the practice complies with the design and sizing criteria in Chapter 5: CapacityTable 3.6 Runoff Reduction Runoff Reduction Technique with RRv RRv Capacity(%of WQv reduced by practice) Capacity Runoff Reduction Techniques(Area Reduction) Conservation of Natural Areas 100% Sheet flow to Riparian Buffers/Filter Strips 100% Tree Planting 100% Disconnection of Rooftop Runoff 100% Runoff Reduction Techniques(Volume Reduction) Tree Pit'/Tree Trench' 100%for tree pits without underdrains and tree trenches 40%for tree pits with underdrains 20% in HSG A or B 10% in HSG C or D Vegetated Swale 15% in Amended HSG Cz 12% in Amended HSG Dz 100%without underdrains Rain Garden' 40%with underdrains 100%without underdrain Stormwater Planter' 40%with underdrains Rainwater Harvesting System 100% 100%without underdrains Porous Pavement 40%with underdrains Green Roof 100% 'For practices with underdrains that require sizing the surface area of the filter bed using Darcy's Law,the designer can elect to oversize the surface area of the filter bed to provide additional storage volume and receive additional RRv credit up to 100%of the WQv required.The total RRv credit shall be the percentage, noted above,applied to the storage volume provided.The storage volume provided shall be considered the volume within the filter media and the volume of ponding occurring during the WQv event. ZAmendments shall be in accordance with Section 5.1.6 Soil Restoration and Section 5.3.4.3.2 Material Specifications. Chapter 3:Stormwater Management Planning 3.13 The standard SMPs with RRv capacity are listed in Table 3.7. For each standard SMP with RRv capacity, a designer can apply the following percentages of WQv towards meeting the RRv sizing criteria, provided the design of the practice complies with the design and sizing criteria in Chapter 6: CapacityFMr Table 3.7 Runoff Reduction d. SMP RRv Capacity(%of WQv reduced by practice) Infiltration Practices 100% Infiltration Bioretention 100% Filtration Bioretention' 40% 40% in HSG A or B Bioslope 20% in HSG C or D 40% in HSG A or B Dry Swale 20% in HSG C or D 'For practices with underdrains that require sizing the surface area of the filter bed using Darcy's Law,the designer can elect to oversize the surface area of the filter bed to provide additional storage volume and receive additional RRv credit up to 100%of the WQv required.The total RRv credit shall be the percentage,noted above,applied to the storage volume provided.The storage volume provided shall be considered the volume within the filter media and the volume of ponding occurring during the WQv event. If the standard SMPs with RRv capacity listed above are being implemented to address the RRv criteria, the practices must be designed to capture runoff near the source. The practices must be localized systems that are installed throughout the site at each runoff source, thereby minimizing the use of traditional "end-of- pipe"treatment systems. By applying a combination of runoff reduction techniques and standard SMPs with RRv capacity, the designer must reduce 100% of the WQv calculated in Step 2. If the RRv calculated in this step is greater than or equal to the WQv calculated in Step 2, the designer has met the RRv requirement and may proceed to Step 6. Unless it can be demonstrated that site limitations exist to provide relief from reducing 100% of the WQv, designers must return to Step 1 to see if an alternative site plan or combination of runoff reduction techniques and standard SMPs with RRv capacity can be applied to achieve compliance with the RRv sizing criteria. Acceptable site limitations include conditions that prevent the use of an infiltration technique and or infiltration of the total WQv, such as seasonal high water table, shallow depth to bedrock, and soils with an infiltration rate less than 0.5 in/hr. For construction activities that cannot reduce the total WQv, the designer shall identify the specific site limitations in the SWPPP. For each area where runoff from newly constructed impervious area is not directed towards a runoff reduction technique or standard SMP with RRv capacity, the designer must provide justification in the SWPPP as to why each of the aforementioned practices are infeasible. If a demonstration of infeasibility cannot be made, then the designer must return to Step 1 to see if an alternative site plan or combination of the runoff reduction techniques and standard SMPs with RRv capacity can be applied to achieve compliance with the RRv sizing criteria. Step 4: Calculate the Minimum RRv Required In Step 4, the designer calculates the minimum RRv required for the construction activity using the criteria in Section 4.3 of this Design Manual and compares this to the runoff reduction achieved in Step 3. In no case shall the runoff reduction achieved from the newly constructed impervious areas be less than the Minimum RRv. Step 5: Apply Standard SMPs to Address Remaining WQv In Step 5, the designer uses standard SMPs (see Table 3.7) such as ponds, stormwater wetlands, or filtering practices, to treat the remaining water quality volume that cannot be reduced by applying runoff reduction techniques and standard SMPs with RRv capacity. The designer must verify that the RRv requirement has been met; otherwise the plan does not comply with the required sizing criteria in Chapter 4. Step 6: Apply Volume and Peak Rate Control Practices if Still Needed to Meet Requirements The channel protection volume, overbank flood control, and extreme flood control must be met for the plan to be completed. In Step 6, the designer may use practices such as infiltration basins, dry detention basins, and blue roofs to meet water quantity requirements, if not already achieved under the previous steps. Chapter 3:Stormwater Management Planning 3•14 Chapter 4: Unified Stormwater Sizing Criteria Section 4.1 Introduction This Chapter presents a unified approach for sizing runoff reduction techniques and standard SMPs to meet pollutant removal goals, reduce channel erosion, prevent overbank flooding, and help control extreme floods. For a summary, please consult Table 4.1 below. The remaining sections describe the sizing criteria in detail and present guidance on how to properly compute and apply the required reduction and storage volumes. The Department has prepared worksheets to assist with these calculations that are available on our website: https://www.dec.nv.qov/index.html. r­� Table 4.1 New York Stormwater Sizing Criteria iL 90% Rule: WQv(acre-feet) _ (P - Rv- A) / 12 Water Quality Rv= 0.05+0.009(I) Volume (WQv) I = Impervious Cover(Percent) P(inches) = 90% Rainfall Event Number(See Figure 4.1)z A= Contributing Area (acres) RRv(acre-feet) = Reduction of the total WQv by application of runoff reduction techniques and standard SMPs with RRv capacity to replicate pre-development Runoff Reduction hydrology. Volume (RRv) The minimum required RRv is defined by the Specific Reduction Factor(S), provided objective technical justification is documented. Default Criterion: Channel CPv (acre-feet) = 24-hr extended detention of post-developed 1-year, 24-hr design Protection Volume storm; remaining after runoff reduction. Where site conditions allow, Runoff reduction (CPv)' of total CPv, is encouraged for Sites Larger than 50 Acres: Distributed Runoff Control - geomorphic assessment to determine the bank full channel characteristics and thresholds for channel stability and bedload movement. Overbank Flood Qp(cfs)=Control the peak discharge from the 10-year storm to 10-year pre- (Qp)' development rates. Extreme Flood Qf(cfs)=Control the peak discharge from the 100-year storm to 100-year pre- PO' development rates. Safely pass the 100-year design storm. Design, construct, and maintain systems sized to capture, reduce, reuse, treat, and Alternative method manage rainfall on-site, and prevent the off-site discharge of the precipitation from all rainfall events less than or equal to the 95th percentile rainfall event, computed by an acceptable continuous simulation model. 'Channel protection, overbank flood, and extreme flood requirements may be waived in some instances if the conditions specified in this Chapter are met. For SMPs involving dams, follow Appendix A, Guidelines for Design of Dams for safe passage of the design flood. 2For required sizing criteria in redevelopment projects and phosphorus limited watersheds refer to Chapter 9 and Section 4.3, respectively. Chapter4: Unified Stormwater Sizing Criteria ­1 Section 4.2 Water Quality Volume (WQv) The Water Quality Volume (WQ ) is intended to improve water quality by capturing and treating runoff from small, frequent design storms that tend to contain higher pollutant levels. New York has defined the WQv as the volume of stormwater runoff, generated from the 90th percentile rain event (90% of all 24-hr design storms, in a given year), that shall be captured and treated by stormwater management practice(s). The WQv is directly related to the amount of impervious cover constructed at a site. Contour lines of the 90% rainfall event are presented in Figure 4.1. The minimum 90% rainfall value shall be 1.0 inch. The following equation shall be used to determine the water quality storage volume WQ (in acre-feet of storage): WQV _ P R2 A Where: WQv =water quality volume (in acre-feet) P = 90% Rainfall Event Number(see Figure 4.1) Rv = 0.05 + 0.009(I), where I is percent impervious cover A = contributing area (acres) na ],1 z a 1.0 � P.5 a P§ 90th Percentile Contour(0.1 in) 0 County Boundary for_,New fork State s Figure 4.1 90th Percentile Rainfall in New York State(NYSDEC, 2013) Chapter 4: Unified Stormwater Sizing Criteria 4-2 Basis of Design for Water Quality As a basis for design, the following assumptions may be made: Measuring Impervious Cover: the measured area of a site plan that does not have permanent vegetative or permeable cover shall be considered total impervious cover. Where site size makes direct measurement of impervious cover impractical, the land use/impervious cover relationships presented in Table 4.2 can be used to initially estimate impervious cover. In site specific planning impervious cover must be calculated based the specific proposed impervious cover. Table 4.2 Land Use and Impervious Cover hillb (Source: .. 00 Land Use Category Mean Impervious Cover(%) Agriculture 2 Open Urban Land* 9 2 Acre Lot Residential 11 1 Acre Lot Residential 14 1/2 Acre Lot Residential 21 1/4Acre Lot Residential 28 1/8 Acre Lot Residential 33 Townhome Residential 41 Multifamily Residential 44 Institutional** 28-41 Light Industrial 48-59 Commercial 68-76 *Open urban land includes developed park land, recreation areas, golf courses, &cemeteries. **Institutional is defined as places of worship, schools, hospitals, government offices, &police and fire stations. Aquatic Resources: More stringent local regulations may be in place or may be required to protect drinking water reservoirs, lakes, or other sensitive aquatic resources. Consult the local authority to determine the full requirements for these resources. SMP Treatment:The final WQv, remaining after application of runoff reduction sizing criterion, shall be treated by an acceptable practice from the list presented in this manual. Please consult Chapter 3 for a list of acceptable practices. Determining Peak Discharge for WQ, Storm:When designing flow splitters for off-line practices, consult the small storm hydrology method provided in Chapter 9. Extended Detention for Water Quality Volume:The water quality requirement for storage systems can be met by providing 24-hrs of the WQ (provided a micropool is specified) extended detention. A local jurisdiction may reduce this requirement to as little as 12-hrs in trout waters to prevent stream warming. Off-site Areas:Where off-site areas will drain to the SMP, calculate imperviousness of the off-site contributing drainage area based on its current condition. If water quality treatment is provided off-line, the practice must only treat on-site runoff. Chapter 4: Unified Stormwater Sizing Criteria 4-3 Section 4.3 Water Quality Volume (WQv) for Enhanced Phosphorus Removai Watersheds For watersheds requiring enhanced phosphorus removal, the WQv shall be sized to capture and treat the 1-yr 24-hr design storm. Refer to Chapter 10 for additional information regarding pollutants of concern. The following equation shall be used to determine the water quality storage volume WQv (in acre-feet of storage): WQV _ P1 'R„ A 12 Where: WQv = water quality volume (in acre-feet) Pi = 1-yr 24-hr design storm (inches) Rv = 0.05 + 0.009(I), where I is percent impervious cover A = Contributing area (acres) Section 4.4 Runoff Reduction Volume (RRv) Runoff reduction shall be achieved by infiltration, groundwater recharge, reuse, recycle, evaporation/evapotranspiration of 100 percent of the post-development water quality volume. The goal of runoff reduction is to replicate pre-development hydrology by maintaining pre-construction infiltration, peak runoff flow, and discharge volume, as well as minimizing concentrated flow, by application of practices that provide source control treatment in a distributed manner before runoff reaches the collection system. This requirement shall be accomplished by application of on-site runoff reduction techniques and/or standard SMPs with runoff reduction capacity. Runoff reduction volume (RRv) shall be calculated using one of the following methods: Area reduction (contributing area or contributing impervious area) in WQv computation (as defined in Chapter 5) Volume reduction using runoff reduction techniques (as defined in Chapter 3, Table 3.6) Volume reduction using standard SMPs with runoff reduction capacity (as defined in Chapter 3, Table 3.7) For practices with underdrains that require sizing the surface area of the filter bed using Darcy's Law, the designer can elect to oversize the surface area of the filter bed to provide additional storage volume and receive additional RRv credit up to 100% of the WQv required. The total RRv credit shall be the percentage, as noted in Tables 3.6 and 3.7, applied to the storage volume provided. The storage volume provided shall be considered the volume within the filter media and the volume of ponding occurring during the WQv event. Volume reduction practices can be designed in series to meet the RRv requirement if the following criteria are met. The first practice in series is sized to capture and treat a portion of the tributary required WQv. The first practice shall be designed with an appropriate overflow to convey runoff above the partial WQv to the next practice in series. The second practice in series must be designed to capture and treat the untreated WQv from the first practice, as well as any additional required WQv from other tributary subcatchments. If the above criteria are met, credit can be taken for the portion of the required WQv that is treated by the first practice. In addition, credit can be taken for RRv, within the first practice, based on the practice's RRv capacity and applied to the portion of WQv provided. For the second practice in series, both RRv and WQv credit can be taken based on the full tributary WQv and practice RRv capacity. Projects that cannot meet 100% of the runoff reduction requirement, due to site limitations that prevent the use of an infiltration practice and/or infiltration of the total WQv, shall identify the specific site limitations in the SWPPP. Typical site limitations include: seasonal high water table, shallow depth to bedrock, and soils with an infiltration rate less than 0.5 in/hr. Chapter 4: Unified Stormwater Sizing Criteria 4-4 In no case shall the runoff reduction achieved from the newly constructed impervious areas be less than the minimum runoff reduction volume (RRvmin) determined by the following equation: P •R„ •Aic•S RRUmin = 12 Where: P = 90% Rainfall Event Number(see Figure 4.1) RRvmin = Minimum runoff reduction volume required from impervious area (acre-ft) Rv = 0.05+0.009(I)where I is 100% impervious Aic = Total area of new impervious cover S = Hydrologic Soil Group (HSG) Specific Reduction Factor(S) The specific reduction factor(S) is based on the HSGs present at a site. The following lists the specific reduction factors for the HSGs: HSG A= 0.55 HSG C = 0.30 HSG B = 0.40 HSG D = 0.20 Runoff reduction techniques are intended to be applied for source control treatment. As such, multiple runoff reduction techniques may be utilized on a site to maximize storage volume and achieve greater reduction. However, reduction cannot be claimed twice for an identical area of the site (e.g., claiming the stream buffers and disconnecting rooftops over the same site area). Section 4.5 Runoff Reduction Volume (RRv) for Enhanced Phosphorus Removal Watersheds For watersheds requiring enhanced phosphorus removal, runoff reduction shall apply the WQv resulting from the 1-yr 24- hr design storm, as calculated in Section 4.3. Similarly, the minimum RRv is calculated using the 1-yr 24-hr design storm and Specified Reduction Factors outlined in Section 4.4. Section 4.6 Stream Channel Protection Volume Requirements (CPv) Stream Channel Protection Volume Requirements (CPv) are designed to protect stream channels from erosion. This goal is accomplished by providing 24-hr extended detention of the 1-year, 24-hr design storm, that remains after runoff reduction. Meeting stream channel protection objectives through runoff reduction is encouraged and the volume reduction achieved through runoff reduction techniques and/or standard SMPs with RRv capacity can be deducted from CPv. Trout waters may be exempt from the 24-hr extended detention requirement, requiring only 12 hrs of extended detention, when there is a direct discharge to the trout water. Detention time shall be calculated using either the center of mass method or plug flow calculation method. For developments greater than 50 acres, with impervious cover greater than 25%, it is recommended that a detailed geomorphic assessment be performed to determine the appropriate level of control. Appendix I provides guidance on how to conduct this assessment. Detention ponds or underground detention systems and vaults are methods to meet the CPv requirement (and subsequent Qp and Qf criteria). Note that, although these practices meet water quantity goals, they are unacceptable for water quality because of poor pollutant removal and need to be coupled with a practice listed in Table 3.2 and Table 3.3. The CPv requirement may also be provided above the water quality (WQv) storage in a wet pond or stormwater wetland. Basis for Determining Channel Protection Storage Volume The following represent the minimum basis for design: TR-55 and TR-20 (or approved equivalent) shall be used to determine peak discharge rates. Chapter 4: Unified Stormwater Sizing Criteria 4- Rainfall data and distribution curves shall be established for the 1-year 24-hr design storm, using the process outlined in Section 4.9. When the pre-development land use is agriculture, the curve number for the pre-developed condition shall be taken as "meadow". Off-site areas shall be modeled as "present condition". The length of sheet flow used in Tc calculations is limited to no more than 150 ft for pre-development conditions and no more than 100 ft for post-development conditions. On areas of extremely flat terrain (<1% average slope), this maximum distance is extended to 250 ft for pre-development conditions and 150 ft for post-development conditions. If the start of a T,flow path is unchanged (undisturbed) from pre-to post-development conditions, then the sheet flow length shall be identical. The CPv storage volume shall be computed using one of the following methods: Center-of-mass detention time: time difference between the center of mass of the inflow hydrograph (entering the SMP) and the center of mass of the outflow hydrograph (leaving the SMP). Plug flow detention time: theoretical average detention time. When CPv is required, the storage volume must be provided. Where a CPv control orifice is provided, the minimum orifice size shall be 3 inches, with acceptable external trash rack or orifice protection (See Appendix C for details of a low flow orifice and trash rack options). CPv shall be addressed for the entire site. If a site consists of multiple design points, CPv shall be determined and provided for each design point. Extended detention storage provided for the CPv does not meet the WQv requirement (that is CPv and WQv shall be treated separately). However, both water quality and channel protection storage may be provided in the same SMP. The Channel Protection Requirements may be waived if: Reduction of the entire CPv is achieved at a site through runoff reduction or infiltration systems. CPv is not required at sites where the 1-year post-development peak discharge is less than or equal to 2.0 cfs without detention or velocity controls. The site directly discharges into a fifth order or larger water body (streams, rivers, or lakes) or tidal waters, where the increase in smaller flows will not impact the stream bank or channel integrity. However, the point of discharge must be adequately protected against scour and erosion by the increased peak discharge. Streams are classified using the New York State Codes Rules and Regulations (NYCRR), Volumes B-F, Parts 800-941. However, this classification system does not provide a numeric stream order. The methodology identified in this Manual is consistence with Strahler-Horton methodology. For an example of stream order identification see Section 4.12. Section 4.7 Overbank Flood Control Criteria (Qp) The primary purpose of the overbank flood control sizing criterion is to prevent an increase in the frequency and magnitude of out-of-bank flooding generated by urban development (i.e., flow events that exceed the bank full capacity of the channel, and therefore must spill over into the floodplain). Basis for Design of Overbank Flood Control When addressing the overbank flooding design criteria, the following represent the minimum basis for design: TR-55 and TR-20 (or approved equivalent) will be used to determine peak discharge rates. Rainfall data and distribution curves shall be established for the 10-year 24-hr design storm, using the process outlined in Section 4.9. Chapter4: Unified Stormwater Sizing Criteria 4­6 When the pre-development land use is agriculture, the curve number for the pre-developed condition shall be taken as "meadow". Off-site areas shall be modeled as "present condition" for the 10-year design storm. The length of sheet flow used in Tc calculations is limited to no more than 150 ft for pre-development conditions and no more than 100 ft for post-development conditions. On areas of extremely flat terrain (<1% average slope), this maximum distance is extended to 250 ft for pre-development conditions and 150 ft for post-development conditions. If the start of Tc flow path is unchanged (undisturbed) from pre-to post-development conditions, then the sheet flow length shall be identical. Overbank Flood Control shall be addressed for the entire site. If a site consists of multiple design points, Overbank Flood Control shall be determined and provided for each design point. Overbank Flood Control requires storage to attenuate the post-development 10-year, 24-hr peak discharge rate (Qp) to pre-development rates. The Overbank Flood Control requirement may be waived if: The site directly discharges into a fifth order or larger water body (streams, rivers, or lakes) or tidal waters, where the increase in smaller flows will not impact the stream bank or channel integrity. However, the point of discharge must be adequately protected against scour and erosion by the increased peak discharge. Refer to Section 4.12 for instructions. A downstream analysis reveals that overbank control is not needed (see Section 4.13). Section 4.8 Extreme Flood Control Criteria (Qf) The intent of the extreme flood criteria is to (a) prevent the increased risk of flood damage from large design storms, (b) maintain the boundaries of the pre-development 100-year floodplain, and (c) protect the physical integrity of stormwater management practices. Basis of Design for Extreme Flood Control Criteria When addressing the extreme flood design criteria, the following represent the minimum basis for design: TR-55 and TR-20 (or approved equivalent) will be used to determine peak discharge rates. Rainfall data and distribution curves shall be established for the 100-year 24-hr design storm, using the process outlined in Section 4.9. When the pre-development land use is agriculture, the curve number for the pre-developed condition shall be taken as "meadow". Off-site areas shall be modeled as "present condition" for the 100-year design storm. The length of sheet flow used in Tc calculations is limited to no more than 150 ft for pre-development conditions and no more than 100 ft for post-development conditions. On areas of extremely flat terrain (<1% average slope), this maximum distance is extended to 250 ft for pre-development conditions and 150 ft for post-development conditions. If the start of T,flow path is unchanged (undisturbed) from pre-to post-development conditions, then the sheet flow length shall be identical. Extreme Flood Control shall be addressed for the entire site. If a site consists of multiple design points, Extreme Flood Control shall be determined and provided for each design point. Extreme Flood Control requires storage to attenuate the post-development 100-year, 24-hr peak discharge rate (Qf)to pre-development rates. The Extreme Flood Control requirement may be waived if: The site directly discharges into a fifth order or larger water body (streams, rivers, or lakes) or tidal waters, where the increase in smaller flows will not impact the stream bank or channel integrity. However, the point of discharge Chapter4: Unified Stormwater Sizing Criteria ­7 must be adequately protected against scour and erosion by the increased peak discharge. Refer to Section 4.12 for instructions. A downstream analysis reveals that 100-year control is not needed (see Section 4.13) Section 4.9 Rainfall Data, Distribution Curves and Hydrologic Modeling Rainfall distribution curves are developed from rainfall data and describe how a storm's total rainfall amount will be distributed over a specific length of time, such as 24 hours. It is based on historic rainfall values, over a wide range of time intervals, for various frequency storms. Properly calculated rainfall distribution curves are critical when evaluating the hydrologic character of a drainage area and when sizing hydraulic structures. Pre- and post-development models should use the same precipitation data source. Rainfall data for the Stream Channel Protection Volume, Overbank Flood Control and Extreme Flood Control design storms shall be taken from: NRCC and NRCS joint collaborative website (http://precip.eas.cornell.edu); or National Oceanic and Atmospheric Administration (NOAA) Precipitation Frequency Data Server(PFDS) (https:Hhdsc.nws.noaa.gov/hdsc/pfds/). Hydraulic and hydrologic modeling software, such as USDA NRCS TR20, HydroCAD, Pond Pack, StormCAD, Hydraflow, and Hydrologic Engineering Center Hydrologic Modeling System (HEC-HMS) and others, shall be used to extract rainfall frequency and duration data, for the project location, to create intensity-duration-frequency (IDF) curves, and then convert into rainfall distribution curves. The following provides the step-by-step process to generate rainfall distribution curves using the NRCC and NRCS website and HydroCAD. This process is similar for both rainfall data sources listed above. 1. Go to the NRCC and NRCS website and select the tab "Data and Products. 2. Use the location map to zoom into the project site. If the marker is not located on the project site, double click on the map to relocate the marker. From the Products list, select "Extreme Precipitation Tables—Text/CSV". At the bottom of the page, set smoothing to "No", then click"Submit". Select"Save As", navigate to the project folder. Rename the file starting with NY- (example: NY-Cicero.txt) and save the file into you project folder. The NY- in the project name is required in order for HydroCAD to place the IDF file in the correct location. 5. Once the file is in the project folder, rename the file to change the ".txt" extension to a ".hci" extension (example: NY-Cicero.hci). This ".hci" extension is required in order for HydroCAD to recognize this as an IDF file. 6. Open or create a model using HydroCAD in the project folder where the IDF file, created above, is located. 7. From the "Settings" drop down select"Calculations", pick the "Rainfall"tab. Click on the "Import Events From..." and select"IDF file". The ".hci"file, saved previously, should be listed in the "Rainfall IDF File:" drop down under the "NY-"tab. 8. Click"View IDF". 9. Click"More IDF data". 10. Select"Convert"tab and under"Rainfall IDF File" select the correct IDF file. 11. Click"Create Mass Curves". Click"OK"to close out of all menus. If prompted click"yes"to overwrite all storm events. 1 From the "Settings" drop down select"Calculations", pick the "Rainfall"tab. In the "Storm Type" drop down navigate to the "NY-"tab and select the newly created mass curve file. 1 If prompted click"yes"to overwrite all storm events. Rainfall data, using the newly created mass curve file, should auto populate into the rainfall data settings. Chapter 4: Unified Stormwater Sizing Criteria -8 Section 4.10 Alternative Methoo New development causes changes to runoff volume, flow rates, timing of runoff and, most importantly, habitat destruction and degradation of the physical and chemical quality of the receiving waterbody. Traditionally, TR-55 and TR-20 (or approved equivalent) are used for evaluation of hydrology and sizing of stormwater management practices. With an increasing need for assessment of the long-term effects of development and maintenance of pre-development hydrology, continuous simulation modeling is an effective alternative method for analysis and evaluation of flow-duration, downstream quality, quantity, biological, and hydro-habitat sustainability. Continuous simulation models utilize historical precipitation records for estimating runoff volumes, duration, and pollutant loading. This method allows for examination of a watershed parameters' response to long term effects of design storms, instead of the response to a site level single theoretical design storm provided by single event-based models. Calculation of WQv using continuous simulation modeling accounts for infiltration, evapotranspiration, depression storage, and system storage, which allows a detailed and objective comparison of alternative treatments to determine if watershed characteristics are maintained by those treatments. Consequently, continuous simulation modeling allows for simulation of runoff reduction techniques and performance of flow duration analyses. An objective application of a continuous simulation model involves a calibrated model for a watershed on interest and incorporation of regional goals. The following lists the guidelines for the design of stormwater management systems using a continuous simulation model: Design, construct, and maintain systems sized to capture, reduce, reuse, treat, and manage rainfall on-site, and prevent the off-site discharge of the precipitation from all rainfall events less than or equal to the 95th percentile rainfall event. The 95th percentile rainfall event is the event whose precipitation total is greater than or equal to 95 percent of all design storms over a given period of record. A minimum period of 20 years precipitation records is required to determine the 95th percentile storm and derive the corresponding design storm. Select a practice(s) that provides infiltration, evapotranspiration, reuse, or recycle of this volume. 100% of the volume of water from storms less than or equal to the 95th percentile event shall not be discharged to surface water. Perform an analysis that shows post-construction flow-duration, shape of the hydrograph, and downstream quality and quantity does not exceed pre-construction hydrology. Site evaluation and soils analysis must conform to the standards provided in this Manual. The stormwater management practices employed must conform to the standards provided in this Manual. Some examples of continuous simulation modeling tools include: Stormwater Management Model (SWMM) is an EPA supported urban runoff hydrology, hydraulics, and runoff quality model with detailed design tools capable of flow routing and storage for surface, sub-surface, stormwater and combined sewer overflow conveyance and groundwater systems, as well as determining the treatment capacity of stormwater management practices. Various applications of SWMM have utilized the detailed features of this model for simulating runoff reduction design features. Source Loading and Management Model for Windows (WinSLAMM) is a mid-range empirical model for evaluation of stormwater runoff loading in urban watersheds. This modeling tool uses small storm hydrology methods and calculates the runoff from historical precipitation data for a given period of time, pollutant loading from various land uses, and allows the user to simulate the stormwater load reduction effected by incorporating control devices. The stormwater management practices provided in WinSLAMM include several SMPs, runoff reduction design details and maintenance BMPs. Hydrologic Simulation Program Fortran (HSPF) is an EPA supported program for simulation of watershed hydrology and water quality. The HSPF model uses information such as the time history of rainfall, temperature, soil, land surface such as land cover and land-use patterns; and land Chapter 4: Unified Stormwater Sizing Criteria ­ management practices to simulate the processes that occur in a watershed. The result of this simulation is a time history of the quantity and quality of runoff from an urban or agricultural watershed. The model also predicts flow rate, sediment load, and nutrient concentrations. A successful example of the use of HSPF for stormwater applications is the Western Washington Hydrologic Model (WWHM). Similar adaptation of the models for applications in New York State will require several verifications such as validation of input variables, accurate precipitation data, and calibration of the model. Section 4.11 Conveyance Criteria In addition to the stormwater treatment volumes described above, this manual also provides guidance on safe and non- erosive conveyance to, from, and through SMPs. Typically, the targeted storm frequencies for safe conveyance to SMPs are the 2-year and 10-year design storms. The 2-year design storm is used to ensure non-erosive flows through roadside swales, overflow channels, over berms within practices. Rainfall depths for the 2-year, 24-hr design storm throughout New York State shall be taken from the NRCC and NRCS joint collaborative website or NOAA-Atlas 14, as outlined in Section 4.9. The 10-year design storm is typically used as a target sizing for outfalls, and as a safe conveyance criterion for open channel practices and overflow channels. The 10-year design storm is recommended as a minimum sizing criterion for closed conveyance systems. Note that some agencies or municipalities may use a different design storm for this purpose. Section 4.12 Stream Order Identification This section provides an example to help identify stream order based on Strahler-Horton Method. A network of streams drain each watershed. Streams can be classified according to their order in that network. A stream that has no tributaries or branches is defined as a first-order stream. When two first-order streams combine, a second-order stream is created, and so on. Figure 4.2 illustrates the stream order concept (Schueler, T. 1995). Evaluation of stream order must be performed using the Watershed Assessment, Tracking and Environmental Results System (WATERS) GeoViewer to determine if quantity controls do not apply. WATERS was developed by the USEPA and utilizes data from the National Hydrography Dataset Plus (NHDPlus). NHDPIus is an integrated suite of geospatial datasets that incorporate features of the National Hydrography Dataset (NHD) and the National Elevation Dataset (NED) at 1:100K scale. This application-ready data set is an outcome of a multi-agency effort aimed at developing many useful variables for water quality and quantity evaluation including stream order. Use the link below to access the WATERS GeoViewer. Link: https://epa.maps.arcgis.com/apes/webappviewer/index.html?id=ada349b9Oc26496ea52aab66aO92593b Chapter 4: Unified Stormwater Sizing Criteria 4-10 KEY 1 WATERSHED BOUNDARY STREAM 2 9 1 AL CONFLUENCE 1Q STREAM ORDER I Figure 4.2 A Network of Headwater and Third-order Streams(Source: Schueler, 1995) Section 4.13 Downstream Analysis Overbank, and extreme flood requirements may be waived based on the results of a downstream analysis. However, all local overbank and extreme flood requirements must be met regardless of the analysis. In addition, such an analysis for overbank and extreme flood control is recommended for larger sites (i.e., greater than 50 acres)to size facilities in the context of a larger watershed. The analysis will help ensure that storage provided at a site is appropriate when combined with upstream and downstream flows. For example, detention at a site may in some instances exacerbate flooding problems within a watershed. This section provides brief guidance for conducting this analysis, including the specific points along the downstream channel to be evaluated and minimum elements to be included in the analysis. Downstream analysis can be conducted using the 10% rule, meaning the analysis should extend from the point of discharge downstream to the point on the stream where the site represents 10% of the total drainage area. For example, the analysis points for a 10-acre area would include points on the stream from the points of discharge to the nearest downstream point with a drainage area of 100 acres. The required elements of the downstream analysis are as follows: Compute pre-development and post-development peak flows and velocities for design storms (e.g., 10-year and 100-year), at all downstream confluences with first order or higher streams up to and including the point where the 10% rule is met. These analyses shall include scenarios both with and without stormwater treatment practices in place, where applicable. Evaluate hydrologic and hydraulic effects of all culverts and/or obstructions within the downstream channel. Assess water surface elevations to determine if an increase in water surface elevations will impact existing buildings and other structures. Alternatively, if a regional H&H model is implemented and approved by a municipality or regional entity, this model can be used to complete the downstream analysis. The design, or exemption, at a site level can be approved if both of the following criteria are met: Chapter 4: Unified Stormwater Sizing Criteria 4.41 Peak flow rates increase by less than 5% of the pre-developed condition for the design storm (e.g., 10-year or 100-year) No downstream structures or buildings are impacted. Section 4.14 Stormwater Hotspots Stormwater Hotspots are defined as areas where land use or activities generate highly contaminated runoff, with concentrations of pollutants in excess of those typically found in stormwater. These areas can include commercial, industrial, institutional, municipal, or transportation activities that, in addition to generating higher concentrations of pollutants, can present a higher risk for spills, leaks or illicit discharges. If a site is designated as a hotspot, a range of stormwater treatment and pollution prevention measures shall be applied to protect surface waters and groundwater. When a development or redevelopment project includes an activity that is designated as a stormwater hotspot, consideration shall be taken to isolate the hotspot from the remaining watershed. To achieve isolation of a stormwater hotspot, the following criteria shall be met: Upgradient flow shall be diverted around the hotspot area and shall be conveyed to a separate stormwater practice (if treatment is required). The hotspot area shall be captured at the source and conveyed to a suitable stormwater practice. All tributary area that is conveyed to the stormwater practice treating the hotspot area, shall be subject to the same treatment requirements as the hotspot. Table 4.3 provides a list of designated stormwater hotspots for the State of New York. The table looks at the illicit discharge potential of each of the activities listed. The potential for an activity to produce an illicit discharge is rated as either high, medium or low. This rating is based on the likelihood that is has a direct connection to a storm drain system (closed system) or that it can produce a transitory discharge (overland flow). These activities are further categorized as: Level 1: Hotspots with anticipated moderate pollutant concentration. Application of infiltration practices shall be restricted to provide two treatment practices in series (i.e. non-infiltration standard SMP, followed by an infiltration practice), both of which are sized to treat the entire WQv. Credit for RRv and WQv treated cannot be taken for the first practice in series. Level 2: Hotspots with anticipated severe pollutant concentrations. Application of infiltration practices is prohibited, and non-infiltration practices shall be applied to meet the RRv criteria. It shall be noted that large highways (average daily traffic (ADT) volume greater than 25,000) are not designated as stormwater hotspots. However, based on the potential for contaminants within stormwater runoff as ADT increases, it is important to ensure that highway stormwater management plans adequately protect groundwater. Not all practices are suitable for treatment of stormwater hotspots. In addition, the design of some practices may need modification to accommodate higher concentrations of pollutants. Refer to Chapters 5 and 6 for practice suitability and design modifications to treat stormwater hotspots. Chapter 4: Unified Stormwater Sizing Criteria 4.1 2 Table 4.3 Designated Stormwater p. E Illicit Discharge Potential Level 1 Level 2 Activities (Infiltration (Infiltration Closed System Overland Flow Restricted) Prohibited) Industrial activities / Industrial activities subject to effluent Medium High ✓ that are eligible for limitation guidelines coverage under the Multi-Sector General Industrial activities Permit for within Sectors C, J, L Stormwater or U that are located within watersheds Medium High Discharges within Associated with requiring enhanced Industrial Activities phosphorus removal (MSGP) All other industrial Medium Medium activities Fueling stations Medium High Petroleum storage facilities High High Uncovered vehicle, aircraft, boat, and Low Medium heavy equipment maintenance facilities Uncovered vehicle, aircraft, boat, and Low Low heavy equipment cleaning facilities Uncovered vehicle, aircraft, boat, and _/ heavy equipment storage areas Low Medium v Uncovered loading/unloading facilities and Low Medium recessed loading areas Public works yard with salt storage Medium High Public works yard without salt storage Medium Medium Facilities that generate or store hazardous Low High materials Wastewater treatment/disposal, solid Low High waste, and composting facilities Nurseries/garden centers Low Medium 'At a minimum, infiltration shall be restricted for all industrial activities within the MSGP. However, certain activities with greater pollutant thresholds may prohibit the use of infiltration Chapter4: Unified Stormwater Sizing Criteria 4.13 This Page is Left Intentionally Blank NEW Department of YCIRK STATE Environmental Conservation Chapter 5: Runoff Reduction Techniques This Chapter presents planning and design of runoff reduction techniques. Runoff reduction planning includes measures for preservation of natural features of the site and reduction of proposed impervious cover. The runoff reduction techniques include practices that enable reductions in the calculated runoff from contributing areas and the required water quality volume. All runoff reduction techniques require proper maintenance. Without proper maintenance, practices will not function as originally designed and may cease to function altogether. The design of all runoff reduction techniques includes considerations for maintenance and maintenance access. For additional information on inspection and maintenance requirements, see Chapter 12. Section 5.1 Planning for Runoff Reduction: Preservation of Natural Features and Conservation Design The first step in planning for stormwater management using runoff reduction is to avoid or minimize land disturbance by preserving natural areas. Development should be strategically located based on the location of resource areas and physical conditions at a site. Also, in finalizing construction, soils must be restored to the original properties and according to the intended function of the proposed practices. Preservation of natural features includes techniques to foster the identification and preservation of natural areas that can be used in the protection of water, habitat and vegetative resources. Conservation design includes laying out the elements of a development project in such a way that the site design takes advantage of a site's natural features, preserves the more sensitive areas and identifies any site constraints and opportunities to prevent or reduce negative effects of development. The green infrastructure planning measures for preservation of natural features and conservation design are outlined in the following sections, and include: Section 5.1.1: Preservation of Undisturbed Areas Section 5.1.2: Preservation of Buffers Section 5.1.3: Reduction of Clearing and Grading Section 5.1.4: Locating Development in Less Sensitive Areas Section 5.1.5: Open Space Design Section 5.1.6: Soil Restoration 5.1.1 Preservation of Undisturbed Areas Important natural features and areas such as undisturbed forested and native vegetated areas, natural terrain, riparian corridors, wetlands and other important site features should be delineated and placed into permanent conservation areas. Key Benefits, Helps to preserve a site's natural hydrology and water balance Can act as a non-structural stormwater feature to promote additional filtration and infiltration Can help to preserve a site's natural character, habitat and aesthetic appeal Has been shown to increase property values for adjacent parcels Can reduce structural stormwater management storage requirement and may be used in runoff reduction calculations (see Section 5.3) Chapter 5: Runoff Reduction Techniques 51 Preserved conservation areas may limit the development potential of a site —With clustering and other development incentives, development yield can be maintained Preserved conservation areas may harbor nuisance i t \'--• wildlife, vegetation, and insects and may present safety /•��'� hazards - Once established, natural conservation areas i.`i ) must be protected during construction and managed after occupancy by a responsible party able to maintain the { �) •.� 1 i areas in a natural state in perpetuity; proper management 1 and maintenance will address nuisance and safety issues if Delineate and define natural conservation areas before performing site layout and design. Ensure that conservation areas and native vegetation are protected in an undisturbed state through the design, -�•�-..r construction and occupancy stages. Check with the municipality to determine if there are local Figure 5.1 Example of natural resource inventory plan laws and ordinances that regulate wetlands, stream (Source: Georgia Stormwater Manual, 2001) buffers, forests or habitat protection. Conservation of natural areas such as undisturbed forested and .•-� `� native-vegetated areas, natural terrain, riparian corridors and , s wetlands on a development project can help to preserve pre- development hydrology of the site and aid in reducing stormwater runoff and pollutant load. Previously disturbed and/or managed forest areas may be considered for permanent conservation if 'they are judged to provide the benefits outlined in this section. - - - Undisturbed vegetated areas also promote soil stabilization and _ provide for filtering and infiltration of runoff. x Natural conservation areas are typically identified through a site- analysis stage using mapping and field-reconnaissance assessments. Areas proposed for protection should be delineated Figure 5.2 Aerial photograph of development project early in the planning stage, long before any site design, clearing illustrating preservation of undisturbed natural areas or construction begins. When done before the concept-plan (Source: Arendt, 1996) phase, the planned conservation areas can be used to guide the layout of a project. Figure 5.1 shows components of a natural resources inventory map with proposed conservation areas delineated. Preservation areas should then be incorporated into site-development plans and clearly marked on all construction and grading plans to ensure that construction activities are kept out of these areas and that native vegetation is undisturbed. The boundaries of each conservation area should be mapped by carefully determining the limit which should not be crossed by construction activity. Once established, natural conservation areas must be protected during construction and managed after occupancy by a responsible party able to maintain the areas in a natural state in perpetuity. Typically, conservation areas are protected by legally enforceable deed restrictions, conservation easements or a maintenance agreement. When one or more of these measures is applied, a permanently protected natural area can be used to reduce the area required for treatment by structural stormwater management measures (see Figure 5.2 for a representative project illustrating natural resource area protection). Chapter 5: Runoff Reduction Techniques 5-2 5.1.2 Preservation of Buffers Description Naturally vegetated buffers should be defined, delineated and preserved along perennial streams, rivers, shorelines and wetlands. Key Benefits Riparian buffers treat stormwater and improve water quality Can be used as nonstructural stormwater infiltration zones Can keep structures out of the floodplain and provide a right-of-way for large flood events Help to preserve riparian ecosystems and habitats Can serve as recreational areas May be used in runoff reduction calculations if the criteria in this section are met Typical Perceived Obstacles and Realities Buffers may result in a potential loss of developable land — Regulatory tools or other incentives may be available to protect the interests of property owners Private landowners may be required to provide public access to privately held stream buffers — Effective buffers can be maintained in private ownership through deed restrictions and conservation easements Nuisance wildlife, vegetation, and insects will be present due to the natural buffer area —Once established, vegetated buffers must be protected during construction and managed after occupancy by a responsible party able to maintain the areas in a natural state in perpetuity; proper management and maintenance will address nuisance issues Using this Practice Delineate and preserve naturally vegetated riparian buffers (as well as vegetated buffers along streams listed as intermittent by the Department) Define the width, identify the target vegetation, and designate methods to preserve the buffer indefinitely - - -„ Ensure that buffers and native vegetation are , protected throughout planning, design, construction and occupancy � .�,• t _ Consult local planning authority for local wetland and/or stream regulations or guidelines for more ° stringent minimum buffer width .». Discussion -° 'a A riparian buffer is a special type of natural conservation area along a stream, wetland or shoreline where development is restricted or prohibited. The primary function of buffers is to Figure 5.3 Buffer around Rondout Creek, Accord, NY protect and physically separate a stream, lake, coastal shoreline or wetland from polluted stormwater discharges from future disturbance or encroachment. If properly designed, a buffer can provide stormwater management functions, can act as a right-of-way during floods, and can sustain the integrity of water-resource ecosystems and habitats. An example of a riparian stream buffer is shown in Figure 5.3. Chapter 5: Runoff Reduction Techniques 5-3 Forested riparian buffers should be maintained and managed and reforestation should be encouraged where no wooded buffer exists. Proper restoration should include all layers of the forest plant community, including understory, shrubs and groundcover, not just trees. A riparian buffer can be of fixed or variable width but should be continuous and not interrupted by impervious areas that would allow stormwater to concentrate and flow into the stream without first flowing through the buffer. Ideally, riparian buffers should be sized to include the 100-year floodplain as well as steep banks and freshwater wetlands. The buffer depth needed to perform properly will depend on the size of the stream and the surrounding conditions, but a minimum 25-ft undisturbed vegetative buffer is needed for even the smallest perennial streams, and a 50-ft or larger undisturbed buffer is ideal. Even with a 25-ft undisturbed buffer, additional zones can be added to extend the total buffer to at least 75 ft from the edge of the stream. The three distinct zones within the 75-ft depth are shown in Figure 5.4. The function, vegetative target and allowable uses vary by zone as described in Table 5.1. These recommendations are minimum standards for most streams. Some streams and watersheds may benefit from additional measures to ensure adequate protection. In some areas, specific state laws or local ordinances already require stricter buffers than are described here. The buffer widths discussed are not intended to modify or supersede wider or more restrictive buffer requirements that are already in place. As stated above, the streamside or inner zone should consist of a minimum of 25 ft of undisturbed mature forest. In addition to runoff protection, this zone provides bank stabilization as well as shading and protection for the stream. This zone should also include wetlands and any critical habitats, and its width should be adjusted accordingly. The middle zone provides a transition between upland development and the inner zone and should consist of managed woodland that allows for infiltration and filtration of runoff. An outer zone allows more clearing and acts as a further setback for impervious surfaces. It also functions to prevent encroachment and filter runoff. It is here that flow into the buffer should be transformed from concentrated flow into sheet flow to maximize ground contact with the runoff. Development within the riparian buffer should be limited only to those structures and facilities that are absolutely necessary. Such limited development should be specifically identified in any codes or ordinances enabling the buffers. When construction activities do occur within the riparian corridor, specific mitigation measures should be required, such as deeper buffers or riparian buffer improvements. Generally, the riparian buffer should remain in its natural state. However, some maintenance and management are periodically necessary, such as planting to minimize concentrated flow, removal of exotic plant species when these species are detrimental to the vegetated buffer and removal of diseased or damaged trees. r.L STREAM a STREAMSIDE MIDDLE ZONE a OUTER ZONE ZONE Figure 5.4: Three-zone stream buffer system(Source: Adapted from Schueler, 1995) Chapter 5: Runoff Reduction Techniques 5-4 RiparianTable 5.1 Adapted Streamside Zone Middle Zone Outer Zone Minimum 25 ft plus wetlands Variable, depending on 25-ft minimum setback from Width stream order, slope, and 100- and critical habitat structures year floodplain (min. 25 ft.) Perennial grasses on steep Vegetative Target slopes, hardy native shrubs, Managed forest, some Forest encouraged, but usually undisturbed mature forest. clearing allowed turfgrass Reforest if necessary. Very restricted (e.g., flood Restricted (e.g., some Unrestricted (e.g., non- Allowable Uses control, utility easements, recreational uses, some structural residential uses, footpaths) stormwater controls, bike including lawn, garden, most paths) stormwater controls) 5.1.3 Reduction of Clearing and Grading Clearing and grading of the site should be limited to the minimum amount needed for the development function, road access and infrastructure (e.g., utilities, wastewater disposal, stormwater management). Site layout should be designed to disturb the smallest possible land area on a site. Key Benefits Preserves more undisturbed natural areas on a development site Areas of a site that are conserved in their natural state retain their natural hydrology and do not contribute to construction erosion Native trees, shrubs and grasses provide natural landscaping, reducing costs and contributing to the overall quality and viability of the environment Typical Perceived Obstacles and Realities Preserving trees during construction is expensive—Minimizing clearing during construction can reduce earth movement and reduce erosion and sediment control costs People prefer large lawns—Lots with trees may have a higher value than those without Preserved conservation areas may harbor nuisance wildlife, vegetation, and insects and may present safety hazards— Once established, natural conservation areas must be protected during construction and managed after occupancy by a responsible party to maintain the areas in a natural state in perpetuity;proper management and maintenance will address nuisance and safety issues Using this Practice Restrict clearing to minimum reqd. for building footprints, construction access, and safety setbacks Establish limits of disturbance for all development activities Site layout should be designed to minimize clearing and grading Avoid mass grading of a site—divide into smaller areas for phased grading Use conservation design, open-space or"cluster' developments Consult local planning authority for local clearing and grading regulations Chapter 5: Runoff Reduction Techniques 5-5 Discussion Minimal disturbance methods should be used to limit the amount of clearing and grading that takes place on a development site, preserving more of the undisturbed vegetation and natural hydrology of a site. A limit of disturbance (LOD) should be established based on the maximum disturbance zone. These maximum distances should reflect reasonable construction techniques and equipment needs, together with the physical situation of the development site, such as slopes or soils. LOD distances may vary by type of development, size of lot or site and by the specific development feature involved. Site "foot-printing"should be used that maps all of the limits of disturbance to identify the smallest possible land area on a site which requires clearing or land disturbance. An example of site foot-printing is illustrated in Figure 5.5. Sites should be designed so that they fit the terrain (see Figure 5.6). During construction, special procedures and equipment that reduce land disturbance should be used. Alternative site designs should be considered to minimize limits of clearing, such as "cluster"developments (see Section 5.1.5). b _ Limits of -- ' = �.. Clearing ti ------ - - l� Yp r � Figure 5.5 Example of site foot-printing (Source: Georgia Figure 5.6 Design plan showing limits of clearing (in dark Stormwater Manual, 2001) shading)(Source: DDNREC, 1997) 5.1.4 Locating Development in Less Sensitive Areas Description Development sites should be located to avoid sensitive resource areas such as floodplains, steep slopes, erodible soils, wetlands, mature forests and critical habitat areas. Buildings, roadways and parking areas should be located to fit the terrain and in areas that will create the least impact. Key Benefits Preserving floodplains provides a natural right-of-way and temporary storage for large flood events; keeps people and structures out of harm's way and helps to preserve riparian ecosystems and habitats Preserving steep slopes and building on flatter areas helps to prevent soil erosion and minimizes stormwater runoff; helps to stabilize hillsides and soils and reduces the need for cut-and-fill and grading Avoiding development on erodible soils can prevent sedimentation problems and water-quality degradation. Areas with highly permeable soils can be used as nonstructural stormwater infiltration zones Fitting the design to the terrain and in less sensitive areas helps to preserve the natural hydrology and drainageways of a site; reduces the need for grading and land disturbance, and provides a framework for site design and layout Chapter 5: Runoff Reduction Techniques 5- Costs will be higher for developments due to increased planning and design, localized construction and less developable land —Developments that protect sensitive areas may have higher market value, less liability for potential natural disasters, such as flooding or slope failures and lower construction costs for areas that require less earthwork or difficult terrain, such as steep slopes or wetland areas to work around Ensure all development activities do not encroach on, fill or alter designated floodplain and/or wetland areas When the reconstruction of a stormwater facility falls within the 100-year floodplain, facility structures shall be protected from physical damage by the 100-year flood. Treatment facilities shall remain fully operational and accessible during the 25-year flood. Outfall pipes in the floodplain may need flap gates to keep floodwaters from backing up into the stormwater facility. Avoid development on steep slope areas and minimize grading and flattening of hills and ridges Leave wetlands, floodplains, and areas of porous or highly erodible soils as undisturbed conservation areas Develop roadway patterns to fit the site terrain, and locate buildings and impervious surfaces away from steep slopes, drainage ways and floodplains Locate sites in areas less sensitive to disturbance or Large Impact Area have a lower value in terms of hydrologic function Development in floodplain areas can reduce the ability of the floodplain to convey stormwater, potentially causing safety problems or significant damage to the site in question, as t �, �)1 P�v well as to both upstream and downstream properties. The entire 100-year full-buildout floodplain should be avoided for clearing or building activities and should be preserved in a Small Impact Area natural, undisturbed state. Where possible, the 500-year = �- floodplain should also be preserved in a natural state and/or designated for parks, recreation or agriculture. Development 11 i on slopes with a grade of 15% or greater should be avoided, r if possible, to limit soil loss, erosion, excessive stormwater runoff and the degradation of surface water. Excessive "'R'�k grading should be avoided on all slopes (Figure 5.7), as should the flattening of hills and ridges. Steep slopes should be kept in an undisturbed natural condition to help stabilize Figure Cut and fill grading steep slopes impacts larger areas (as than flatter slopes(Source: MPCA, 1989) hillsides and soils. On steep slopes, new development, re- grading, or stripping of vegetation must be minimized. Area with Areas of a site with hydrologic soil group A and B soils, erodible soils (consult Natural Resources Conservation Service website for hydrological soil groups) such as sands and sandy loam A soils, should be conserved as much as possible, and these B c «A»and«B» areas should ideally be incorporated into undisturbed natural ' B soils are more porous— or open-space areas (Figure 5.8). Conversely, buildings C preserve and other impervious surfaces should be located on those undisturbed A if possible portions of the site with the least permeable soils. Similarly, A B areas on a site with highly erodible or unstable soils should soils ands should A s be be avoided for land-disturbing activities and buildings to used for impervious prevent erosion and sedimentation problems as well as surfaces and buildings potential structural problems. These areas should be left in Figure 5.8 Using soil mapping to guide development an undisturbed and vegetated condition. (Source: Georgia Stormwater Manual, 2001) Chapter 5: Runoff Reduction Techniques 5-7 The layout of roadways and buildings on a site should generally conform to the landforms on a site (Figure 5.9). Natural drainage ways and stream buffer areas should be preserved by designing road layouts around them. Buildings should be sited to use the natural grading and drainage system and avoid the unnecessary disturbance of vegetation and soils. Houses located on Roads on ridge lines "brow"of ridge or upland areas 00 00 ti 000 m oil] DODO 0 -t 0 Vegetated drainage swales Undisturbed vegetation Natural drainageways on slopes preserved Figure 5.9 Preserving the Natural topography of a Site (Source: Adapted from Prince George's County, 1999) Roadway patterns on a site should be chosen to provide access schemes which match the terrain. In rolling or hilly terrain, streets should be designed to follow natural contours to reduce clearing and grading. In flatter areas, a .....m . traditional grid pattern of streets or"fluid"grids which / Grading ` bend and may be interrupted by natural drainage ways / sG nsolls may be more appropriate. In much the same way that a �.■ a development should be designed to conform to the terrain :Clearing& of the site, layout should also be designed so that the sr Grading ■• H$G-C Soils�ill �� ■�• ♦Selective a i ■ Clearing& areas of development are placed in the locations of the ,,� 1♦ Gradin site that minimize the hydrologic impact of the project. -� �. '.'. This is accomplished by steering development to areas of the site that are less sensitive to land disturbance or have •�, ;n Flow Patte a lower value in terms of hydrologic function. Figure 5.10 1; Af- p�-�� ..•-soils shows a development site where the natural features __� �`.+1�Wetland have been mapped in order to delineate the hydrologically sensitive areas. Through careful site planning, sensitive areas can be set aside as natural open space areas. In many cases, such areas can be used as buffer spaces between land uses on or between adjacent sites. Figure 5.10 Guiding development to less sensitive site areas (Source: Georgia Stormwater Manual, 2001) 5.1.5 Open Space Design Description Conservation development, clustering or open space design incorporates smaller lot sizes to reduce overall impervious cover while providing more undisturbed open space and protection of water resources. Key Benefit!tu Can be used to preserve natural hydrology and drainageways Can be used to preserve and protect natural conservation areas and other site resources Reduces the need for grading and land disturbance Reduces infrastructure needs and overall development costs Allows flexibility to developers to implement creative site designs including better stormwater management practices Chapter 5:Runoff Reduction Techniques 6- Typical Perceived Obstacles and Realities Smaller lot sizes and compact development may be perceived by developers as less marketable — Open space designs can be highly desirable and have economic advantages such as cost savings and higher market appreciation Lack of speed and certainty in the review process may be of concern — Consult with the local review authority to review requirements; prospective homebuyers may be reluctant to purchase homes due to concerns regarding management of the community open space—Proper methods and implementation of maintenance agreements are available;natural open space reduces maintenance costs and can help keep association fees down Cluster developments appear incompatible with adjacent land uses and are equated with increased noise and traffic— Open space design allows preservation of natural areas, using less space for streets, sidewalks, parking lots, and driveways;incorporating buffers into the design can help alleviate incompatibility with other competing land uses Using this Practice Use a site design which concentrates development and preserves open space and natural areas of the site Locate the developed portion of the cluster areas =: in the least sensitive areas of the site Consult with the municipality to find out whether there is a local law or ordinance for cluster ,_ s development, open space design, conservation r design or flexible subdivisions Where allowed by the municipality, utilize reduced setbacks and frontages, and narrower right-of- &' way widths to design non-traditional lot layouts within the cluster Figure 5.11 Aerial view of an open space or"cluster"subdivision Discussion (Source: Georgia Stormwater Manual, 2001) Conservation development, also known as "open space residential design" (OSRD), or clustering, is a green infrastructure planning technique that concentrates structures and impervious surfaces in a compact area in one portion of the development site in exchange for o providing open space, natural areas or agricultural lands elsewhere on the site. Typically, smaller lots and/or o nontraditional lot designs are used to cluster development and create more conservation areas on the site. a Conservation development has many benefits compared with conventional development or residential subdivisions: this technique can reduce impervious cover, stormwater pollution, construction costs, and the need for grading and landscaping, while providing for the conservation of natural areas. Figure 5.11 and Figure 5.12 show examples of open space developments. Figure 5.12 Open space or"cluster" subdivision example (Source: Georgia Stormwater Manual, 2001) Along with reduced imperviousness, conservation design provides a host of other environmental benefits lacking in most conventional designs. These developments reduce potential pressure to encroach on conservation and buffer areas because enough open space is usually reserved to accommodate these protection areas. As less land is cleared during the construction process, alteration of the natural Chapter 5: Runoff Reduction Techniques _ hydrology and the potential for soil erosion are also greatly diminished. Perhaps most importantly, open space design reserves 25 to 50 percent of the development site in conservation areas that would not otherwise be protected. Conservation development can also be significantly less expensive to build than conventional projects. Most of the cost savings are due to reduced infrastructure cost for roads and stormwater management controls and conveyances. While conservation developments are frequently less expensive to build, developers find that these properties often command higher prices than those in more conventional developments. Several studies estimate that residential properties in developments with open space garner premiums that are higher than conventional subdivisions and moreover, sell or lease at increased rates. Once established, common open space and natural conservation areas must be managed by a responsible party able to maintain the areas in a natural state in perpetuity. Typically, the conservation areas are protected by legally enforceable deed restrictions, conservation easements, and maintenance agreements. Flexible lot shapes and setback and frontage distances allow site designers to create attractive and unique lots that provide homeowners with enough space while allowing for the preservation of natural areas in a residential subdivision. A narrower Right-of-Way will consume less land that may be better used for housing lots and allow for a more compact site design. Figure 5.13 and Figure 5.14 illustrate various nontraditional lot designs. _ a TV Figure 5.13 Lots with reduced front and side setbacks Zipper Lots Angled Z-Lots Alternative Lot Widths Figure 5.14 Nontraditional lot design (Source: LILI, 1992) 5.1.6 Soil Restoration Description Soil Restoration, in accordance with the latest version of the NYSDEC Deep-Ripping and Decompaction, is a required practice applied across areas of a development site where soils have been disturbed and will be vegetated in order to recover the original properties and porosity of the soil. Healthy soil is vital to a sustainable environment and landscape. A deep, well-drained soil, rich in organic matter, absorbs rainwater, helps prevent flooding and soil erosion, filters out water pollutants, and promotes vigorous plant growth that requires less irrigation, pesticides, and fertilizer. Soil Restoration is applied in the cleanup, restoration, and landscaping phase of construction followed by the permanent establishment of an appropriate, deep-rooted groundcover to help maintain the restored soil structure. Soil restoration includes mechanical decompaction, compost amendment, or both. Refer to Section 5.3.4.3.2 for material specifications. Chapter 5: Runoff Reduction Techniques 5.1.10 Many runoff reduction practices need Soil Restoration measures applied over and adjacent to the practice to achieve runoff reduction performance. (See typical compacted soil in Figure 5.15). Consult individual profile sheets for specific design criteria. Key Benefits f! More marketable buildings and landscapes Less stormwater runoff, better water quality Healthier, aesthetically pleasing landscapes Increased porosity on redevelopment sites where impervious cover is converted to pervious Achieves performance standards on runoff reduction + practices r Decreases runoff volume generated and lowers the demand on runoff control structures Enhances direct groundwater recharge Figure 5.15 Shows typical compacted soils that nearly reach the bulk density of concrete (Schueler et al 2000) Promotes successful long-term revegetation by restoring soil organic matter, permeability, drainage and water holding capacity for healthy root system development of trees, shrubs and deep-rooted ground covers, minimizing lawn chemical requirements, plant drowning during wet periods, and burnout during dry periods Typical Perceived Obstacles and Realities Higher cost due to soil restoration- application of soil de-compaction and enhancement may have additional initial cost;however, they provide benefit in reducing the need for conveyance structures. Space constraints and obstruction for use of equipment-post construction space may limit the ability of some of the de-compaction equipment, however, alternative equipment and sensible planning help overcome this obstacle. Discussion Tilling exposes compacted soil devoid of oxygen to air and recreates temporary air space. In addition, research has shown that the incorporation of organic compost, can greatly improve temporary water storage in the soil and subsequent runoff reduction through infiltration and evapotranspiration. Soils that have a permanent high water table close to the surface (0-12 inches), either influenced by a clay or other highly impervious layer of material, may have bulk densities so naturally high that compaction has little added impact on infiltration (Lacey 2008). However, these soils will still benefit from the addition of compost. The water holding capacity, penetration, structural stability, and fertility of clay soils were improved with compost mixing (Avnimelech and Cohen 1988). Table 5.2 describes various soil disturbance activities related to land development, soil types and the requirements for soil restoration for each activity. Soil Restoration or modification of curve numbers is a required practice. Restoration is applied across areas of a development site where soils have been compacted and will be vegetated according to the criteria defined in Table 5.2. If Soil Restoration is not applied according to these criteria, designers are required to: Increase the calculated WQv by factoring in the compacted areas (including areas of cut or fill, heavy traffic areas on site, or Impervious Cover reduction in redevelopment projects unless aeration or full soil restoration is applied, per Table 5.2). Change by one level the post-construction hydrologic soil group (HSG) to a less permeable group than the original condition. This is applied to all volumetric and discharge rate control computations. Chapter 5: Runoff Reduction Techniques 5.1 i Table 5.2 Soil Restoration Requirements : Type of Soil Disturbance Soil Restoration Requirement Comments/Examples No soil disturbance Restoration not permitted Preservation of Natural Features Minimal soil disturbance Restoration not required Clearing and grubbing HSG A&B HSG C&D Areas where topsoil is stripped only Protect area from any ongoing -no change in grade apply 6 inches of Aerate*and apply 6 construction activities. topsoil inches of topsoil HSG A&B HSG C& D Areas of cut or fill Aerate and apply 6 Apply full Soil inches of topsoil Restoration** Heavy traffic areas on site (especially in a zone 5-25 ft around Apply full Soil Restoration**de-compaction buildings but not within a 5 ft and compost enhancement) perimeter around foundation walls) Keep construction equipment from Areas where Runoff Reduction crossing these areas. To protect newly and/or Infiltration practices are Restoration not required but may be applied installed practice from any ongoing applied construction activities construct a single- phase operation fence area Soil Restoration is required on Redevelopment projects redevelopment projects in areas where existing impervious area will be converted to pervious area *Aeration includes the use of machines such as tractor-drawn implements with coulters making a narrow slit in the soil, a roller with many spikes making indentations in the soil, or prongs which function like a mini-subsoiler. **Refer to latest version of NYSDEC Deep-Ripping and Decompaction. Using this Practice During periods of relatively low to moderate subsoil moisture, the disturbed subsoils are returned to rough grade and the following Soil Restoration steps applied: Apply 3 inches of compost over subsoil Till compost into subsoil to a depth of at least 12 : - inches using a cat-mounted ripper, tractor-mounted disc, or tiller, mixing, and circulating air and compost T into subsoils. Rock-pick until uplifted stone/rock materials of 4 inch - and larger size are cleaned off the site. Apply topsoil to a depth of 6 inches. t Vegetate as required by approved plan. Figure 5.16 Soil aerator implement At the end of the project an inspector should be able to push a 3/8 inch metal bar 12 inches into the soil just with body weight. Figure 5.16 and Figure 5.17 show two attachments used for soil decompaction. Tilling (step 2 above) should not be performed within the drip line of any existing trees or over utility installations that are within 24 inches of the surface. Chapter 5: Runoff Reduction Techniques 512 Compost Specifications - Compost shall be aged, from plant derived materials, free of viable weed seeds, have no visible free water or dust produced when handling, pass through a half inch screen and have a pH suitable to grow desired plants. ` �r t Maintenance A simple maintenance agreement should identify where Soil Restoration is applied, where newly restored areas are/cannot be cleared, who the responsible parties are to ensure that routine vegetation improvements are made (i.e.,thinning, invasive plant removal, etc.). Soil compost amendments within a filter strip or grass 6 A channel should be located in a public right of way, or within a dedicated stormwater or drainage easement. Figure 5.17 Soil aerator implement First year maintenance operations includes: Initial inspections for the first six months (once after each storm greater than a half inch) Reseeding to repair bare or eroding areas to assure grass stabilization Develop a watering plan specific to the species and size of the planting(s)to prevent over/under watering. Fertilization may be needed in the fall after the first growing season to increase plant vigor Ongoing Maintenance: Two points help ensure lasting results of decompaction: Planting the appropriate ground cover with deep roots to maintain the soil structure Keeping the site free of vehicular and foot traffic or other weight loads. Consider pedestrian footpaths. (Sometimes it may be necessary to de-thatch the turf every few years) Chapter 5: Runoff Reduction Techniques 5.13 Section 5.2 Planning for Runoff Reduction: Reduction of Impervious Cover Once sensitive resource areas and site constraints have been avoided, the next step is to minimize the impact of land alteration by reducing impervious areas. Reduction of impervious cover includes methods to reduce the amount of rooftops, parking lots, roadways, sidewalks and other surfaces that do not allow rainfall to infiltrate into the soil, in order to reduce the volume of stormwater runoff, increase groundwater recharge, and reduce pollutant loadings that are generated from a site. See Table 5.3 for a list of the impervious cover reduction techniques described in the detailed practice sheets in this section. I Table 5.3 Planning Practices for Reduction of Impervious Cover Practice Description Roadway Reduction Minimize roadway widths and lengths to reduce site impervious area. Sidewalk Reduction Minimize sidewalk lengths and widths to reduce site impervious area. Driveway Reduction Minimize driveway lengths and widths to reduce site impervious area. Cul-de-sac Reduction Minimize the number of cul-de-sacs and incorporate landscaped areas to reduce their impervious cover. Building Footprint Reduction Reduce the impervious footprint of residences and commercial buildings by using alternate or taller buildings while maintaining the same floor to area ratio. Reduce imperviousness on parking lots by eliminating unneeded spaces, providing compact Parking Reduction car spaces and efficient parking lanes, minimizing stall dimensions, using porous pavement surfaces in overflow parking areas, and using multi-storied parking decks where appropriate. 5.2.1 Roadway Reduction Description Roadway lengths and widths should be minimized on a development site where possible to reduce overall imperviousness. Key Benefits Reduces the amount of impervious cover and associated runoff and pollutants generated Reduces the costs associated with road construction and maintenance Typical Perceived Obstacles and Realities Local codes may not permit shorter or narrower roads —Meet with local officials to discuss waivers for alternative designs that will address concerns of access, snow stockpiling, and parking The public may view narrow roads as unsafe—Narrower roads in fact reduce the speeds at which vehicles drive; many maintenance and emergency vehicles can in fact access narrow roads Narrow and shorter roads do not have enough parking —Provisions can be made in the design of a site to accommodate off-street parking Using this Practice Consider different site and road layouts that reduce overall street length Minimize street width by using narrower street designs that are a function of land use, density and traffic demand Use smaller side-yard setbacks to reduce total road length Consult with local highway and planning officials to determine if narrower roads and smaller setbacks are accepted or whether waivers or variances will be needed Chapter 5: Runoff Reduction Techniques 5•14 The use of alternative road layouts that reduce the total length of roadways can significantly reduce overall imperviousness of a development site. Site designers are encouraged to analyze different site and roadway layouts to see if they can reduce overall street length. In addition, residential streets and private streets within commercial and other development should be designed for the minimum required pavement width needed to support travel lanes, on-street parking and emergency access. Figure 5.18 shows options for narrower street designs. In many instances, on-street parking can be reduced to one lane or eliminated on local access roads with less than 200 average daily traffic (ADT) and on short cul-de-sacs street. One-way, single- lane, loop roads are another way to reduce the width of lower-traffic streets. r ing4 � ran. i imw�udJy L:fli'�'... 26'PAVE WIDTH [118'PAVEWIDTH 10'DRAINAGE SWALE 6'DRAINAGE SWALE 4'SIDEWALK T UTILITY T UTILITY 60'RIGHT OF WAY 36'RIGHT OF WAY Figure 5.18 Potential design options for narrower roadway widths Refer the American Association of State Highway Transportation Officials (AASHTO) "A Policy on Geometric Design of Highways and Streets", latest edition, and for recommendations on minimum travel lane and shoulder width. In addition, refer to the NYSDOT Highway Design Manual Chapter 2, latest edition, for further recommendations. Where AASHTO and NYSDOT differ on recommendations, NYSDOT guidance should be used. Consideration should be given to incorporating pedestrian and bicycle access into roadway design. In addition, evaluate opportunities to reduce impervious surfaces through application of green infrastructure techniques, such as porous pavement. Chapter 5: Runoff Reduction Techniques 5.15 Table 5.4 Minimum Width of Traveled Way (F for Specified Design Volume d. Design speed Under 400 400 to 2000 Over 2000 (miles per hour) 20 201 20 22 25 201 20 22 30 201 20 22 35 201 22 22 40 201 22 22 45 20 22 22 50 20 22 22 55 22 22 222 60 22 22 222 65 22 22 222 Width of graded shoulder on each side of road (ft) All speeds 2 4 6 An 18 ft minimum width may be used for roadways with design volumes under 250 veh/day. 2 Consider using lane width of 24 ft where substantial truck volumes are present or agricultural equipment frequently uses the road From: A Policy on Geometric Design of Highways and Streets, (Table 6-5. Minimum Width of Traveled Way and Shoulders)2018 7t" Edition, by the American Association of State Highway and Transportation Officials, Washington, D.C. Used by permission. 5.2.2 Sidewalk Reduction Sidewalk lengths and widths should be minimized on a development site where possible to reduce overall imperviousness. Key Benefits Reduces the amount of impervious cover and associated runoff and pollutants generated Reduces the costs associated with construction and maintenance Reduces the individual homeowner's responsibility for maintenance, such as snow clearance Typical Perceived Obstacles and Realities Sidewalks on only one side of the street may be perceived as unsafe—Accident research shows sidewalks on one side are nearly as safe as sidewalks on both Homebuyers are perceived to want sidewalks on both sides — Some actually prefer not to have a sidewalk in front of their home, and there is no market difference between homes with and without sidewalks directly in front. Local codes may not permit narrower, alternative, or the elimination of a sidewalk—Meet with local officials to discuss waivers for alternative designs that will address concerns of accessibility and safety issues. Chapter 5: Runoff Reduction Techniques 5-16 Locate sidewalks on only one side of the street where applicable (may not apply in downtown and village areas where walkability is important) Provide common walkways linking pedestrian areas Use alternative sidewalk and walkway surfaces Shorten front setbacks to reduce walkway lengths Consult with local highway and planning officials to determine if alternative sidewalk designs and paving materials are allowed or whether waivers or variances will be needed Discussion Most local codes require that sidewalks be placed on both sides of residential streets (e.g., double sidewalks) and be constructed of impervious concrete or asphalt. For state and federally funded projects, the standard width of a sidewalk is 5 ft. Many subdivision codes also require sidewalks to be 4 to 6 ft wide and 2 to 10 ft from the street. J These codes are enforced to provide sidewalks as a safety + .� measure. r '� Developers may wish to consider allowing sidewalks on f . only one side of the street or eliminating them where they don't make sense. Sidewalks should be designed with the goal of improving pedestrian movement and diverting it away from the street. Developers may also consider reducing sidewalk widths and placing them farther from the street. In addition, sidewalks should be graded to drain to front yards rather than the street, or planters could be used as filters placed between sidewalk and road. Alternative surfaces for sidewalks and walkways should be Figure 5.19 Sidewalk with common walkways linking pedestrian considered to reduce impervious cover(Figure 5.19). In areas(Source: MA EOEA, 2005) addition, building and home setbacks should be shortened to reduce the amount of impervious cover from entry walks. Chapter5: Runoff Reduction Techniques -5.47 5.2.3 Driveway Reduction Description Driveway lengths and widths should be minimized on a development site where possible to reduce overall imperviousness. Key Benefits Reduces the amount of impervious cover and associated runoff and pollutants generated Typical Perceived Obstacles and Realities Alternative driveway surfaces make snow removal more difficult— Careful site design, material selection and homeowner education can help alleviate the concern Developers perceive alternative surfaces as less marketable — "Green"development projects are increasingly being sought by consumer. Homeowners have concerns regarding access with shared driveways —Proper site design, shared driveway agreements and homeowner education will alleviate access issues Local codes may not permit shorter or narrower driveways or driveways with porous surfaces —Meet with local officials to discuss waivers for alternative designs Using this Practice Use shared driveways that connect two or more homes Use alternative driveway surfaces Use smaller lot front building setbacks to reduce total driveway length Use shared driveway agreements for maintenance Consult with local highway and planning officials to determine if alternative driveway designs and paving materials are allowed or whether waivers or variances will be needed Discussion Most local subdivision codes are not very explicit as to how driveways must be designed. Most simply require a standard apron to connect the street to the driveway but don't specify width or surface material. Typical residential driveways range from 12 ft wide for one-car driveways to 20 ft for two. While shared driveways are discouraged or prohibited by many communities, they can reduce impervious cover and should be encouraged with enforceable maintenance agreements and easements (Figure 5.20). The typical 400-800 square ft of impervious cover per driveway can be minimized by using narrower driveway widths, reducing the length of driveways, or using alternative surfaces such as double-tracks, reinforced grass or permeable paving materials (Figure 5.21). F r Figure 5.20 Reduced driveway lengths by using shared Figure 5.21 Permeable pavers as an alternative driveway driveways(Source: MA EOEA, 2005) surface Chapter 5: Runoff Reduction Techniques 5-18 Building and home setbacks should be shortened to reduce the Typical30ft amount of impervious cover from driveways and entry walks. A E Setback setback of 20 ft is more than sufficient to allow a car to park in a Se 0' driveway without encroaching into the public right of way and reduces driveway and walk pavement by more than 30 percent compared with a setback of 30 ft (see Figure 5.22). 5.2.4 Cul-de-sac Reduction Description Minimize the number of cul-de-sacs and incorporate landscaped areas i Reduction in to reduce their impervious cover. The radius of a cul-de-sac should be Surfacesns the minimum required to accommodate emergency and maintenance �- - - - vehicles. Alternative turnarounds should also be considered. Figure 5.22 Reduced driveway and walkway Key Benefits lengths by using reduced setbacks (Adapted from: MPCA, 1989) Reduces the amount of impervious cover, associated runoff and pollutants generated Increases aesthetics by allowing for natural or landscaped areas rather than pavement Typical Perceived Obstacles and Realities Emergency and maintenance vehicles require a large turning radius —Many newer vehicles are available with small turning radii School buses require a large turning radius - Verify school bus pick-up plans. Not every cul-de-sac will need to accommodate school bus turning radii Homeowners like the "end of the road" appeal of cul-de-sacs— This appeal can be accommodated using loop roads or lots that back onto open space areas Local codes may not permit smaller or alternative cul-de-sac designs—Meet with local officials to discuss waivers for alternative designs that will address concerns of access Using this Practice Reduce the radius of the turnaround bulb or consider alternative cul-de-sac design, such as "tee"turn-a-rounds or looping lanes Apply site design strategies that minimize dead-end streets Create a pervious island or a stormwater bioretention area in the cul-de-sac center to reduce impervious area Consult with local highway and planning officials to determine if alternative cul-de-sac designs are allowed or whether waivers or variances will be needed Discussion Alternative turnarounds are end of the street designs that replace fully17 paved cul-de-sacs and reduce the amount of impervious cover created If11 in developments. Cul-de-sacs are local access streets with a closed circular end that allows for vehicle turnarounds. Many of these cul-de- sacs can have a radius of more than 40 ft. From a stormwater �- perspective, cul-de-sacs create a huge bulb of impervious cover, increasing the amount of runoff. For this reason, reducing the size of cul-de-sacs through the use of alternative turnarounds or eliminating them altogether can reduce the amount of impervious cover created at a site. Numerous alternatives create less impervious cover than the traditional 40-ft cul-de-sac. These alternatives include reducing cul-de- Figure 5.23 T-shaped turnaround option (Source: sacs to a 30-ft radius and creating hammerheads, loop roads and Center for Watershed Protection, 2005) pervious islands in the cul-de-sac center(see Figure 5.23, Figure 5.24 and Figure 5.25). Chapter 5: Runoff Reduction Techniques 5 u Sufficient turnaround area is a significant factor to consider in the design of cul-de-sacs. In particular, the types of vehicles entering the cul-de-sac should be considered. Fire trucks, service vehicles and school buses are often cited as needing large turning radii. However, , some fire trucks are designed for smaller turning radii. In addition, many newer large service vehicles are designed with a triaxle (requiring a smaller turning radius), and many school buses usually do not enter individual cul-de-sacs. Another option for designing cul- de-sacs involves the placement of a pervious island in the center. Vehicles only travel along the outside of the cul-de-sac when turning, leaving an unused "island" of pavement in the center. These islands 24 ` can be attractively landscaped and also designed as bioretention Figure 5.24 Loop road option (Source: Center for areas to treat stormwater(see Section 6.4 of this Manual). Watershed Protection, 2005) The most recent AASHTO guidelines should be used for cul-de-sac and alternative turnaround designs, and the design should create no more impervious surface than specified in the AASHTO guidelines. 20- W lV�" r Ii f fI� f III Irl I+ _ q_ SQUARED END 8 smiq METRIC m V.S. CUSTOMARY Ift] VEHICLE 1y - L W L P 10 2D 3f3 60 su 1� 3D 5a 1DD W, w, R �^ R r rr �� t ( 3ox R- ] / � I I � o �1lI1 If If � I1] I I � II Fd m[30 ft]far SIJ CIRCULAR CIRCULAR-OFFSET CIRCULAR—ALL PAVED -C- -u- -E- DESIGN VEHICLE METRIC rn u.s. CuSTDMARY ft] R M R I W P 10 G 30 19] WO-12 IWB-401 13 B q2 25 SU 3 WB-15 Ewe-50 15 1 10 47 130 e� �y Ii ii It t ID T 6 rI L TY T-TYPE Y-TYPE BRAN:-I' From:A Policy on Geometric Design of Highways and Streets, 2004, by the American Association of State Highway and Transportation Officials,Washington, D.C. Used by permission. P= Passenger Car SU = Single-Unit Truck WB =Wheel Base-applies to semitrailer Figure 5.25 Types of cul-de-sacs and dead-end streets Chapter 5: Runoff Reduction Techniques 5-20 5.2.5 Building Footprint Reduction Description The impervious footprint of residences and commercial buildings can be reduced by using alternate or taller buildings while maintaining the same floor-to-area ratio. Key Benefits Reduces the amount of impervious cover and associated runoff and pollutants generated Typical Perceived Obstacles and Realities Taller buildings are perceived to have higher construction and maintenance costs— Costs for taller buildings and associated parking may be offset by reduced land and construction and maintenance costs Local codes may not permit taller buildings — Consider alternative locations that do allow taller buildings, or meet with local officials to discuss waivers for alternative designs Using this Practice Use alternate or taller building designs to reduce the impervious footprint of buildings. Consolidate functions and buildings or segment facilities to reduce footprints of structures. Reduce directly connected impervious areas. Consult with local planning officials to determine allowed building heights and whether variances will be needed for alternative designs. Discussion In order to reduce the imperviousness associated with the footprint and rooftops of buildings and other structures, alternative and/or vertical (taller) building designs should be considered. Consolidate functions and buildings, as required, or segment facilities to reduce the footprint of individual structures. Figure 5.26 shows the reduction in impervious footprint by using a taller building design, and Figure 5.27 and Figure 5.28 show residential examples of reduced footprints. / / J ------------�' Four Story Building (75% Less Impervious Cover) Figure 5.26 Reduction of impervious cover by building up rather than out (Source: Georgia Stormwater Manual, 2001) Chapter 5: Runoff Reduction Techniques -21 Figure 5.27 Taller apartments create a smaller Figure 5.28 Taller houses create a smaller impervious footprint impervious footprint (Source: City of Portland, OR, 2001) (Source: Center for Watershed Protection, 2005) 5.2.6 Parking Area Reduction Reduce the overall imperviousness associated with parking lots by eliminating unneeded spaces, providing compact car spaces, minimizing stall dimensions, incorporating efficient parking lanes, using multi-storied parking decks and using porous paver surfaces or porous concrete in overflow parking areas where feasible. Key Benefits Reduces the amount of impervious cover, associated runoff and pollutants generated Reduces construction costs, long-term operation and maintenance costs, and the need for larger stormwater facilities Improves aesthetics of an area by increasing vegetative surfaces and reducing the feeling of a large, paved urban area Typical Perceived Obstacles and Realities Developers desire excess parking and fear losing customers during peaks —Potential loss of customers due to reduced parking is unknown however, often times parking areas are not full during peak periods Parking may spill over into residential or commercial areas when full —Include preferential parking provisions for residents or parking enforcement with meters Trend to larger vehicles such as SUVs— Stall width requirements in most local parking codes are much larger than the widest SUVs Structured parking is more expensive than surface lots — Costs for structured parking may be offset by land costs or by constructing garages above or below an actual building Porous pavement surfaces are more expensive to install and maintain —Alternative surfaces may reduce the need for deicing treatments as well as alleviate the need for larger stormwater treatment elsewhere on the site Using this Practice Reduce the number of unnecessary parking spaces by examining minimum parking ratio requirements, and set a maximum number of spaces Reduce the number of un-needed parking spaces by examining the site's accessibility to mass transit Minimize individual parking stall dimensions, consulting local codes to determine if a waiver or variance is required Examine the traffic flow of the parking lot design to eliminate un-needed lanes/drive aisles Chapter5: Runoff Reduction Techniques •22 Consider parking structures and shared parking arrangements between non-competing uses Use alternative porous surface for overflow areas or main parking areas if not a high-traffic parking lot Use landscaping or vegetated stormwater practices in parking lot islands Provide incentives for compact and hybrid cars Setting maximums for parking spaces, minimizing stall dimensions, using structured parking, encouraging shared parking, using alternative porous surfaces can all reduce parking footprint and site imperviousness. Some Planning Boards require that only a portion of the minimum parking spaces be constructed, and that space be provided to construct the remaining required spaces if needed. Many parking lot designs result in far more spaces than actually required. This problem is exacerbated by a common practice of setting parking ratios to accommodate the highest hourly parking during the peak season. By determining average parking demand instead, a lower maximum number of parking spaces can be set to accommodate most of the demand. Table 5.5 provides examples of conventional parking requirements and compares them to average parking demand. In addition, the number of parking spaces needed may be reduced by a site's accessibility to public transportation. modifiedTable 5.5 Conventional Minimum Parking Ratios D Parking Requirement Actual Average Land Use Parking Demand Parking Ratio Typical Range New York Example* 2 spaces per dwelling 1 2 spaces per dwelling unit, 1.11 spaces per Single family homes unit .5-2.5 plus 1 per auxiliary unit dwelling unit 5 spaces per 1000 sf 4 5.5 for>2000 sf 3.97 per 1000 sf Shopping center GFA .0-6.5 Net Floor Area GFA Convenience store 3.3 paces per 1000 sf 2.0-10.0 7 per for<2000 sf GFANet Floor Area Industrial 1 space per 1000 sf 0.5-2.0 1 space per employee 1.48 per 1000 sf GFA GFA Medical/dental office 5.7 spaces per 1000 sf 4.5-10.0 6.7 per 1000 sf of net floor 4.11 per 1000 sf GFA area GFA GFA=Gross floor area of a building without storage or utility spaces, *Town of Amherst Zoning Ordinance, net floor area is 0.75 to 0.9 of GFA, allows for alternate parking plans (hftp://www.amherst.ny.us/pdf/planning/compplan/Zcrc/p7.pdf) Another technique to reduce the parking footprint is to minimize the dimensions of the parking spaces. This can be accomplished by reducing both the length and width of the parking stall. Parking stall dimensions can be further reduced if compact spaces are provided. Another method to reduce the parking area is to incorporate efficient parking lanes such as using one-way drive aisles with angled parking rather than the traditional two-way aisles. Structured parking decks are another method for significantly reducing the overall parking footprint by minimizing surface parking. Figure 5.29 shows a parking deck used for a commercial development. Shared parking in mixed-use areas and structured parking are techniques that can further reduce the conversion of land to impervious cover. A shared parking arrangement could include usage of the same parking lot by an office space that experiences peak parking demand during the weekday with a church that experiences parking demands during the weekends and evenings. Provide a written agreement for the parties to sign that specifies usage and maintenance. Chapter 5: Runoff Reduction Techniques 5_23 Using alternative surfaces such as porous pavers or porous concrete is an effective way to reduce the amount of runoff generated by parking lots. They can replace conventional asphalt or concrete in both new developments and redevelopment projects. Figure 5.30 is an example of grass pavers used at an ��"►►.,, overflow lot. Alternative pavers can also capture and treat runoff r � from other areas on the site. r .irk, �,�-_•. When possible, expanses of parking should be broken up with ��`''�: landscaped islands at or below the grade of the parking area, ,"� G `' � AOF.0." with curb cuts. These islands could include shade trees and shrubs (see Figure 5.31) or landscaped stormwater management"islands"such as filter strips, swales and , bioretention areas (see Section 5.3.2, Section 5.3.3, Section 5.3.5, Section 6.4 and Section 6.5 of this Manual). Figure 5.29 Structured parking at an office park (Source: Georgia Stormwater Manual, 2001) 1 ■ Figure 5.30 Grass pavers for parking Figure 5.31 Expanses of parking area"Broken-Up"with (Source: Georgia Stormwater Manual, 2001) Landscape Features Chapter 5: Runoff Reduction Techniques 5-24 Section 5.3 Runoff Reduction Techniques Runoff Reduction is best achieved through the reduction of the effective impervious surface area of the catchment and minimization of disturbed area. This is particularly the case where pre-development soils demonstrate significant infiltration capacity. This section presents a series of runoff reduction principles and practices that can be incorporated in the site design to allow for micromanagement of runoff, promote groundwater recharge, increase losses through evapotranspiration and emulate the preconstruction hydrology, resulting in reduced water quality treatment volume. Runoff Reduction techniques utilize the natural features of the site and promote runoff reduction. By using these principles, the techniques in this Chapter provide an opportunity for distributed runoff control from individual sources, flow routing, infiltration, treatment and reduction of total water quality volume. Acceptable runoff reduction techniques are explained in this section of the Manual. Deviation from these requirements must be documented and justified. Refer to the Fact Sheets at the end of each practice section in Chapter 5 for key considerations of each runoff reduction technique, including performance criteria, practice suitability, implementation considerations, pollutant removal capability, and runoff reduction credit. The computation runoff reduction fall under two general methods. The first group of practices includes site design techniques that a designer could factor in by subtracting conserved areas from the total site area, resulting in reduced WQv and CPv. The second group of practices provide runoff reduction by storage of volume runoff and are computed accordingly. The following basic principles must be applied to all runoff reduction technique design applications: Must be appropriately sized for its contributing area (pervious and impervious cover). Contributing areas, depending on final grading, flow path, impervious cover disconnection, and varying levels of micromanagement of the flow, may require subcatchment delineation. For all runoff reduction techniques that involve infiltration, soil testing is required to confirm soil permeability and depth to seasonal high water table/bedrock. Testing must be performed within the limits of the proposed practice and follow the requirements in Appendix D. If any other calculation methods are utilized (e.g. TR-55), all the contributing areas and related practices must be modeled according to the requirements of the selected method. Must be designed with an overflow sized to safely pass the 100-year 24-hour storm event and convey storm flows to facilities designed for quantity control, if required. A stone drainage layer shall be incorporated in most practices to enhance structural integrity, storage, drainage, and infiltration. The following table allows designers to evaluate each standard SMP and determine which practice(s) are feasible for application to a specific site. Feasibility is based on thresholds that shall be met for four key site conditions: 1. Soil Permeability: This column outlines the permeability requirements for underlying soils at the location of a proposed SMP. The designer should perform an initial investigation of the NRCS hydrologic soil groups at the site to determine soil characteristics. Please note that more detailed geotechnical tests are usually required, in accordance with Appendix D. 2. Depth to Seasonal High Water Table: This column indicates the minimum depth to the seasonally high water table from the bottom elevation of the SMP section. 3. Contributing Area: This column indicates the minimum or maximum contributing area that is considered optimal for a practice. The minimum contributing area shall not be reduced, and the maximum shall not be increased, except where specific design criteria are met or additional engineering analysis is performed to support an adjusted area. 4. Max Site Slope: This column indicates the preferred maximum slope of the area proposed for installation of a practice. Existing slopes may exceed these values with proper engineering to ensure slope stability and non- erosive runoff velocities from the contributing area. Chapter 5: Runoff Reduction Techniques _2 I Table 5.6 Runoff Reduction Feasibility Matri - % GI Design Underlying Soils Depth to Water Contributing Area Max Site Table(ft) Slope Conservation of Natural Areas No Restriction No Restrictions 10,000 sf(min) No Restrictions Sheet Flow to Riparian Buffers No Restriction 150 ft(pervious) or Filter Strips No Restrictions 75 ft(impervious) 5%/10% Tree Planting No Restriction 2 No Restrictions 10% Underdrains required for Tree Pit 2 No Restrictions 10% f�<0.5 inch/hr Tree Trench f�>_0.5 inch/hr 2 No Restrictions 10% Disconnection of Rooftop 000 sf/filter path,1 No Restriction No Restrictions No Restrictions Runoff (max) Vegetated Swale No Restriction No Restrictions 5 ac(max) 0.5%-4%and 3:1 (h:v) Underdrains required for 1 1,000 sf/garden Filtration Rain Garden 2 No Restrictions f�<0.5 inch/hr (max) Infiltration Rain Garden fc>_0.5 inch/hr 2' 1,000 fa/gj rden No Restrictions Underdrains required for 1 15,000 sf/planter Filtration Stormwater Planter 2 No Restrictions fc<0.5 inch/hr (max) Infiltration Stormwater Planter fc>_0.5 inch/hr 2' 15,000 saf/p)lanter No Restrictions Rainwater Harvesting System NA NA No Restrictions NA Porous Pavement fc>_0.5 inch/hr 2' <3 times surface 10% area Green Roof NA NA Roof Size 10%/25% 'When in sole source aquifer increase to 4 ft NA=Not Applicable Chapter 5: Runoff Reduction Techniques -2 5.3.1 Conservation of Natural Areas (RR-1) Conservation of natural areas is an area reduction practice designed to retain the pre-development hydrologic and water quality characteristics of undisturbed natural areas by permanently conserving these areas on a site. Undisturbed natural areas include: forest retention areas; reforestation areas; stream and river corridors; shorelines; wetlands, vernal pools, and associated vegetated buffers; and undisturbed open space. BA4P — �ocArfo i i i k f a w i r NA7'ClRA i _ AREA C�rv.SE�e ION 7YPr Ate) $TAT HIGHWAY Figure 5.32 Schematic Diagram of Conservation of Natural Area. Areas with cross-hatching are being designated as a permanent conservation area and shall be removed from the total contributing site area when calculating water quality volume. Chapter 5: Runoff Reduction Techniques 5-27 5.3.1.1 Feasibility Natural conservation areas must be delineated and permanently protected through establishment of a legal conservation easement. State regulated wetlands and associated adjacent areas can be placed into a legal conservation easement. RRv credit can be taken for the associated adjacent areas in the area reduction calculation. However, RRv credit cannot be taken for the area of the State regulated wetland itself. RRv credit can be taken for conservation areas containing cross-county ski trails and hiking/walking trails in the area reduction calculation. However, credit cannot be taken if the trail fragments the contiguous area. Managed turf including, but not limited to, playgrounds, parks, athletic fields, and cemeteries are not acceptable for conservation. 5.3.1.2Treatment 5.3.1.2.1 Design Criteria Conservation areas shall have a minimum contiguous area of 10,000 sf. If multiple, separate conservation areas are provided on the same site, then each area must meet the minimum contiguous area. Delineation of conservation areas shall be performed to maximize contiguous land area and avoid fragmentation. Conservation areas shall be permanently protected through establishment of a legal conservation easement that clearly specifies how the natural area vegetation shall be managed. Boundaries of a conservation area must be delineated with permanent physical markers. Conservation areas cannot be disturbed and shall be protected throughout construction with appropriate structural barriers. The limits of disturbance along conservation areas shall be clearly shown on all construction drawings, staked out in the field and delineated by orange construction fencing prior to commencing construction activities. 5.3.1.2.2 Sizing Criteria When computing water quality volume, the area to be designated as a conservation area is subtracted from the total contributing area to a given design point. This reduction shall only be applied for undisturbed natural areas that are located within the property boundaries of the site, are solely controlled by the property owner, and contribute runoff to the design point. The area reduction credit shall only be applied towards the required RRv for the design point to which the conservation area is tributary. This practice is not applicable if credit for Sheet flow to Riparian Buffer, or another area reduction practice, is already being taken for the same area. Conservation areas shall not receive runoff from impervious area. Contributing areas that contain existing or new impervious surfaces shall be designed according to Sheet flow to Riparian Buffer requirements. When calculating peak discharge rates or volumes, the total contributing area associated with conservation areas must be included in the hydrologic/hydraulic analyses and an appropriate curve number must be applied. If the conservation area is tributary to a downstream SMP, then the practice must be sized to accommodate the total flow generated from the entire tributary watershed. 5.3.1.2.3 Design Example Base Data Total contributing area = 10 acres Contributing impervious area = 3 acres 90% Rainfall Event Number= 1.0 inch Area to be protected as natural conservation area = 3 acres. *In this scenario the conservation area is not receiving runoff from upstream areas and is subtracted from the contributing area to the design point: 10-3=7 acres Chapter5: Runoff Reduction Techniques •28 First, compute the required WQv, per Chapter 4: I = (AA p\I(100) ( I 3 acres )(100) 10 acres I = 30% RV = 0.05 + 0.0091 RV = 0.05 + (0.009)(30) RV = 0.32 P •RV•A WQv 12 (1.00 inches)(0.32)(10 acres) W Qv 12 WQv = 0.267 of Next compute the Area Reduction WQv, accounting for the area reduction from the natural conservation area. When calculating the Area Reduction WQv, the previously calculated Rv(0.32) remains unchanged: RV = 0.32 P •RV•A W Qv 12 (1.00 inches)(0.32)(7 acres) W Qv 12 WQV = 0.187 of Then compute the RRV Provided, taking into account the natural conservation area: RRV Provided = Required WQv —Area Reduction WQv RRV Provided = 0.267 of— 0.187 of RRV Provided = 0.080 of Chapter 5: Runoff Reduction Techniques 5-29 Fact Sheet: Conservation of Natural Areas (RR-1) t Description: Area reduction practice designed to maintain pre- ' -; development hydrologic and water quality characteristics of undisturbed natural areas by permanently conserving them. �rl Key Considerations FEASIBILITY STORMWATER MANAGEMENT SUITABILITY Natural conservation areas require legal conservation easement 40 Water Quality Areas must not be disturbed during construction • Channel Protection TREATMENT • Overbank Flood Protection Minimum area= 10,000 sf Extreme Flood Protection Delineate boundaries of conservation area with permanent physical • marker O Runoff Reduction Conservation areas shall not receive runoff from impervious areas • Treatment of Hotspots Area to be designated as a conservation area is subtracted from the total contributing area to a given design point when computing WQv 0 Linear Applications Total contributing area associated with conservation areas must be ✓suitable for this practice included in the hydrologic/hydraulic analyses when calculating peak discharge rates/volumes IMPLEMENTATION CONSIDERATIONS ® Capital Cost toMaintenance Burden ® Safety Risk Landscaping L= Low M = Moderate H =High NA= Not Applicable POLLUTANT REMOVAL Phosphorus ® Nitrogen ® Metals ® Pathogens Total Suspended Solids G=Good F= Fair P= Poor *= May provide partial benefits RUNOFF REDUCTION CREDIT 100%area reduction towards RRv Chapter 5: Runoff Reduction Techniques 5.3.2 Sheet Flow to Riparian Buffers or Filter Strips (RR-2) An area reduction practice where runoff is directed towards natural riparian buffers and vegetated filter strips for source control treatment, infiltration, reduction in velocity, and pollutant removal. Riparian buffers are natural or reforested vegetated areas along streams, rivers, and other waterbodies that protect water quality through bank stabilization, erosion and sediment control, reduced flood impacts, and filtration of nutrients. Vegetated filter strips are areas of permanent vegetation designed to treat sheet flow from adjacent surfaces and remove pollutants through filtration and infiltration. • CONTRIBUTING IMPERVIOUS SURFACE 75' MAX PRETREATMENT PEA GRAVEL DIAPHRAGM } CONTRIBUTING #� "` d ' PERVIOUS SURFACE ADJACENT ! WATERCOURSE UNDISTU17 RBED SOIL FIRST 10' OF FILTER 2% MAX SLOPE CONTRIBUTING LAND USES FLOW UNDISTURBED RIPARIAN EUPPER 150' MAX SPREADER 35' MIN (CONTRIBUTING SLOPE C57.) 107. MAX SLOPE (AS REQUIRED) 60 MIN (CONTRIBUTING SLOPE 5%-10%) 6% MAX SLOPE SHEET FLOW TO RIPARIAN BUFFER PROFILE VIEW CONTRIBUTING IMPERVIOUS SURFACE _ 75' MAX PRETREATMENT PEA = GRAVEL DIAPHRAGM ;;• CONTRIBUTING DENSE TURF COVER PERVIOUS SURFACE AMENDED SOIL FIRST 10' OF FILTER 2% MAX SLOPE CONTRIBUTING LAND USES FLOW GRASS FILTER STRIP 150' MAX SPREADER 35' MIN (CONTRIBUTING SLOPE <57.) 10% MAX SLOPE (AS REOUIRED)60' MIN (CONTRIBUTING SLOPE 5%-10%) 8% MAX SLOPE SHEET FLOW TO FILTER STRIP PROFILE VIEW Figure 5.33 Sheet Flow to Riparian Buffers or Filter Strips (RR-2) Chapter 5: Runoff Reduction Techniques 5-31 5.3.2.1 Feasibility Riparian buffers and vegetated filter strips must be delineated and permanently protected through establishment of a legal conservation easement. For rooftop disconnections draining directly to a buffer, either the disconnection of rooftop runoff or sheet flow to riparian buffer runoff reduction method shall be used, but not both. 5.3.2.2 Conveyance Intercept stormwater runoff near the source before it becomes concentrated and then distribute this flow evenly (as sheet flow) to the buffer or filter strip to promote natural infiltration. Install an upgradient level spreader to establish sheet flow, if necessary, as seen in Figure 5.33. A mechanism for reducing erosive velocities to non-erosive should be provided to reduce erosion or damage to a buffer or filter strip. Recommended buffer widths for various uses are indicated in Figure 5.34. Carefully constructed berms can be placed around natural depressions and below undisturbed vegetated areas with porous soils to provide for additional runoff storage and/or infiltration of flows. human land use lag stream _ I I I 0' 50, 100' 150' 200' 250' 300' bank stabilization AM fisheries habitat � nutrient removal sediment Canlrol �)♦ Hood Control wildlife habitat Figure 5.34 Preservation of buffers for various environmental quality goals 5.3.2.3 Pretreatment Pretreatment shall be provided through a pea gravel diaphragm installed upgradient of the buffer or filter strip. If runoff is being conveyed via sheet flow from a surface level impervious area, then the pea gravel diaphragm shall be installed along the downgradient edge of the impervious area. The pea gravel diaphragm shall have the minimum dimensions 12 inch width by 24 inch depth. 5.3.2.4 Treatment 5.3.2.4.1 Design Criteria Runoff shall enter the buffer or filter strip as overland sheet flow. If sheet flow cannot be achieved due to upgradient slopes, then a flow spreader shall be installed upgradient of the practice. Siting and sizing of this practice must address runoff reduction requirements and cannot result in overflow to undesignated areas. The NYS Freshwater Wetlands Act regulates the 100-ft adjacent area of NYS designated wetlands. If the regulated stream or adjacent wetland area conforms to the treatment criteria defined herein, then credit can be taken for the area. Chapter 5: Runoff Reduction Techniques 5-32 Riparian buffers cannot be disturbed and shall be protected throughout construction with appropriate structural barriers. The limits of disturbance along the riparian buffer shall be clearly shown on all construction drawings, staked out in the field and delineated by orange construction fencing prior to commencing construction activities. The design, installation, and management shall be in accordance with Table 5.7. Table • for • to Riparian Sheet Flow to Vegetated Filter Strip' Design Criteria Sheet Flow to Riparian Buffer Sheet Flow to Vegetated Filter Strip Soil and Ground Cover Undisturbed soils and native Amended soils per Table 5.11 and vegetation dense turf cover.' Adjacent drainage to natural Source control treatment of directly Typical Application stream buffer or conservation adjacent impervious area area Compost Amendments No Yes Filter Strip Width Equal the contributing area width Maximum Length of Contributing 150 ft total length with Flow Path 75 ft total from impervious surfaces 5%without upgradient flow spreader Maximum Slope of Contributing Area >5 to 10%with upgradient flow spreader >10% practice not permitted Maximum Slope, First 10 Ft of Less than 2% Less than 2% Buffer/Filter Maximum Buffer/Filter Overall Slope 6% 8% Minimum Flow Length through 35 ft for contributing area slope of 0%to<5% Buffer or Filter Strip 60 ft for contributing area slope of 5%to 10% Protection During Construction Locate outside the limits of disturbance and protect with ESC practices Stage 'See the NYS Standards and Specifications for Erosion and Sediment Control for the design of flow spreaders 'Credit can be taken for sheet flow to existing vegetated filter strips that meet all design criteria of this table and have established dense turf cover. In this case, amended soils would not be required. 5.3.2.4.2 Sizing Criteria Calculate the required water quality volume for the riparian buffer or filter strip using the contributing area. Once the required water quality volume is determined, size the buffer and/or filter strip in accordance with Table 5.7. If all other criteria of this section are met, the practice receives 100% runoff reduction credit. This reduction may only be applied for buffers or filter strips that are located within the property boundaries of the site, are solely controlled by the property owner, and contribute runoff to the design point. The area reduction credit can only be applied towards the required RRv for the design point to which the buffer or filter strip is tributary. Reduced areas are not deducted when calculating quantity controls for larger storms. In HSG C and D, buffer or filter strip length shall be increased by 15% and 20%, respectively. The buffer or filter strip length shall be determined using the below equation for filter length based on the SCS TR- 55 travel time equation. If the calculated buffer or filter strip length is less than the minimum flow length through the buffer or filter strip, in Table 5.7, the minimum length must be used. L — (T1.25)(p20.625\/So.5) \\ //``0.338nJ\ Chapter 5: Runoff Reduction Techniques 5-33 L = length of filter strip parallel to flow path (ft) T=travel time through filter strip (6 minutes min. based on TR-55) P2 = 2-yr 24-hr rainfall depth (inches) SL= filter strip slope (ft/ft) n = Manning's coefficient for buffer or filter strip 5.3.2.4.3 Design Example Base Data Total contributing area = 3.40 acres HSG Group = C Contributing impervious area = 0.20 acres Travel time = 6 minutes 90% Rainfall Event Number= 1.00 inches 2-yr 24-hr rainfall depth = 3.43 inches Contributing area slope = 5.5% Overall filter strip slope = 8% Contributing area width = 50 ft Manning's coefficient= 0.24 First, compute the required WQv, per Chapter 4: \ I = (LY—P I(100) I (0.20 acres\ (100) 3.40 acres) I = 6% RT, = 0.05 + 0.009I RT, = 0.05 + (0.009)(6) RV = 0.10 WQv = P R� A W v _ (1.00 inches)(0.10)(3.40 acres) Q 12 WQv = 0.028 of Next, determine the filter strip width. The filter strip minimum width, per Table 5.7, must equal the contributing area width. The filter strip width is 50 ft. Then, calculate the filter strip based on the proposed design conditions: L — (T1.25)(p20.625)(50.5) 0.338n L — (61.25)(3.430.625)(0.080.5) (0.338)(0.24) L = 70.7ft The calculated filter length is 70.7 ft. Based on Table 5.7, the minimum filter strip length required is 60 ft for contributing area slopes between 5% and 10%. As the calculated filter length is greater than the minimum required filter length, therefore the calculated length must be provided. As such,the filter strip length proposed is 70.7 ft. Chapter 5: Runoff Reduction Techniques 5-34 In addition, the filter strip is in HSG C soils and must be increased by an additional 15%. Therefore, the proposed filter strip length is increased from 70.7 ft to 81.31 ft. Assuming all other feasibility and design requirements have been met, the designed filter strip receives 100% RRv credit of 0.028 af. Chapter 5: Runoff Reduction Techniques 5-35 Fact Sheet: Sheet Flow to Riparian Buffers or Filter Strips (RR-2) Area reduction practice designed to direct runoff towards natural riparian buffers and vegetated filter strips. This practice acts as source control, provides treatment, promotes � infiltration, reduces velocity, and removes pollutants. (Photo Source: Fund for Lake Michigan) k Key Considerations FEASIBILITY STORMWATER MANAGEMENT SUITABILITY Riparian buffers and vegetated filter strips require the establishment of a Water Quality legal conservation easement Areas must not be disturbed during construction • Channel Protection CONVEYANCE • Overbank Flood Protection Intercept runoff near source and distribute as sheet flow to buffer or filter • Extreme Flood Protection strip Runoff Reduction High flow bypass should be utilized to reduce damage to buffer/filter strip PRETREATMENT ® Treatment of Hotspots Gravel diaphragm on upgradient side of buffer/filter strip Linear Applications TREATMENT ✓suitable for this practice Runoff should enter as sheet flow IMPLEMENTATION CONSIDERATIONS The maximum slope for the contributing area is 5%without an upgradient ® Capital Cost flow spreader, and 10%with an upgradient flow spreader. The slope of the contributing area shall not exceed 10% ® Maintenance Burden The maximum length of contributing flow path is 150 ft total length with 75 ® Safety Risk ft total from impervious surfaces The maximum slope, for the first 10 ft of the filter, shall be less than 2% 0 Landscaping The maximum overall slope of a riparian buffer is 6%. The maximum L= Low M = Moderate H =High overall slope for a vegetated filter strip is 8% NA= Not Applicable The minimum flow length through the buffer or filter strip is 35 ft for contributing area slope of 0%to< 5%, and 60 ft for contributing area POLLUTANT REMOVAL(See Table 10.4) slope of 5%to 10% Phosphorus Not applicable if credit for Disconnection of Rooftop Runoff, or another area reduction practice, is already being taken for the same area ® Nitrogen Buffer length shall be increased by 15%-20% in HSG C and D O Metals respectively OPathogens ® Total Suspended Solids G=Good F= Fair P= Poor RUNOFF REDUCTION CREDIT 100% RRv provided Chapter 5: Runoff Reduction Techniques 5.3.3 Tree Planting/Tree Pit/Tree Trench (RR-3) Tree plantings are existing or newly planted trees in a natural setting that can be applied as a runoff reduction technique for Area Reduction. REFER TO APPENDIX H FOR TREE SPECIES. 2—INCH MIN CALIPER OR 6—FOOT MIN HEIGHT FOR NEW TREE PLANTINGS 4—INCH MIN CALIPER OR 5—FOOT MIN HEIGHT FOR EXISTING TREES 3" MIN SHREDDED HARDWOOD MULCH CONTRIBUTING FINISHED IMPERVIOUS AREA I[GRADE LAWN FILTER MEDIA 3' MIN DEPTH OR ROOT BALL DEPTH, WHICHEVER IS GREATER 5' MIN 10' MAX FOR NEW TREE PLANTINGS 20' MAX TO CANOPY FOR EXISTING TREES SHEET FLOW FROM ASPHALT PAVEMENT OR THROUGH CURB DROP PROFILE VIEW Figure 5.35 Tree Planting (RR-3) Chapter 5: Runoff Reduction Techniques 5-37 Tree pits refer to individually planted trees in contained areas, such as street trees within sidewalks or curbed islands, that can be applied as a runoff reduction technique for Volume Reduction. CURB OR ANCHORED FRAME AT PERIMETER OF TREE PIT TO SUPPORT TREE GRATE j V MIN PLAN VIEW 3 CURB OR ANCHORED " MIN SHREDDED FRAME AT PERIMETER OF HARDWOOD MULCH TREE PIT To SUPPORT TREE GRATE 3" 6" MIN PERFORATED UNDERDRAIN (IF REQUIRED) FILTER MEDIA 36" MIN DEPTH 6" IN NO. 57 STONE DRAINAGE LAYER � (WASHED, NO FINES) 2' MIN DEPTH I------ --TT ` WHERE UNDERDRAIN IS REQUIRED, PROVIDE I _ ____ _ _ I 10" MIN NO. 57 STONE DRAINAGE LAYER ROOT BARRIER WASHED, NO FINES DRAINAGE� PROFILE VIEW ' ( ) FILTER FABRIC 24" MIN SEPARATION TO SEASONAL HIGH WATER TABLE/BEDROCK REFER TO APPENDIX H SUGGESTED PLANT LIST CURB OR ANCHORED FRAME AT PERIMETER 3" MIN SHREDDED OF TREE PIT TO SUPPORT TREE GRATE HARDWOOD MULCH TREE GRATE FILTER MEDIA 36" MIN DEPTH I I 1 -L- DRAINAGE FILTER FABRIC — — — — SECTION A-A VIEW 6" MIN PERFORATED UNDERDRAIN (IF REQUIRED) TRANSITION TO SOLID PIPE BEYOND LIMITS OF TREE PIT (TYP) Figure 5.36 Tree Pit(RR-3) Chapter 5: Runoff Reduction Techniques 5-38 Tree trenches are linearly planted trees along an impervious surface, such as roads or sidewalks, that capture surface flow and are connected by an underground stone reservoir with perforated pipe to maximize infiltration for credit as a runoff reduction technique for Volume Reduction. Tree trenches can support surface or subsurface flow. 12" MIN PERFORATED LIMIT OF SUBSURFACE CLEAN CUT INFlLTRAT1pN PIPE STORAGE MEDIA r r r rTTe r r r r r r r r I r r r C AJ CATCH BASIN INLET PLAN VIEW in 10' O.C. MIN. REFER TO APPENDIX H SUGGESTED PLANT LIST CATCH BASIN INLET 3" MIN SHREDDED CLEAN OUT HARDWOOD MULCH FILTER MEDIA 36" MIN DEPTH --------- -------- --- -- 2' MIN NO. 2 STONE DRAINAGE --------- --- — ----------- ------ LAYER (WASHED, ROOT BARRIER V NO FINES) DRAINAGE FILTER FABRIC 2' DEPTH = 12" MIN PERFORATED 24" MIN INFILTRATION PIPE SEPARATION TO SEASONAL HIGH STRUCTURAL SOIL OR PROPRIETARY WATER TABLE/BEDROCK SOIL CELL PRODUCT CAPABLE OF PROFILE VIEW SUPPORTING WALKING SURFACE ABOVE AND TREE ROOT GROWTH (TYP) 3" MIN SHREDDED HARDWOOD CLEAN OUT FILTER MEDIA r i 36" MIN DEPTH 24" MIN NO. 2 STONE DRAINAGE LAYER DRAINAGE FILTER FABRIC _ r (WASHED. NO FINES) 12" MIN INFILTRATION PIPE r 24" MIN SEPARATION TO SEASONAL HIGH SECTION A-A VIEW WATER TABLE/BEDROCK Figure 5.37 Tree Trench Subsurface Flow(RR-3) Chapter 5: Runoff Reduction Techniques 5-39 12" MIN INFILTRATION PIPE A DOME OR INLET SIDEWALK CURBED TREE OVERFLOW GRATE CURB INLET (3" MIN WIDTH} TRENCH ENCLOSURE STABILIZED INLET TRENCH DRYIIN STABILIZED PRETREATMENT PLAN VIEW { OPTION 1: 10' O.C. MIN. GABION BASKET DROP CURB INLET DOME OR INLETAw OVERFLOW GRATE 3" MIN SHREDDED HARDWOOD MULCH FILTER MEDIA IV— 36" MIN DEPTH --------------- " " 24" MIN NO. 2 STONE ❑RAINAGE LAYER (WASHED. NO FINES) 12" MIN INFILTRATION PIPE 24" MIN PROFILE V[EW SEPARATION TO SEASONAL HIGH WATER TABLE/BEDROCK TRENCH DRAIN DROP CURB INLET ROADWAY -r STABILIZED PRETREATMENT��r OPTION 1: GABION BASKET 1 DRAINAGE FILTER FABRIC SECTION A-A VIEW Figure 5.38 Tree Trench Surface Flow(RR-3) Chapter 5: Runoff Reduction Techniques 5-40 5.3.3.1 Feasibility Tree species selection shall take overhead and underground utilities into consideration, where applicable. Ideally, the tree root ball will be placed on native subsoil to prevent sinking. In scenarios requiring filter media to be placed below the root ball, it is recommended that media be hand tamped in 6-inch lifts based on the size of the root ball. Consultation with a Landscape Architect is recommended under these scenarios. Tree pits and tree trenches may be applied as practices for urban stormwater management (see Chapter 8). Conserved existing trees shall be non-invasive, healthy trees with a root system that will not be impacted by the proposed development. Tree pits with more than one tree per pit shall have underlying soils with an infiltration rate greater than or equal to 0.50 inch/hr, as confirmed by required geotechnical testing (see Appendix D), unless underdrains are provided. Tree trenches shall not be used unless the underlying soils have an infiltration rate greater than or equal to 0.50 inch/hr, as confirmed by required geotechnical testing (see Appendix D). Tree trenches and tree pits with more than one tree per pit shall have a 2 ft min. separation to the seasonal high water table and bedrock, including sound bedrock, fractured bedrock or karst geology. Tree trenches, tree pits and tree plantings shall not be used to treat stormwater hotspots. In areas of known contamination, or if contamination is discovered during excavation, contaminant levels must be evaluated by a qualified professional and state remediation program to determine if infiltration is permitted. Tree plantings are not applicable if credit for another area reduction practice is already being taken for the same area. Tree pits designed adjacent to public or private roadways shall have a maximum spacing of 30 ft on center. Tree trenches shall meet the separation requirements as listed in Table 5.8. Vertical separation shall be taken from the bottom of the stone drainage layer. Horizontal separation shall be taken from the closest side of the filter media. SeparationTable 5.8 Tree Trench Minimum Vertical Separation Horizontal Separation Structures Structures With Design Seasonal High Bedrock'2 Without Foundation Water Supply Septic Variant Water Table'2 Foundation Waterproofing4 Well/Reservoir System3,5 Waterproofing Tree Trench 2 ft 2 ft loft O ft 100 ft 50 ft 'Sound bedrock,fractured bedrock or karst geology as documented by on-site soil testing. 24 ft in sole source aquifers. 'Septic systems are inclusive of distribution boxes and absorption fields. 4Separation requirements shown are specific to the soil media.Trees shall be appropriately set back from structures. 51f underdrains are proposed,minimum setback shall be 100 ft. 5.3.3.2 Conveyance Stormwater runoff shall be intercepted near the source and conveyed to the practice as sheet flow or concentrated flow with a flow dissipater upon entrance into the practice. Runoff from adjacent building roofs can be captured and directed into tree trenches. Roof drains shall discharge at the surface of the tree trench or connect to a storm sewer structure for flow dissipation, prior to entering the tree trench. Direct connections to the subsurface infiltration pipe are not permitted. Adequate pretreatment shall be provided. Tree pit underdrain systems shall be designed to create an internal water storage using one of the following methods: Chapter 5: Runoff Reduction Techniques 5411 Provide an upturned elbow, set 10 inches above the bottom of practice (Refer to Appendix C); Set the outlet pipe invert, at the outlet control structure, 10 inches above the bottom of practice; or Increase the drainage layer depth to provide 8 inches of stone below the underdrain. Tree trenches shall be equipped with a subsurface infiltration reservoir, below the soil media, consisting of a 12 inch minimum perforated pipe (infiltration pipe) embedded within a stone drainage layer. The stone drainage layer shall be extended a minimum of 12 inches on all sides of the infiltration pipe. Alternatively, approved proprietary underground infiltration systems, meeting the design criteria in Section 6.3, may be used in place of the infiltration pipe. Tree trenches shall have a subsurface emergency overflow pipe within an outlet control structure and the invert shall be set at or above the top of the infiltration pipe. 5.3.3.3 Treatment 5.3.3.3.1 Design Criteria Flush curbs shall only be used around tree pits and tree trenches if pedestrian protection fencing is installed around the perimeter of the practice. For tree pits and tree trenches, where the open surface area does not meet the filter media minimum width or length requirements, the filter media shall extend to meet the minimum dimensions beneath the adjacent hardscape. The portion of the filter media that extends beneath hardscape surfaces shall be substituted with a structural filter media meeting the requirements in Table 5.9. Tree plantings, pits and trenches shall meet the following design requirements: Table 5.9 Design Criteria for Tree Plantings, Pits and Trenches Design Criteria Tree Trenches Tree Pits Tree Plantings Maximum Slope of Contributing Area 10% Tree Species Species shall be chosen from Chapter 11 or a local list of native species Minimum Size—New Deciduous trees: 2-inch caliper Trees Evergreen trees: 6 ft. height Minimum Size— Deciduous trees: 2-inch caliper Existing Trees Evergreen trees: 6 ft. height Minimum Tree Spacing 10 ft. O.C. N/A N/A Maximum Horizontal Separation from loft Contributing Impervious Area—New Trees Maximum Horizontal Separation from Canopy within 20 ft Contributing Impervious Area—Existing Trees Chapter 5: Runoff Reduction Techniques 5-42 Tree pits and Tree Trenches shall consist of the following design specifications: Table1 Tree Pit& Tree Trench Design • • Tree Trenches Tree Pits Tree Planting Ponding' Depth 6 inch max. below lowest inlet Surface Depth 3 inch min. for new plantings Layer' Material Shredded Hardwood Mulch Applicability As Required N/A Structural Depth Per Manufacturer N/A Filter Media Material CU-Structural Soil®or demonstrated equivalent; or Modular soil cell system infilled with filter media Depth 36 inches min. Width 5 ft min. Filter Media' Length Determined by available space 5 ft min. ASTM C-33 Sand: 60%-75% Material Topsoi13: 25%-40% Common planting soil Applicability Required Required N/A 6 inch min. without Drainage Depth 24 inch min. underdrain N/A Layer 10 inch min. with underdrain Material No. 2 stone, washed, no fines AASHTO No. 57 stone, N/A washed, no fines Applicability Required Required N/A Drainage Filter Fabric Materia12 Non-woven, polypropylene geotextile with flow rate greater than 125 gpm/sf(ASTM D4491)and Apparent Opening Size US#70 sieve(ASTM D4751) Infiltration Applicability Required N/A N/A Pipe Material 12" min. perforated PVC or HDPE laid level or approved underground proprietary practice Applicability N/A As Required N/A Underdrain Material 6" perforated PVC or HDPE laid at 0.5%slope min. at 30 ft max. O.C. Footnotes: 'Required for all Design Variants 2Or acceptable alternatives,such as a 3 inch minimum layer of pea gravel 3Topsoil shall conform to NYSDOT Standard Specification 713-01 for Roadside Mix or Specialty Planting Mix. Construction Requirements Heavy equipment traffic must be limited in the vicinity of both existing and proposed tree planting areas. Where existing trees are proposed as tree plantings, the design development and construction process must: Inventory existing trees on-site; Identify trees to be protected; Protect the identified trees and surrounding soils during construction by limiting clearing, grading and compaction within the drip line of the canopy; and Protect and maintain identified trees post-construction. Chapter 5: Runoff Reduction Techniques •• 3 5.3.3.3.2 Sizing Criteria Area Reduction (Tree Planting) Credit for impervious area reduction shall be the following: Mature tree canopy less than 16 ft diameter: half the area of the tree canopy. Mature tree canopy greater than or equal to 16 ft diameter: 100 SF per tree. When computing the required water quality volume to a given design point, subtract the impervious area contributing by sheet flow, to an existing or new tree, from the total contributing impervious area. Reduced areas are not deducted when calculating quantity controls for larger storms. Volume Reduction (Tree Pit/Tree Trench) Depth of stone reservoir shall be designed to account for the total tributary area, in-situ soil characteristics, as well as water quality volume and quantity control requirements. Systems shall be designed to ensure that the peak water surface elevation for the 10-year, 24-hr design storm does not overtop the system and shall safely convey runoff from greater storm events. The depth of soil media shall be sized, based on the principles of Darcy's Law, to treat the WQv for the surface discharge tributary to each tree pit/trench. The filter area shall be sized based on the principles of Darcy's Law. Calculate the minimum bottom area: _ (WQ,)(df) Af (k)(hf + df)(tf) Where: Af= Filter area (so WQv= Water Quality Volume (co df= Depth of filter(ft) k= Permeability flow rate of filter media (1 ft/day) hf=Average height of ponding (ft) (0.5 ft max.) tf= Maximum filter bed drain time (2 days) 5.3.3.4 Landscaping For planting guidance for stormwater management facilities, refer to Chapter 11. Permanent vegetative cover shall achieve 80% uniform density established over the entire contributing pervious area, before runoff is directed into the facility. Chapter5: Runoff Reduction Techniques •44 Fact Sheet: Tree Planting/Tree Pit/Tree Trench (RR-3) Description: Tree planting is an area reduction practice using existing or newly planted trees. Tree pits are a volume reduction practice using trees planted in contained areas. Key Considerations FEASIBILITY STORMWATER MANAGEMENT SUITABILITY • Tree plantings are not applicable if credit for another area reduction ® Water Quality practice is already being taken for the same area Trees shall be non-invasive and not be disturbed during construction • Channel Protection Tree pits shall have underlying soils with an infiltrate greater than or equal ® Overbank Flood Protection to 0.50 inch/hr, unless underdrains are provided Extreme Flood Protection Tree trenches shall have underlying soils with an infiltration rate greater than or equal to 0.50 inch/hr ® Runoff Reduction Tree trenches and tree pits shall have a 2 ft min. separation to the seasonal high water table and bedrock Treatment of Hotspots Overhead clearance shall be taken into consideration when selecting tree ® Linear Applications species ✓suitable for this practice CONVEYANCE IMPLEMENTATION CONSIDERATIONS Tree pit underdrain systems shall be designed to create an internal water storage 0 Capital Cost Tree trenches shall be equipped with a subsurface infiltration reservoir ® Maintenance Burden Stormwater runoff shall be intercepted near the source and conveyed to the practice as sheet flow Safety Risk TREATMENT Landscaping The maximum slope of the contributing area is 10% L= Low M = Moderate H =High The maximum horizontal separation from the contributing impervious area NA= Not Applicable is 10 ft(new trees)or within 20 ft of the canopy(existing trees) Drainage filter fabric shall separate and wrap the soil media and stone POLLUTANT REMOVAL(See Table 10.4) drainage layer of tree trenches ® Phosphorus For area reduction subtract the total area contributing by sheet flow to an existing or new tree from the total area when computing WQv O Nitrogen For volume reduction, systems should ensure that the peak water surface ® Metals elevation for the 10-year, 24-hr design storm does not overtop the system ® Pathogens O Total Suspended Solids G=Good F= Fair P= Poor RUNOFF REDUCTION CREDIT • 100%area reduction towards RRv(plantings) • 100% RRv provided (trenches and pits) • 40% RRv provided (tree pits with underdrains) Chapter 5: Runoff Reduction Techniques 5.3.4 Disconnection of Rooftop Runoff(RR-4) Direct runoff from rooftop areas to designated filter area(s) to reduce runoff rates. When disconnection of rooftop runoff meets the design requirements, the practice provides an impervious area reduction when computing the water quality volume requirements. AMEND SOILS WHEN NECESSARY PEA GRAVEL DIAPHRAGM APPLY 3" MIN COMPOST AND A NATIVE GRASS TILL 7O DEPTH OF B" MIN f"r AND SHRUBS .'. . , ... .. . . . r ROOF DRAIN DOWNSPOUT } STABILIZED APRON OR SPLASH BLOCK. 18^ PLAN VIEW MIN A ROOF DRAIN DOWNSPOUT STABILIZED APRON OR SPLASH BLOCK r BUILDING PEA GRAVEL DIAPHRAGM NATIVE GRASS ?4m MIN v r 18„ AMEND SOILS WHEN NECESSARY MIN APPLY 3" MIN COMPOST AND TILL TO DEPTH of 8- MIN 5' MIN SEPARATION FILTER PATH LENGTH = 40' MIN TO BUILDINGS OR FOUNDATIONS PROFILE VIEW FILTER PATH NATIVE GRASS w IDTH = 74' MIN 3" MIN I _r I SECTION A-A VIEW �AMEND SOILS WHEN NECESSARY APPLY 3" MIN COMPOST AND TILL TO DEPTH OF 8" MIN Figure 5.39 Disconnection of Rooftop Runoff(RR-4) Chapter 5: Runoff Reduction Techniques 5-46 5.3.4.1 Feasibility Disconnect shall be designed such that redirected runoff drains away from buildings and foundations. Disconnection can be used on any post-construction Hydrologic Soil Group. However, the erodibility of the soils must be considered. For soil Groups A or B where existing soils have been compacted by construction activities, the filter path area shall be mechanically decompacted. For Soil Groups C or D the filter path area shall include amended soil, as defined in Table 5.11 below. Disconnection cannot result in overflow to areas not designated as the filter path. For disconnections draining directly to a buffer, either the disconnection of rooftop runoff or sheet flow to riparian buffer runoff reduction method shall be used, but not both. 5.3.4.2 Conveyance Flow from the downspout shall be spread over a filter path, extending down-gradient from the structure. A pea gravel diaphragm shall be installed at the downspout outlet to distribute flows evenly across the filter path. 5.3.4.3Treatment 5.3.4.3.1 Design Criteria The filter path shall be a minimum of 3 inches lower than the surrounding area in order to keep flow in the path. Similarly, filter path shall be level perpendicular to flow to discourage flow concentration. Amendments to soils within the filter path shall be implemented only when deemed necessary. Rooftop disconnection shall meet the following design criteria: Table 5.11 Design Criteria for Rooftop Disconnection Design Criteria Required Elements Maximum tributary rooftop 1,000 sf per disconnection filter path area Width = minimum 10 ft Filter path geometry Length = minimum 40 ft Filter path slope <2%, or<5%with turf reinforcement Filter path separation to 5 ft buildings or foundations Amended soils within filter Apply 3 inches of compost over entire area of filter path and till to a depth path of 8 inches (HSG C or D). Refer to Section 5.3.4.3.2 for material specification. 5.3.4.3.2 Material Specification Compost shall be derived from plant material and meet the general criteria set forth by the U.S. Composting Seal of Testing Assurance (STA) program. The compost shall be the result of the biological degradation and transformation of plant-derived materials under conditions that promote anaerobic decomposition. The material shall be well composted, free of viable weed seeds, and stable with regard to oxygen consumption and carbon dioxide generation. The compost shall have a moisture content that has no visible free water or dust produced when handling the material. It shall meet the following criteria: 100% of the material shall pass through a 'h inch screen; Chapter 5: Runoff Reduction Techniques 547 The pH of the material shall be between 5.5 and 8.5; Manufactured inert material (plastic, concrete, ceramics, metal, etc.) shall be less than 1.0% by weight; The organic matter content shall be > 35%; Soluble salt content shall be less than 6.0 mmhos/cm; Shall be mature and stable per the appropriate test(s) as specified by STA; Carbon/nitrogen ratio shall be less than 25:1; Must meet USEPA part 503 levels for heavy metals; The compost should have an optimum dry bulk density ranging from 40 to 50 Ibs/cf. However, certain fully mature coarse textured composts may be lower; and Compost shall not include manure. 5.3.4.3.3 Sizing Criteria When computing the required water quality volume to a given design point, subtract the total disconnected impervious area contributing by sheet flow to the filter path from the total impervious area. Disconnected impervious areas are not deducted when calculating quantity controls for larger storms. 5.3.4.3.4 Design Example Base Data (9) 1,000 sf homes proposed for rooftop disconnection Total site area = 8.54 acres Total impervious area = 3.17 acres 90% Rainfall Event Number= 1.00 inch First, compute the required WQv, per Chapter 4:I = (APA \I(100) I (3.17 acres\ (100) 8.54 acres) I = 37% RV = 0.05 + 0.0091 RV = 0.05 + (0.009)(37) RV = 0.38 P •RV•A WQv 12 (1.00 inches)(0.38)(8.54 acres) W Qv 12 WQV = 0.270 of Next compute the area reduction WQv, accounting for the area reduction from disconnected roofs. Area to be disconnected = (9 houses)(1,000 sf) 43,560 sf/acre Chapter 5: Runoff Reduction Techniques -48 Area to be disconnected = 0.21 acres Reduced impervious area = 3.17 acres — 0.21 acres Reduced impervious area = 2.96 acres I = (A'A---p )(100) I (2.96 acres\ (100) 8.54 acres) I = 35% RV = 0.05 + 0.0091 RV = 0.05 + (0.009)(35) RV = 0.37 P •RV•A WQv 12 (1.00 inches)(0.37)(8.54 acres) W Qv 12 WQV = 0.263 of Then compute the RR Provided, taking into account the rooftop disconnection: RRV Provided = Required WQV —Area Reduction WQV RRV Provided = 0.270 of— 0.263 of RRV Provided = 0.007 of Chapter 5: Runoff Reduction Techniques 5-49 Fact Sheet: Disconnection of Rooftop Runoff (RR-4) ' •-• • '. Area reduction practice that directs rooftop runoff to • . . . . • . • • • designated filter areas. . * ••� (Photo Source: Harford County, Maryland) �s FEASIBILITY STORMWATER MANAGEMENT SUITABILITY • Redirected runoff shall drain away from buildings and foundations 40 Water Quality Erodibility of soils shall be considered , Channel Protection For HSG C or D, disconnection shall include amended soil within the filter is Flood Protection path For disconnections draining directly to a buffer, either the disconnection of Extreme Flood Protection rooftop runoff or sheet flow to riparian buffer runoff reduction method shall ® Runoff Reduction be used, but not both CONVEYANCE Treatment of Hotspots Flow from the downspout shall be spread over a filter path, extending Linear Applications down-gradient from the structure ✓suitable for this practice TREATMENT IMPLEMENTATION CONSIDERATIONS Maximum tributary rooftop area is 1,000 sf per disconnection filter path to Capital Cost Maximum flow length of tributary rooftop is 75 ft Filter paths shall be a minimum of 10 ft wide and 40 ft long 0 Maintenance Burden • Maximum filter path slope is <2%without turf reinforcement and <5%with ® Safety turf reinforcement is Landscaping • Minimum filter path separation to buildings or foundations is 5 ft Filter path should be 2 to 4 inches below surrounding grade and level L= Low M = Moderate H =High perpendicular to flow path NA= Not Applicable POLLUTANT REMOVAL(See Table 10.4) ® Phosphorus ® Nitrogen ® Metals 0 Pathogens O Total Suspended Solids G=Good F= Fair P= Poor -fir = May provide partial benefits RUNOFF REDUCTION CREDIT 100% RRv provided Chapter 5: Runoff Reduction Techniques 5.3.5 Vegetated Swale (RR-5) Vegetated swales are a volume reduction practice designed to convey stormwater, in a maintained, turf-lined Swale, at a low velocity, to promote natural treatment and infiltration. A properly designed, constructed, and maintained Swale (or, in some cases natural drainage path) can be used in both residential and non-residential areas to treat and convey runoff from roadways and other impervious surfaces. A vegetated Swale can be an alternative to underground storm sewers or lined open channels. IMPORTANT NOTE:CONVENTIONAL GRASSED OR LINED WATERWAYS USED FOR CONVEYANCE OR DIVERSION SHALL BE STABILIZED IN ACCORDANCE WITH THE NYSDEC STANDARDS AND SPECIFICATIONS FOR EROSION AND SEDIMENT CONTROL, LATEST EDITION. CONVENTIONAL WATER QUALITY TREATMENT (WET AND DRY SWALES) SHALL BE DESIGNED IN ACCORDANCE WITH CHAPTER 6. STABILIZED INLET 3:1 (H:V) - INLET MAx PIPE - - 0.59.-4% EDGE OF PAVEMENT S` SHEET FLOW -ROADWAY PEA GRAVEL DIAPHRAGM TO SWALE PLAN VIEW ENERGY REOJIRED FOR ENERGY DISSIPATION) QVER$ANK FLOOD WUv MAX PONDING DEPTH 4" ADJACENT CONTROL ROADWAY 2'-6' L +6" MIN 3:1 (H:V) MAX FREEBOARD SIDE SLOPE PEA GRAVEL DIAPHRAGM WRAPPED IN DRAINAGE SECTION A A VIEW FILTER FABRIC (IF REOUIREO FOR ENERGY DISSIPATION) Figure 5.40 Vegetated Swale (RR-5) Chapter 5: Runoff Reduction Techniques 5-51 5.3.5.1 Feasibility Local codes may not allow swales instead of curb gutter or closed drainage pipes —Meet with local officials to discuss waivers for alternative designs. 5.3.5.2 Conveyance Vegetated swales shall safely convey flows from the largest design storm directed to the practice. 5.3.5.3Treatment 5.3.5.3.1 Design Criteria Vegetated swales shall have a trapezoidal or parabolic shape. For sediment capture, vegetation shall be kept at a minimum height of 4 to 6 inches. The design, installation, and management shall be in accordance with the following Table. Table • for • • Design Criteria Required Elements Maximum Contributing 5 acres Area Maximum WQv Peak Flow 3 cfs Rate Bottom Width 2 ft minimum, 6 ft maximum Maximum Side Slopes 3 horizontal: 1 vertical Longitudinal Slope 0.5% minimum, 4% maximum Minimum Swale Length 100 ft(inclusive of driveway culverts) Manning's Coefficient 0.03 to 0.15(Refer to Appendix G) Conveyance of WQv Peak 4 in maximum flow depth at a velocity<_ 1 fps Discharge Check dams may be required to achieve criteria Conveyance of 10-Year 6 in of freeboard at a velocity<_5 fps Peak Discharge Required WQv Retention 10 minutes for point discharge at the inlet 5 minutes for sheet flow or multi-point discharge along swale length 5.3.5.3.2 Sizing Criteria The WQ for a vegetated swale is computed in accordance with the uniform sizing criteria methods outlined in Chapter 4. Design flows are calculated using small storm hydrology (Appendix B), and conventional hydrology methods in conjunction with Manning's equation for open channel flow. First, calculate the required WQv, per Chapter 4. Then, use the Water Quality Peak Flow Rate (WQF) Calculation (Appendix B)to compute the peak discharge. Next using the proposed swale geometry, calculate the WQv flow top width: WxwQ„ = b + (2)(Side Slope)(d) Where: WwQv= WQv flow top width (ft) b = Bottom width (ft) d = WQv maximum flow depth (ft) Using the calculated WQv flow top width and WQv flow depth as the height, calculate the wetted perimeter: P, = b + (d2 + [(Side slope)(d)]2)1/z (2) Where: Pv,= WQv flow wetted perimeter(ft) Chapter 5: Runoff Reduction Techniques 5- 2 Using the calculated WQv flow top width, calculate the Area (AWQv) of the WQv flow in square feet: (d)(b + WwQv) Ax,av = 2 Using the calculated area and WQF, calculate the WQv peak discharge velocity (V): V = W QF AwQv Calculate the required swale length. Proposed swale length must be greater than or equal to the required swale length: Lr = (WQv Retention Time)(60)(V) LP �! Lr Where: Lr= Required swale length (ft) Lp = Provided swale length (ft) Where the WQv peak discharge velocity is greater than 1 fps: Select a check dam height and calculate the required check dam spacing and number of check dams required, based on the check dam standard within the NYSDEC Standards and Specifications for Erosion and Sediment Control: CH CS S L L P C = CS Where: Cs = Check dam spacing (ft) CH = Check dam height (ft) SL= Longitudinal slope of channel (ft/ft) C = Number of check dams required Use computer modeling to determine the 10-year 24-hr flow depth and calculate the top width and flow area of the 10-year storm event. W10 = b + (2)(Side Slope)(d1o) _ (d1o)(b +Wio) A10 2 Where: Wio = 10-year storm flow top width (ft) dio = 10-year 24-hr flow depth Alo=Area of 10-year 24-hr flow (so Determine the available freeboard using computer modeling and calculate the 10-yr 24-yr velocity: V10 = (1.49 n W / \ 110J2/3 `SL)112 Where: V,o= 10-year peak discharge velocity (fps) Pw10 = Wetted perimeter during 10-year 24-hr storm. Chapter5: Runoff Reduction Techniques •53 If all criteria have been met, calculate the RRv provided based on the HSG: (HSG A or B) Volume Reduction WQv = WQV x 20% (HSG C or D) Volume Reduction WQV = WQV x 10% (HSG Modified C)Volume Reduction WQV = WQV x 15% (HSG Modified D) Volume Reduction WQV = WQV x 12% RRv Provided = WQV — Volume Reduction WQV 5.3.5.4 Landscaping For planting guidance for stormwater management facilities, refer to Chapter 11. Permanent vegetative cover shall achieve 80% uniform density established over the entire contributing pervious area, before runoff is directed into the facility. Chapter 5: Runoff Reduction Techniques 5-54 Fact Sheet: Vegetated Swale (RR-5) IL Description Volume reduction practice designed to convey stormwater at a low velocity to promote treatment and infiltration. a - Key A YYYYY Considerations FEASIBILITY STORMWATER MANAGEMENT SUITABILITY Local codes may not allow swales instead of curb gutter or closed • Water Quality drainage pipes. Meet with local officials to discuss waivers for alternative designs. • Channel Protection TREATMENT • Overbank Flood Protection Maximum contributing area is 5 acres • Extreme Flood Protection Maximum WQv peak discharge rate is 3 cfs 0 Runoff Reduction Swale bottom width shall be 2 ft minimum and 6 ft maximum • Treatment of Hotspots Swale side slopes shall be a maximum of 3 horizontal: 1 vertical O Linear Applications Swale longitudinal slope shall be 0.5% minimum and 4% maximum ✓suitable for this practice Swale length shall be 100 ft, inclusive of driveway culverts IMPLEMENTATION CONSIDERATIONS During the WQv event, the maximum flow depth is 4 inches with a ® Capital Cost maximum velocity of 1 fps. Check dam(s)may be required to meet these criteria 19 Maintenance Burden During the 10-year event, the swale shall have a minimum freeboard of 6 ® Safety inches at a maximum velocity of 5 fps Landscaping The required WQv retention time within the swale is 10 minutes for point discharge at the inlet and 5 minutes for sheet flow or multi-point discharge L= Low M = Moderate H =High along the swale length NA= Not Applicable POLLUTANT REMOVAL(See Table 10.4) 0 Phosphorus ONitrogen ® Metals 0 Pathogens O Total Suspended Solids G=Good F= Fair P= Poor RUNOFF REDUCTION CREDIT 20% RRv provided in HSG A or B 10% RRv provided in HSG C or D 15% RRv provided in Modified HSG C 12% RRv provided in Modified HSG D Chapter 5: Runoff Reduction Techniques _. 5.3.6 Rain Gardens (RR-6) A rain garden is intended to manage and treat small volumes of stormwater runoff from impervious surfaces. Treatment is achieved using a conditioned planting soil bed and planting materials to filter runoff stored within a shallow depression. Rain gardens are designed as a passive filtration system without an underdrain system connected to the storm drain system. A stone drainage layer is used for dispersed infiltration. The system consists of an inflow component, a shallow ponding area over a planted soil bed, mulch layer, stone drainage layer, plantings and an overflow mechanism to convey larger rain events to the storm drain system or receiving waters. COMPACTED EARTH BERM EMERGENCY OVERFLOW r-30 FT MAX FROM ROOF DRAIN DOWNSPOUT 10 FT MIN FROM FOUNDATION -� — — — — — — — — ROOF DRAIN DOWNSPOUT WITH SPLASH BLOCK TO STABILIZED SHEET FLOW INLET ST ST ALTERNATE: ENGTH. x ydp'T I I ROOF DRAIN TO DAYLIGHT I AREA OF FILTER MEDIA — — — — — — — I WATER QUALITY A MAX PONDING DEPTH = 12" LARGER STORM EVENT MAX PONDING DEPTH = 18" PLAN VIEW WATER QUALITY MAX PONDING DEPTH = 12" LARGER STORM EVENT ALTERNATE: MAX PONDING DEPTH = 18" COMPACTED ROOF DRAIN TO REFER TO APPENDIX H FOR EARTH BERM DAYLIGHT SUGGESTED PLANT LIST t7VERFL[]W 3" MIN SHREDDED STABILIZED HARDWOOD MULCH INLET �'.. .................:...j 12-18" FILTER MEDIA 6" MIN NO. 53 STONE DRAINAGE DRAINAGE FILTER� LAYER (WASHED, NO FINES) FABRIC 24" MIN SEPARATION TO SEASONAL HIGH WATER TABLE/BEDROCK y SECTION A-A VIEW Figure 5.41 Infiltration Rain Garden (RR-6) Chapter 5: Runoff Reduction Techniques 5-56 A rain garden is intended to manage and treat small volumes of stormwater runoff from impervious surfaces. Treatment is achieved using a conditioned planting soil bed and planting materials to filter runoff stored within a shallow depression. Rain gardens are designed as a passive filtration system with an underdrain system connected to the storm drain system. A stone drainage layer is used for dispersed infiltration. The system consists of an inflow component, a shallow ponding area over a planted soil bed, mulch layer, stone drainage layer, plantings and an overflow mechanism to convey larger rain events to the storm drain system or receiving waters. COMPACTED EARTH BERM OUTLET PIPE I 30 FT MAX FROM ROOF DRAIPI DOWNSPOI.I OUTLET $TFtUCTl1RE 10 FT MIN FROM F€7UNDATION �.Y — —— — — — — — ROOF DRAIN DOWNSPOUT z NTH SPLASH BLOCK TO STABILIZED � SHEET FLOW INLET ......-_.- ....... ST ST 20' ALTERNATE; :{ ROOF DRAIN TO DAYLIGHT iENTfi X +MLr # CAP OR PLUG � ............................ ....... 6" MIN PERFORATED � — — — — — — — I UNDERDRAIN AREA OF FILTER MEDIA WATER QUALITY .'I� MAX PONDING DEPTH = 1Z"LARGER STORM EVENT PLAN VIEW MAY PONDING DEPTH = le EMERGENCY OVERFLOWN WATER QUALITY MAX PONDING DEPTH = 12" LARGER STORM EVENT MAXALTE PONDING DEPTH = 18- OMPAC ROOF ATE; REFER TO APPENDIX H FOR ORTH P PERM ROOF BRAIN T(} SUGGESTED PLANT LIST EARTH BERM DAYLIGHT OUTLET STRUCTURE 1 — — — —�- EMERGENCY OVERFLUIM STABILIZED—,--,' �� 4 P" 3" LAIN SHREDDED INLET HARDY MULCH 18-24" FILTER ........: I MEDIA DRAINAGE FILTER FABRIC I 10" MIN NO. 57 STCNE DRAINAGE $" MIN PERFORATED ,,} LAYER (WASHED. NO FINES) UNDERDRAIN PERFORATED UNDERDRAIN LOUTLET PIPE kON HEADER PIPE To OUTLET SE SEASONAL HIGH N TO STRUCTURE WATER TABLE/SEDRO K SECTION A-A VIEW Figure 5.42 Filtration Rain Garden (RR-6) Chapter 5: Runoff Reduction Techniques 5-57 5.3.6.1 Feasibility The practice shall not be located in areas with heavy tree cover. The surface area of rain gardens shall be designed and constructed with no longitudinal or lateral slope. Infiltration rain gardens shall have underlying soils with an infiltration rate greater than or equal to 0.50 inch/hr, as confirmed by required geotechnical testing (see Appendix D). If the infiltration rate is less than 0.50 inch/hr or geotechnical testing is not provided the practice shall be designed as a filtration rain garden with underdrains. In areas of known contamination, or if contamination is discovered during excavation, contaminant levels must be evaluated by a qualified professional and state remediation program to determine if infiltration is permitted. Filtering practices can be used to treat stormwater runoff in areas of known or discovered contamination; however, an impermeable liner shall be provided below the stone drainage layer and on all sides. The maximum contributing area shall be 1,000 sf per rain garden. Rain gardens may be applied as a practice for urban stormwater management (see Chapter 8). Rain gardens shall be located a maximum of 30 ft from the downspout or impervious area treated. Parking lot or roadway runoff shall not be directed to rain gardens for treatment. Rain gardens shall be located down gradient and meet the separation requirements as listed in Table 5.13. Vertical separation shall be taken from the bottom of the stone drainage layer. Horizontal separation shall be taken from the maximum water surface elevation (Extreme Flood peak water surface elevation). Where 2 ft separation cannot be met, an impermeable liner shall be provided at the bottom of the stone drainage layer and all sides. SeparationTable 5.13 Rain Garden Minimum Vertical Separation Horizontal Separation Seasonal Structures Structures With Design High Water Bedrock'2 Without Foundation Water Supply Septic Variant Table'2 Foundation Waterproofing Well/Reservoir System' Waterproofing Infiltration Rain 50 ft Garden 2ft 2ft loft Oft 100ft Filtration Rain Garden 100 ft 'Sound bedrock,fractured bedrock or karst geology as documented by on-site soil testing. 24 ft in sole source aquifers. 'Septic systems are inclusive of distribution boxes and absorption fields. 5.3.6.2 Conveyance Runoff must enter at the surface of the soil media. Runoff shall be directed to rain gardens at a non-erosive rate through downspouts, shallow swales or short distances of sheet flow. To prevent erosion, an energy dissipater, such as riprap or splash blocks, shall be placed below downspouts or where stormwater enters the rain garden. Except where a liner is provided, underdrain systems shall be designed to create an internal water storage using one of the following methods: Provide an upturned elbow, set 10 inches above the bottom of practice; Set the outlet pipe invert, at the outlet control structure, 10 inches above the bottom of practice; or Increase the drainage layer depth to provide 8 inches of stone below the underdrain. Outlet(s) shall be designed to ensure non-erosive outlet conditions. An emergency spillway or overflow device shall be provided to safely convey stormwater exceeding the Extreme Flood. Chapter 5: Runoff Reduction Techniques 5_58 5.3.6.3Treatment 5.3.6.3.1 Design Criteria Rain gardens shall consist of the following treatment components: Table •en Design Specification!P Infiltration Rain Garden Filtration Rain Garden Ponding' Depth 12 inch max. (WQv) 18 inch max. (Extreme Flood) Depth 3 inch min. Surface Layer' Material Shredded Hardwood Mulch or Non-Invasive Living Mulch Depth 12 inches min. 18 inches min. 18 inches max. 24 inches max. Filter Media' ASTM C-33 Sand: 60%-75% Material Topsoil3: 25%-40% Depth 6 inches min. 10 inches min. Drainage Layer' Material AASHTO No. 57, stone washed, no fines Drainage Filter Material2 Non-woven, polypropylene geotextile with flow rate greater than 125 gpm/sf Fabric' (ASTM D4491)and Apparent Opening Size US#70 sieve (ASTM D4751) Applicability N/A As Required Impermeable Liner 12-24 inch of clay soil (min. 50% passing#200 sieve and max. permeability Material 1 x 10-5 cm/sec)or 40 mil HDPE geomembrane Applicability N/A Required Underdrain Material 6" perforated PVC or HDPE laid at 0.5% slope min. at 30 ft max. O.C. Footnotes: 'Required for all Design Variants 2Or acceptable alternatives,such as a 3 inch minimum layer of pea gravel 3Topsoil shall conform to NYSDOT Standard Specification 713-01 for Roadside Mix or Specialty Planting Mix. 5.3.6.3.2 Sizing Criteria The required WQv is to be provided above the top of the filter media. Infiltration and filtration rain gardens shall be sized based on the principles of Darcy's Law. Calculate the minimum bottom area: _ (WQ,,)(df) Af (k)(hf +df)(tf) Where: Af= Surface area of filter bed (so WQv= Water Quality Volume (cf) df= Filter bed depth (ft) k= Permeability flow rate of filter media (1 ft/day) hf=Average height of ponding (ft) (0.5 ft max.) tf= Design filter bed drain time (2 days) 5.3.6.4 Landscaping For planting guidance for stormwater management facilities, refer to Chapter 11. Permanent vegetative cover shall achieve 80% uniform density established over the entire contributing pervious area, before runoff is directed into the facility. Chapter 5: Runoff Reduction Techniques5_59 Fact Sheet: Rain Garden (RR-6) -( Passive filtration system to manage and treat small volumes of stormwater runoff from impervious surfaces. The system consists of an inflow component, a shallow ponding area over a planted soil bed, mulch layer, stone drainage layer, plantings and an overflow mechanism to convey larger rain events to the storm drain system or receiving waters. FEASIBILITY STORMWATER MANAGEMENT SUITABILITY • Surface area of rain gardens shall be designed and constructed with no ® Water Quality longitudinal or lateral slope Infiltration rain gardens shall have underlying soils with an infiltration rate ® Channel Protection greater than or equal to 0.50 inch/hr ® Overbank Flood Protection Filtration rain gardens shall have underlying soils with an infiltration rate greater than or equal to 0.50 inch/hr, unless underdrains are provided 40 Extreme Flood Protection Surface area shall not exceed a loading ratio of 5:1 (drainage area to rain ® Runoff Reduction garden, where drainage area is assumed to be 100% impervious) Maximum contributing area shall be 1,000 sf per rain garden ® Treatment of Hotspots Rain gardens shall be located 30 ft maximum from the downspout or ® Linear Applications impervious area treated ✓suitable for this practice Parking lot or roadway runoff shall not be directed to rain gardens CONVEYANCE IMPLEMENTATION CONSIDERATIONS Runoff must enter at the surface of the soil media o Capital Cost Runoff shall be directed to rain gardens at a non-erosive rate through ® Maintenance Burden downspouts, shallow swales o short distances of sheet flow Safety Underdrain systems shall be designed to create an internal water storage Landscaping Outlet(s)shall be designed to ensure non-erosive outlet conditions L= Low M = Moderate H =High An emergency spillway or overflow device shall be provided to safely NA= Not Applicable covey stormwater exceeding the Extreme Flood TREATMENT POLLUTANT REMOVAL(See Table 10.4) Maximum ponding depth shall be 12 inches during the WQv event and 18 ® Phosphorus inches during the Extreme Flood event o Nitrogen Infiltration rain gardens shall have a 12 inch minimum and 18 inch O maximum filter media depth Metals Filtration rain gardens shall have an 18 inch minimum and 24 inch ® Pathogens maximum filter media depth Total Suspended Solids • Infiltration rain gardens shall have a 6 inch minimum stone drainage layer G=Good F= Fair P= Poor p= Fair/Good Filtration rain gardens shall have a 10 inch minimum stone drainage layer RUNOFF REDUCTION CREDIT Underdrains are required for filtration rain gardens 100% RRv provided without underdrains 40% RRv provided with underdrains Chapter 5: Runoff Reduction Techniques 5.3.7 Stormwater Planter (RR-7) A stormwater planter is intended to manage and treat small to moderate volumes of stormwater runoff from adjacent impervious surfaces. Treatment is achieved using a conditioned planting soil bed and planting materials to filter runoff stored within a shallow depression. Stormwater planters are designed as a passive filtration system without an underdrain system or with an underdrain connected to the storm drain system. The system consists of an inflow component, a shallow ponding area over a planted soil bed, mulch layer, stone drainage layer, plantings and an overflow mechanism to convey larger rain events to the storm drain system. WATER QUALITY OVERFLOW CONTROL MAX PONDING DEPTH = 12" LARGER STORM EVENT REFER TO APPENDIX H FOR MAX PONDING DEPTH = 18" SUGGESTED PLANT LIST' STABILIZED INLET ROOF DRAIN INLET PIPE 4 3" MIN SHREDDED l HARDWOOD MULCH 18-30" FILTER MEDIA OUTLET PIPE _ I 6' MIN NO. 57 STONE DRAINAGE ———— LAYER (WASHED, NO FINES) DRAINAGE FILTER w 24" MIN FABRIC SEPARATION TO SEASONAL HIGH WATER TABLE/BEDROCK INFILTRATION STORMWATER PLANTER SECTION VIEW WATER QUALITY 4V3" VERFLOW CONTROL MAX PONDING DEPTH = 12" LARGER STORM EVENT FER TO APPENDIX H FOR MAX PONDING DEPTH = 18' GGESTED PLANT LIST ABILIZED INLET ROOF DRAIN INLET PIPE SHREDDED HARDWOOD MULCH . : l I 18-30" FILTER MEDIA OUTLET PIPE 10" MIN NO. 57 STONE DRAINAGE LAYER (WASHED, NO FINES) DRAINAGE FILTER—/—— ————— 24" MIN FABRIC SEPARATION TO SEASONAL HIGH 6" MIN PERFORATED WATER TABLE/BEDROCK UNDERDRAIN Q FILTRATION STORMWATER PLANTER SECTION VIEW Figure 5.43 Stormwater Planters (RR-7) Chapter 5: Runoff Reduction Techniques 5-61 5.3.7.1 Feasibility Materials suitable for stormwater planter walls include stone, concrete, brick, clay, plastic, wood, or other durable material. Treated wood shall not be used. Stormwater planters shall be designed and constructed with no longitudinal or lateral slope. The maximum contributing area shall be 15,000 sf per stormwater planter. Stormwater planters may be applied as a practice for urban stormwater management(see Chapter 8). Parking lot or roadway runoff shall not be directed to stormwater planters for treatment. Infiltration stormwater planters shall have underlying soils with an infiltration rate greater than or equal to 0.50 inch/hr, as confirmed by required geotechnical testing (see Appendix D). Filtration stormwater planters shall have underlying soils with an infiltration rate greater than or equal to 0.50 inch/hr, as confirmed by required geotechnical testing (see Appendix D), unless underdrains are provided. In areas of known contamination, or if contamination is discovered during excavation, contaminant levels must be evaluated by a qualified professional and state remediation program to determine if infiltration is permitted. Filtering practices can be used to treat stormwater runoff in areas of known or discovered contamination however an impermeable liner shall be provided at bottom of stone drainage layer and all sides. Stormwater planters shall be located down gradient and meet the separation requirements as listed in Table 5.15. Vertical separation shall be taken from the bottom of the stone drainage layer. Horizontal separation shall be taken from the maximum water surface elevation (Extreme Flood peak water surface elevation). Where 2 ft separation cannot be met, an impermeable liner shall be provided at the bottom of the stone drainage layer and all sides. Separation,r: Table 5.15 Stormwater Planter Minimum Vertical Separation Horizontal Separation Seasonal Structures Structures With Design High Water Bedrock'2 Without Foundation Water Supply Septic Variant Table'2 Foundation Waterproofing Well/Reservoir System' Waterproofing Infiltration Stormwater 50 ft Planter 2ft 2ft loft Oft 100ft Filtration Stormwater 100 ft Planter 'Sound bedrock,fractured bedrock or karst geology as documented by on-site soil testing. 24 ft in sole source aquifers. 'Septic systems are inclusive of distribution boxes and absorption fields. 5.3.7.2 Conveyance Runoff must enter at the surface of the soil media. Runoff shall be directed to stormwater planters at a non- erosive rate through shallow swales, drainpipe, or short distances of sheet flow. To prevent erosion an energy dissipater, such as riprap or splash blocks, shall be placed below downspouts or where stormwater enters the planter. Except where a liner is provided, underdrain systems shall be designed to create an internal water storage using one of the following methods: Provide an upturned elbow, set 10 inches above the bottom of practice (See Appendix C) Set the outlet pipe invert, at the outlet control structure, 10 inches above the bottom of practice; or Increase the drainage layer depth to provide 8 inches of stone below the underdrain. Outlet(s) shall be designed to ensure non-erosive outlet conditions. Chapter5: Runoff Reduction Techniques •62 An emergency spillway or overflow device shall be provided to safely convey stormwater exceeding the Extreme Flood. 5.3.7.3 Treatment 5.3.7.3.1 Design Criteria Stormwater planters shall consist of the following treatment components: Table •rmwater Planter Design Specifications Infiltration Stormwater Planter Filtration Stormwater Planter Ponding' Depth 12 inch max. (WQv) 18 inch max. (Extreme Flood) Surface Depth 3 inch min. Layer' Material Shredded Hardwood Mulch or Non-Invasive Living Mulch Depth 18 inches min. 30 inches max. Filter Media' Material ASTM C-33 Sand: 60%-75% Topsoil3: 25%-40% Drainage Depth 6 inches min. 10 inches min. y f La er Materia12 AASHTO No. 57 stone, washed, no fines Drainage Material Non-woven, polypropylene geotextile with flow rate greater than 125 gpm/sf Filter Fabric' (ASTM D4491)and Apparent Opening Size US#70 sieve (ASTM D4751) Applicability N/A As Required Impermeable 12-24 inch of clay soil (min. 50% passing#200 sieve and max. permeability Liner Material 1 x 10-5 cm/sec) or 40 mil HDPE geomembrane Applicability N/A Required Underdrain Material 6" perforated PVC or HDPE laid at 0.5%slope min. at 30 ft max. O.C. Footnotes: 'Required for all Design Variants ZOr acceptable alternatives,such as a 3 inch minimum layer of pea gravel 3Topsoil shall conform to NYSDOT Standard Specification 713-01 for Roadside Mix or Specialty Planting Mix. 5.3.7.3.2 Sizing Criteria The required WQv is to be provided above the top of the filter media. Infiltration and filtration stormwater planters shall be sized based on the principles of Darcy's Law. Calculate the minimum bottom area: _ (WQ,,)(df) Af (k)(hf +df)(tf) Where: Af= Surface area of filter bed (so WQv= Water Quality Volume (cf) df= Filter bed depth (ft) k= Permeability flow rate of filter media (1 ft/day) hf=Average height of ponding (ft) (0.5 ft max.) tf= Design filter bed drain time (2 days) Chapter 5: Runoff Reduction Techniques _63 5.3.7.4 Landscaping For planting guidance for stormwater management facilities, refer to Chapter 11. Permanent vegetative cover shall achieve 80% uniform density established over the entire contributing pervious area, before runoff is directed into the facility. Chapter 5: Runoff Reduction Techniques 5-64 Fact Sheet: Stormwater Planters (RR-7) w Passive filtration system to manage and treat small to moderate volumes of stormwater runoff from adjacent impervious surfaces. The system consists of an inflow component, a shallow ponding area over a planted soil bed, mulch layer, stone drainage layer, plantings and an overflow mechanism to convey larger rain events to the storm drain system. FEASIBILITY STORMWATER MANAGEMENT SUITABILITY • Stormwater planters shall be designed and constructed with no ® Water Quality longitudinal or lateral slope •Maximum contributing area shall be 15,000 sf per stormwater planter Channel Protection ®Parking lot or roadway runoff shall not be directed to stormwater planters Overbank Flood Protection Infiltration stormwater planters shall have underlying soils with an ® Extreme Flood Protection infiltration rate greater than or equal to 0.50 inch/hr ® Runoff Reduction Filtration stormwater planters shall have underlying soils with an infiltration ® Treatment of Hotspots rate greater than or equal to 0.50 inch/hr, unless underdrains are provided CONVEYANCE 0 Linear Applications Runoff must enter at the surface of the soil media ✓suitable for this practice Runoff shall be directed to stormwater planters at a non-erosive rate IMPLEMENTATION CONSIDERATIONS through shallow swales, drainpipe, or short distances of sheet flow Capital Cost Underdrain systems shall be designed to create an internal water storage ® Maintenance Burden Outlet(s)shall be designed to ensure non-erosive outlet conditions Safety An emergency spillway or overflow device shall be provided to safely convey stormwater exceeding the Extreme Flood Landscaping TREATMENT L= Low M = Moderate H =High Maximum ponding depth shall be 12 inches during the WQv event and 18 NA= Not Applicable inches during the Extreme Flood event POLLUTANT REMOVAL(See Table 10.4) • Stormwater planters shall have a 18 inch minimum and 30 inch maximum ® Phosphorus filter media depth • Infiltration stormwater planters shall have a 6 inch minimum stone O Nitrogen drainage layer 0 Metals • Filtration stormwater planters shall have a 10 inch minimum stone Pathogens drainage layer Underdrains are required for filtration stormwater planters O Total Suspended Solids G=Good F= Fair P= Poor f= Fair/Good *NA=Not enough data available,more research needed RUNOFF REDUCTION CREDIT 100% RRv provided without underdrains 40% RRv provided with underdrains Chapter 5: Runoff Reduction Techniques 5.3.8 Rainwater Harvesting System (RR-8) A rainwater harvesting system captures and stores stormwater runoff, to be used for irrigation or filtered and reused for non-potable water activities. The storage system is located either above or below ground and constructed on-site, or delivered as a prefabricated system. The basic components of a rainwater harvesting system include: a watertight storage tank, secure cover, a debris/mosquito screen, a coarse inlet filter with a clean-out, a valve, an overflow pipe, a manhole or access hatch, a drain for cleaning, and an extraction system (tap or pump). Additional features might include: a water level indicator, a bubbler and/or a heater to prevent freezing, a sediment trap, a connector pipe to an additional tank for increased storage, etc. If located above ground, the storage system is typically placed on riser blocks or a gravel pad to aid in gravity drainage of collected runoff and to prevent the accumulation of overflow water around the system. A rain barrel is a small above ground tank, usually between 50 and 100 gallons, that can be installed directly next to a downspout, most commonly for residential applications. A cistern is a larger tank that can be installed above ground or below ground, depending on the structural capacity of the material, most commonly used for commercial applications. i I1a� GROW•EL •PROVIDE Figure 5.44 Rainwater Harvesting System (RR-8) Chapter 5: Runoff Reduction Techniques 5-66 47MPECHANICAL NAL HAND PUMP BE REPLACED WITH PUMP CONCRETE PAD SOLID FINISHED MANHOLE GRADE ROOF SLAB COLTER MIN COVER TO . MEET LOADING i 1 REQUIREMENTS ROOF DRAIN INLET EMERGENCY 1 \ `: OVERFLOW STORAGE LEVEL 12" MIN N0. 2 STONE PROFILE VIEW 6" MIN HAND PUMP MOUNTING ROOF DRAIN PAD (IF REOUIRED) INLET OPTIONAL HAND PUMP SOLID F=-- --�---� MANHOLE s , --. - --- ---- -^-- - i COVER + i EMERGENCY + OVERFLOW I 1 L- PLAN VIEW Figure 5.45 Underground Concrete Rainwater Harvesting Tank (RR-8) Chapter 5: Runoff Reduction Techniques 5-67 5.3.8.1 Feasibility The contributing area to rainwater harvesting systems is limited by the calculated water demand established for the proposed reuse application(s). It is critical that a detailed water demand analysis be performed to size the system appropriately. RWH systems and the water reuse program shall be actively monitored to ensure that stored water is used on a consistent basis, such that the system is emptied between storm events to allow for subsequent capture of rooftop runoff. If water cannot be utilized in advance of predicted heavy rainfall, then the tank shall be drained to accommodate necessary storage. Harvested rainwater shall not be used for drinking or watering food plants. Pipes or storage units shall be clearly marked "not for consumption". Systems shall be located indoors, buried below the frost line, or winterized to withstand seasonal temperature fluctuations, unless the system is drained and decommissioned prior to the cold weather season. Winterization methods include perimeter insulation, insulation of the inlet/outlet pipe and lining with heat tape, and/or an aeration system. If the system is used year-round, then the water level in the system must be lowered at the beginning of winter to prevent possible ice damage and provide necessary storage for capturing rooftop runoff from the spring snow melt. For small rain barrels, it is recommended that the system be disconnected from the roof gutters and placed indoors during the winter months. In this case, downspout piping must be temporarily extended to the ground and directed away from the structure foundation. Consideration shall be given to minimize thermal fluctuations and algae growth by locating system in shade, providing fence or landscape screen, or providing an aeration system. The system shall be maintained periodically to ensure effective storage of stormwater while reducing the growth of algae and limiting the potential for mosquito breeding. 5.3.8.2 Conveyance The conveyance system shall keep reused stormwater or greywater separate from potable water piping systems. An emergency overflow shall be provided to discharge stormwater, if the storage capacity is exceeded, at a non- erosive velocity. The overflow shall be conveyed to a stabilized outfall. 5.3.8.3 Treatment To obtain runoff reduction credit, at a minimum, the information below must be provided in the SWPPP: Identify the rooftop area(s) proposed for capture in the rain barrel or cistern collection system; Provide calculations verifying the WQv sizing criteria; Identify the material specifications or manufacturer/model for the selected rain barrel or cistern; Identify installation techniques; Identify maintenance requirements for continued operation of the practices; Provide a water budget analysis; and Identify how water will be used to ensure that the system will be available for subsequent rainfall events. Chapter 5: Runoff Reduction Techniques _68 5.3.8.3.1 Sizing and Design Criteria Rainwater harvesting (RWH) systems shall be sized to provide adequate storage for the design storm, which is either the Extreme Flood, or a smaller event if a portion of stormwater is bypassed around the system. The storage volume shall be dictated by the water demand, which is the quantity of water that can reasonably be reused for on-site non-potable or irrigation applications. A detailed water demand analysis shall be performed to ensure that the system is appropriately sized for periods of consecutive wet-weather or drought conditions. If water is being reused for non-potable applications, a mechanism shall be in-place to provide a supplementary water source, during periods of system maintenance or drought conditions. Runoff reduction credit is applied if the storage volume within the system, and correlated water demand, are equal to or greater than the WQ,,. 5.3.8.3.2 Design Example Base Data Total tributary area = 3,000 sf Percent impervious area = 100% 90% Rainfall Event Number= 1.0 inch First, compute the required WQ,,, per Chapter 4:I = (LPA \I(100) (0.07 acres)(100) I 0.07 acres I = 100% Rv = 0.05 + 0.0091 Rv = 0.05 + (0.009)(100) Rv = 0.95 P •Rv-A WQv 12 (1.00 inches)(0.95)(0.07 acres) W Qv 12 WQv = 0.006 of = 241 cf Next compute the required storage volume in gal/cf: Vol = (WQv)(7.5gal1cf) Vol = (241 cf)(7.5gal1cf) Vol = 1,808 gal Therefore, to provide RRv for the area draining to the practice, a cistern/rain barrel that can hold at least 1,808 gallons is required. Chapter 5: Runoff Reduction Techniques 5_69 Fact Sheet: Rainwater Harvesting Systems (RR-8) Description: Practice to capture and store stormwater runoff to be used for irrigation or filtered and reused for non-potable water applications. The storage systems are located either above or below ground and are either constructed on-site or pre-fabricated of various materials. The basic components of a rainwater harvesting system include: a watertight storage container, secure cover, a debris/mosquito screen, a coarse inlet filter with a clean-out, a valve, an overflow pipe, a manhole or access hatch, a drain for cleaning, and an extraction system (tap, pump, or valve). FEASIBILITY STORMWATER MANAGEMENT SUITABILITY Contributing area is limited by the calculated water demand established Water Quality for the proposed reuse application(s). A water demand analysis shall be performed to size the system ® Channel Protection Harvested rainwater shall not be used for drinking or watering food plants. Overbank Flood Protection Pipes or storage units shall be clearly marked"not for consumption" Systems shall be located indoors, buried below the frost line or winterized, • Extreme Flood Protection unless the system is drained and decommissioned prior to the cold 0 weather season Runoff Reduction Thermal fluctuations and algae growth shall be minimized by locating the • Treatment of Hotspots system in the shade, providing fence or landscape screening, or providing an aeration system 0 Linear Applications CONVEYANCE ✓suitable for this practice Conveyance system shall keep reused stormwater or greywater separate IMPLEMENTATION CONSIDERATIONS from potable water piping systems. Emergency overflow shall be provided to discharge stormwater, if the Capital Cost story capacity is exceeded, at a non-erosive velocity. Maintenance Burden The overflow shall be conveyed to a stabilized outfall ® Safety TREATMENT o Landscaping Shall be sized to provide adequate storage for the design storm, which is either the Extreme Flood, or a smaller event if a portion of stormwater is L= Low M = Moderate H =High bypassed around the system. NA= Not Applicable The storm volume shall be dictated by the water demand, which is the POLLUTANT REMOVAL(See Table 10.4) quantity of water than can reasonably be reused for on-site non0potable or irrigation applications. ei Phosphorus A detailed water demand analysis shall be performed ® Nitrogen If water is being reused for non-potable applications, a mechanism shall ® Metals be in-place to provide a supplementary water source, during periods of system maintenance or drought conditions ® Pathogens Storage volume within the system, and correlated water demand, shall be O Total Suspended Solids greater than or equal to the WQv to receive RRv credit G=Good F= Fair P= Poor *= May provide partial benefits RUNOFF REDUCTION CREDIT 100% RRv provided Chapter 5: Runoff Reduction Techniques 5.3.9 Porous Pavement (RR-9) Porous pavement is a broadly defined group of pervious surfaces that can be applied as an alternative to typical impervious surfaces for road, driveway, sidewalk, or plaza applications. These systems are designed to convey rainfall through the surface into an underlying reservoir that provides structural support, filters pollutants, temporarily stores runoff, and promotes infiltration. Porous pavements are designed to reduce the effective impervious area on a site; thereby reducing design volumes and peak discharge rates. These systems must be designed to support applicable loading, and carefully constructed and maintained to ensure long-term function. 3°' MIN TOP COURSE POROUS ASPHALT PAVEMENT 3" MIN BINDER COURSE POROUS ASPHALT PAVEMENT 1" MIN NO. 2 STONE CHOKER COURSE (WASHED, NO FINES) 12" MIN NO, 4A STONE RESERVOIR (WASHED, NO FINES) DRAINAGE FILTER FABRIC 24" MIN SEPARATION TO SEASONAL HIGH WATER TABLE/BEDROCK ROAD,DRIVE,AND PARKING LOT WITHOUT UNDERDRAIN SECTION VIEW 3" MIN TOP COURSE POROUS ASPHALT PAVEMENT 1" MIN NO, 2 STONE CHOKER COURSE WASHED, NO FINES) " MIN NO. 4A STONE RESERVOIR {WASHED, NO FINES) r — DRAINAGE FILTER FABRIC 24" MIN SEPARATION TO SEASONAL HIGH WATER TABLE/BEDROCK PEDESTRIAN WALKWAY WITHOUT LINDERDRAIN SECTION VIEW VISN " PVC PERFORATED OBSERVATION WELL TH LOCKABLE CAP OLID FRAME AND COVER SET 6" PVC PERFORATED OBSERVATION WELL CONCRETE COLLAR WITH LOCKABLE CAP SOLID FRAME AND COVER SET IN CONCRETE COLLAR PER 01 DESIGN 01 SECTION 01 PER --,{� - - ---- TDURANAGE LAYER MIN NO. 57 NE 00 U� DESIGN SECTION (WASHED, r l)0 �— NO FINES) WQv MAX 24" MIN PONDING DEPTH 24" MIN FOOT PLATE 6" MIN SOLID SEPARATION TO SEASONALO HIGHH HEADER PIPE SEASONAL HIGH WATER TABLE/BEDROCK 6' PERFORATED WATER TABLE/BEDROCK UNDERDRAIN SET 30' Q.C. MAX OBSERVATION WELL WITH UNDERDRAIN OBSERVATION WELL WITHOUT UNDERDRAIN SECTION VIEW SECTION VIEW Figure 5.46 Porous Asphalt Pavement (RR-9) Chapter 5: Runoff Reduction Techniques 5-71 JOINT SPACING AND FILLER PER MANUFACTURER RECOMMENDATIONS POROUS PAVERS PAVER RESTRAINT PER MANUFACTURER RECOMMENDATIONS 2" BEDDING COURSE PER MANUFACTURER RECOMMENDATIONS 1" MIN NO. 2 STONE CHOKER COURSE (WASHED. NO FINES) J 8" MIN NO. 4A - STONE RESERVOIR (WASHED, NO FINES) DRAINAGE FILTER FABRIC ———— — — ——— — — 24" MIN SEPARATION TO SEASONAL HIGH WATER TABLE/BEDROCK POROUS PAVER WITHOUT UNDERDRAIN SECTION VIEW 4" MIN. POROUS CONCRETE CONCRETE THICKNESS AND x REINFORCEMENT DESIGNED PER TRAFFIC LOADING 1" MIN NO. 2 STONE CHOKER COURSE (WASHED, NO FINES) LEVEL 8" MIN NO, 4A STONE RESERVOIR (WASHED, NO FINES) i Iff-L 7 12" MIN NO. 4A C STONE RESERVOIR (WASHED. NO FINES) DRAINAGE FILTER FABRIC —— — — — — — — — — — 24" MIN SEPARATION TO SEASONAL HIGH WATER TABLE/BEDROCK C7 POROUS CONCRETE WITHOUT UNDERDRAIN SECTION VIEW Figure 5.47 Porous Pavers & Concrete (RR-9) Chapter 5: Runoff Reduction Techniques 5-72 Design Variants Porous pavement systems can be broken into two general design variants: 1. Porous Pavement Systems - Level 1 (Non-Vehicle Traffic): Designed to support light-duty, non-vehicle traffic only. Filter layer is typically sized to accommodate only rainfall that falls directly on the surface of the system. Generally, consist of porous pavers and flexible porous pavement. 2. Porous Pavement Systems - Level 2 (Vehicle Traffic). Designed to support heavy-duty structural load and/or accommodate storage of larger storm events. Filter layer must be sized to store the entire WQv for the tributary area and can be sized to accept runoff from adjacent impervious areas. Generally, consist of porous asphalt pavement, porous concrete, traffic-rated porous pavers, porous gravel with stabilization grid/cell, stabilized grass grid/cell and grass block pavers. 5.3.9.1 Feasibility Porous pavements shall be used in low dust areas and areas with low vehicle traffic volume. The systems shall be designed with the capability of bearing the anticipated vehicle and traffic loads. Porous pavements may be applied as practices for urban stormwater management (see Chapter 8). Sand and other winter traction materials shall not be used on porous pavement systems. Porous pavement systems shall not be used to treat stormwater hotspots. In areas of known contamination, or if contamination is discovered during excavation, contaminant levels must be evaluated by a qualified professional and state remediation program to determine if infiltration is permitted. Slope across the finished surface shall not exceed 10%. Slope across the bottom of the stone reservoir shall not exceed 5%. Where surface slope exceeds 5%, the stone reservoir shall be stepped to meet this criteria and underdrains shall be used to distribute runoff through the reservoir evenly. The contributing area to porous pavements shall not exceed 3 times the surface area of the porous system. Porous pavements shall meet the separation requirements as listed in Table 5.17. Vertical separation shall be taken from the bottom of the stone drainage layer. Horizontal separation shall be taken from the closest side of the filter media. Porous Pavement Minimum Separation Vertical Separation Horizontal Separation Structures Seasonal Structures With Design High Water Bedrock'2 Without Foundation Water Supply Septic Variant Table',2 Foundation Waterproofing Well/Reservoir System34 Waterproofing Level 1 loft 0 ft 2ft 2ft 100ft 50ft Level 2 25 ft loft 'Sound bedrock,fractured bedrock or karst geology as documented by on-site soil testing. 24 ft in sole source aquifers. 3Septic systems are inclusive of septic tanks,distribution boxes,and absorption fields. 41f underdrains are proposed, minimum setback shall be 100 ft. Porous pavement systems shall not be used unless the underlying soils have an infiltration rate greater than or equal to 0.50 inch/hr, as confirmed by required geotechnical testing (see Appendix D). Chapter 5: Runoff Reduction Techniques 5-73 Where underlying soils have an infiltration rate less than 2 inch/hr, underdrains shall be provided. If underlying soils have an infiltration rate greater than or equal to 2 inch/hr, underdrains are not required. If porous pavement systems are constructed in engineered fill soils, then the following criteria shall be met: In-situ/natural soil layer below the porous pavement system shall have an infiltration rate greater or equal to the engineered fill soils, as determined by geotechnical testing (Appendix D); Soils proposed for engineered fill shall be classified as suitable using Table 5.18 and Figure 5.48; Soils proposed for engineered fill shall have a minimum infiltration rate of 0.50 inch/hr and a material gradation similar to the in-situ/natural soils, as determined by geotechnical testing; After placement of engineered fill, permeability testing (Appendix D) shall be performed to confirm the actual in place infiltration rate. If engineered fill material requirements are not met, the material shall be removed; and The required vertical separation shall be measured from the existing grade of in-situ/natural soil. Engineered fill soils shall not be used to meet separation requirements. HydrologicTable 5.18 .p Soil Texture Class Hydrologic Soil Minimum Infiltration Rate Suitability Group (inch/hr) Sand A 8.27 Loamy sand A 2.41 Suitable for engineered fill for infiltration practice Sandy loam B 1.02 design Loam B 0.52 Silt loam C 0.27 Sandy clay loam C 0.17 Clay loam D 0.09 Not suitable for Silt clay loam D 0.06 engineered fill for Sandy clay D 0.05 infiltration practice design Silty clay D 0.04 Clay D 0.02 Chapter 5: Runoff Reduction Techniques -74 IN 9D 70 claY 4p 150 ¢ b mq� p�r -go C� sandy clay rti^ 40 —clay — clay loam silty �� 30 s:�ndy clay loam cl:ry IOU V V V VL 4 ?f} V loam 5i11 sandy loam 10 lnam Jim silt sand v:jnd ter, i, �o o °n 'o 4 Sand Separate, % Figure 5.48 USDA Soil Textural Classification The following requirements shall be in place, during construction: At the time of installation, extremely high or low temperatures shall be avoided. System areas shall be clearly marked before any site work begins to avoid soil disturbance and compaction. Heavy equipment traffic shall be restricted from areas of existing or proposed porous pavements. Construction of upstream areas shall be completed, and adequate vegetative cover shall be established over the entire tributary pervious area, before draining to the porous pavement system. Subsurface area shall be excavated to the proposed depth of the porous pavement section. Existing subgrade shall not be compacted or subject to excessive construction equipment prior to placement of drainage filter fabric and stone reservoir. Where erosion of subgrade has caused accumulation of fine materials and/or surface ponding, this material shall be removed, and the underlying soils scarified to a minimum depth of 6 inches. Place drainage filter fabric, or acceptable alternative, and stone drainage layer, immediately after approval of subgrade preparation to prevent accumulation of debris or sediment. To ensure proper management post-construction, the following activities shall be avoided: Application of sand during winter months. Only use plow or snow removal equipment that is suitable for the specific type of porous pavement. Do not place dumpsters on or immediately upgradient of the pavement surface. Do not store or place dirt, grit, mulch, sand, or other similar materials on or near the pavement surface. 5.3.9.2 Conveyance Runoff shall be conveyed to the practice via sheet flow. When designing porous pavement systems for treatment of adjacent areas, the stone reservoir shall be designed with additional capacity. Chapter5: Runoff Reduction Techniques 5•75 5.3.9.3 Pretreatment If pervious adjacent areas discharge to the porous pavement system, then pretreatment shall be provided by grass filter strip and minimum 24 inch wide by 12 inch deep pea gravel diaphragm for that area. Refer to Table 6.2 for pretreatment sizing criteria. 5.3.9.4 Treatment 5.3.9.4.1 Design Criteria Depth of stone reservoir shall be designed to account for the total contributing area, traffic load, in-situ soil characteristics, as well as water quality volume and quantity control requirements. Table • •us Pavement Design Specifications Porous Asphalt Porous Concrete Porous Paver3 Depth 3 inch min. 4 inch min. Per manufacturer specifications Surface Portland Cement Type I or II Layer' NYSDOT Approved Top (ASTM C 150), No. 8(ASTM 33), Material Course Porous Asphalt Agg.:Cement Ratio 4:1 to 4.5:1 Per manufacturer Pavement Specification Water/Cement Ratio 0.28-0.35 specifications Reinforcement designed per traffic loading Applicability Level 1: N/A N/A N/A Binder Level 2: Required Course Depth 3 inch min. Material NYSDOT Approved Binder Course Porous Asphalt Pavement Specification Applicability N/A N/A Required Bedding Depth 2 inch min. or per manufacturer specifications Course Material Per manufacturer specifications Choker Depth 1 inch min. Course' Material NYSDOT No.2 stone, washed, no fines Level 1: 8 inch min. 8 inch min. Stone Depth Level 2: 12 inch min. See Section 5.3.9.4.2 Reservoir' See Section 5.3.9.4.2 Material NYSDOT NoAA stone, washed, no fines Applicability Required when underdrain is provided Drainage Depth 10 inch min. Layer Material AASHTO No. 57 stone,washed, no fines Drainage Materia12 Non-woven, polypropylene geotextile with flow rate greater than 125 gpm/sf(ASTM D4491) Filter Fabric' and Apparent Opening Size US#70 sieve(ASTM D4751) Applicability Underlying infiltration rates greater than or equal to 0.50 inch/hr and less than 2.0 inch/hr Underdrain Material 6" perforated PVC or HDPE laid at 0.50%min. 30 ft max. O.C. Underdrain invert shall be set at or above the WQv peak water surface elevation. Observation Material 6 inch min. perforated vertical PVC or HDPE pipe, with lockable cap installed flush with the Well' surface. Footnotes: 'Required for all Design Variants ZOr acceptable alternatives,such as a 3 inch minimum layer of pea gravel 3Porous Paver specifications include proprietary grid and geocell structures filled with permeable material specified by the product manufacturer. Chapter 5: Runoff Reduction Techniques ••7 5.3.9.4.2 Sizing Criteria First, calculate the minimum depth of the stone reservoir needed to store the WQ storm event. The calculated minimum depth shall be compared to the minimum reservoir depth in Table 5.19 and the higher value shall be used. Where underdrains are proposed, the invert of the underdrain shall be set at an elevation above the WQv. WQv dp Ap . Where: Dp = Calculated minimum depth of stone reservoir(ft) WQv= Water Quality Volume (co Ap= Surface area of porous pavement (so 4 = Porosity (assume 0.40) Next calculate the required total length of underdrain piping (LT), then calculate the required number of underdrains (N), rounding up to the nearest whole number: AP LT S P N L _ LT U Where: Sp = spacing between underdrain pipes (ft on-center) (max. 30 ft) Lu = design length of underdrain pipe (ft) Chapter 5: Runoff Reduction Techniques 5-77 Fact Sheet: Porous Pavement (RR-9) A broadly defined group of pervious surfaces that can be - -_ applied as an alternative to typical impervious surfaces for road, driveway, sidewalk, or plaza applications. Designed to convey rainfall through the Vlt surface into an underlying reservoir that provides structural support, filters pollutants, temporarily stores runoff, and promotes infiltration. Key Considerations FEASIBILITY STORMWATER MANAGEMENT SUITABILITY Use in low dust areas and area with low traffic volume Water Quality Shall be designed with the capability of bearing the anticipated vehicle • Channel Protection and traffic loads Sand and winter traction materials shall not be used Overbank Flood Protection Maximum slope across the finished surface is 10% • Extreme Flood Protection * Maximum slope across the bottom of the stone reservoir is 5% 0 Runoff Reduction • Where surface slope exceeds 5%, the stone reservoir shall be stepped with underdrains • Treatment of Hotspots * Minimum separation to bedrock/high water table is 2 ft 0 Linear Applications • Minimum infiltration rate of underlying soil is 0.50 inch/hr suitable for this practice Where underlying soils have an infiltration rate less than 2 inch/hr ✓ underdrains shall be provided IMPLEMENTATION CONSIDERATIONS Heavy equipment shall be restricted from area before, during and after Capital Cost construction Contributing area to porous pavements shall not exceed 3 times the © Maintenance Burden surface area of the porous system O Safety CONVEYANCE Landscaping Runoff shall enter practice through sheet flow Low M = Moderate H =High When designing systems for treatment of adjacent areas, the stone L=NA L Not Applicable reservoir shall be designed with additional capacity PRETREATMENT POLLUTANT REMOVAL(See Table 10.4) s If pervious adjacent areas discharge to the system, a grass filter strip and ® Phosphorus minimum 24 inch wide by 12 inch deep pea gravel diaphragm shall be provided Nitrogen TREATMENT ® Metals Depth of stone reservoir shall be designed to account for the total ® Pathogens contributing area,traffic load, in-situ soil characteristics and WQv and quantity control requirements O Total Suspended Solids System shall be designed to ensure the peak water surface elevation for G=Good F= Fair P= Poor the 10-year, 24-hr design storm does not rise above the stone reservoir RUNOFF REDUCTION CREDIT Where underdrains are provided, the invert of the underdrain shall be set at an elevation above the required WQv storage 100%(40%)of the runoff reduction volume provided by this practice without underdrains (with underdrains) Chapter 5: Runoff Reduction Techniques 5.3.10 Green Roofs (RR-10) Green roofs represent an alternative to traditional impervious roof " sr� 11111 z surfaces. These systems consist of underlying waterproofing and : - drainage materials and an overlying soil media that is designed to support plant growth. Stormwater runoff is captured and temporarily � '7W � stored in the soil media, where it is subjected to evaporation and ,. - transpiration, with any excess runoff conveyed back into the storm ..�r � _ drain system. There are two types of green roof systems: intensive green roof systems and extensive green roof systems. Intensive green roof r systems have a thick layer of soil media that supports a diverse plant community that may include trees. Extensive green roof systems have 7. a much thinner layer of soil media that supports a plant community that is comprised primarily of drought tolerant vegetation. ROOF FLASHING PROTECTED BY COUNTER FLASHING l e 6" MIN OVERFLOW .b PROTECTED ABOVE GRATE, a OVERFLOW FILTER TEM MEDIA 6-24" FILTER MEDIA DRAINAGE LAYER (VARIES) —————— —————— I _ - PROTECTIDN LAYER ROOT BARRIER WATERPROOFING ROOF DECK DRAINAGE FILTER FABRIC EDGE OF ROOF DRAIN BUILDING INTENSIVE GREEN ROOF PROFILE VIEW ROOF FLASHING PROTECTED BY COUNTER FLASHING 6" MIN ABOVE OVERFLOW PROTECTED FILTER GRATE OVERFLOW 3-6" FILTER MEDIA SYSTEM MEDIA I DRAINAGE LAYER (VARIES) u —- PROTECTION LAYER ROOT BARRIER WATERPROOFING ROOF DECK DRAINAGE FILTER FABRIC EDGE OF ROOF DRAIN BUILDING EXTENSIVE GREEN ROOF PROFILE VIEW Figure 5.49 Green Roofs (RR-10) Chapter 5: Runoff Reduction Techniques 5-79 5.3.10.1 Feasibility Green roofs shall only be used to replace traditional impervious roof surfaces. They shall not be used to treat any stormwater runoff generated elsewhere on the development site. Intensive green roof systems shall be installed on flat or tiered roofs with a maximum slope of 10%. Extensive green roof systems shall be installed on flat roofs or roofs with a maximum slope of 10%. If strapping and drainage layer stabilization measures are installed, then the maximum slope shall be increased to 25%. The green roof waterproofing system shall have a warranty for repair due to water damage. Access to the green roof shall be provided for maintenance. 5.3.10.2 Conveyance An overflow system shall be designed to safely convey stormwater runoff out of the drainage layer and off the rooftop when the drainage layer becomes saturated and when larger storm events exceed the storage capacity. Typical overflow systems include: Inlets set slightly above the surface elevation of the green roof; Protected overflow system with the overflow grate set at the drainage layer elevation, covered by No. 2 stone and protected by a ballast guard wrapped in drainage filter fabric; or Scuppers with downspouts. 5.3.10.3 Treatment 5.3.10.3.1 Design Criteria A licensed structural engineer must conduct a structural analysis of the system and any structural requirements necessary to support the additional load from soil, vegetation, water, snow and, where applicable, pedestrians. As a fire resistance measure, non-vegetative materials, such as stone or pavers shall be installed around all rooftop openings and at the base of all walls that contain openings. Green roof systems shall be designed to provide enough storage for the WQv storm event. Prior to construction of the drainage system, the waterproofing system must be fully tested to ensure watertight seal over a 24-hour period. Chapter 5: Runoff Reduction Techniques _80 Green roof systems shall consist of the following treatment components: Table1 Green Roof System Design • • Extensive Intensive Roof Flashing' Depth 6 inches min. above filter media and protect by counter flashing Depth 3—6 inches 6—24 inches Synthetic moisture retention material, or Filter Media' 80% lightweight inorganic material Material 15%organic material 5%sand Drainage Filter Non-woven, polypropylene geotextile with flow rate greater than 125 Fabric' Materiala gpm/sf(ASTM D4491)and Apparent Opening Size US#70 sieve (ASTM D4751) Depth Governed by the required storage capacity of the green roof system and the structural capacity of the rooftop Synthetic or inorganic materials(e.g. stone, polyethylene tray systems, Drainage drainage mat/board, geocomposite drain, flat drain)capable of both Layer' Material retaining water and providing efficient drainage when the layer becomes saturated. or, stone layer washed, no fines with perforated PVC or HDPE underdrain Protection Material A water-permeable, synthetic fiber with resistance to strains induced by Layer' point loads or puncture Root Barrier' Material Physical root barrier that has not been infused with pesticides, metals or leachable chemicals Waterproofing' Material Synthetic rubber, modified bitumen or thermoplastic sheet membrane Footnotes: 'Required for all Design Variants ZFor intensive green roofs,additional depth can be provided if roof is designed to support the load. 30r acceptable alternatives,such as a 3 inch minimum layer of pea gravel 5.3.10.3.2 Sizing Criteria Water Quality Calculate provided WQv, using assumed depth of soil media and drainage layer. WQ,, = (AGR) [(Dsm)( // nsm) + IDDL)(nDL)1 Where: AcR = Green roof surface area (so DsM = Depth of the soil media (ft) DDL= Depth of the drainage layer(ft) nsM = Maximum water retention of the soil media, as determined by ASTM E2399 (decimal) nog= Maximum water retention of the drainage layer, as determined by ASTM E2393 (decimal) WQv= Water Quality Volume (cf) Chapter 5: Runoff Reduction Techniques 5-51 Water Quantity When designing green roof systems for water quantity the system can be modeled in multiple ways, including the following two options: Assume a curve number of 98 to model the roof as an impervious surface, that discharges to the defined storage volume within the green roof system. Calculate a modified curve number, using the NRCS (SCS) Rainfall-Runoff method, which accounts for storage volume within a green roof system and any additional runoff that would discharge to the design point. 1,000 CN = S+ 10 S = (di)(0j) + (d2)(02)+...(dx)(Ox) Where: CN = Curve Number S = Maximum basin retention (inches) d = Depth of each component layer(inches) 4) = Porosity of each component layer(decimal) 5.3.10.4 Landscaping For planting guidance for stormwater management facilities, refer to Chapter 11. Permanent vegetative cover shall achieve 80% uniform density established over the entire contributing pervious area, before runoff is directed into the facility. Chapter 5: Runoff Reduction Techniques 5-82 Fact Sheet: Green Roofs (RR-10) Practice in which stormwater runoff is captured and temporarily stored in the soil media, where it is subjected to evaporation and transpiration, with any excess runoff conveyed back into the storm 4` drain system. These systems consist of underlying waterproofing and drainage materials and an overlying soil media that is designed to support plant growth. Key Considerations FEASIBILITY STORMWATER MANAGEMENT SUITABILITY Shall only be used to replace traditional impervious roof surfaces and shall ® Water Quality not be used to treat any stormwater runoff generated elsewhere on the development site ® Channel Protection * Systems shall be installed on flat or tiered roofs with a maximum slope of ® Overbank Flood Protection 10%. If strapping and drainage layer stabilization measures are installed, the maximum slope is increased to 25%for extensive green roof systems ® Extreme Flood Protection Waterproofing system shall have a warranty for repair due to water 0 Runoff Reduction damage Access to the green roof shall be provided • Treatment of Hotspots CONVEYANCE Linear Applications Overflow system shall be designed to safely convey stormwater runoff ✓suitable for this practice TREATMENT IMPLEMENTATION CONSIDERATIONS A licensed structural engineer must conduct a structural analysis of the system and any structural requirements necessary to support the Capital Cost additional load o A non-vegetative fire resistance measure shall be installed around all Maintenance Burden rooftop openings and at the base of all walls that contain openings Safety Systems shall be designed to provide enough storage for the WQv storm © Landscaping eve nt Prior to construction of the drainage system, the waterproofing system L= Low M = Moderate H =High must be fully tested to ensure watertight seal over 24-hr period NA= Not Applicable Roof flashing shall be providing a minimum of 6 inches above the filter POLLUTANT REMOVAL(See Table 10.4) media and protected by counter flashing Extensive green roofs shall have a 3 inch minimum and 6 inch maximum ® Phosphorus filter media depth * Intensive green roofs shall have a 6 inch minimum and 24 inch maximum Nitrogen filter media depth ® Metals OPathogens O Total Suspended Solids G=Good F= Fair P= Poor RUNOFF REDUCTION CREDIT 100% RRv provided Chapter 5: Runoff Reduction Techniques 5.3.11 Stream Daylighting (RR-11) Stream Daylight previously culverted/piped streams to restore natural habitats, better attenuate runoff by increasing the storage size, promoting infiltration, and help reduce pollutant loads where feasible and practical. Stream daylighting may be credited as an Impervious Area Reduction practice for redevelopment projects in accordance with Chapter 9. Stream daylighting involves uncovering a stream or a section of a stream that had been artificially enclosed in the past to accommodate development. The original enclosure of rivers and streams often took place in urbanized areas through the use of large culvert operations that often integrated the storm sewer system and combined sanitary sewers. The daylighting operation, therefore, often requires overhauls or updating of storm-drain systems and re-establishing stream banks where culverts once existed. When the operation is complete, what was once a linear pipe of heavily polluted water can become a meandering stream with dramatic improvements to both aesthetics and water quality. Where combined sewer overflow (CSO) separation and other upgrades to storm-sewer systems are part of a daylighting project, significant water-quality improvements can be expected during wet-weather events. Also, as ultraviolet radiation is one of the most effective ways to eliminate pathogens in water, exposing these streams to sunlight could significantly decrease pathogen counts in the surface water. ti. � a wry ^*• '. c .Now VW "aM,WC4FE MkWW A5S0CtATES PHCTD VOCLPE MA SOW/,BSMMFES Figure 5.50 Before and after daylighting Blackberry Creek in Berkeley, CA(Source: Stormwater Magazine, Nov/Dec 2001) Stream daylighting can play an integral role in neighborhood restoration and site redevelopment efforts. Aside from improvements to infrastructure, stream daylighting can restore floodplain and aquatic habitat areas, reduce runoff velocities and be integrated into pedestrian walkway or bike- path design. 5.3.11.1 Feasibility Limitations Daylighting a stream can be expensive - Costs for daylighting streams are often comparable to costs for replacing culverts. Maintenance of daylighted stream areas can be intensive during the first years the stream is established — Once the banks are well established, regular maintenance is similar to that required in any public green space such as trash removal, mowing and general housekeeping. Finding the original stream channel may be difficult—examine historic records, soils, and up and downstream channel characteristics. Political backing and public support is more difficult for daylighting streams than for surface restoration because the culvert is not seen — Provide proper public education and outreach about the benefits and how safety issues will be addressed. Chapter 5: Runoff Reduction Techniques ••84 Stream daylighting can generally be applied most successfully to sites with considerable open or otherwise vacant space. This space is required to: 1) Potentially reposition the stream in its natural stream bed; 2) Accommodate the meandering that will be required if a natural channel is being designed and 3) Provide adjacent floodplain area to store water in large storm-flow situations. Consider daylighting when a culvert replacement is scheduled. Restore historic drainage patterns by removing closed drainage systems and constructing stabilized, vegetated streams, see Figure 5.50. Carefully examine flooding potential, utility impacts and/or prior contaminated sites. Consider runoff pretreatment and erosion potential of restored streams/rivers. 5.3.11.2 Treatment 5.3.11.2.1 Sizing and Design Criteria Stream daylighting is applicable only to redevelopment projects as an impervious area reduction type practice in accordance with Chapter 9. The sizing of the stream channel must, at minimum, equal or exceed the existing drainage capacity of the piped drainage system. The impervious area reduction credited under Chapter 9 would be equal to the area of imperviousness removed for streams buried and piped under impervious areas. For streams buried and piped under pervious areas, the impervious area reduction credited would be equal to the planar area of the bed and banks of the daylighted stream. 5.3.11.3 Landscaping For planting guidance for stormwater management facilities, refer to Chapter 11. Chapter 5: Runoff Reduction Techniques 5-85 Fact Sheet: Stream Daylighting *V 11`'1- sw r FT ` ' + '� `A k° A practice involving uncovering a stream ?�! •. or a section of a stream that had been artificially enclosed in the past to accommodate development. -- '' Stream daylighting previously culverted/piped streams .'." restores natural habitats, better attenuates runoff, promotes infiltration, and helps reduce pollutant loads. Photo Source: Harford County, Maryland) tilt�,<..�+911E r" � - �'_ ' G�,.��• �M f ' .1 Key Considerations FEASIBILITY STORMWATER MANAGEMENT SUITABILITY Finding original stream channel can be difficult • Water Quality Consider this option when a culvert replacement is scheduled 40 Channel Protection Consider: flood potential, proper contaminated sites, erosion potential is Overbank Flood Protection TREATMENT 40 Extreme Flood Protection Only applicable as an impervious area reduction for redevelopment 0 projects Runoff Reduction Sizing of channel must meet or exceed existing drainage capacity ` Treatment of Hotspots ® Linear Applications ✓suitable for this practice IMPLEMENTATION CONSIDERATIONS Capital Cost Maintenance Burden ® Safety Landscaping L= Low M = Moderate H =High NA= Not Applicable POLLUTANT REMOVAL(See Table 10.4) ® Phosphorus Nitrogen ® Metals Pathogens Total Suspended Solids G=Good F= Fair P= Poor RUNOFF REDUCTION CREDIT 100% impervious area reduction towards RRv Chapter 5: Runoff Reduction Techniques Chapter 6: Standard Stormwater Management Practices This Chapter outlines performance criteria for five groups of standard stormwater management practices (SMPs)to meet water quality treatment goals. These include ponds, wetlands, infiltration practices, filtering practices and open channel systems. Each group of SMPs have six performance criteria: Feasibility: Identify site considerations that may restrict use of a practice. Conveyance: Convey runoff to and from the practice in a manner that is safe, minimizes erosion, maximizes pretreatment, mimics existing hydrology to the greatest extent practical, and prevents disruption to natural channels. Convey runoff through the practice in a manner that promotes maximum treatment, and detention/infiltration. Pretreatment:Trap coarse sediments and debris before they enter the practice, to reduce the maintenance burden and ensure long-term performance of the practice. Treatment: Provide water quality treatment through design elements that maximize pollutant removal. Landscaping: Reduce secondary environmental impacts through landscaping design that minimizes disturbance of natural stream systems, complies with environmental regulations, and enhances the pollutant removal and aesthetic value of the practice. For planting guidance for stormwater management facilities, refer to Chapter 11. Maintenance: Preserve the long-term performance of a practice through regular inspection and maintenance activities, as well as design elements that ease the maintenance burden. Refer to Chapter 12 for guidance on inspection and maintenance activities. IMPORTANT NOTES: 1. THIS CHAPTER PRESENTS REQUIRED PERFORMANCE CRITERIA BY USE OF DEFINITIVE LANGUAGE LIKE "SHALL" OR"MUST," WHICH MEANS THAT THOSE CRITERIA SHALL BE USED IN ALL APPLICATIONS. 2. FACT SHEETS FOR EACH DESIGN VARIANT WITHIN THE FIVE SMP GROUPS ARE PRESENTED AT THE END OF EACH SECTION AND SUMMARIZE THE KEY PERFORMANCE CRITERIA FOR EACH PRACTICE. THESE FACT SHEETS ARE FOR REFERENCE AND MAY NOT BE INCLUSIVE OF ALL REQUIREMENTS. 3. ANY PRACTICE THAT CREATES A DAM IS REQUIRED TO FOLLOW THE GUIDANCE PRESENTED IN THE GUIDELINES FOR DESIGN OF DAMS(APPENDIX A) AND MAY REQUIRE A PERMIT FROM THE NYSDEC. FOR THE MOST RECENT COPY OF THIS DOCUMENT, CONTACT THE NEW YORK STATE DEPARTMENT OF ENVIRONMENTAL CONSERVATION, DAM SAFETY SECTION. AN EVALUATION OF HAZARD CLASSIFICATION MUST BE INCLUDED IN THE DESIGN REPORT FOR STORMWATER PONDS OR WETLANDS CREATED BY A DAM. Chapter 6:Standard Stormwater Management Practices 61 The following table allows designers to evaluate each standard SMP and determine which practice(s) are feasible for application to a specific site. Feasibility is based on thresholds that shall be met for four key site conditions: 1. Soil Permeability: This column outlines the permeability requirements for underlying soils at the location of a proposed SMP. The designer should perform an initial investigation of the NRCS hydrologic soil groups at the site to determine soil characteristics. Please note that more detailed geotechnical tests are usually required, in accordance with Appendix D. 2. Depth to Seasonal High Water Table: This column indicates the minimum depth to the seasonally high water table from the bottom elevation of the SMP section. 3. Contributing Area: This column indicates the minimum or maximum contributing area that is considered optimal for a practice. The minimum contributing area shall not be reduced, and the maximum shall not be increased, except where specific design criteria are met or additional engineering analysis is performed to support an adjusted area. 4. Max Site Slope: This column indicates the preferred maximum slope of the area proposed for installation of a practice. Existing slopes may exceed these values with proper engineering to ensure slope stability and non- erosive runoff velocities from the contributing area. StandardTable 6.1 SMP SMP Design Soil Permeability Separation to Contributing Max Site Group Water Table(ft) Area(acres) Slope Micropool ED 10 (min)4 Wet Pond fc<_0.014 inch/hr, unless Ponds impermeable liner provided 01,2 15% Wet ED Pond (see Section 6.1.4.1) 25(min)a Multiple Pond Shallow Wetland ED Shallow Wetland fc<_0.014 inch/hr, unless 01'2 25 (min) Wetlands Pond/Wetland System impermeable liner provided 15% Pocket Wetland (see Section 6.2.4.1) Oz 5(min) Gravel Wetland 01,2 5 (max) Infiltration Trench 5 (max) Varies Infiltration Basin Infiltration fc>0.5 inch/hr 23 (10/25/50 max) 15% Dry Well 1 (max) Underground Infiltration 10(max) Surface Sand Filter 10(max) Underground Sand Filter No Restriction 2 (max) Filters Perimeter Sand Filter 2 10% Infiltration Bioretention fc>0.5 inch/hr Filtration Bioretention 5 (max) No Restriction Bioslope 150 ft(max) 3:1 (h:v) Dry Swale 2 p o Channels Wet Swale No Restriction below water 5 (max) longitudinal table When treating stormwater hotspots, increase separation to 2 ft. 2 When located in a sole source aquifer, increase separation to 2 ft. 3 When located in a sole source aquifer, increase separation to 4 ft. 4 Minimum contributing area for ponds can be reduced if a water balance analysis is performed in accordance with Section 6.1.4.2. Chapter 6:Standard Stormwater Management Practices 6-2 Section 6.1 Stormwater Ponds Stormwater ponds are practices that have either a permanent pool of water, or a combination of a permanent pool and extended detention, and some elements of a shallow marsh with storage equivalent to the entire WQv. There are four design variants, which include: P-1 Micropool Extended Detention Pond (Figure 6.1) P-2 Wet Pond (Figure 6.2) P-3 Wet Extended Detention Pond (Figure 6.3) P-4 Multiple Pond System (Figure 6.4) Refer to the Fact Sheets at the end of this section for key considerations of each pond design variant, including performance criteria, practice suitability, implementation considerations, pollutant removal capability, and runoff reduction credit. IMPORTANT NOTES: 1. STORMWATER PONDS DESIGNED ACCORDING TO THIS MANUAL MAY ACT AS A COMMUNITY AMMENITY, AND MAY PROVIDE SOME LEVEL OF HABITAT VALUE. HOWEVER, THEY CANNOT BE ANTICIPATED TO FUNCTION AS NATURAL LAKES OR PONDS. TO ENSURE LONG-TERM FUNCTION AS INTENDED, THEY MUST BE PROPERLY MAINTAINED. 2. DRY EXTENDED DETENTION PONDS (WITHOUT A PERMANENT POOL)ARE NOT CONSIDERED AN ACCEPTABLE OPTION FOR MEETING WATER QUALITY TREATMENT OBJECTIVES. Chapter 6:Standard Stormwater Management Practices 6-3 Micropool Extended Detention Pond (P-1) A micropool extended detention pond is a variation of a wet extended detention pond, where a small micropool is maintained at the outlet of the pond. The micropool prevents resuspension of previously settled sediments and prevents clogging of the low flow orifice. The outlet structure is sized to detain the water quality volume within the pond for 24-hrs, or 12-hrs when discharging to trout waters. OUTLET CONTROL STRUCTURE STABILIZED WITH INTERNAL WEIR OUTLET OUTLET PIPE STABILIZED EMERGENCY SPILLWAY ° AQUATIC BENCH STABILIZED OVERFLOW WEIR 25' POND BUFFER AT TOE OF SLOPE STABILIZED INLET } MCROPOOL INLET } PIPE } 1 FOREBAY 1 t T COMPACTED - EARTH BERM SAFETY BENCH (AS REQUIRED) MAINTENANCE ACCESS PLAN VIEW 1' MIN TOP OF EMBANKMENT FREEBOARD EMERGENCY SPILLWAY BEYOND -------------------- -EKxJRF I�+ F{ _0_I7 C rvTrt4�----------------- ----- ----_-----------------.._$ [3�g13ANK EL99P--C9Q�?P1QI.-----_-------_-- ------------------------ HAfiIAI -PRQI� �ON----------------------- --------------------------- ---------------------------- FOREBAYoil MICROPOOL _g-P IJ'_QQL_ ____gP Rt+dANQNT POO �a 3 10 AX1 A 15% MAH TRASH AQUATIC RACK SLOPE STABILIZED INLET BENCH 18" MAX TOP OF EMBANKMENT 10' MIN STABILIZED OUTLET 15' AVG IMPERMEABLE LINER BEYOND � } (AS REQUIRED) OUTLLET CE CONTROL STABILIZED OVERFLOW WEIR 20% MIN WQv WITHIN INTERNAL WEIR COMBINED PERMANENT POOL SECTION VIEW Figure 6.1 Micropool Extended Detention Pond (P-1) Chapter 6:Standard Stormwater Management Practices 6-4 Wet Pond (P-2) A wet pond is a stormwater basin constructed of a permanent pool of water having a storage volume equal to the water quality volume. Stormwater runoff displaces the water already present in the pool. Temporary storage can be provided above the permanent pool elevation for larger flows. INLET STABILIZED PIPE INLET STABILIZED SAFETY BENCH OVERFLOW WEIR (AS REQUIRED) _ OUTLET AQUATIC BENCH STRUCTURE CONTROL COMPACTED WITH INTERNAL WEIR �� _ - EARTH BERM FOREBAY PERMANENT POOL I OUTLET1I PIPE 1, 1 ° � I I � _ — 25' POND BUFFER AT TOE OF SLOPE STABILIZED EMERGENCY SPILLWAY MAINTENANCE STABILIZED ACCESS OUTLET PLAN VIEW TOP OF EMBANKMENT BEYOND STABILIZED OVERFLOW 1` MIN TOP OF EMBANKMENT WEIR FREEBOARD FOREBAY WET POOL EMERGENCY SPILLWAY BEYOND - -------- EXTREME FLOOD_CONTROL__ _ CS-uEFDA4K-- 12-QQUJB.QL_ ANNEL PROTECTION _______ PERM. POOL _ -...- OOL P----- --- 1$ MAX I a 15% MAX MAXI STABILIZED SLOPE STABILIZED INLET 1007. WQv WITHIN COMBINED AQUATIC OUTLET PERMANENT POOL BENCH OUTLET CONTROL IMPERMEABLE LINER 10' MIN STRUCTURE WITH 15' AVG INTERNAL WEIR (AS REQUIRED) (TYP) TRASH RACK SECTION VIEW Figure 6.2 Wet Pond (P-2) Chapter 6:Standard Stormwater Management Practices 6-5 Wet Extended Detention Pond (P-3) A wet extended detention pond is a wet pond where the water quality volume is split evenly between the permanent pool and extended detention storage above the permanent pool. During storm events, water is detained above the permanent pool and released over time. STABILIZED EMERGENCY SPILLWAY STABILIZED 25' POND BUFFER ` OUTLET AT TOE OF SLOPE / ,✓ �� ` r �yl/ OUTLET PIPE OUTLET CONTROL STRUCTURE WITH PERMANENT POOL ' J INTERNAL WEIR COMPACTED 1 IJ I AQUATIC BENCH EARTH BERM 1� J STABILIZED SAFETY BENCH I iff JJ OVERFLOW WEIR (AS REQUIRED) f rOR£BAY STABILIZED INLET INLET -� PIPE MAINTENANCE ACCESS PLAN VIEW TOP OF EMBANKMENT 1' MIN FREEBOARD EMERGENCY SPILLWAY ................g-EXTREME-FLOOD_CONTROL-_________------ BEYOND -----------------s_OVERBAN-K-FLOOD CONTROL-------------- -------------------g QiJANNEL-PRCTEQILO�--------------------- --------------------4-LOOM WQY--------------------------- FOREBAY WET POOL —;_ PERM. POOL �—PERM. POOL .._ ea 3 MAX1 TRASH 15% MAX AQUATIC SLOPE RACK STABILIZED INLET BENCH 1$" MAX TOP OF EMBANKMENT 10 MIN 50% MIN WQv WITHIN STABILIZED OUTLET BEYOND 15' AVG COMBINED PERMANENT POOL OUTLET CONTROL STABILIZED OVERFLOW WEIR (TYP) IMPERMEABLE LINER STRUCTURE WITH (AS REQUIRED) INTERNAL WEIR SECTION VIEW Figure 6.3 Wet Extended Detention Pond (P-3) Chapter 6:Standard Stormwater Management Practices 6-6 Multiple Pond System (P-4) Multiple pond systems consist of constructed facilities that provide water quality and quantity volume storage in two or more cells. The multiple cells create high surface area to volume ratios, complex microtopography, longer pollutant removal pathways, and improved downstream protection. STABILIZED INLET SAFETY BENCH (AS REQUIRED) INLET PIPE �/ -`r COMPACTED EARTH BERM STABILIZED EMERGENCY SPILLWAY 1 \ OUTLET CONTROL \ STRUCTURE WITH INTERNAL WEIR OUTLET PIPE FOREBAY STABILIZED d � OUTLET Y 4 CELL .3 N CELL 2 i 25' POND BUFFER AT TOE OF SLOPE STABILIZED OVERFLOW WEIR (TYP) MAINTENANCE AQUATIC BENCH (TYP) ACCESS EMERGENCY SPILLWAY BEYOND PLAN VIEW TOP OF EMBANKMENT 1' MIN FREEBOARD ------------------------$£7fTREME FLOOD CONTROL------------------------- ..........................Z_OAERBANK FLOOD CONTROL $GHANNEL PROTECTION -------------------------- --------------------------------------- -_ ------- ________ �100%WQ-VV----------------------------- FO CELL j CELL 2 CELL3 7----�--- PERM. POOL CTYPI 4-6' 18" MAX Qj TRASH 50% MIN WQv RACK STABILIZED WITHIN COMBINED 159e MAX INLET PERM. POOL AQUATIC BENCH SLOPE TOP OF 10' MIN 15' AVG OUTLET CONTROL EMBANKMENT STABILIZED OVERFLOW (TYP) IMPERMEABLE LINER STRUCTURE WITH BEYOND (TYP) WEIR (TYP) (AS REQUIRED) INTERNAL WEIR SECTION VIEW OUTLET PIPE TO STABILIZED OUTLET Figure 6.4 Multiple Pond System (P-4) Chapter 6:Standard Stormwater Management Practices 6-7 6.1.1 Feasibility Stormwater ponds shall not be located within jurisdictional waters, including wetlands. Evaluate the site to determine the Hazard Class, and to determine what design elements are required to ensure dam safety (see Appendix A). For the most recent copy of this document, contact the New York State Department of Environmental Conservation, Dam Safety Division, at: 518-402-8151. Stormwater ponds shall not be located in areas with natural slopes greater than 15%, unless a slope stability analysis is performed by a qualified geotechnical engineer. Stormwater ponds shall be located in areas with underlying soils that have an infiltration rate less than or equal to 0.014 inch/hr, unless an impermeable liner is provided in accordance with Section 6.1.4.1. Stormwater ponds shall meet the minimum separation requirements listed in Table 6.2 below. Vertical separations shall be taken from the bottom of pond. Horizontal separations shall be taken from the maximum water surface elevation (Extreme Flood peak water surface elevation) of the pond. • . 6 Vertical Separation Horizontal Separation Structures Structures Water Seasonal Septic Sanitary Design Variant High Water �Sound Without With Supply System Sewer Table',2 Bedrock Foundation Foundation Well/ 3,4 Main Waterproofing4 Waterproofing4 Reservoir Micropool Extended Detention Pond (P-1) Wet Pond (P-2) Oft Oft 25ft 25ft 25ft 50ft 25ft Wet Extended Detention Pond (P-3) Multiple Pond System (P-4) 'As documented by on-site geotechnical testing. 2 Separation shall be increased to 2 ft in sole source aquifers or when treating stormwater hotspots. 3 Septic systems are inclusive of septic tanks,distribution boxes,and absorption fields. Practices shall have 50 ft separation to septic tanks and distribution boxes. Practices shall have 100 ft separation to absorption fields. 4 Ponds shall be located downgradient of structures and septic systems. Design P-1 shall have a minimum contributing area of 10 acres. The minimum contributing area can be reduced to 5 acres, if a water balance calculation is performed in accordance with Section 6.1.4.2. Designs P-2, P-3, and P-4 shall have a minimum contributing area of 25 acres. The minimum contributing area can be reduced to 10 acres, if a water balance calculation is performed in accordance with Section 6.1.4.2. The use of stormwater ponds (with the exception of design P-1) on trout waters is strongly discouraged, as available evidence suggests that these practices can increase stream temperatures. However, designs P-2, P-3, and P-4 can be used on trout waters if designed off-line and under shade to minimize thermal impacts. For design P-1 the outlet structure is sized to detain the water quality volume for 24-hrs, or 12-hrs when discharging to trout waters. 6.1.2 Conveyance Inlet Protection Inlet points must be stabilized to ensure non-erosive conditions. If riprap or other channel liner is used, it shall extend 1 ft below the permanent pool elevation. Chapter 6:Standard Stormwater Management Practices 6 Inlet pipe(s) shall have a slope no flatter than 0.5% (1% for pipes smaller than 12 inches diameter) and inverts shall be located at or above the permanent pool elevation. A controlled outlet shall be provided for each pond, using one or more of the following methods: An outlet structure located within the embankment, with a pipe invert set at the permanent pool elevation that extends downward to the structure; An outlet structure located within the embankment, with a submerged reverse-slope pipe that extends downward from the structure to an inflow invert set 1 ft minimum below the permanent pool elevation and 1 ft minimum above the bottom of the pond; An outlet structure located within the embankment, with an adequately sized downward elbow with an extension that extends 1 ft below the permanent pool elevation; An outlet structure located partially within the embankment, with outlet openings in the face of the structure; and/or A stabilized auxiliary spillway(s) designed to safely convey storm events at or below the Extreme Flood Event. The auxiliary spillway shall not be located in fill, where possible. Where a CPv control orifice is provided (See Section 4.6 for CPv requirements and waivers), one of the following methods shall be applied: Minimum 3 inch low flow orifice installed in an internal weir plate within the outlet structure with acceptable external trash rack or orifice protection (See Appendix C for details of a low flow orifice and trash rack options). Minimum 3 inch low flow external orifice installed in the face of the outlet structure (See Appendix C for details of a low flow orifice and trash rack options). Orifice protection shall be provided. An emergency spillway shall be provided to safely convey stormwater exceeding the Extreme Flood. The emergency spillway shall be offset from the principal and auxiliary spillways. A stilling basin, outlet protection, level spreader, or other energy dissipator shall be used to reduce flow velocities from the principal spillway to non-erosive velocities at the discharge. (See Appendix G for a table of erosive velocities for grass and soil). If a pond daylights to a channel or stream, care shall be taken to minimize tree clearing along the downstream flow path. Prior to tree clearing next to a stream or wetland, all necessary permits shall be obtained. Excessive use of riprap shall be avoided to reduce channel or stream warming. The channel immediately below a pond outfall shall be modified to prevent erosion and conform to natural dimensions in the shortest possible distance. Non-clogging Low Flow Orifice A 3 inch minimum low flow orifice shall be provided, with acceptable external trash rack or internal orifice protection (See Appendix C for details of a low flow orifice and trash rack options). Trash racks shall be installed at a shallow angle to prevent ice formation. Alternative methods are to employ a broad crested rectangular, V-notch, or proportional weir, protected by a half- round CMP that extends at least 12 inches below the permanent pool (See Appendix C for details). When a standard weir is used, the minimum slot width shall be 3 inches. 6.1.3 Pretreatment For each stormwater pond, pretreatment equaling a minimum of 10% of the WQv shall be provided at each pond inflow point, unless an inflow point provides less than 10% of the total design storm flow to the pond. The forebay storage volume counts toward the total WQv requirement. In sole source aquifers, 100% of the WQv for stormwater runoff from designated hotspots shall be provided in pretreatment. Chapter 6:Standard Stormwater Management Practices • Pretreatment shall be achieved with a sediment forebay, or an equivalent upstream pretreatment device. When a sediment forebay is applied, it shall meet the following design criteria: Shall consist of a separate cell, formed by an acceptable earthen or structural barrier. Berms and weirs separating the forebay and treatment cells shall be constructed with native or imported clay or very low hydraulic conductivity soils. Depth: 4 to 6 ft. Outlet designed to ensure non-erosive flows into the pond. Optional: a fixed vertical sediment depth marker should be installed in the forebay to measure sediment deposition overtime. Optional: the bottom of the forebay may be hardened using concrete, asphalt, paver blocks, or grouted riprap, to ease sediment removal. 6.1.4 Treatment 6.1.4.1 Design Criteria Table • Ponds Design • • P-1 P-2 P-3 P-4 Freeboard' Depth 1 ft min. measured from Extreme Flood elevation to top of embankment Applicability As required,when pond slope requirements or any other required safety feature cannot be Perimeter met Fencing Installed at or above the maximum water surface level and must consider access for required Location maintenance to be performed Applicability As required, for>_3:1 (h:v)side slopes above permanent pool Safety Bench Slope 6% max. Width 10 ft min., 15 ft average Slope 15% max. Slope to <_3:1 (h:v)from inner bench edge to pond basin floor Aquatic Bench' Pond Floor Width 10 ft min., 15 ft average Depth 18 inch max. from permanent pool elevation to inner bench edge Applicability As required, see Section 6.1.4.1 Impermeable Liner Material 12-24 inch of clay soil (min. 50% passing#200 sieve and max. permeability 1 x 10.5 cm/sec) or 40 mil HDPE geomembrane Slope 15% max. Maintenance Width 12 ft min. Access' Material Able to withstand loading of maintenance equipment and vehicles Footnotes: 'Required for all Design Variants Impermeable Liner When a pond is located in areas listed below, an impermeable liner shall be required. Underlying soils have an infiltration rate greater than 0.014 inch/hr, (Appendix D); or Geotechnical testing is not performed; or Chapter 6:Standard Stormwater Management Practices 610 Underlying soils consist of gravel or fractured bedrock. When required, the impermeable liner shall be installed for the entire wetted perimeter and extend a minimum of 12 inches above the permanent pool elevation. Maintenance Access A maintenance access easement shall extend to the practices from a public or private road. Adequate maintenance access must extend to the forebay, safety bench, outlet structure/overflow, auxiliary and emergency spillways and must have sufficient area to allow vehicles to turn around. Where applicable, access to the outlet structure shall be provided by lockable manhole cover or grate to allow operation of valves and other controls. Pond Drain All ponds shall be equipped with a mechanism that can completely drain the pond within 24-hrs, as follows: A portable trash pump with suction hose, filter sock, and discharge hose; or A drain pipe, sized as noted in DEC Dam Design Guidelines (Appendix A), with an elbow or protected intake within the pond to prevent sediment deposition. In this case, the drain pipe shall be equipped with an adjustable gate valve that is designed to prevent rapid draw down, is located at a point where it will not be normally inundated, is located to allow for safe operation, and is protected from vandalism or improper use (i.e. lockable cover, or within the outlet structure). The approving jurisdiction or MS4 shall be notified before draining a stormwater pond. Ponds shall not be drained during the spring season. Safety Features Both the safety bench and the aquatic bench must be landscaped to discourage access to the deep pool. The vegetation must be established before pond is rendered in-service. The principal spillway opening shall not permit access by small children and shall be protected with some form of grating (pipe, rebar, etc.) having a maximum opening of 8 inches on center. End walls above pipe outfalls greater than 48 inches in diameter shall be fenced to prevent fall hazard. AQUATIC BENCH SAFETY BENCH 10' MIN, 15' AVG 10' MIN, 15' AVG PERMANENT EMERGENT — POOL — WEN VEGETATIOATION 6% MAX SLOPE 18' MAX 157 MAX SLOPE 3 1 MAX ; BASIN FLOOR Figure 6.5 Slope Diagram for Pond Benches Pond Buffer A vegetated buffer shall extend 25 ft outward from the maximum water surface elevation (Extreme Flood peak water surface elevation) of the pond or to the toe of the embankment, whichever is greater. The vegetated buffer shall be contiguous with other buffer areas that are required by existing regulations (e.g., stream buffers). Chapter 6:Standard Stormwater Management Practices •1 i 6.1.4.2 Sizing Criteria Provide water quality treatment storage to capture the computed WQv from the contributing area, through a combination of forebay (if applicable), permanent pool and extended detention (WQv-ED), as outlined in Table 6.4. The volume of the permanent pool cannot be applied as available detention (dry storage). CPv storage must be provided above the permanent pool. WQv cannot be met by simply providing CPS storage, as a percentage of the WQv must always be provided within the permanent pool. %W Qv Design Variation Permanent Pool Extended Detention P-1 20% min. 80% max. P-2 100% 0% P-3 50% min. 50% max. P-4 50% min. 50% max. A minimum flow path of 1.5:1 (i.e. length to relative width) shall be provided from the inflow points to the outflow points across the stormwater pond. If a forebay is used for pretreatment, the forebay shall be included in this ratio. Provide a minimum pond surface area to contributing area ratio of 1:100. Design P-1 micropool shall be 4 to 6 ft depth. Designs P-2, P-3, and P-4 shall have a permanent pool with a minimum depth of 3 ft and a maximum depth of 8 ft. A preferred depth of 4 to 6 ft is optimal for pond function. Multiple Pond Systems (P-4) shall be separated by constructed berms with overflow weirs between the cells. Equalizer pipes between the cells are not allowed. Water Balance Analysis If the minimum contributing area to a pond cannot be achieved, then a water balance analysis shall be performed, using the following equation, to calculate the required minimum depth of the permanent pool to prevent a nuisance condition. The water balance ensures that there is sufficient inflow to the pond to compensate for infiltration and evapotranspiration losses during a 30-day summer drought, without causing unacceptable drawdown in the permanent pool depth. DP > ET+INF+RES Where: DP = minimum depth of permanent pool (inches) ET= summer evapotranspiration rate (5 inches) INF = monthly infiltration loss (10.1 inches per Impermeable Liner Design Specifications) RES =water reservoir for factor of safety (P-1=48 inches min; P-2, P-3 and P-4=36 inches min) Chapter 6:Standard Stormwater Management Practices 612 6.1.5 Landscaping For planting guidance for stormwater management facilities, refer to Chapter 11. Permanent vegetative cover shall achieve 80% uniform density established over the entire contributing pervious area, before runoff is directed into the facility. A landscaping plan for a stormwater pond and its buffer shall be prepared to indicate how the hydrologic zones will be stabilized and established with vegetation and show the selection and layout of corresponding plant species. Safety benches and slopes of the pond must be established with vegetation before the pond is rendered in- service. It is required to excavate large and deep holes around the proposed planting sites and backfill these with uncompacted topsoil. Planting holes shall be three times deeper and wider than the diameter of the rootball (of balled and burlap stock), and five times deeper and wider for container grown stock. Woody vegetation shall not be planted or allowed to grow within 15 ft of the toe of any berm or slope and 25 ft from the principal spillway structure. Chapter 6:Standard Stormwater Management Practices 6-13 Fact Sheet: Micropool Extended Detention Pond (P-1) Description: A variation of a wet extended detention pond, where only a small micropool is maintained at the outlet of the pond. The micropool prevents resuspension of previously settled sediments and prevents clogging of the low flow orifice. (Photo Source: Ohio EPA) PERFORMANCE CRITERIA STORMWATER MANAGEMENT SUITABILITY FEASIBILITY • Water Quality Shall not be located within jurisdictional waters, including wetlands O Channel Protection Unless a slope stability analysis is performed, shall not be located in O Overbank Flood Protection areas with natural slopes greater than 15% 0 Extreme Flood Protection Underlying soils shall have an infiltration rate less than or equal to 0.014 inch/hr, unless an impermeable liner is provided • Runoff Reduction Minimum contributing area is 10 acres. Minimum contributing area can be O Treatment of Hotspots reduced to 5 acres if a water balance calculation is performed Size outlet structure to detain WQv for 24 hrs (12 hrs to trout waters) 0 Linear Applications CONVEYANCE ✓suitable for this practice Inlet points shall be stabilized to ensure non-erosive conditions IMPLEMENTATION CONSIDERATIONS Inlet pipe slope >_0.5% (1%for pipes smallerthan 12 inches diameter) ® Capital Cost A controlled outlet structure shall be provided ® Maintenance Burden An emergency spillway shall be provided PRETREATMENT Safety Risk Minimum 10%WQv shall be provided at each inlet point V/ Landscaping 100%of WQv for stormwater runoff from designated hotspots shall be L= Low M = Moderate H =High provided in pretreatment in sole source aquifers NA= Not Applicable TREATMENT POLLUTANT REMOVAL(See Table 10.3) 1 ft min. freeboard O Phosphorus i 3:1 max. side slope in safety(where required)and aquatic bench O Nitrogen 0 Min. 12 ft wide maintenance access is required at a max. 15%slope Metals Provide a mechanism that can completely drain the pond in 24 hrs Min. flow path of 1.5:1 (length to relative width)from all inlet points to the O Pathogens outflow points across the pond O Total Suspended Solids Min. pond surface area to contributing area ratio of 1:100 G=Good F= Fair P= Poor Micropool shall be 4 ft min.to 6 ft max. depth Permanent pool shall be sized for 20% min. WQv RUNOFF REDUCTION CREDIT Extended detention shall be sized for 80% max. WQv 0% RRv provided Chapter 6:Standard Stormwater Management Practices Fact Sheet: Wet Pond (P-2) Description: A stormwater basin constructed of a permanent pool of water having a storage volume equal to the water quality volume. Stormwater runoff displaces the water already resent in the pool. ;•. � p Y p PERFORMANCE CRITERIA STORMWATER MANAGEMENT SUITABILITY FEASIBILITY O Water Quality Shall not be located within jurisdictional waters, including wetlands O Channel Protection Unless a slope stability analysis is performed, shall not be located in ® Overbank Flood Protection areas with natural slopes greater than 15% Extreme Flood Protection Underlying soils shall have an infiltration rate less than or equal to 0.014 inch/hr, unless an impermeable liner is provided • Runoff Reduction Minimum contributing area is 25 acres. Minimum contributing area can be 0 Treatment of Hotspots reduced to 10 acres if a water balance calculation is performed Size outlet structure to detain WQv for 24 hrs (12 hrs to trout waters) 0 Linear Applications CONVEYANCE ✓suitable for this practice Inlet points shall be stabilized to ensure non-erosive conditions IMPLEMENTATION CONSIDERATIONS Inlet pipe slope >_0.5% (1%for pipes smaller than 12 inches diameter) ® Capital Cost A controlled outlet structure shall be provided Maintenance Burden An emergency spillway shall be provided PRETREATMENT Safety Risk Minimum 10%WQv shall be provided at each inlet point © Landscaping 100%of WQv for stormwater runoff from designated hotspots shall be L= Low M = Moderate H =High provided in pretreatment in sole source aquifers NA= Not Applicable TREATMENT POLLUTANT REMOVAL(See Table 10.3) 1 ft min. freeboard 10 Phosphorus * 3:1 max. side slope in safety(where required)and aquatic bench ® Nitrogen Min. 12 ft wide maintenance access is required at a max. 15%slope O Metals Provide a mechanism that can completely drain the pond in 24 hrs Min. flow path of 1.5:1 (length to relative width)from all inlet points to the ® Pathogens outflow points across the pond O Total Suspended Solids Min. pond surface area to contributing area ratio of 1:100 G=Good F= Fair P= Poor Micropool shall be 3 ft min.to 8 ft max. depth Permanent pool shall be sized for 100%WQv RUNOFF REDUCTION CREDIT Extended detention shall be sized for 0%WQv 0% RRv provided Chapter 6:Standard Stormwater Management Practices Fact Sheet: Wet Extended Detention Pond (P-3) Description: A wet pond where the water quality volume is split evenly between the permanent pool and extended detention storage above the permanent pool. Za (Photo Source: Blaine, Minnesota Water Resources Division) /y PERFORMANCE CRITERIA STORMWATER MANAGEMENT SUITABILITY FEASIBILITY to Water Quality Shall not be located within jurisdictional waters, including wetlands Channel Protection Unless a slope stability analysis is performed, shall not be located in ® Overbank Flood Protection areas with natural slopes greater than 15% O Extreme Flood Protection Underlying soils shall have an infiltration rate less than or equal to 0.014 inch/hr, unless an impermeable liner is provided ® Runoff Reduction Minimum contributing area is 25 acres. Minimum contributing area can be O Treatment of Hotspots reduced to 10 acres if a water balance calculation is performed Size outlet structure to detain WQv for 24 hrs (12 hrs to trout waters) Linear Applications CONVEYANCE ✓suitable for this practice Inlet points shall be stabilized to ensure non-erosive conditions IMPLEMENTATION CONSIDERATIONS Inlet pipe slope >_0.5% (1%for pipes smaller than 12 inches diameter) Capital Cost A controlled outlet structure shall be provided ® Maintenance Burden An emergency spillway shall be provided PRETREATMENT Safety Risk Minimum 10%WQv shall be provided at each inlet point ® Landscaping 100%of WQv for stormwater runoff from designated hotspots shall be L= Low M = Moderate H =High provided in pretreatment in sole source aquifers NA= Not Applicable TREATMENT POLLUTANT REMOVAL(See Table 10.3) 1 ft min. freeboard 10 Phosphorus • 3:1 max. side slope in safety(where required)and aquatic bench O Nitrogen Min. 12 ft wide maintenance access is required at a max. 15%slope O Metals Provide a mechanism that can completely drain the pond in 24 hrs Min. flow path of 1.5:1 (length to relative width)from all inlet points to the ® Pathogens outflow points across the pond O Total Suspended Solids • Min. pond surface area to contributing area ratio of 1:100 G=Good F= Fair P= Poor Micropool shall be 3 ft min.to 8 ft max. depth Permanent pool shall be sized for 50% min. WQv RUNOFF REDUCTION CREDIT Extended detention shall be sized for 50% max. WQv 0% RRv provided Chapter 6:Standard Stormwater Management Practices Fact Sheet: Multiple Pond System (P-4) Description: Consist of constructed facilities that provide water quality and quantity volume storage in two or more cells. The multiple cells create high surface area to volume ratios, complex microtopography, longer pollutant - removal pathways, and improved downstream protection. (Photo Source: Monroe County, New York) a PERFORMANCE CRITERIA STORMWATER MANAGEMENT SUITABILITY FEASIBILITY Water Quality Shall not be located within jurisdictional waters, including wetlands ® Channel Protection Unless a slope stability analysis is performed, shall not be located in Overbank Flood Protection areas with natural slopes greater than 15% Extreme Flood Protection Underlying soils shall have an infiltration rate less than or equal to 0.014 inch/hr, unless an impermeable liner is provided ® Runoff Reduction Minimum contributing area is 25 acres. Minimum contributing area can be O Treatment of Hotspots reduced to 10 acres if a water balance calculation is performed Size outlet structure to detain WQv for 24 hrs (12 hrs to trout waters) 0 Linear Applications CONVEYANCE ✓suitable for this practice Inlet points shall be stabilized to ensure non-erosive conditions IMPLEMENTATION CONSIDERATIONS Inlet pipe slope >_0.5% (1%for pipes smaller than 12 inches diameter) Capital Cost A controlled outlet structure shall be provided © Maintenance Burden An emergency spillway shall be provided PRETREATMENT Safety Risk Minimum 10%WQv shall be provided at each inlet point ® Landscaping 100%of WQv for stormwater runoff from designated hotspots shall be L= Low M = Moderate H =High provided in pretreatment in sole source aquifers NA= Not Applicable TREATMENT POLLUTANT REMOVAL(See Table 10.3) 1 ft min. freeboard O Phosphorus 3:1 max. side slope in safety(where required)and aquatic bench O Nitrogen Min. 12 ft wide maintenance access is required at a max. 15%slope Metals Provide a mechanism that can completely drain the pond in 24 hrs Min. flow path of 1.5:1 (length to relative width)from all inlet points to the ® Pathogens outflow points across the pond O Total Suspended Solids Min. pond surface area to contributing area ratio of 1:100 G=Good F= Fair P= Poor Micropool shall be 3 ft min.to 8 ft max. depth Permanent pool shall be sized for 50% min. WQv RUNOFF REDUCTION CREDIT Extended detention shall be sized for 50% max. WQv 0% RRv provided Chapter 6:Standard Stormwater Management Practices Section 6.2 Stormwater Wetlands Stormwater wetlands are practices that create shallow marsh areas to treat urban stormwater and often incorporate small permanent pools and/or extended detention storage to achieve the full WQv. Design variants include: W-1 Shallow Wetland (Figure 6.6) W-2 ED Shallow Wetland (Figure 6.7) W-3 Pond/Wetland System (Figure 6.8) W-4 Pocket Wetland (Figure 6.9) W-5 Gravel Wetland (Figure 6.10) Refer to the Fact Sheets at the end of this section for key considerations of each wetland design variant, including performance criteria, practice suitability, implementation considerations, pollutant removal capability, and runoff reduction credit. IMPORTANT NOTES: 1. ANY PRACTICE THAT CREATES A DAM IS REQUIRED TO FOLLOW THE GUIDANCE PRESENTED IN THE GUIDELINES FOR DESIGN OF DAMS (APPENDIX A)AND MAY REQUIRE A PERMIT FROM THE NYSDEC. FOR THE MOST RECENT COPY OF THIS DOCUMENT, CONTACT THE NEW YORK STATE DEPARTMENT OF ENVIRONMENTAL CONSERVATION, DAM SAFETY SECTION. AN EVALUATION OF HAZARD CLASSIFICATION MUST BE INCLUDED IN THE DESIGN REPORT FOR STORMWATER WETLANDS CREATED BY A DAM. 2. STORMWATER WETLANDS DESIGNED ACCORDING TO THIS MANUAL MAY ACT AS A COMMUNITY AMMENITY, AND MAY PROVIDE SOME LEVEL OF HABITAT VALUE. HOWEVER, THEY CANNOT BE ANTICIPATED TO FUNCTION AS NATURAL WETLANDS. TO ENSURE LONG-TERM FUNCTION AS INTENDED, THEY MUST BE PROPERLY MAINTAINED. Chapter 6:Standard Stormwater Management Practices 6-18 Shallow Wetland (W-1) A shallow wetland is intended for water quality treatment only, and provides the majority of the treatment volume within a combination of high and low marsh areas. The only deep portions of the design are the forebay at the inlet and a small micropool at the outlet. Shallow wetlands cannot be used for extended detention, so the outlet structure should be simplified. To meet quantity control requirements, this design variant can be installed parallel to a dry detention basin or another detention practice. STABILIZED OVERFLOW WEIR 00'��_�`� ��#0 PRETREATMENT %%% FOREBAY • • LOW MARSH .~ •MIN 30% SURFACE AREA HIGH MARSH ' x MIN 357 SURFACE AREA X r • * 11 25' VEGETATED BUFFER `♦ 7 1 .q4� ` STABILIZED {l INLET S♦ r t` r j INLET PIPE +4%6 MICROPOOL i STABILIZED 1. EMERGENCY l' OVERFLOW d • I MAINTENANCE ACCESS -,UILLI CONTROL STRUCTURE OUTLET PIPE PLAN VIEW STABILIZED OUTLET TOP OF EMBANKMENT TOP OF BEYOND 1' MIN EMBANKMENT PRETREATMENT Si FREEBOARD EMERGENCY FOREBRY OWEIR MICROPObL OVERFLOW _ POOL BEYOND - WQv)- d' 6" A ----- ---- 34' MIN 1 MAxHIGH MAR _ - - = TRASH 5TABELIZED DEPTHRACKINLET SLOPE: OUTLET CONTROL STABILIZED IMPERMEABLE LINER LOW MARSH (TYP) STRUCTURE OUTLET (AS REQUIRED) DEPTH: V-18" SLOPE: 5:1 MAX SECTION VIEW Figure 6.6 Shallow Wetland (W-1) Chapter 6:Standard Stormwater Management Practices 6-19 Extended Detention Shallow Wetland (W-2) The extended detention shallow wetland design is similar to the shallow wetland, except that part of the water quality treatment volume is provided as extended detention above the surface of the marsh and released over a period of 24-hrs. An outlet structure is used to create the pool and a small orifice is placed in the outlet structure above the bottom of the wetland to create a shallow permanent pool. Storm events that are greater than the design volume can be released through the top of the outlet structure and/or through an emergency spillway channel. 25' VEGETATED STABILIZED BUFFER STABILIZED EMERGENGY OUTLET SAFETY BENCH OVERFLOW OUTLET PIPE (AS REQUIRED) k—r--- --------------- COMPACTED j EARTH BERM 1 -------- OUTLET 1 r J. 7 1 / r y F.r 1 CONTROL 1 r •--- -----y s- <' r' 1 STRUCTURE MICROROQL 1 I I I h I I .'•.y'�.•r✓• 1 ~_ 1 _ 1 1 HIGH MARSH MIN 35% 1 SURFACE t • f a 1 AREA i d d 1 LOW MARSH 1 I I ! 1 MIN 30% V d PRETREATMENT 1 ! rl }r j SURFACE FOREBAY r AREA STABILIZEDINLET r I z r INLET PIPE 4 `-.__—_ - 1 �`ar�rssr"rrrr rrrriwrrrrr�rr� •, MAINTENANCE STABILIZED STABILIZED ACCESS OVERFLOW WEIR OVERFLOW WEIR V MIN FREEBOARD TOP OF EMBANKMENT PLAN VIEW TOP OF BEYOND EXTREME FLOOD CONTROL PERM. POOL EMBANKMENT PRETREATMENT OVERBANK FLOOD CONTROL (50% MIN WOv) EMERGENCY FOREBAY CHANNEL PROTECTION MICROPOOL OVERFLOW -- -- -- - - - ------ BEYOND f7l 3 4'-6'1 MA 4' MIN 1 MAX LOW MARSH (TYP) TRASH STABILIZED DEPTH: 6"-18" RACK INLET SLOPE: 5:t MAX OUTLET CONTROL IMPERMEABLE STRUCTURE LINER HIGH MARSH (TYP) STABILIZED (AS REQUIRED) DEPTH: 6" MAX OUTLET SLOPE: 5:1 MAX SECTION'VIEW Figure 6.7 Extended Detention Shallow Wetland (W-2) Chapter 6:Standard Stormwater Management Practices 6-20 Pond/Wetland System (W-3) The pond/wetland system has two separate cells: a wet pond and a shallow marsh. The wet pond traps sediment and reduces runoff velocities prior to entering the wetland. An outlet structure is used to create the pool and a small orifice is placed in the outlet structure above the bottom of the wetland to create a shallow permanent pool. Storm events that are greater than the design volume can be released through the top of the outlet structure and/or through an emergency spillway channel. STABILIZED EMERGENCY OVERFLOW STABILIZED OUTLET - 25' VEGETATED BUFFER OUTLET PIPE EXTENDED DETENTION OUTLET CONTROL SHALLOW WETLAND STRUCTURE WET EXTENDED MAINTENANCE SAFETY BENCH MICROPOOL DETENTION ACCESS (AS REOUiRED) POND AQUATIC f BENCH 1f. J, PRETREATMEN FOREBAY STABILIZED OVERFLOW COMPACTED LOW MARSH HIGH MARSH STABILIZED WEIR (TYP) EARTH BERM MIN 30% MIN 35% INLET PLAN VIEW SURFACE AREA SURFACE AREA INLET PIPE TOP OF EMBANKMENT BEYOND (TYP) PRETREATMENT STABILIZED OVERFLOW FOREBAY WEIR (TYP) EXTREME FLOOD CONTROL 1' MIN TOP OVERBANK FLOOD CONTROL FREEBOARD EMBANKMENT CHANNEL PROTECTION EMERGENCY POND _ PERM. POOL (50% MIN WOV M-ICROPOOL OVERFLOW -- -- ---- -� ----- -- ----- ---_ - BEYOND ------ --------_ _ _ _ _ -___---_ _ c - 1 MA 4' MIN 1 MAX 4 MIN 1MA IMPERMEABLE LOW MARSH (TYP) LINER DEPTH: 6'-18" (AS REQUIRED) SLOPE: 5:1 MAX 4'-6' HIGH MARSH (TYP) TRASH RACK STABILIZED DEPTH: 6' MAX OUTLET CONTROL INLET SLOPE: 5:1 MAX STRUCTURE STABILIZED OUTLET SECTION VIEW Figure 6.8 Pond/Wetland System (W-3) Chapter 6:Standard Stormwater Management Practices 6-21 Pocket Wetland (W-4) The pocket wetland requires excavation down to the water table for a reliable water source to support the wetland system. They cannot be used for extended detention, so the outlet structure should be simplified to meet water quality objectives. To meet quantity control requirements, they can be installed parallel to dry detention basins or another detention practice. STABILIZED .��'~� "' STABILIZED EMERGENCY OUTLET OVERFLOW 6 +� MICROPOOL I 'r� HIGH MARSH MIN 35% SURFACE AREA �. f `*■i COMPACTED y .` `'� ♦ EARTH BERM t LOW MARSH \ . ; s MIN 307 SURFACE AREA 3 ■� �� �t STABILIZED OVERFLOW WEIR OUTLET CONTROL �■ STRUCTURE OUTLET PIPE \' \ -� '- "■ 5' VEGETATED BUFFER ■ MAINTENANCE ACCESS �� ��'• STABILIZED \ �'� �� FOREBAY INLET �•' INLET PIPE • } PLAN VIEW TOP OF TOP OF STABILIZED EMBANKMENT EMBANKMENT OVERFLOW WEIR EMERGENCY BEYOND PERM. POOL 1' MIN OVERFLOW BEYOND PRETREATMENT [100% WOV} FREEBOARD FOREBAY ,,t MICROPOOL 11iAA TRASH RACK _.._...-. DEPTH: 6" MAX - - OUTLET CONTROL STRUCTURE STABILIZED SLOPE: 5.1 MAX F"' INLET HIGH MARSH (TYP) BOTTOM OF PRACTICE SET !—STABILIZED LOW MARSH (TYP) AT OR BELOW SEASONAL OUTLET IMPERMEABLE LINER DEPTH: 6°—18° AS REOUIRED HIGH WATER TABLE { ) SLOPE: 5:1 MAX SECTION VIEW Figure 6.9 Pocket Wetland (W-4) Chapter 6:Standard Stormwater Management Practices 6-22 Gravel Wetland (W-5) The gravel wetland system consists of one or more treatment cells that are filled with crushed rock or gravel and designed to allow stormwater to flow subsurface through the root zone of the constructed wetland, where pollutant removal takes place. This practice provides both aerobic and anaerobic treatment zones for enhanced pollutant removal. STABILIZED OUTLET EQUALIZER PIPE OUTLET & EMERGENCY 25' VEGETATED BUFFER OVERFLOW PIPE ���r� �������� OUTLET COMPACTED r CONTROL EARTH BERM STRUCTURE I ! CELL 1 ! r J ! CELL 2 ! I ! lI ai PERFORATED DISTRIBUTION 1t DRAIN (TYP) MAINTENANCE _ ACCESS PERFORATED RISER PIPE FILET PIPE COLLECTOR DRAIN PERFORATED RISER PIPE �� �►� STABILIZED INLET PRETREATMENT FOREBAY PLAIN VIEW EMERGENCY OVERFLOW 6" PVC/HDPE PERFORATED RISER OUTLET CONTROL PIPE STRUCTURE WITH LOCKABLE CAP AT ALL 6" PVC PERFORATED TEES EQUALIZER PIPE INVERT RISER PIPE WITH ELEV SET AT 50% OF WDv DESIGN STORM LOCKABLE COVER AT I ENDS OF DISTRIBUTION 2' MAX 100% WQv DRAINS FILTER MEDIA — 8- MIN DEPTH PEA GRAVEL 3" MIN DEPTH I 2' MIN NO, 2 STONE I I FILTER LAYER (WASHED, NO FINES) DISTRIBUTION $ DRAIN INVERT SET 2" ABOVE L— — ---- - BOTTOM OF STONE 6" MIN PVC HDPE 6" MIN. PVC COLLECTOR©RAIN PRIMARY OUTLET PIPE PERFORATED 15' MIN/3D' MAX INVERT SET 4- MIN ABOVE DISTRIBUTION LAID LEVEL SEPARATION STONE FILTER LAYER DRAIN LAID SECTION VIEW ON CENTER LEVEL Figure 6.10 Gravel Wetland (W-5) Chapter 6:Standard Stormwater Management Practices 6-23 6.2.1 Feasibility Stormwater wetlands shall not be located within existing jurisdictional wetlands. In some limited cases, a permit may be granted to convert an existing degraded wetland, in the context of local watershed restoration efforts. The designer shall contact the authority having jurisdiction for permitting requirements. Stormwater wetlands shall not be located on areas with natural slopes greater than 15%, unless a slope stability analysis is performed by a qualified geotechnical engineer. Stormwater wetlands (with the exception of W-5) shall not be used when discharging to trout waters. Designs W-1 and W-4 shall be designed for water quality only. All other storm events shall be diverted. Wetlands (with the exception of W-4) can be applied on sites with an underlying water supply aquifer or when treating a stormwater hotspot, if a minimum separation distance of 2 ft is provided between the bottom of the wetland and the elevation of the seasonal high water table. In addition, for design (W-5), an impermeable liner shall be provided between the bottom of gravel and seasonal high water table. The contributing area to stormwater wetlands shall meet the requirements listed in Table 6.5. 1 Table 6.5 Stormwater Wetland Contributing Area Requirements Design Variant Contributing Area Shallow Wetland (W-1) 25 acres minimum Extended Detention Shallow Wetland (W-2) 25 acres minimum Pond/Wetland System (W-3) 25 acres minimum Pocket Wetland (W-4) 5 acres minimum Gravel Wetland (W-5) 5 acres maximum Stormwater wetlands shall meet the minimum separation requirements listed in Table 6.6. Vertical separations shall be taken from the bottom of wetland. Horizontal separations shall be taken from the maximum water surface elevation (Extreme Flood peak water surface elevation) of the wetland. Vertical Separation Horizontal Separation Structures Structures Water Seasonal Septic Sanitary Design Variant High Water Sound Without With Supply System Sewer Table',2 Bedrock' Foundation Foundation Well/ 3,4 Main Waterproofing4 Waterproofing4 Reservoir Shallow Wetland (W-1) Extended Detention Shallow Wetland (W-2) Pond/Wetland O ft O ft 25 ft 25 ft 25 ft 50 ft 25 ft System(W-3) Pocket Wetland (W-4) Gravel Wetland (W-5) As documented by on-site geotechnical testing. 2 With the exception of W-4,separation shall be increased to 2 ft in sole source aquifers or when treating stormwater hotspots. 3 Septic systems are inclusive of septic tanks,distribution boxes,and absorption fields. 4 Wetlands shall be located downgradient of structures and septic systems. Chapter 6:Standard Stormwater Management Practices -24 6.2.2 Conveyance Inlet Protection Inlets shall be designed to ensure non-erosive conditions. Outlet Structure/Outfall Protection For Designs W-1, W-2, W-3, &W-4, a controlled outlet shall be provided for each wetland, using one of the following methods: An outlet structure located within the embankment, with a pipe invert set at the permanent pool elevation that extends downward to the structure; An outlet structure located within the embankment, with a submerged reverse-slope pipe that extends downward from the structure to an inflow invert set 1 ft minimum below the permanent pool elevation and 1 ft minimum above the bottom of the pond; An outlet structure located within the embankment, with an adequately sized downward elbow with an extension that extends 1 ft below the permanent pool elevation; An outlet structure located partially within the embankment, with outlet openings in the face of the structure; or Where a CPv control orifice is provided (See Section 4.6 for CPv requirements and waivers), one of the following methods shall be applied: Minimum 3 inch low flow orifice installed in an internal weir plate within the outlet structure with acceptable external trash rack or orifice protection (See Appendix C for details of a low flow orifice and trash rack options). Minimum 3 inch low flow external orifice installed in the face of the outlet structure (See Appendix C for details of a low flow orifice and trash rack options). Orifice protection shall be provided. An emergency spillway shall be provided to safely convey stormwater exceeding the Extreme Flood. A stilling basin, outlet protection, level spreader, or other energy dissipator shall be installed to reduce flow velocities from the spillway to non-erosive velocities. (See Appendix G for a table of erosive velocities for grass and soil). For Design W-5, the following outlet design criteria shall apply: The primary outlet invert shall be located 4 inches below the elevation of the wetland soil surface to maintain a subsurface water level. The primary outlet shall be open or vented to prevent siphoning. An outlet control structure shall be designed with a 3 inch minimum orifice (with acceptable internal orifice protection) to drain the WQv in a minimum of 24 hrs and a maximum of 48 hrs. A maintenance outlet shall be installed at the bottom of stone elevation to completely drain the wetland within 48 hours. This outlet shall remain plugged during regular operation. 6.2.3 Pretreatment For each stormwater wetland, pretreatment equaling a minimum of 10% of the WQv shall be provided at each wetland inflow point, unless an inflow point provides less than 10% of the total design storm flow to the wetland. The forebay storage volume counts toward the total WQv requirement. In sole source aquifers, pretreatment equivalent to 100% of the WQv shall be provided for runoff from designated stormwater hotspots. The forebay storage volume does not count toward the total WQv requirement. Pretreatment shall be achieved with a sediment forebay, or an equivalent upstream pretreatment device. When a sediment forebay is applied, it shall meet the following design criteria: Shall consist of a separate cell, formed by an acceptable earthen or structural barrier. Berms and weirs separating the forebay and treatment cells shall be constructed with native or imported clay or very low hydraulic conductivity soils. Depth: 4 to 6 ft. Outlet designed to ensure non-erosive flows into the pond. Chapter 6:Standard Stormwater Management Practices _2 Optional: a fixed vertical sediment depth marker should be installed in the forebay to measure sediment deposition overtime. Optional: the bottom of the forebay may be hardened using concrete, asphalt, paver blocks, or grouted riprap, to ease sediment removal. Chapter 6:Standard Stormwater Management Practices 6-26 6.2.4 Treatment 6.2.4.1 Design Criteria A Table 6.7 Stormwater Wetland Design Specifications W-1 W-2 W-3 W-4 W-5 Freeboard' Depth 1 ft min. measured from design storm elevation to top of embankment Design Storm WQv Extreme Flood WQv Extreme Flood Applicability N/A N/A N/A N/A Required Filter Media Depth 8 inch min. Material NYSDOT Standard Specification 713-01 Topsoil-Wetland Applicability N/A N/A N/A N/A Required Pea Gravel Depth 3 inch min. Material ASTM D448 No. 6 Stone, Porosity=32% Applicability N/A N/A N/A N/A Required Filter Course Depth 24 inch min. Material No. 2 stone, washed, no fines Applicability N/A N/A N/A N/A Required Drainage Course Depth 3 inch min. below distribution drain Material AASHTO No. 57 stone, washed, no fines Applicability As required, for>_3:1 (h:v)side slopes above permanent pool N/A Safety Bench Width 10 ft min., 15 ft average measured outward from the normal water edge Slope 6% max. Applicability N/A N/A N/A N/A Required Equalizer Pipe Material 12" min. solid PVC/HDPE laid level Depth Inlet set at 50%of WQv Storage Applicability N/A N/A N/A N/A Required Distribution Drain Material 6 inch perforated PVC/HDPE laid level Spacing 15—30 ft Depth 2 inch above bottom of stone layer Applicability N/A N/A N/A N/A Required Riser Material 6 inch perforated PVC/HDPE with inlet grate at the end of each distribution drain Spacing 15 ft min. Depth 6 inch-24 inch above soil surface Applicability As Required, see Section 6.2.4.1 Impermeable Liner 12-24 inch of clay soil (min. 50% passing#200 sieve and max. permeability 1 x 10-5 Material cm/sec) or 40 mil HDPE geomembrane Slope 15% max. Maintenance Access' Width 12 ft min. Material Able to withstand loading of maintenance equipment and vehicles Footnotes: 'Required for all Design Variants. Chapter 6:Standard Stormwater Management Practices -27 Impermeable Liner When a stormwater wetland is located in areas listed below, an impermeable liner shall be required. Underlying soils have an infiltration rate greater than 0.014 inch/hr, (Appendix D); or Geotechnical testing is not performed; or Underlying soils consist of gravel or fractured bedrock. When required, the impermeable liner shall be installed for the entire wetted perimeter and extend a minimum of 12 inches above the permanent pool elevation. This shall apply to all treatment cells and include the berms and weirs. Maintenance Access A maintenance access easement shall extend to the practices from a public or private road. Adequate maintenance access must extend to the forebay, safety bench (where required), outlet structure/overflow, emergency spillway and must have sufficient area to allow vehicles to turn around. Where applicable, access to the outlet structure shall be provided by lockable manhole cover or grate. Pond Buffer A vegetated buffer shall extend 25 ft outward from the maximum water surface elevation (Extreme Flood peak water surface elevation) of the wetland. The vegetated buffer shall be contiguous with other buffer areas that are required by existing regulations (e.g., stream buffers). 6.2.4.2 Sizing Criteria Design Variants W-1,W-2,W-3, and W-4 The surface area of the entire stormwater wetland shall be at least 1% of the contributing area (1.5% for design W-1). A minimum flow path ratio of 2:1 (length to relative width) shall be provided from the inflow point(s) to the outflow point(s) across the stormwater wetland. This path may be achieved by constructing microtopography using internal berms (e.g., high marsh wedges or rock filter cells). If a forebay is used for pretreatment, the forebay shall be included in this ratio. Stormwater wetlands shall meet the geometric requirements listed in Table 6.8: JL Table 6.8 Stormwater Wetland Geometry Requirements Wetland Zone Depth Side %Surface %WQv Storage Slope Area Forebay' 4 ft-6 ft 3:1 max. - 10% min. High Marsh 6 inches max. 5:1 max. 35% min. - below permanent pool Low Marsh 6-18 inches 5:1 max. 30% min. - below permanent pool Micropool' 4 ft min. 3:1 max. - 10% min. Pond (Design W-3) 4 ft min. 3:1 max. - 25% min. Extended Detention (W-2& 3 ft max. above 50% max. (not including W-3, if required) permanent pool 3:1 max. - permanent pool) 'For design W-1, W-2&W-4, the cumulative WQv storage within the forebay and micropool shall be at least 25%. The micropool shall be provided and located at the practice outlet to protect the low flow pipe from clogging and prevent sediment resuspension. Chapter 6:Standard Stormwater Management Practices -28 To promote greater nitrogen removal, rock beds may be used as a medium for growth of wetland plants. The rock shall be 1 to 3 inches in diameter, placed up to the permanent pool elevation, and open to flow-through from either direction. Design Variant W-5 A minimum of one treatment cell shall be provided. The practice shall provide WQv storage, with 10% in the forebay and 90% above the treatment cell. When discharging to trout waters, a minimum of two treatment cells shall be provided. The practice shall provide WQv storage, with 10% in the forebay, and the remaining WQv equally divided above each treatment cell. Where multiple treatment cells are provided, they shall be separated by an acceptable earthen or structural barrier connected with an equalizer pipe or a stabilized overflow weir. Berms and weirs separating the treatment cells shall be constructed with native or imported clay or very low hydraulic conductivity soils. A minimum flow path ratio of 2:1 (length to relative width) shall be provided from the inflow point(s)to the outflow point within each treatment cell and the minimum flow path length shall be 15 ft. 6.2.5 Landscaping For planting guidance for stormwater management facilities, refer to Chapter 11. Permanent vegetative cover shall achieve 80% uniform density established over the entire contributing pervious area, before runoff is directed into the facility. A landscaping plan for a stormwater wetland and its buffer shall be prepared to indicate how the hydrologic zones will be stabilized and established with vegetation and show the selection and layout of corresponding plant species. Chapter 6:Standard Stormwater Management Practices 6-29 Fact Sheet: Shallow Wetland (W-1) Description: A shallow wetland is intended for water quality treatment only, " and provides the majority of the treatment volume within a combination of high and low marsh areas. The only deep portions of the design are the forebay at the inlet and a small micropool at the outlet. Shallow wetlands cannot be used for extended detention, so the outlet structure should be simplified. To meet quantity control requirements, this design variant can be installed parallel to a dry detention basin or another detention practice. g (Photo Source: City of Redmond, Washington) PERFORMANCE CRITERIA STORMWATER MANAGEMENT SUITABILITY FEASIBILITY O Water Quality Shall not be located within jurisdictional wetlands 40 Channel Protection Unless a slope stability analysis is performed, wetlands shall not be ® Overbank Flood Protection located on areas with natural slopes greater than 15% 40 Extreme Flood Protection Shall not be used when discharging to trout waters In hotspots or an underlying water supply aquifer, a min separation of 2 ft • Runoff Reduction shall be provided between the bottom of the wetlands and the seasonal 0 Treatment of Hotspots high water table Min contributing area is 25 acres is Linear Applications CONVEYANCE ✓suitable for this practice Inlets shall have non-erosive conditions IMPLEMENTATION CONSIDERATIONS A controlled outlet shall be provided ® Capital Cost The outlet structure shall be located within the embankment Maintenance Burden An emergency spillway shall be provided with an energy dissipator installed to reduce flow velocities © Safety Risk PRETREATMENT © Landscaping 10%WQv pretreatment shall be provided for each wetland inflow point L= Low M = Moderate H =High In sole source aquifers, 100%WQv pretreatment shall be provided for NA= Not Applicable runoff from hotspots POLLUTANT REMOVAL(See Table 10.3) Pretreatment shall be achieved with a sediment forebay, or equivalent ® Phosphorus upstream pretreatment device TREATMENT ® Nitrogen Surface area of the entire wetland shall be at least 1.5%of the O Metals contributing area Pathogens Min flow path ratio of 2:1 (length to relative width)from inflow point(s)to the outflow point(s) ® Total Suspended Solids Micropool shall be provided and located at the practice outlet G=Good F= Fair P= Poor Min 12 inches of freeboard shall be provided, measured from the WQv RUNOFF REDUCTION CREDIT elevation to the top of embankment 0% RRv provided Chapter 6:Standard Stormwater Management Practices Fact Sheet: Extended Detention Shallow Wetland (W-2) Description: Similar to the shallow wetland in design however, part of the water quality treatment volume is provided as extended detention above the surface of the marsh and released over a period of 24-hrs. An outlet n structure is used to create the pool and a small orifice is placed in the outlet structure above the bottom of the wetland to create a shallow permanent Aft pool. (Photo Source: Minnesota Pollution Control Agency) • • • PERFORMANCE CRITERIA STORMWATER MANAGEMENT SUITABILITY FEASIBILITY O Water Quality Shall not be located within jurisdictional wetlands O Channel Protection Unless a slope stability analysis is performed, wetlands shall not be ® Overbank Flood Protection located on areas with natural slopes greater than 15% Extreme Flood Protection Shall not be used when discharging to trout waters In hotspots or an underlying water supply aquifer, a min separation of 2 ft • Runoff Reduction shall be provided between the bottom of the wetlands and the seasonal 0 Treatment of Hotspots high water table Min contributing area is 25 acres 0 Linear Applications CONVEYANCE ✓suitable for this practice Inlets shall have non-erosive conditions IMPLEMENTATION CONSIDERATIONS A controlled outlet shall be provided ® Capital Cost The outlet structure shall be located within the embankment Maintenance Burden An emergency spillway shall be provided with an energy dissipator installed to reduce flow velocities © Safety Risk PRETREATMENT © Landscaping 10%WQv pretreatment shall be provided for each wetland inflow point L= Low M = Moderate H =High In sole source aquifers, 100%WQv pretreatment shall be provided for NA= Not Applicable runoff from hotspots POLLUTANT REMOVAL(See Table 10.3) Pretreatment shall be achieved with a sediment forebay, or equivalent upstream pretreatment device ® Phosphorus TREATMENT ® Nitrogen Surface area of the entire wetland shall be at least 1%of the contributing ® Metals area Min flow path ratio of 2:1 (length to relative width)from inflow point(s)to ® Pathogens the outflow point(s) O Total Suspended Solids Micropool shall be provided and located at the practice outlet G=Good F= Fair P= Poor Min 12 inches of freeboard shall be provided, measured from the Extreme Flood elevation to the top of embankment RUNOFF REDUCTION CREDIT 0% RRv provided Chapter 6:Standard Stormwater Management Practices Fact Sheet: Pond/Wetland System (W-3) Description: Practice with two separate cells: a wet pond and a shallow marsh. The wet pond traps sediment and reduces runoff velocities prior to entering the wetland. An outlet structure is used to create the pool and a small orifice is placed in the outlet structure above the bottom of the wetland to create a shallow permanent pool. q. PERFORMANCE CRITERIA STORMWATER MANAGEMENT SUITABILITY FEASIBILITY to Water Quality Shall not be located within jurisdictional wetlands O Channel Protection Unless a slope stability analysis is performed, wetlands shall not be ® Overbank Flood Protection located on areas with natural slopes greater than 15% Extreme Flood Protection Shall not be used when discharging to trout waters In hotspots or an underlying water supply aquifer, a min separation of 2 ft , Runoff Reduction shall be provided between the bottom of the wetlands and the seasonal ® Treatment of Hotspots high water table Min contributing area is 5 acres 0 Linear Applications CONVEYANCE ✓suitable for this practice Inlets shall have non-erosive conditions IMPLEMENTATION CONSIDERATIONS A controlled outlet shall be provided ® Capital Cost The outlet structure shall be located within the embankment Maintenance Burden An emergency spillway shall be provided with an energy dissipator installed to reduce flow velocities © Safety Risk PRETREATMENT © Landscaping 10%WQv pretreatment shall be provided for each wetland inflow point L= Low M = Moderate H =High In sole source aquifers, 100%WQv pretreatment shall be provided for NA= Not Applicable runoff from hotspots POLLUTANT REMOVAL(See Table 10.3) Pretreatment shall be achieved with a sediment forebay, or equivalent upstream pretreatment device ® Phosphorus TREATMENT ® Nitrogen Surface area of the entire wetland shall be at least 1%of the contributing ® Metals area Min flow path ratio of 2:1 (length to relative width)from inflow point(s)to ® Pathogens the outflow point(s) O Total Suspended Solids Micropool shall be provided and located at the practice outlet G=Good F= Fair P= Poor Min 12 inches of freeboard shall be provided, measured from the Extreme Flood elevation to the top of embankment RUNOFF REDUCTION CREDIT 0% RRv provided Chapter 6:Standard Stormwater Management Practices Fact Sheet: Pocket Wetland (W-4) Description: Requires excavation down to the water table for a reliable water source to support the wetland system. 4' (Photo Source: British Columbia Wildlife Federation) • •r4nlrk PERFORMANCE CRITERIA STORMWATER MANAGEMENT SUITABILITY FEASIBILITY O Water Quality Shall not be located within jurisdictional wetlands Channel Protection Unless a slope stability analysis is performed, wetlands shall not be ® Overbank Flood Protection located on areas with natural slopes greater than 15% Extreme Flood Protection Shall not be used when discharging to trout waters Min contributing area=25 acre • Runoff Reduction CONVEYANCE • Treatment of Hotspots Inlets shall have non-erosive conditions 0 Linear Applications A controlled outlet shall be provided ✓suitable for this practice The outlet structure shall be located within the embankment IMPLEMENTATION CONSIDERATIONS An emergency spillway shall be provided with an energy dissipator installed to reduce flow velocities Capital Cost PRETREATMENT Maintenance Burden 10%WQv pretreatment shall be provided for each wetland inflow point © Safety Risk In sole source aquifers, 100%WQv pretreatment shall be provided for © Landscaping runoff from hotspots Pretreatment shall be achieved with a sediment forebay, or equivalent L= Low M = Moderate H =High upstream pretreatment device NA= Not Applicable TREATMENT POLLUTANT REMOVAL(See Table 10.3) Surface area of the entire wetland shall be at least 1%of the contributing ® Phosphorus area Min flow path ratio of 2:1 (length to relative width)from inflow point(s)to ® Nitrogen the outflow point(s) ® Metals Micropool shall be provided and located at the practice outlet Pathogens Min 12 inches of freeboard shall be provided, measured from the WQv elevation to the top of embankment O Total Suspended Solids G=Good F= Fair P= Poor RUNOFF REDUCTION CREDIT 0% RRv provided Chapter 6:Standard Stormwater Management Practices Fact Sheet: Gravel Wetland (W-5) Description: Consists of one or more treatment cells that are filled with crushed rock or gravel and designed to allow stormwater to flow subsurface t through the root zone of the constructed wetland, where pollutant removal r takes place. This practice provides both aerobic and anaerobic treatment zones for enhanced pollutant removal. (Photo Source: University of New Hampshire Stormwater Center) • •N • PERFORMANCE CRITERIA STORMWATER MANAGEMENT SUITABILITY FEASIBILITY O Water Quality Shall not be located within jurisdictional wetlands ® Channel Protection Unless a slope stability analysis is performed, wetlands shall not be Overbank Flood Protection located on areas with natural slopes greater than 15% o Extreme Flood Protection In hotspots or an underlying water supply aquifer, an impermeable liner shall be provided in addition to min 2 ft separation between the bottom of ® Runoff Reduction gravel and seasonal high water table Treatment of Hotspots Max contributing area is 5 acres CONVEYANCE ® Linear Applications • Inlets shall have non-erosive conditions ✓suitable for this practice • The outlet structure shall be located within the embankment IMPLEMENTATION CONSIDERATIONS An emergency spillway shall be provided with an energy dissipator Capital Cost installed to reduce flow velocities The primary outlet invert shall be located 4 inches below the elevation of Maintenance Burden the wetland soil service and be open or vented ® Safety Risk The outlet control structure shall be designed with a 3 inch min orifice to © Landscaping drain the WQv in a min of 24 hrs and a max of 48 hrs PRETREATMENT L= Low M = Moderate H =High NA= Not Applicable 10%WQv pretreatment shall be provided for each wetland inflow point In sole source aquifers, 100%WQv pretreatment shall be provided for POLLUTANT REMOVAL(See Table 10.3) runoff from hotspots ® Phosphorus Pretreatment shall be achieved with a sediment forebay, or equivalent O upstream pretreatment device Nitrogen TREATMENT o Metals Surface area of the entire wetland shall be at least 1%of the contributing ® Pathogens area O Min flow path ratio of 2:1 (length to relative width)from inflow point(s)to Total Suspended Solids the outflow point(s) G=Good F= Fair P= Poor Micropool shall be provided and located at the practice outlet RUNOFF REDUCTION CREDIT Min 12 inches of freeboard shall be provided, measured from the Extreme Flood elevation to the top of embankment 0% RRv provided Chapter 6:Standard Stormwater Management Practices Section 6.3 Stormwater Infiltration Practices Stormwater infiltration practices capture and temporarily store the WQv allowing it to infiltrate into the soil over a maximum two-day period. Design variants include the following: 1-1 Infiltration Trench (Figure 6.11) 1-2 Infiltration Basin (Figure 6.12) 1-3 Dry Well (Figure 6.13) 1-4 Underground Infiltration (Figure 6.14) Refer to the Fact Sheets at the end of this section for key considerations of each infiltration practice design variant, including performance criteria, practice suitability, implementation considerations, pollutant removal capability, and runoff reduction credit. IMPORTANT NOTES: 1. PROVIDING ADEQUATE PRETREATMENT IS CRITICAL TO LONG-TERM PERFORMANCE OF INFILTRATION PRACTICES. 2. TO ASSUE THAT INFILTRATION RATES ARE PRESERVED LONG-TERM, POST-CONSTRUCTION INSPECTION AND MAINTENANCE ACTIVITIES MUST BE CLEARLY DEFINED IN ACCORDANCE WITH CHAPTER 12. Chapter 6:Standard Stormwater Management Practices 6-35 Infiltration Trench (1-1) Infiltration trenches are excavated trenches filled with stone, designed to capture and temporarily store runoff in the stone reservoir, where it exfiltrates into the surrounding native soils. COMPACTED EARTHEN BERM A A LENGTH OVERFLOW AS WEIR, WIDTH REOUIRED VARIES PRETREATMENT GRASS FILTER STRIP OBSERVATION WELL WITH LOCKABLE CAP PLAN VIEW PRETREATMENT GRASS FILTER STRIP ALTERNATIVE SURFACE fi- PVC PERFORATED TREATMENT WITH OBSERVATION WELL CONTRIBUTING TOPSOIL AND LAWN IMPERVIOUS COMPACTED SURFACE EARTHEN BERM 00 o0 f 0 1 4" PEA GRAVEL 1 0 1 0 i DRAINAGE FILTER 1 © 1 FABRIC W 1 4'-0" NO. 2 STONE RESERVOIR 1 00 1 MAX (WASHED, NO FINES) C 0 i 1 0 i 1 o i L--, 11 FOOT PLATE 24" MIN SEPARATION TO SEASONAL HIGH WATER TABLE/BEDROCK Q SECTION A-A VIEW Figure 6.11 Infiltration Trench (1-1) Chapter 6:Standard Stormwater Management Practices 6-36 Infiltration Basin (1-2) Infiltration basins are vegetated excavations designed to capture and temporarily store stormwater runoff to promote infiltration into the surrounding native soils. 51AE3iLIZLU OUTLET OUTLET PIPE MAINTENANCE OUTLET CONTROL ACCESS STRUCTURE EDGE OF PAVEMENT—,,,, INLET PIPE �J SHEET FLOW TO FOREBAY TITi BOTTOM AREA STABILIZED COMPACTED STABILIZED OVERFLOW WEIR PLAN VIEW EARTHEN EMERGENCY BERM OVERFLOW TOP OF EMBANKMENT 1' MIN ABILIZED OVERFLOW WEIR FREEBOARD EMERGENCY OVERFLOW EXTREME FLOOD CONTROL BEYOND S_L R�RS.�9�F�i?PR�t7N.TR�L S7 CHANNELPR�TUTIQ� _ -®?o4�wQ�— INLET" STABILIZED 4" MINSEASDNAL OUTLET CONTROL OUTLET SEPARATION STRUCTURE HIGH WATER TABLE/ BEDROCK SECTION VIEW Figure 6.12 Infiltration Basin (1-2) Chapter 6:Standard Stormwater Management Practices 6-37 Dry Well (1-3) Dry wells consist of shallow excavations filled with stone or underground perforated structures surrounded by stone, that are designed to intercept and temporarily store runoff to promote infiltration into the surrounding native soils. ALTERNATIVE 3: SHEET FLOW FROM IMPERVIOUS SURFACL OPEN GRATE FOR SURFACE FLOW OR SOLID COVER FOR DIRECT PIPE ALTERNATIVE I: DISCHARGE ROOF DRAIN SURFACE SOLID FRAME AND COVER DISCHARGE PIPE SET IN CONCRETE COVER LOCATION STAKE/HUB SPLASH MESH BLOCK SCREEN FINISHED GRADE IGI 17 Y01 YPI J YGI MI IGI BUILDING ALTERNATIVE 2: lol DIRECT ROOF DRAIN I,1 CONNECTION too IGI sJ n 77-1 Ypl I iai n PRETREATMENT IGI p SEDIMENTATION BASIN 6" PVC PERFORATED OBSERVATrON WELL WITH j LOCKABLE COVER ._ DRAINAGE FILTER FABRIC� 12" NO. 2 STONE FILTER LAYER EQUALIZER PIPE (WASHED. NO FINES) (IF REQUIRED) 24' MIN SEPARATION TO SECTION VIEW SEASONAL HIGH WATER TABLE/ BEDROCK Figure 6.13 Dry Well (1-3) Chapter 6:Standard Stormwater Management Practices 6-38 Underground Infiltration (1-4) Underground infiltration systems are practices, typically installed below parking lots and other impervious surfaces, designed to capture and temporarily store stormwater runoff in pre-manufactured pipes, vaults or other modular structures, while infiltrating into the surrounding soils. DRAINAGE FILTER BACKFILL FABRIC FINISH GRAD: PROVIDE MINIMUM COVER PER MANUFACTURE REQUIREMENTS BASED ON — — ANTICIPATED TRAFFIC L — 24" MIN No. 2 STONE FILTER LAYER'I—/ END CAP SEPARATION TO SEASONAL HIGH (WASHED, NO FINES) DEPTH AND GROUNDWATER/ BEDROCK WIDTH OF STONE PER PROPRIETARY SYSTEM REQUIREMENTS UNDERGROUND INFILTRATION CHAMBER UNDERGROUND INFILTRATION CHAMBER SIDE VIEW N0, 2 STONE FILTER LAYER (WASHED, NO FINES) PER MINIMUM DIMENSIONS, REQUIRED STORAGE, DRAINAGE FILTER FABRIC OR AS REQUIRED BY MANUFACTURER FINISH GRADE BACKFILL PROVIDE MINIMUM COVER PER MANUFACTURER'S REQUIREMENTS BASED .+ G" MIN ON ANTICIPATED TRAFFIC I I. UNDERGROUND INFILTRATION PIPE 6" MIN 24" MIN SEPARATION TO 12" SEASONAL HIGH MIN WATER TABLE/ BEDROCK AS NEEDED BASED ON HEADER - PIPE/FITTING GEOMETRY UNDERGROUND INFILTRATION PIPE SECTION VIEW SOLID FRAME AND COVER SET 6" PVC OBSERVATION WELL IN CONCRETE COLLAR WITH LOCKABLE COVER FINISH SURFACE PROVIDE MINIMUM I COVER PERr � MANUFACTURER'S ZZ REQUIREMENTS t .� s +�* r* BASED ON =�::� ANTICIPATED TRAFFIC i- NO. 2 STONE FILTER LAYER :I (WASHED, NO FINES) STORMWATER DEPTH AND WIDTH OF STONE PER PROPRIETARY SYSTEM ___ «w �� MODULES REQUIREMENTS - i_..iF' Ji_T:_.I%1. _ 24" MIN SEPARATION TO DRAINAGE FILTER FABRIC SEASONAL HIGH WATER TABLE/ BEDROCK UNDERGROUND INFILTRATION MODULE SYSTEM SECTION VIEW Figure 6.14 Underground Infiltration (1-4) Chapter 6:Standard Stormwater Management Practices 6-39 6.3.1 Feasibility To be suitable for infiltration, underlying soils shall have an infiltration rate (fc) of at least 0.5 in/hr, as confirmed by field geotechnical tests. The minimum geotechnical testing shall be consistent with Appendix D. Underground infiltration systems likely qualify as a Class V injection well based upon the definition of a subsurface fluid distribution system (i.e. "an assemblage of perforated pipes, drain tiles, or other similar mechanisms intended to distribute fluids below the surface of the ground"). Refer to the EPA UIC Program for system registration requirements. Designers must be selective with the design of infiltration on sites with karst geology, shallow bedrock and soils, and hotspot land uses. Projects located over karst geology must provide runoff reduction by techniques that do not involve large infiltration basins and deep, concentrated recharge to the ground. A geotechnical assessment is recommended for infiltration and recharge at small scales. Infiltration practices shall not be located on areas with natural slopes greater than 15%, unless a slope stability analysis is performed by a qualified geotechnical engineer. Underground infiltration systems may be applied as a practice for urban stormwater management (Chapter 8). Urban fill soils shall not be used for infiltration practices. Urban fill in considered soil that includes unsuitable materials such as brick, cement, asphalt, demolition debris, etc. If infiltration practices are constructed in engineered fill soils, then the following criteria shall be met: In-situ/natural soil layer below the infiltration system shall have an infiltration rate greater or equal to the engineered fill soils, as determined by geotechnical testing (Appendix D); Soils proposed for engineered fill shall be classified as suitable using Table 6.9 and Figure 6.15; Soils proposed for engineered fill shall have a minimum infiltration rate of 0.50 inch/hr and a material gradation similar to the in-situ/natural soils, as determined by geotechnical testing; After placement of engineered fill, permeability testing (Appendix D) shall be performed to confirm the infiltration rate. If engineered fill material requirements are not met, the material shall be removed; The required vertical separation shall be measured from the existing grade of in-situ/natural soil. Engineered fill soils shall not be used to meet separation requirements; and Construction of infiltration practices on slopes, through cut and fill operations, shall utilize the existing cut material to the greatest extent possible. The downhill berm shall be designed to prevent seeps, breakouts and slippage through the berm and at the interface of the in-situ/natural and fill material. A slope stability analysis shall be performed by a qualified geotechnical engineer. HydrologicTable 6.9 .p Soil Texture Class Hydrologic Soil Minimum Infiltration Rate Suitability Group (inch/hr) Sand A 8.27 Loamy sand A 2.41 Suitable for engineered fill for infiltration practice Sandy loam B 1.02 design Loam B 0.52 Silt loam C 0.27 Sandy clay loam C 0.17 Clay loam D 0.09 Not suitable for Silt clay loam D 0.06 engineered fill for Sandy clay D 0.05 infiltration practice design Silty clay D 0.04 Clay D 0.02 Chapter 6:Standard Stormwater Management Practices 640 Figure 6.15 USDA Soil Textural Classification 100 90 ry0 \ so �° 70 clay ' f t� 6{1 — ,p e,4 h?fir. 5{1 silly �s G� sandy clays 4 —clay — j/ clay loam 'ilt 30 randy clay loam clay Inam 4� {} loam rill 4andy loam 10 lodm lnamy silt sand mind Sand Separate,% — Runoff from designated stormwater hotspots shall not be directed to an infiltration practice, unless two treatment practices are provided in series (i.e. non-infiltration standard SMP followed by an infiltration practice), both of which shall be sized to treat the entire WQv. In areas of known contamination, or if contamination is discovered during excavation, contamination levels must be evaluated by a qualified professional and the state remediation program to determine if infiltration is permitted. Infiltration practices shall meet the minimum separation requirements listed in Table 6.10. Vertical separation shall be taken from the bottom of practice, or stone reservoir where applicable. Horizontal separations shall be taken from the maximum water surface elevation (Extreme Flood peak water surface elevation) of the practice. Table1 Infiltration Practice Minimum SeparationRequirements Vertical Separation Horizontal Separation Structures Structures Water Seasonal Septic Sanitary Design Variant High Water Sound Without With Supply System Sewer Table',' Bedrock' Foundation Foundation Well/ 3,4 Main Waterproofing4 Waterproofing4 Reservoir Infiltration Trench 25 ft 0 ft (1-1) Infiltration Basin 25 ft (1-2) Dry Well (1-3) 10 ft(single dry well) 2 ft 2 ft 25 ft(multiple dry wells in series) 100 ft 50 ft 25 ft Underground Infiltration 25 ft System(1-4) Infiltration 25 ft loft Bioretention (F-4) 'Sound bedrock,fractured bedrock or karst geology as documented by on-site geotechnical testing 2 Separation shall be increased to 4 ft in sole source aquifer 3 Septic systems are inclusive of septic tanks,distribution boxes,absorption fields 4Infiltration practices shall be located downgradient of structures and septic systems Chapter 6:Standard Stormwater Management Practices 641 The maximum contributing area shall meet the requirements listed in Table 6.11. Contributing: Table 6.11 Infiltration Practice Maximum Area Requirements Design Variant Maximum Contributing Area Infiltration 5 ac Trench (1-1) Infiltration Basin 10 ac(where fc of underlying soils 0.50 to 5.0 in/hr OR Contributing Impervious Area <_ 10 acres) (1-2) 25 ac(where fc of underlying soils>5.0 to 10.0 in/hr AND Contributing Impervious Area<_ 15 acres) 50 ac(where fc of underlying soils> 10 in/hr AND Contributing Impervious Area<_20 acres) Dry Well (1-3) 0.50 ac(for larger contributing areas, use multiple dry wells in series) Underground 10 ac Infiltration (1-4) Infiltration Basin Example 1: Contributing Area = 13 acres Contributing Impervious Area = 13 acres Infiltration Rate = 6 in/hr Under these design criteria, the maximum contributing area is 25 acres, and the designer can convey the entire contributing area to one infiltration basin. Infiltration Basin Example 2: Contributing Area = 23 acres Contributing Impervious Area = 17 acres Infiltration Rate = 4 in/hr Under these design criteria, the maximum contributing area is 10 acres to one basin, since the infiltration rate and contributing impervious area do not meet the criteria for a maximum contributing area of 25 acres. Therefore, designer must convey the contributing area to at least three separate infiltration basins. Construction Requirements Practice areas shall be clearly marked before any site work begins and heavy equipment traffic shall be restricted to avoid soil disturbance and compaction. The Erosion and Sediment Control plan shall clearly indicate how sediment will be prevented from entering the practice areas. For Design I-1, large tree roots shall be trimmed flush with the trench sides to prevent puncturing or tearing of the filter fabric. The side walls shall be roughened where sheared and sealed by heavy equipment. Permanent vegetative cover with 80% uniform density shall be established over the entire contributing pervious drainage area before runoff is directed into the facility. Infiltration practices shall never serve as a sediment control device during site construction phase and shall be installed at the end of the construction sequence, to the greatest extent practical. 6.3.2 Conveyance Infiltration practices shall be sized to store and infiltrate the required WQv. If inflow exceeds the storage capacity under larger storm events, then an adequate outlet pipe or overflow shall be designed to provide safe conveyance. If computed flow velocities exceed erosive velocities, the overflow shall be properly stabilized. Runoff conveyed to an infiltration practice by pipe or concentrated flow, under all storm events, shall utilize a pretreatment device or flow dissipator to reduce flow velocity prior to entering the practice. If flow velocity cannot be reduced to non-erosive conditions, then the practice shall be designed off-line (refer to Appendix C) by use of a flow regulator or flow splitter diversion structure to divert the WQv to the practice and allow larger flows to bypass the practice. An emergency spillway shall be provided to safely convey stormwater exceeding the Extreme Flood at non- erosive velocities. Chapter 6:Standard Stormwater Management Practices 642 6.3.3 Pretreatment Prior to entering an infiltration practice, the following pretreatment volume shall be provided: 25% of the WQv for fc<_ 10.00 in/hr. 50% of the WQv for fc> 10.00 in/hr. Adequate pretreatment for Designs 1-1, 1-2, 1-3, and 1-4 shall include one of the following: Sedimentation chamber, plunge pool, or forebay, sized in accordance with Section 6.4.3; or Vegetated swale with check dams (Maximum velocity of 1 fps for water quality flow). Approved proprietary pretreatment device (Refer to Chapter 9). For Design 1-1: when runoff is conveyed to the practice via sheet flow, adequate pretreatment also includes a grass filter strip sized in accordance with Table 6.13. For Design 1-4: a manufacturer approved pretreatment system. Exit velocities from pretreatment devices shall be designed to ensure non-erosive outlet conditions. 6.3.4 Treatment 6.3.4.1 Design Criteria Table •n Practice Design Specifications 1-1 1-2 1-3 1-4 Applicability N/A Required N/A N/A Freeboard Depth 1 ft. min. measured from top of Extreme Flood elevation to top of embankment Applicability Required N/A N/A N/A Pea Gravel Depth 4 inch Material ASTM D448 No. 6 stone, Porosity=32% Applicability Required N/A Required As Required Stone Reservoir Depth 4 ft. max. N/A 1 ft. min. on Per proprietary all sides &bottom requirements Material No. 2 stone, washed, no fines; Porosity=40% Storage' Depth Within reservoir 6 ft. max. As Required As Required Side Slope N/A 3:1 (h:v) max. N/A N/A Observation Well Applicability Required N/A Required N/A Material 6 inch min. perforated PVC or HDPE pipe with lockable cap Applicability Required N/A Required Required Drainage Filter Fabric 3 Non-woven, polypropylene geotextile with flow rate greater than 125 gpm/sf Material (ASTM D4491)and Apparent Opening Size US#70 sieve (ASTM D4751) Applicability As Required Required As Required As Required Slope 15% max. Maintenance Access' Width 12 ft. min. Material Able to withstand loading of maintenance equipment and vehicles Footnotes: 'Required for all Design Variants 2An Underground Injection Control Permit may be required when certain conditions are met. Designer must Consult EPA's Underground Injection Control Program Fact Sheet for further information. 30r acceptable alternatives,such as a 3 inch minimum layer of pea gravel Chapter 6:Standard Stormwater Management Practices •43 General All infiltration practices shall be designed to fully drain within 48-hrs of the maximum storm event for which it was designed. Designs 1-1 and 1-2 shall account for reduced infiltration rates under frozen conditions. All infiltration practices shall be designed such that the length, width, or diameter is greater than the depth in order to satisfy the UIC criteria. Refer to Section 6.3.1. Maintenance Access A maintenance access easement shall extend to the practices from a public or private road. Adequate maintenance access must extend to the pretreatment device, outlet structure/overflow, emergency spillway, and must have sufficient area to allow vehicles to turn around. Where applicable, access to the outlet structure shall be provided by lockable manhole cover or grate. 6.3.4.2 Sizing Criteria Infiltration practices shall be designed to exfiltrate the entire WQv through the bottom surface area of the practice (vertical sides are not considered in sizing). Design 1-1: calculate the minimum surface area of an infiltration trench using the following equation: _ W QV AT 0 -dt Where: AT = Surface area of the infiltration trench (so WQv= Water Quality Volume (co 0 = Porosity (assume 0.4) dt= Depth of trench (ft) Design 1-2: calculate the minimum bottom area of an infiltration basin using the following equation: _ WQv Ab d b Where: Ab= Bottom area of the infiltration basin (so WQv= Water Quality Volume (co db = Depth of basin (ft) (measured from bottom to first outlet) Design 1-3: calculate the Water Quality Volume provided by dry wells using the following equation: WQv = N•Vw Vw = V + V V` = 7T rZ •H V = (7r• [(r+ t+ ts)Z — (r +t)Z]) •H•0.40 Where: WQv = Water Quality Volume (co N = Number of dry wells VW =Volume provided per dry well (co V; = Inside volume of dry well (co VS =Volume of stone reservoir (co r= Inside radius of dry well (ft) H = Inside height of dry well (ft) t= Thickness of dry well wall (ft) t5 = Thickness of stone reservoir (ft) Chapter6:Standard Stormwater Management Practices 644 Design 1-4: calculate the minimum stone area of underground infiltration systems using the following equation: _ WQv Ab d Where: Ab= Bottom area of the infiltration basin (so WQv= Water Quality Volume (co dp = Depth of bottom stone (ft) (measured from bottom of stone to bottom of chambers) Design 1-4: calculate the Water Quality Volume provided by underground infiltration systems using the following equation: WQv = Ust + V ys Where: WQv=Water Quality Volume (co Vst= Volume of stone reservoir(co (assume 40% voids) Vsys= Volume of system (cf) (excluding volume of stone) For Design 1-4, the system shall be sized using hydrologic modeling, hydrologic calculations or calculations provided by the manufacturer, to demonstrate that the water quality and quantity control objectives have been met. For Designs 1-1, 1-3, and 1-4, the bottom of the stone reservoir shall be laid level, so that runoff will infiltrate through the entire bottom surface area. 6.3.5 Landscaping For planting guidance for stormwater management facilities, refer to Chapter 11. Permanent vegetative cover shall achieve 80% uniform density established over the entire contributing pervious area, before runoff is directed into the facility. For Design 1-2 stabilizing vegetation shall be provided throughout the practice. Chapter 6:Standard Stormwater Management Practices 6-45 Fact Sheet: Infiltration Trench (1-1) Description: Excavated trenches filled with stone, designed to capture and temporarily store runoff in the stone reservoir, where it exfiltrates into the surrounding native soils. •=ii • PERFORMANCE CRITERIA STORMWATER MANAGEMENT SUITABILITY FEASIBILITY O Water Quality Underlying soils shall have an min. infiltration rate of 0.50 inch/hr O Channel Protection Practices shall not be located on areas with natural slopes > 15% ® Overbank Flood Protection Urban fill soils shall not be used for infiltration practices 0 Extreme Flood Protection Max contributing area is 5 acres O Runoff Reduction Min 2 ft separation to seasonal high-water table or bedrock Two treatment practices in series both sized to treat the entire WQv(non- 0 Treatment of Hotspots infiltration standard SMP followed by an infiltration practice)shall be 0 Linear Applications provided for hotspot treatment ✓suitable for this practice CONVEYANCE * suitable with exceptions Practice shall be size to store and infiltrate the WQv IMPLEMENTATION CONSIDERATIONS An outlet pipe or overflow for safe conveyance shall be provided in the © Capital Cost event inflow exceeds the storage capacity under larger storm events o Maintenance Burden An emergency spillway shall be provided Runoff conveyed by pipe or concentrated flow shall utilize a pretreatment ® Safety Risk device or flow dissipator to reduce velocity prior to entering the practice ® Landscaping PRETREATMENT L= Low M = Moderate H =High Pretreatment volume shall be 25%WQv for fc<_ 10.00 inch/hr or 50% NA= Not Applicable WQv for fc> 10.00 inch/hr POLLUTANT REMOVAL(See Table 10.3) TREATMENT O Phosphorus Stone reservoir max. depth is 4 ft O Stone reservoir shall have a 40% porosity Nitrogen An observation well with lockable cap shall be provided ® Metals A min. 12 ft wide maintenance access, max. 15%slope, may be required ® Pathogens Design to fully drain within 48 hrs of max. storm event for which it was O Total Suspended Solids designed Design shall account for reduced infiltration rates under frozen conditions G=Good F= Fair P= Poor Length or width of the practice shall be greater than the depth RUNOFF REDUCTION CREDIT 100% RRv provided Chapter 6:Standard Stormwater Management Practices Fact Sheet: Infiltration Basin (1-2) Description: Vegetated excavations designed to capture and temporarily store stormwater runoff to promote infiltration into the surrounding native soils. (Photo Source: Clark County,Washington) PERFORMANCE CRITERIA STORMWATER MANAGEMENT SUITABILITY FEASIBILITY to Water Quality Underlying soils shall have an min. infiltration rate of 0.50 inch/hr O Channel Protection Practices shall not be located on areas with natural slopes > 15% ® Overbank Flood Protection Urban fill soils shall not be used for infiltration practices 0 Extreme Flood Protection Max contributing area is 10 acres, 25 acres or 50 acres depending on O underlying soil infiltration rates and contributing impervious area Runoff Reduction Min 2 ft separation to seasonal high-water table or bedrock ® Treatment of Hotspots • Two treatment practices in series both sized to treat the entire WQv(non- Linear Applications infiltration standard SMP followed by an infiltration practice)shall be provided for hotspot treatment ✓suitable for this practice �c suitable with exceptions CONVEYANCE IMPLEMENTATION CONSIDERATIONS Practice shall be size to store and infiltrate the WQv Capital Cost An outlet pipe or overflow for safe conveyance shall be provided in the event inflow exceeds the storage capacity under larger storm events ® Maintenance Burden An emergency spillway shall be provided ® Safety Risk Runoff conveyed by pipe or concentrated flow shall utilize a pretreatment Landscaping device or flow dissipator to reduce velocity prior to entering the practice PRETREATMENT L= Low M = Moderate H =High NA= Not Applicable Pretreatment volume shall be 25%WQv for fc<_ 10.00 inch/hr or 50% POLLUTANT REMOVAL(See Table 10.3) WQv for fc> 10.00 inch/hr TREATMENT O Phosphorus 1 ft min. freeboard shall be provided ® Nitrogen 6 ft max. basin depth ® Metals Provide a min. 12 ft wide maintenance access at a max. 15%slope O Pathogens Design to fully drain within 48 hrs of max. storm event for which it was designed O Total Suspended Solids Design shall account for reduced infiltration rates under frozen conditions G=Good F= Fair P= Poor Length or width of the practice shall be greater than the depth RUNOFF REDUCTION CREDIT TREATMENT 100% RRv provided Stabilizing vegetation shall be provided throughout practice Chapter 6:Standard Stormwater Management Practices Fact Sheet: Dry Well (1-3) Description: Shallow excavations filled with stone or underground perforated structures surrounded by stone, that are designed to intercept and temporarily 1 store runoff to promote infiltration into the surrounding native soils. (Photo Source: Alpha Environmental) Key Considerations PERFORMANCE CRITERIA STORMWATER MANAGEMENT SUITABILITY FEASIBILITY to Water Quality Underlying soils shall have an min. infiltration rate of 0.50 inch/hr O Channel Protection Practices shall not be located on areas with natural slopes > 15% ® Overbank Flood Protection Urban fill soils shall not be used for infiltration practices 0 Extreme Flood Protection Max contributing area per drywell is 0.50 acre (for larger contributing O areas, use multiple dry wells in series) Runoff Reduction Min 2 ft separation to seasonal high-water table or bedrock ® Treatment of Hotspots • Two treatment practices in series both sized to treat the entire WQv(non- 40 Linear Applications infiltration standard SMP followed by an infiltration practice)shall be provided for hotspot treatment ✓suitable for this practice �c suitable with exceptions CONVEYANCE IMPLEMENTATION CONSIDERATIONS Practice shall be size to store and infiltrate the WQv Capital Cost An outlet pipe or overflow for safe conveyance shall be provided in the event inflow exceeds the storage capacity under larger storm events ® Maintenance Burden An emergency spillway shall be provided ® Safety Risk Runoff conveyed by pipe or concentrated flow shall utilize a pretreatment Landscaping device or flow dissipator to reduce velocity prior to entering the practice PRETREATMENT L= Low M = Moderate H =High NA= Not Applicable Pretreatment volume shall be 25%WQv for fc<_ 10.00 inch/hr or 50% POLLUTANT REMOVAL(See Table 10.3) WQv for fc> 10.00 inch/hr TREATMENT O Phosphorus A stone reservoir shall be provided around the dry well, extending 1 ft ® Nitrogen min. on all sides and bottom of the dry well A min. 12 ft wide maintenance access, max. 15%slope, may be required 10 Metals Design to fully drain within 48 hrs of max. storm event for which it was ® Pathogens designed O Total Suspended Solids Length, width or diameter of the practice shall be greater than the depth G=Good F= Fair P= Poor RUNOFF REDUCTION CREDIT 100% RRv provided Chapter 6:Standard Stormwater Management Practices Fact Sheet: Underground Infiltration (1-4) Description: Practices that are typically installed below parking lots and other impervious surfaces, designed to capture and temporarily store stormwater runoff in pre-manufactured pipes, vaults or other modular structures, while infiltrating into the surrounding soils. PERFORMANCE CRITERIA STORMWATER MANAGEMENT SUITABILITY FEASIBILITY to Water Quality Underlying soils shall have an min. infiltration rate of 0.50 inch/hr O Channel Protection Practices shall not be located on areas with natural slopes > 15% ® Overbank Flood Protection Urban fill soils shall not be used for infiltration practices 0 Extreme Flood Protection Max contributing area per underground infiltration system is 10 acres O Runoff Reduction Min 2 ft separation to seasonal high-water table or bedrock Two treatment practices in series both sized to treat the entire WQv(non- 0 Treatment of Hotspots infiltration standard SMP followed by an infiltration practice)shall be 0 Linear Applications provided for hotspot treatment ✓suitable for this practice CONVEYANCE * suitable with exceptions Practice shall be size to store and infiltrate the WQv IMPLEMENTATION CONSIDERATIONS An outlet pipe or overflow for safe conveyance shall be provided in the © Capital Cost event inflow exceeds the storage capacity under larger storm events An emergency spillway shall be provided Maintenance Burden Runoff conveyed by pipe or concentrated flow shall utilize a pretreatment ® Safety Risk device or flow dissipator to reduce velocity prior to entering the practice Landscaping PRETREATMENT L= Low M = Moderate H =High Pretreatment volume shall be 25%WQv for fc<_ 10.00 inch/hr or 50% NA= Not Applicable WQv for fc> 10.00 inch/hr POLLUTANT REMOVAL(See Table 10.3) TREATMENT Designers shall provide stone reservoir per proprietary requirements O Phosphorus A min. 12 ft wide maintenance access, max. 15%slope, may be required ® Nitrogen Design to fully drain within 48 hrs of max. storm event for which it was ® Metals designed O Pathogens Length or width of the practice shall be greater than the depth O Total Suspended Solids G=Good F= Fair P= Poor RUNOFF REDUCTION CREDIT 100% RRv provided Chapter 6:Standard Stormwater Management Practices Section 6.4 Stormwater Filtering Practices Stormwater filtering practices capture and temporarily store the WQv and pass it through a filter of sand, or soil. Filtered runoff may be collected and returned to the conveyance system or allowed to partially exfiltrate into the soil. Design variants include: F-1 Surface Sand Filter (Figure 6.16) F-2 Underground Sand Filter (Figure 6.17) F-3 Perimeter Sand Filter (Figure 6.18) F-4 Infiltration Bioretention (Figure 6.19) F-5 Filtration Bioretention (Figure 6.20) F-6 Bioslopes (Figure 6.21) Refer to the Fact Sheets at the end of this section for key considerations of each filtering practice design variant, including performance criteria, practice suitability, implementation considerations, pollutant removal capability, and runoff reduction credit. Chapter 6:Standard Stormwater Management Practices 6-50 Surface Sand Filter (F-1) A surface sand filter consists of a pretreatment sedimentation chamber or other pretreatment that discharges to an open sand filter bed designed to treat stormwater runoff, then return it to the conveyance system through a perforated underdrain system. 6" FAIN PERFORATED UNDERDRAIN SET 30' OC MAX FLOW DIVERSION PRETREATMENT 6" MIN PERFORATED STRUCTURE FOREBAY FILTER MEDIA UNDERDRAIN HEADER PIPE A I J A INLET PIPE RISER PIPE STABILIZED INLET STABILIZED EMERGENCY PLAN VIEW OVERFLOW TOP OF EMBANKMENT FLOW PERFORATED BEYOND DIVERSION RISER PIPE STABILIZED EMERGENCY STRUCTURE TRANSITION TO SOLID EXTREME FLOOD MAX OVERFLOW PIPE 'BELOW PONDING DEPTH=18" PERMANENT POOL WQv MAX PONDING STABILIZED DEPTH=12" 25% WQv MIN INLET BYPASS - - - - - - - OU TLET BYPASS INLET (OPTIONAL) MIN TOPSOILtih` (OPTIONAL) INLET PIPE 18"-24" ASTM C-33 UNDISTURBED EARTH CONCRETE SAND FILTER MEDIA DRAINAGE FILTER FABRIC (TYP) OUTLET PIPE 10" NO 57 STONE DRAINAGE LAYER (WASHED, NO FINES) 24" MIN 6" MIN PERFORATED SEPARATION TO SEASONAL UNDERDRAIN HEADER PIPE HIGH WATER TABLE/ BEDROCK SECTION A-A VIEW Figure 6.16 Surface Sand Filter(F-1) Chapter 6:Standard Stormwater Management Practices 6-51 Underground Sand Filter (F-2) An underground sand filter is a practice where piped stormwater runoff is conveyed to an underground vault, consisting of a pretreatment sedimentation chamber that overflows to a sand filter bed designed to treat stormwater runoff, then return it to the conveyance system through an outlet pipe. OUTLET PIPE FILTER MEDIA BED FILTER MEDIA BAFFLE WALL A q s OVERFLOW INLET PIPE UNDERDRAIN CHAMBER CLEANOUT (TYP) 6" MIN PERFORATED UNDERDRAIN SET 30' OC MAX PLAN VIEW SEDIMENTATION OVERFLOW CATCH BASIN BASIN FILTER BED CHAMBER CHAMBER GRATE OR SOLID SOLID MANHOLE MANHOLE COVER SOLID MANHOLE COVER COVER I —mow-- ———— ——— -------- �� 5' MIN +ram INLET PIPE b TEMPORARY - PONDiNG �' k J ..�: 'i�.a ate+.✓ wJ��.�ier PERMANENT MANHOLE POOL STEPS (TYP) UNDISTURBED 12" MIN 6" MIN UNDERDRAIN DRAINAGE \'OULTET PIPE EARTH NO. 2 STONE PERFORATED CLEANOUT (TYP) FILTER UNDERDRAIN FABRIC SEMON A-A VIEW 3" MIN NO 57 STONE CHOKER �r77 ,77 COURSE (WASHED. NO FINES) 18"--24" ASTM C-33 CONCRETE r-- - SAND FILTER MEDIA 1 O" NO 57 STONE DRAINAGE LAYER (WASHED, NO FINES) SECTION B-B VIEW Figure 6.17 Underground Sand Filter(F-2) Chapter 6:Standard Stormwater Management Practices 6-52 Perimeter Sand Filter (F-3) A perimeter sand filter is a practice where stormwater runoff is conveyed via sheet flow to an underground vault with open grates that consists of a pretreatment sedimentation chamber that overflows to a sand filter bed designed to treat stormwater runoff, then return it to the conveyance system through an outlet pipe. OVERFLOW WEIR (TYP) r INLET GRATE ' �+ . AT SURFACE (rYP) 6" MIN PERFORATED UNDERDRAIN FILTER MEDIA W 5i1 rC ..yY 4 Y T A SOLID MANHOLE COWER AT SURFACE (TYP) n ' EMERGENCY OVERFLOW WEIR OVERFLOW CHAMBER OUTLET PIPE PLAN VIEW FILTER PAVEMENT SEDIMENTATION MEDIA CHAMBER CHAMBER EXTREME FLOOD MAX --- — PONDING DEPTH=18" W4v MAX PONDING DEPTH=12" —— — — Y—0 12"-24" ASTM C-33 CONCRETE SAND FILTER �, ��• Or MEDIA +�a�� DRAINAGE FILTER 12' MIN FAB RIC NO. 2 STONE _—�— _-� FA IC 57 STONE 6' PERFORATED DRAINAGE LAYER UNDERDRAIN (WASHED, NO FINES) SECTION A-A VIEW Figure 6.18 Perimeter Sand Filter(F-3) Chapter 6:Standard Stormwater Management Practices 6-53 Infiltration Bioretention (F-4) Infiltration bioretention areas are shallow stormwater controls that utilize vegetation and engineered filter media to capture, treat, and infiltrate stormwater runoff into the underlying soils. �+y ey.':r`�t7F i�+�}•'�S'rii"C'frrrre�.nnYn�s C°k�a L s'f PRETREATMENT GRASS FILTER STRIP "•' ±` af "„F °tyY, 1 'tsi A, ll_F ya+�:r ,".{�fftiv ,•,�� .!':era.... �.. •S4'{.pr Ar��rA..l''4µ fn,1�`Yy'f•[.4}��,A�IK �yY�' PEA GRAVEL DIAPHRAGM 18" MIN WIDTH 24" MIN DEPTH Ilk w + OVERFLOW STRUCTURE OUTLET PIPE PLAN VIEW LARGER STORM OVERFLOW STRUCTURE MAX PONDINGDEPTH=1$" PRETREATMENT GRASS FILTER STRIP GRATE INLET SET AT WQV PONDING DEPTH WATER QUALITY PAVEMENT MAX PONDING -DEPTH=12" PRETREATMENT GRAVEL DIAPHRAGM aae MEDIA � w` "2.5' 4 ` 3" MIN SHREDDED HARDWOOD MULCH — �Y- 5" MIN NO 57 STONE DRAINAGE — LAYER (WASHED, NO FINES) DRAINAGE FILTER FABRIC T UNDISTURBED EARTH 24" MIN SEPARATION OUTLET PIPE BEYOND TO SEASONAL HIGH WATER TABLE/ BEDROCK SECTION A-A VIEW Figure 6.19 Infiltration Bioretention (F-4) Chapter 6:Standard Stormwater Management Practices 6-54 Filtration Bioretention (F-5) Filtration bioretention areas are shallow stormwater control that utilize vegetation and engineered filter media to capture and treat stormwater runoff, then return it to the conveyance system through a perforated underdrain system. OVERFLOW STRUCTURES PRETREATMENT GRASS FILTER STRIP ' r r .. +���' �T�'i�� i�'. �.sal�•�:i} ��Si ti'` +F�: ?'Y};S;F�x',,^;' 6" MIN PVC PERFORATED , n �.; + 4i,=.:ti UNDERDRAIN tis IP 7 q � Yq fw w ±• i 1. ti+, fi.l.jTn' -;7.r r7t•, 5 a[', c! 77 �Yf PEA GRAVEL DIAPHRAGM :4= r � .. r's ��{rr �"k�' 18" MIN WIDTH 24- MIN DEPTH ?k+r +e,t Sil Lil L G: +j•n�^:r a;.,t� " .�jet.!_ it y a r • 1 SJ F OUTLET PIPE PLAN VIEW LARGER STORM OVERFLOW STRUCTURE MAX PONDING PRETREATMENT GRASS FILTER STRIP GRATE INLET SET AT WQV DEPTH=18" PONDING DEPTH WATER QUALITY PAVEMENT MAX PONDING EPTH=12" PRETREATMENT GRAVEL �LTER w •9e:'. ��� `'+� " DIAPHRAGM,MEDIA _ ti 5' 4 3" MIN SHREDDED HARDWOOD MULCH 10" MIN NO 57 STONE DRAINAGE LAYER (WASHED, NO FINES) DRAINAGE FILTER FABRIC UNDISTURBED EARTH 24" MIN OUTLET PIPE BEYOND SEPARATION TO SEASONAL 6" MIN PVC PERFORATED UNDERDRAIN HIGH WATER TABLE/ BEDROCK SECTION A-A VIEW Figure 6.20 Filtration Bioretention (F-5) Chapter 6:Standard Stormwater Management Practices 6-55 Bioslope (F-6) Bioslopes are installed adjacent to impervious surfaces, along embankments or slopes, and use a permeable engineered filter media to treat sheet flow stormwater runoff. These are designed with limited longitudinal slopes to force flow down through the engineered filter media and into an underdrain for conveyance. CONTRIBUTING PEA PRETREATMENT IMPERVIOUS GRAVEL GRASS FILTER AREA DIAPHRAGM STRIP BIOSLOPE WIDTH 24" MIN. 5� MAX SLOPE Z% SLOPE 8% MAX SLOPE 12" MIN. FILTER MEDIA 4 14" MIN I I I AX 1 NO. 57 STONE DRAINAGE I LAYER (WASHED, I ,; NO FINES) 36' DRAINAGE FILTERFABRIC 2" MIN 6" PERFORATED L UNDERDRAIN 24" MIN SEPARATION TO 24" MIN SEASONAL HIGH WATER TABLE/BEDROCK Figure 6.21 Bioslope (F-6) Chapter 6:Standard Stormwater Management Practices 6-56 6.4.1 Feasibility The maximum contributing area shall be: Designs F-1: 10 acres Designs F-2 and F-3: 2 acres Designs F-4 and F-5: 5 acres The maximum contributing flow path length shall be: Design F-6: 100 ft from impervious surfaces and 150 ft total. Designs F-1, F-2, F-3, and F-5, and F-6 shall have a minimum 2 ft separation between the bottom of the stone drainage layer and seasonal high water table or karst geology. For Designs F-1, F-5, and F-6, where 2 ft separation cannot be met, an impermeable liner shall be provided at bottom of drainage layer and all sides. Designs F-1, F-2, F-3, F-4 and F-5 shall be designed and constructed level, with no longitudinal or lateral slope. Design F-6 shall have a maximum 5% slope along the contributing impervious flow path. Design F-4 shall meet the minimum separation requirements outlined in Table 6.10. Design F-5 shall have a 100 ft minimum separation to septic systems. Design F-4 shall have underlying soils with an infiltration rate greater than or equal to 0.50 inch/hr. The minimum geotechnical testing shall be consistent with Appendix D. If underdrains are provided or the infiltration rate is less than 0.50 inch/hr, then the practice shall meet the criteria of Design F-5. Designs F-4, F-5 and F-6 may be applied as practices for urban stormwater management (see Chapter 8). Design F-6 may only be applied for access road; sidewalk, bike path or walking path projects, surfaced with an impervious cover; highway; and linear utility projects. Filtering practices can be used to treat stormwater runoff from a designated hotspot, when meeting the following design criteria: Designs F-1, F-5, and F-6: an impermeable liner shall be provided at bottom of drainage layer and all sides. Design F-4: runoff shall be directed to two practices in series (i.e. non-infiltration standard SMP followed by an infiltration practice), both of which are sized to treat the entire WQ,,. In areas of known contamination, or if contamination is discovered during excavation, the following design criteria shall be met: Design F-1, F-5, and F-6: an impermeable liner shall be provided at bottom of drainage layer and all sides. Design F-4: contamination levels must be evaluated by a qualified professional and the state remediation program to determine if infiltration is permitted. Construction Requirements Practice areas shall be clearly marked before any site work begins and heavy equipment traffic shall be restricted to avoid soil disturbance and compaction. The Erosion and Sediment Control plan shall clearly indicate how sediment will be prevented from entering the practice areas. Permanent vegetative cover with 80% uniform density shall be established over the entire contributing pervious drainage area before runoff is directed into the facility. Filtration practices shall never serve as a sediment control device during site construction phase. Ideally, the practices shall be installed at the end of the construction sequence. Chapter6:Standard Stormwater Management Practices •57 6.4.2 Conveyance Runoff that is conveyed to Designs F-1, F-2, F-3, F-4, and F-5 by pipe or concentrated flow, shall utilize a pretreatment device or flow dissipator to reduce flow velocity prior to entering the filter media. If flow velocity cannot be reduced to non-erosive conditions, then the practice shall designed off-line (refer to Appendix C) by use of a flow regulator or flow splitter diversion structure to divert the WQv to the practice and allow larger flows to bypass the practice. For Design F-6, the distance between the impervious surface and the practice shall be no more than 30 ft to avoid re-concentration of stormwater runoff and/or erosion of the engineered media. Runoff shall be conveyed by overland sheet flow only. Designs F-1, F-2, F-3, F-5 and F-6 shall be equipped with a perforated pipe underdrain in a washed stone drainage layer. For Design F-5, except where a liner is provided, underdrain systems shall be designed to create an internal water storage using one of the following methods: Provide an upturned elbow, set 10 inches above the bottom of practice (See Appendix C) Set the outlet pipe invert, at the outlet control structure, 10 inches above the bottom of practice; or Increase the drainage layer depth to provide 8 inches of stone below the underdrain. Filtering practice outlet(s) shall be designed to ensure non-erosive outlet conditions. Designs F-1, F-2, F-3, F-4 and F-5 shall include an emergency spillway or overflow chamber with outlet pipe to safely convey stormwater exceeding the Extreme Flood. Designs F-4 and F-5 shall be equipped with an outlet mechanism designed to meet the maximum ponding depths, defined in Table 6.14. This can be accomplished with an overflow weir, an overflow structure or a combination of the two. Multiple outlet mechanisms may be necessary. The outlet must be able to convey flows exceeding the WQv storm. 6.4.3 Pretreatment 6.4.3.1 Design Criteria Adequate pretreatment for Designs F-1, F-2, and F-3 shall incorporate a pretreatment volume equivalent to at least 25% of the required WQv, within one of the following pretreatment devices: A sedimentation chamber, plunge pool or forebay with a length to width ratio of 1.5:1; or Approved proprietary pretreatment device (Refer to Chapter 9). Adequate pretreatment for Designs F-4, and F-5 shall incorporate one of the following: Sheet flow to minimum 24 inch wide by 12 inch deep pea gravel diaphragm and grass filter strip; or Concentrated flow through a vegetated swale into a flow spreader; or Concentrated flow into a flow spreader that discharges into a minimum 24 inch wide by 12 inch deep pea gravel diaphragm to a grass filter strip; or Concentrated flow into a sedimentation chamber, plunge pool or forebay with a length to width ratio of 1.5:1 that is sized to hold a pretreatment volume equivalent to 25% of the required WQv; or Concentrated flow into an approved proprietary pretreatment device (Refer to Chapter 9)that discharges into a flow spreader. Sheet flow into gabion baskets or stone and curb check dams, when located within parking lot or roadway islands, medians or bumpouts (Refer to Chapter 8). Adequate pretreatment for Design F-6 shall incorporate the following: Sheet flow to a minimum 24 inch wide by 12 inch deep pea gravel diaphragm and grass filter strip. Chapter 6:Standard Stormwater Management Practices _58 Sizing of Grass Filter Strip The grass filter strip shall be sized using the guidelines in Table 6.13. I Table 6.13 Guidelines for Grass Filter Strip Pretreatment Sizing Parameter Impervious Parking Lots/Roads Residential Lots Max. Inflow Approach Length (ft) 35 75 75 150 Grass Filter Strip Slope <_2% 2-8% <_2% 2-8% <_2% 2-8% <_2% 2-8% Min. Grass Filter Strip Length (ft) 10 15 20 25 10 12 15 18 Sizing of Sedimentation Chamber Calculate the minimum surface area of the sedimentation using the Camp-Hazen equation: AS = (-1)(Wo/ [ln(1 —E)] Where: As= Sedimentation chamber surface area (sf) E = Sediment basin efficiency (use 0.90) Ws = Particle settling velocity (ft/sec) use 0.0004 ft/sec for imperviousness (1) <_ 75% use 0.0033 ft/sec for I > 75% Qo= Discharge rate from basin = (WQ /24-hr/3600s) WQv= Water Quality Volume (cf) This equation reduces to: As= (0.066) (WQv) sf for 1 <_ 75% As= (0.0081) (WQv) sf for I > 75% Calculate the maximum depth of the sedimentation chamber: ds = (%PT)(WQv) As Where: As= Sedimentation chamber surface area (sf) ds= Depth of sedimentation chamber(ft) %PT= Percent WQv pretreatment required WQv= Water Quality Volume (cf) If proposed depth of sedimentation chamber is less than the maximum depth of sedimentation chamber, calculate the new minimum surface area of sedimentation chamber: A = WQv s ds proposed If multiple sedimentation chambers are provided to meet the minimum surface area, then the surface area shall be distributed across the structures. The percentage of the surface area provided by each structure shall correlate to the percentage of contributing impervious area to each structure. Chapter 6:Standard Stormwater Management Practices6_59 6.4.4 Treatment 6.4.4.1 Design Criteria General For Designs F-1, F-2, F-3, F-4, F-5, the surface of the filter media shall be completely level. For Design F-2, the minimum internal structure height shall be 5 ft. For Design F-5, the ends of underdrains, not terminating in an observation well, shall be capped. Designs F-4 and F-5 shall use the standard material for the filter media, as listed in Table 6.14. However, is the practice is being constructed in a phosphorus impaired watershed Designs F-4 and F-5 shall use the enhanced material for the filter media, as listed in Table 6.14. For Design F-5, the practice filter bed surface area can be oversized to provide additional storage volume and receive additional RRv credit up to 100% of the WQv required. Refer to Section 4.4. For Design F-6, the following criteria shall apply: The underdrain system shall discharge to a storm drainage structure or a stable outfall. The underdrain shall be capped at the beginning of run. Must be adequately designed to safely pass flows that exceed the design storm flows. Embankment slopes shall be 4:1 or flatter. Longitudinal slopes (parallel with the embankment) shall be no more than 5%. Minimum width of filter media shall be 2 feet. Ponded water shall not be permitted above the filter media. The filter media shall have an initial infiltration rate of 50 inch/hr and an infiltration rate of 28 inch/hr. For sizing, an infiltration rate of 10 inch/hr shall be used in calculations as a factor of safety. Chapter 6:Standard Stormwater Management Practices 6-60 F-1 F-2 F-3 F-4 I F-5 F-6 Applicability N/A N/A N/A As Required As Required Required Pea Gravel Diaphragm Depth 24 inch min. Material ASTM D448 No. 6 Stone, Porosity=32% Applicability Required Required Required Required Required N/A Ponding 12 inch max. (WQv) Depth 18 inch max. (Extreme Flood) Applicability Optional Required N/A I Required I Required N/A Depth 3 inch min. Choker Surface Layer Course: AASHTO Shredded Hardwood Mulch Material Topsoil No. 57 N/A or Non-Invasive Living N/A stone, Mulch washed, no fines Depth 18-24 inch 12-24 inch 30-48 inch 12 inch min. Standard ASTM C-33 Sand: 60%-75% Filter Media Material Topsoil': 25%-40% Blend of Stone, Sand: ASTM C-33 concrete sand ASTM C-33 Sand:85%-95% Perlite, Dolomite, Enhanced Topsoil/Organics: 5%-15% Gypsumz Material P-Index: 12 to 30 Drainage Depth 10 inch 6 inch 10 inch >_14 inch Layer' Material AASHTO No. 57 stone, washed, no fines Applicability Required Required Required N/A Required Required Underdrain 6" perforated PVC or HDPE laid at 0%slope at 30 ft max. O.C. with internal water storage; Material in all other cases, 6" perforated PVC or HDPE laid at 0.5%slope min. at 30 ft max. O.C. Drainage Filter Applicability Required Required Required Required Required Required Fabric Materials Non-woven, polypropylene geotextile with flow rate greater than 125 gpm/sf(ASTM D4491) and Apparent Opening Size US#70 sieve(ASTM D4751) Applicability As Required N/A I N/A I N/A I As Required I As Required Impermeable 12-24 inch of clay soil (min. 50% passing#200 sieve and max. permeability 1 x 10-5 Liner Material cm/sec) or 40 mil HDPE geomembrane Slope 15% max. Maintenance Width 12 ft. min. Access' Material Able to withstand loading from maintenance equipment and vehicles Footnotes: 'Required for all Design Variants ZDesign Variant F-6: • Stone: No.89, no recycled material, non-limestone material mineral aggregate • Perlite:Agricultural grade,free of toxic materials(0-30%passing No.18 Sieve,0-10%passing No.30 Sieve)1 cy/3 cy of stone • Dolomite:CaMg(CO3)2(calcium magnesium carbonate)Agricultural grade,free of toxic materials(100%passing No.8 Sieve,0% passing No.16 Sieve) 10 Ibs/cy perlite • Gypsum:CaSO4.2H2O(hydrated calcium sulfate). Non-calcined,agricultural grade,free of toxic materials(100%passing No.8 Sieve, 0%passing No.16 Sieve)1.5 Ib/cy perlite 3Enhanced Filter Media shall be used within watersheds requiring enhanced phosphorus removal. Refer to Chapter 4 for impaired watershed information. 'Topsoil shall conform to NYSDOT Standard Specification 713-01 for Roadside Mix or Specialty Planting Mix. 5For Designs F-4 and F-5,the organic component shall not consist of compost. 60r acceptable alternatives,such as a 3 inch minimum layer of pea gravel Chapter 6:Standard Stormwater Management Practices 6•• 1 Maintenance Access A maintenance access easement shall extend to the practices from a public or private road. Adequate maintenance access must extend to the pretreatment device, outlet structure/overflow, emergency spillway, and must have sufficient area to allow vehicles to turn around. For Designs F-2, F-3, F-4 and F-5, access shall be provided by lockable manhole cover or grate to the practice/outlet structure. For Design F-6 access shall be provided from the adjacent impervious surface. 6.4.4.2 Sizing Criteria Design Variants (F-1 through F-5) The practice shall have a minimum of 50% WQv provided in ponding above the filter media. In addition, the practice shall be sized to capture, retain and filter the entire WQv event without overflow or bypass. A permeability flow rate (k) for filter media shall be for water quality and quantity sizing as follows: Sand: 3.5 ft/day (City of Austin 1988) Bioretention: 1 ft/day The filter area shall be sized based on the principles of Darcy's Law. Calculate the minimum bottom area: _ (WQ,)(df) Af (k)(hf + df)(tf) Where: Af= Filter area (so WQv= Water Quality Volume (co df= Depth of filter(ft) k= Permeability flow rate of filter media (ft/day) hf=Average height of ponding (ft) (0.5 ft max.) tf= Maximum filter bed drain time (days) (use 1.67 days for sand filters, 2 days for bioretention) Design Variants (F-6) Generally only the WQv is treated by a bioslope, so another practice may be necessary to provide CPv extended detention. However, for some smaller sites, a bioslope could provide some benefit towards detaining a portion of the full CPS. The width of filter media shall be sized, to treat the WQv for the surface discharge tributary to the bioslope. The length of the bioslope is equal to the length of the contributing area. Calculate the minimum filter media width required, using the calculations below. The minimum filter media width shall be no less than 24 inches. First, calculate the required WQv, per Chapter 4. Then, calculate the Water Quality Peak Flow Rate (Appendix B). Calculate the required filter media width: W _ (43,200)(WQF) (k)(L) Where: W= Bioslope width (ft) WQF = Water Quality Peak Flow Rate (cfs) k= Permeability flow rate of filter media (10 in/hr) L = Bioslope length (ft) Chapter 6:Standard Stormwater Management Practices - 2 6.4.5 Landscaping For planting guidance for stormwater management facilities, refer to Chapter 11. Permanent vegetative cover shall achieve 80% uniform density established over the entire contributing pervious area, before runoff is directed into the facility. A landscaping plan for Designs F-4 and F-5 shall be prepared to indicate how the practice bottom surface area and side slopes will be stabilized and established with vegetation and show the selection and layout of corresponding plant species. Chapter 6:Standard Stormwater Management Practices 6-63 Fact Sheet: Surface Sand Filter (F-1) Description: Consists of a pretreatment sedimentation chamber or other pretreatment that discharges to an open sand filter bed designed to treat stormwater runoff, then return it to the conveyance system through a perforated underdrain system. _ x (Photo Source: Chesapeake Stormwater Network) e t' PERFORMANCE CRITERIA STORMWATER MANAGEMENT SUITABILITY FEASIBILITY O Water Quality Max. contributing area is 10 acres O Channel Protection Minimum 2 ft separation to seasonal high-water table or bedrock, unless ® Overbank Flood Protection an impermeable liner is provided Extreme Flood Protection Design and construct level,with no longitudinal or lateral slope Impermeable liner shall be provided at the bottom of the drainage layer • Runoff Reduction and all sides when accepting hotspot runoff 0 Treatment of Hotspots CONVEYANCE O Linear Applications Runoff conveyed by pipe or concentrated flow shall utilize a pretreatment V suitable for this practice device or flow dissipator to reduce flow velocity prior to entering the filter media IMPLEMENTATION CONSIDERATIONS If flow velocity cannot be reduced to non-erosive conditions,the practice ® Capital Cost shall be designed off-line Equip practice with a perforated pipe underdrain in a washed stone Maintenance Burden drainage layer O Safety Risk Outlet(s)shall be designed to ensure non-erosive outlet conditions O Landscaping An emergency spillway or overflow chamber with outlet pipe to safely convey stormwater exceeding the Extreme Flood shall be included L= Low M = Moderate H =High NA= Not Applicable PRETREATMENT POLLUTANT REMOVAL(See Table 10.3) Pretreatment shall provide min 25%WQv using a sedimentation chamber, plunge pool or forebay with a length to width ratio of 1.5:1, or an approved ® Phosphorus proprietary pretreatment device 10 Nitrogen TREATMENT Practice shall be sized (including pretreatment)to temporarily hold the O Metals WQv prior to filtration ® Pathogens Max ponding is 12 inches(WQv)and 18 inches(Extreme Flood) O Total Suspended Solids Depth of filter media shall be 18 inches min and 24 inches max G=Good F= Fair P= Poor Depth of drainage layer shall be 10 inches RUNOFF REDUCTION CREDIT Min 12 ft wide maintenance access shall be provided 15% max slope 0% RRv provided Chapter 6:Standard Stormwater Management Practices =r- Fact Sheet: Underground Sand Filter (F-2) Description: A practice where piped stormwater runoff is conveyed to an underground vault, consisting of a pretreatment sedimentation chamber that overflows to a sand filter bed designed to treat stormwater runoff, then return it to the conveyance system °P' through an outlet pipe A (Photo Source: Water Online) Key Considerations �t PERFORMANCE CRITERIA STORMWATER MANAGEMENT SUITABILITY FEASIBILITY O Water Quality Max contributing area is 2 acres O Channel Protection Minimum 2 ft separation to seasonal high-water table or bedrock ® Overbank Flood Protection Design and construct level,with no longitudinal or lateral slope ® Extreme Flood Protection CONVEYANCE • Runoff Reduction Runoff conveyed by pipe or concentrated flow shall utilize a pretreatment device or flow dissipator to reduce flow velocity prior to entering the filter 0 Treatment of Hotspots media 0 Linear Applications If flow velocity cannot be reduced to non-erosive conditions,the practice shall be designed off-line ✓suitable for this practice Equip practice with a perforated pipe underdrain in a washed stone IMPLEMENTATION CONSIDERATIONS drainage layer ® Capital Cost Outlet(s)shall be designed to ensure non-erosive outlet conditions Maintenance Burden An emergency spillway or overflow chamber with outlet pipe to safely convey stormwater exceeding the Extreme Flood shall be included O Safety Risk PRETREATMENT Landscaping Pretreatment shall provide min 25%WQv using a sedimentation chamber, L= Low M = Moderate H =High plunge pool or forebay with a length to width ratio of 1.5:1, or an approved NA= Not Applicable proprietary pretreatment device TREATMENT POLLUTANT REMOVAL(See Table 10.3) Practice shall be sized (including pretreatment)to temporarily hold the 10 Phosphorus WQv prior to filtration ® Nitrogen Min internal structure height is 5 ft O Metals Max ponding is 12 inches(WQv)and 18 inches(Extreme Flood) Depth of filter media shall be 18 inches min and 24 inches max ® Pathogens Depth of drainage layer shall be 10 inches O Total Suspended Solids Min 12 ft wide maintenance access shall be provided 15% max slope G=Good F= Fair P= Poor RUNOFF REDUCTION CREDIT 0% RRv provided Chapter 6:Standard Stormwater Management Practices Fact Sheet: Perimeter Sand Filter (F-3) Description: A practice where stormwater runoff is conveyed via sheet flow 'w I y to an underground vault with open grates that consists of a pretreatment sedimentation chamber that overflows to a sand filter bed designed to treat stormwater runoff, then return it to the conveyance system through an outlet pipe. (Photo Source: Greensboro, North Carolina, Department of Water Resources) X • • • PERFORMANCE CRITERIA STORMWATER MANAGEMENT SUITABILITY FEASIBILITY to Water Quality Max contributing area is 2 acres O Channel Protection Minimum 2 ft separation to seasonal high-water table or bedrock ® Overbank Flood Protection Design and construct level,with no longitudinal or lateral slope ® Extreme Flood Protection CONVEYANCE • Runoff Reduction Runoff conveyed by pipe or concentrated flow shall utilize a pretreatment device or flow dissipator to reduce flow velocity prior to entering the filter 0 Treatment of Hotspots media ® Linear Applications • If flow velocity cannot be reduced to non-erosive conditions,the practice shall be designed off-line ✓suitable for this practice Equip practice with a perforated pipe underdrain in a washed stone IMPLEMENTATION CONSIDERATIONS drainage layer ® Capital Cost Outlet(s)shall be designed to ensure non-erosive outlet conditions Maintenance Burden An emergency spillway or overflow chamber with outlet pipe to safely convey stormwater exceeding the Extreme Flood shall be included O Safety Risk PRETREATMENT Landscaping Pretreatment shall provide min 25%WQv using a sedimentation chamber, L= Low M = Moderate H =High plunge pool or forebay with a length to width ratio of 1.5:1, or an approved NA= Not Applicable proprietary pretreatment device TREATMENT POLLUTANT REMOVAL(See Table 10.3) Practice shall be sized (including pretreatment)to temporarily hold the 10 Phosphorus WQv prior to filtration ® Nitrogen Max ponding is 12 inches(WQv)and 18 inches(Extreme Flood) O Metals Depth of filter media shall be 12 inches min and 24 inches max Depth of drainage layer shall be 10 inches ® Pathogens Min 12 ft wide maintenance access shall be provided 15% max slope O Total Suspended Solids G=Good F= Fair P= Poor RUNOFF REDUCTION CREDIT 0% RRv provided Chapter 6:Standard Stormwater Management Practices Fact Sheet: Infiltration Bioretention (F-4) Description: Shallow stormwater controls that utilize vegetation and engineered filter media to capture, treat, and infiltrate stormwater runoff into the underlying soils. N - Y • • • PERFORMANCE CRITERIA STORMWATER MANAGEMENT SUITABILITY FEASIBILITY O Water Quality Underlying soils shall have an min. infiltration rate of 0.50 inch/hr O Channel Protection Design and construct level,with no longitudinal or lateral slope O Overbank Flood Protection Max contributing area is 5 acres 611 Extreme Flood Protection Min 2 ft separation to seasonal high-water table or bedrock ® Runoff Reduction ® Two treatment practices in series both sized to treat the entire WQv(non- infiltration standard SMP followed by an infiltration practice)shall be ® Treatment of Hotspots provided for hotspot treatment Linear Applications CONVEYANCE ✓suitable for this practice Runoff conveyed by pipe or concentrated flow shall utilize a pretreatment IMPLEMENTATION CONSIDERATIONS device or flow dissipator to reduce flow velocity prior to entering the filter media o Capital Cost If flow velocity cannot be reduced to non-erosive conditions,the practice shall be designed off-line Maintenance Burden Outlet(s)shall be designed to ensure non-erosive outlet conditions © Safety Risk An emergency spillway or overflow chamber with outlet pipe to safely © Landscaping convey stormwater exceeding the Extreme Flood shall be included L= Low M = Moderate H =High PRETREATMENT NA= Not Applicable Pretreatment shall provide min 25%WQv POLLUTANT REMOVAL(See Table 10.3) TREATMENT O Phosphorus Practice shall be sized (including pretreatment)to temporarily hold the ® Nitrogen WQv prior to filtration Max ponding is 12 inches(WQv)and 18 inches(Extreme Flood) ® Metals Depth of filter media shall be 30 inches min and 48 inches max O Pathogens Depth of drainage layer shall be 6 inches ® Total Suspended Solids Min 12 ft wide maintenance access shall be provided 15% max slope G=Good F= Fair P= Poor RUNOFF REDUCTION CREDIT 100% RRv provided Chapter 6:Standard Stormwater Management Practices Fact Sheet: Filtration Bioretention (F-5) Description: Shallow stormwater controls that utilize vegetation and engineered filter media to capture and treat stormwater runoff, then return it .3 to the conveyance system through a perforated underdrain system. PERFORMANCE CRITERIA STORMWATER MANAGEMENT SUITABILITY FEASIBILITY O Water Quality Max contributing area is 5 acres O Channel Protection Minimum 2 ft separation to seasonal high-water table or bedrock, unless ® Overbank Flood Protection an impermeable liner is provided O Extreme Flood Protection Design and construct level,with no longitudinal or lateral slope Impermeable liner shall be provided at the bottom of the drainage layer ® Runoff Reduction and all sides when accepting hotspot runoff ® Treatment of Hotspots CONVEYANCE O Linear Applications Runoff conveyed by pipe or concentrated flow shall utilize a pretreatment V suitable for this practice device or flow dissipator to reduce flow velocity prior to entering the filter media IMPLEMENTATION CONSIDERATIONS If flow velocity cannot be reduced to non-erosive conditions,the practice ® Capital Cost shall be designed off-line Equip practice with a perforated pipe underdrain in a washed stone Maintenance Burden drainage layer ® Safety Risk Underdrain systems shall include an upturned elbow, set 10 inches above the bottom of practice Landscaping Outlet(s)shall be designed to ensure non-erosive outlet conditions L= Low M = Moderate H =High NA= Not Applicable An emergency spillway or overflow chamber with outlet pipe to safely convey stormwater exceeding the Extreme Flood shall be included POLLUTANT REMOVAL(See Table 10.3) PRETREATMENT 10 Phosphorus Pretreatment shall provide min 25%WQv ® Nitrogen TREATMENT O Metals Practice shall be sized (including pretreatment)to temporarily hold the WQv prior to filtration 10 Pathogens Max ponding is 12 inches(WQv)and 18 inches(Extreme Flood) O Total Suspended Solids Depth of filter media shall be 30 inches min and 48 inches max G=Good F= Fair P= Poor Depth of drainage layer shall be 10 inches RUNOFF REDUCTION CREDIT Min 12 ft wide maintenance access shall be provided 15% max slope To apply the CPv waiver for this practice, the surface area of the practice 40% RRv provided shall be sized to provide 100% RRv for the 1-year 24-hour storm event Chapter 6:Standard Stormwater Management Practices Fact Sheet: Bioslope (F-6) s v psi Description: Installed along embankments or other slopes and use a •,ram permeable engineered filter media to treat sheet flow stormwater runoff. They are designed with limited longitudinal slopes to force flow through an engineered filter media and to an underdrain for conveyance. (Photo Source: Atlanta Regional Commission) • •N • PERFORMANCE CRITERIA STORMWATER MANAGEMENT SUITABILITY FEASIBILITY O Water Quality Max contributing flow path shall be 100 ft from impervious surfaces and ® Channel Protection 150 ft total ® Overbank Flood Protection Minimum 2 ft separation to seasonal high-water table or bedrock, unless an impermeable liner is provided Extreme Flood Protection Max slope along the contributing impervious flow path is 5% ® Runoff Reduction Impermeable liner shall be provided at the bottom of the drainage layer ® Treatment of Hotspots and all sides when accepting hotspot runoff CONVEYANCE ® Linear Applications The distance between the impervious surface and the practice shall be no V suitable for this practice more than 30 ft IMPLEMENTATION CONSIDERATIONS Runoff shall be conveyed by overland sheet flow only ® Capital Cost Equip practice with a perforated pipe underdrain in a washed stone Maintenance Burden drainage layer Outlet(s)shall be designed to ensure non-erosive outlet conditions © Safety Risk PRETREATMENT O Landscaping Pretreatment shall provide min 25%WQv with a pea gravel diaphragm L= Low M = Moderate H =High and grass filter strip NA= Not Applicable TREATMENT POLLUTANT REMOVAL(See Table 10.3) Depth of filter media shall be 14 inches min ® Phosphorus Depth of drainage layer shall be 14 inches min O Nitrogen Min 12 ft wide maintenance access shall be provided 15% max slope Maintenance access shall be provided from the adjacent impervious Metals surface ® Pathogens ® Total Suspended Solids G=Good F= Fair P= Poor RUNOFF REDUCTION CREDIT 40% RRv provided for HSG A or B 20% RRv provided for HSG C or D Chapter 6:Standard Stormwater Management Practices i� 1 Section 6.5 Open Channel Systems Open channel systems are vegetated open channels that are explicitly designed to capture and treat the full WQv within dry or wet cells formed by check dams or other means. Design variants include: 0-1 Dry Swale (Figure 6.22) 0-2 Wet Swale (Figure 6.23) Chapter 6:Standard Stormwater Management Practices 6-70 Dry Swale (0-1) Dry swales are a vegetated conveyance channel designed to include a filter bed of prepared soil that may overlay an underdrain system. Dry swales are sized to allow the entire WQv to be filtered or infiltrated through the bottom of the Swale. STABILIZED INLET PRETREATMENT f OREBAY rINLET CHECK DAM -- PIPE - 3:1 (H:V) - -- 1F MAX ;i - 0.5%-4% FT low y 6" PERFORATED y `� ----- UNDERDRAIN " T h � EDGE OF PAVEMENT L SHEET FLOW ROADWAY PEA GRAVEL DIAPHRAGM TO SWALE PLAN VIEW WQv MAX PONDING DEPTH = 12" (MID—POINT OF CHANNEL FLOW PATH), 18- (END—POINT OF CHANNEL FLOW PATH) OIERBANK FLOOD ADJACENT CONTROL 2, 8' ROADWAY 5% I I � I _ 3:1 (H.V) MAX n 77 e kY - SIDE SLOPE —1 � r - k5r30" FILTER MEDIA =, 6" MIN FREEBOARD DRAINAGE FILTER FABRIC PEA GRAVEL t " ' (TYP) DIAPHRAGM 10" NO 57 STONE DRAINAGE LAYER 24" MIN SEPARATION I,, L-� `i; (WASHED, NO FINES) TO SEASONAL HIGH WATER 6" PERFORATED TABLE/BEDROCK P UNDERDRAIN SECTION A-A VIEW Figure 6.22 Dry Swale (0-1) Chapter 6:Standard Stormwater Management Practices 6-71 Wet Swale (0-2) Wet swales are a vegetated conveyance channel designed to retain water/create marshy conditions that support wetland vegetation. A seasonal high water table or poorly drained soils are necessary to retain water. The wet swale essentially acts as a linear shallow wetland treatment system, where the WQv is retained. STABILIZED INLET PRETREATMENT u FOREBAY INLET CHECK DAM PIPE 3:1 (H:V) J --- MAX 0.5%-4% y } "M _. EDGE OF PAVEMENT A SHEET FLOW —ROADWAY— PEA GRAVEL DIAPHRAGM TO SWALE PLAN VIEW WOv MAX PONDING DEPTH 12' (MID-POINT OF CHANNEL FLOW PATH), 18" (END-POINT OF CHANNEL FLOW PATH) OVERBANK FLOOD ADJACENT CONTROL 2'-8' ROADWAY 5%• — - 3:1 (H:V) MAX SIDE SLOPE 6" MIN �BOTTOM OF PRACTICE SET PEA GRAVEL FREEBOARD AT OR BELOW SEASONAL DIAPHRAGM HIGH WATER TABLE WRAPPED IN DRAINAGE FILTER FABRIC SECTION A-A VIEW Figure 6.23 Wet Swale (0-2) Chapter 6:Standard Stormwater Management Practices 6-72 6.5.1 Feasibility 0-1 shall be applied for land uses such as roads, highways, residential development, and pervious areas. 0-2 shall not be applied in residential areas because of the potential for stagnant water and ponding. 0-1 shall have a minimum 2 ft separation between the bottom of the stone drainage layer and seasonal high water table or bedrock. Where separation cannot be met, an impermeable liner shall be provided at bottom of drainage layer and all sides. 0-1 can be used to treat stormwater runoff from a designated hotspot. However, an impermeable liner shall be provided at bottom of drainage layer and all sides. Design 0-2 shall not be used to treat stormwater runoff from a designated hotspot. The maximum contributing area shall be 5 acres. 6.5.2 Conveyance Swales shall be designed to safely convey up to and including the Extreme Flood Event. Channels shall be designed to drain the entire WQv within 48-hrs after the storm event. When runoff sheet flows from an impervious surface to an open channel system, a maximum 6 inch drop from the edge of impervious surface to a minimum 24 inch wide by 12 inch deep pea gravel diaphragm shall be provided. Where culvert pipes are proposed, the pipe shall have a minimum diameter of 12 inches and minimum slope of 0.50%, designed to convey the Overbank Flood event while safely conveying the Extreme Flood event. 6.5.3 Pretreatment Prior to entering the open channel system, 10% of the WQv shall be provided as pretreatment. The following pretreatment devices are appropriate for use with open channel systems. Pretreatment sedimentation chamber sized in accordance with Section 6.4.3. Plunge pool or forebay. Provide check dams, or other low flow control structure capable of draining the channel within 48 hours, at inlet pipes and/or driveway crossings. For runoff conveyed via sheet flow, provide a 24 inch wide by 12 inch deep pea gravel diaphragm at the downgradient edge of the impervious surface. In this case, the maximum contributing surface slope shall be 5%. Approved proprietary pretreatment device (Refer to Chapter 9). Chapter 6:Standard Stormwater Management Practices -73 6.5.4 Treatment 6.5.4.1 Design Criteria Open channel practices shall meet the design criteria outlined in the table below: TableOpen Channel Design • • O-1 O-2 Freeboard' Depth 6 inch min. measured from Overbank Flood elevation to top of swale Ponding Depth 12 inch max. at mid-point of channel flow path during WQv Storm 18 inch max. at end point of channel flow path during WQv Storm Width 2 ft min. 8 ft max. Channel Longitudinal 0.5% min. Slope 4% max. Side Slope 3:1 (h:v) max. Applicability Required N/A Filter Mediae Depth 30 inches Standard ASTM C-33 Sand: 75%-85% Material Topsoi13,4: 15%-25% Applicability Required N/A Drainage Depth 10 inches min. Layer Material AASHTO No. 57 stone, washed, no fines Applicability Required N/A Drainage Filter Fabric Materials Non-woven, polypropylene geotextile with flow rate greater than 125 gpm/sf (ASTM D4491)and Apparent Opening Size US#70 sieve(ASTM D4751) Applicability As Required N/A Impermeable 12-24 inch of clay soil (min. 50% passing#200 sieve and max. permeability Liner Material 1 x 10-5 cm/sec) or 40 mil HDPE geomembrane Applicability Required N/A Underdrain Material 6" min. perforated PVC or HDPE Depth 1 ft max. Check Dams' Side Slopes 2:1 max. Spacing Refer to Section 6.5.4.2 Material Well graded stone matrix 2 to 9 inches Footnotes: 'Required for all Design Variants 2Enhanced Filter Media shall be used within watersheds requiring enhanced phosphorus removal. 3Topsoil shall conform to NYSDOT Standard Specification 713-01 for Roadside Mix or Specialty Planting Mix. 4The organic component shall not consist of compost. 5Or acceptable alternatives,such as a 3 inch minimum layer of pea gravel Chapter 6:Standard Stormwater Management Practices ••7 6.5.4.2 Sizing Criteria First, compute the required WQv, per Chapter 4: Next, select proposed dimensions of the open channel for the bottom width, side slopes, channel length and channel height, and longitudinal slope. Then calculate the top width and area of the WQv flow based on the WQv flow depth: WwQ„ = b + (2)(Side Slope)(d) (d)(b + WwQ„) AwQ„ = 2 Where: WNQv= WQv flow top width (ft) b = Bottom width (ft) d = WQv maximum flow depth (ft) AWQv=Area of WQv flow (so Calculate the required swale length. The proposed channel length shall be greater than or equal to the required swale length. L = WQv r AwQ„ LP �! Lr Where: Lr= Required channel length (ft) Lp = Proposed channel length (ft) Calculate the channel volume provided in the WQv flow event. The volume of the channel shall be greater or equal to the required WQv. Vc = LP 'AwQ„ VC > W QV Select a check dam height and calculate the required check dam spacing and number of check dams required, based on the check dam standard within the NYSDEC Standard and Specifications for Erosion and Sediment Control. CH CS S L L P C = CS Where: Cs = Check dam spacing (ft) CH = Check dam height (ft) SL= Longitudinal slope of channel (ft/ft) C = Number of check dams (round down) Determine the 2-year average flow depth and calculate the top width and flow area of the 2-year storm event. W2 = b + (2)(Side Slope)(d2) A2 _ (d2)(b +W2) 2 Chapter 6:Standard Stormwater Management Practices 6-7 Where: W2 = 2-year storm flow top width (ft) d2 = 2-year 24-hr flow depth A2 =Area of 2-year 24-hr flow (so Calculate the 2-yr velocity within the channel using Manning's equation to ensure non-erosive conditions. PWZ = b + (d22 + [(Side Slope)(d2)]2)1/2(2) V2 = (1.49 1 2 12/3 (SL) 1/2 \P, Where: V2 = 2-yr velocity (fps) n = Manning's coefficient (See Appendix G) Pw2 = Wetted perimeter during 2-year 24-hr storm Confirm that a minimum of 6 inches of freeboard is provided during the Overbank Flood event. 6.5.5 Landscaping For planting guidance for stormwater management facilities, refer to Chapter 11. Permanent vegetative cover shall achieve 80% uniform density established over the entire contributing pervious area, before runoff is directed into the facility. Chapter 6:Standard Stormwater Management Practices 6-76 Fact Sheet: Dry Swale (0-1) Description: Vegetated channels that are explicitly designed and constructed to capture and treat stormwater runoff within dry cells. Dry swales include a filter bed of prepared soil and are sized to filter or infiltrate the entire WQ,. 3 •l W � _ Key Considerations PERFORMANCE CRITERIA STORMWATER MANAGEMENT SUITABILITY FEASIBILITY ® Water Quality Shall be applied for land uses such as roads, highways, residential ® Channel Protection development, and pervious areas 0 Overbank Flood Protection Min 2 ft separation to seasonal high water table or bedrock, unless • impermeable liner is provided Extreme Flood Protection Impermeable liner shall be provided for hotspots 10Runoff Reduction Max contributing area is 5 acres 0 Treatment of Hotspots CONVEYANCE Linear Applications An underdrain shall be provided Shall have non-erosive outlet conditions ✓suitable for this practice IMPLEMENTATION CONSIDERATIONS Design to drain the entire WQv within 48 hrs after the storm event For sheetflow from impervious surfaces, a max 6 inch drop to a pea ® Capital Cost gravel diaphragm shall be provided ® Maintenance Burden Where culvert pipes are proposed, the pipe shall have a min 12 inch diameter and a min slope of 0.50%, designed to convey the Overbank ® Safety Risk Flood event and safely convey the Extreme Flood event O Landscaping PRETREATMENT L= Low M = Moderate H =High 10%WQv shall be provided as pretreatment NA= Not Applicable TREATMENT POLLUTANT REMOVAL(See Table 10.3) Min 6 inch freeboard shall be provided from the Overbank Flood elevation 0 Phosphorus to the top of swale Nitrogen Max ponding depth during WQv event is 12 inch at the mid-point of the channel flow path and 18 inch at the end point of the channel flow path ® Metals Filter media depth shall be 30 inches 0 Pathogens Min drainage layer depth shall be 10 inches Total Suspended Solids Bottom width shall be a min of 2 ft and a max of 8 ft G=Good F= Fair P= Poor Channel slope shall be 0.50% min and 4.0%max Max 3:1 side slope RUNOFF REDUCTION CREDIT Check dams shall be provided 40% RRv provided for HSG A or B 20% RRv provided for HSG C or D Chapter 6:Standard Stormwater Management Practices Fact Sheet: Wet Swale (0-2) Description: Vegetated channels that are explicitly designed and constructed to capture and treat stormwater runoff. Wet swales retain water to support wetland vegetation and essentially act as a linear shallow wetland treatment system, where the WQv is retained. (Photo Source: Maryland State Highway Administration) PERFORMANCE CRITERIA STORMWATER MANAGEMENT SUITABILITY FEASIBILITY ® Water Quality Shall not be applied in residential areas ® Channel Protection Max contributing area is 5 acres O Overbank Flood Protection CONVEYANCE • Extreme Flood Protection Shall have non-erosive outlet conditions ® Runoff Reduction Design to drain the entire WQv within 48 hrs after the storm event For sheet flow from impervious surfaces, a max 6 inch drop to a pea Treatment of Hotspots gravel diaphragm shall be provided O Linear Applications Where culvert pipes are proposed, the pipe shall have a min 12 inch ✓suitable for this practice diameter and a min slope of 0.50%, designed to convey the Overbank Flood event and safely convey the Extreme Flood event IMPLEMENTATION CONSIDERATIONS PRETREATMENT ® Capital Cost 10%WQv shall be provided as pretreatment ® Maintenance Burden TREATMENT to Safety Risk Min 6 inch freeboard shall be provided from the Overbank Flood elevation ® Landscaping to the top of swale Max ponding depth during WQv event is 12 inch at the mid-point of the L= Low M = Moderate H =High channel flow path and 18 inch at the end point of the channel flow path NA= Not Applicable Bottom width shall be a min of 2 ft and a max of 8 ft POLLUTANT REMOVAL(See Table 10.3) Channel slope shall be 0.50% min and 4.0%max 10 Phosphorus Max 3:1 side slope O Nitrogen Check dams shall be provided OMetals 0 Pathogens O Total Suspended Solids G=Good F= Fair P= Poor RUNOFF REDUCTION CREDIT 0%of the runoff reduction volume provided by this practice Chapter 6:Standard Stormwater Management Practices Chapter 7: Stormwater Management Design Examples This Chapter presents design examples for hypothetical developments in the State of New York that are intended to provide guidance on implementation of the Six-Step Process. The Chapter is divided into four sections, each providing an example of the most commonly used standard stormwater management practices. These design examples represent specific design nuances or elements and do not represent a full stormwater pollution prevention plan. Section 7.1 Using data from the example project, this section walks through watershed/subcatchment delineation, times of concentration, the six-step process based on Chapter 4, and design and sizing for conservation of natural areas, filtration bioretention and wet pond in accordance with Chapter 6. Section 7.2 Uses modified data from the example project to design and size a filtration bioretention and infiltration basin in a designated hotspot that meets the requirements of Chapter 4 and Chapter 6. Section 7.3 Uses modified data from the example project to design and size a dry swale that meets the requirements of Chapter 4 and Chapter 6. Section 7.4 Uses modified data from the example project to design and size multiple dry wells in series that meet the requirements of Chapter 4 and Chapter 6. Section 7.1 Sizing Example — Conservation, Bioretention and Wet Pond The site data listed below are for the hypothetical residential development (Table 7.1). 1 Table 7.1 Site Data Total Parcel Area 33.8 acres Existing Site Cover Vacant undeveloped woods and grass with an on-site wetland Existing Soils 59%C soils and 41% D soils with ono Soil Slope Phase"D"with unit name inclusive of slopes greater than 25/o or Soil Slope Phase"E"or"F" Depth to Bedrock 15 ft below existing grade Depth to Seasonal High 10 ft below existing grade Water Table Wetlands No existing NYSDEC wetlands on-site Existing federally regulated wetland on-site Watershed Does not discharge to a watershed requiring enhanced phosphorus removal Principal, Primary or Sole Does not lie within an aquifer Source Aquifer Hotspot The proposed development is not a hotspot(Section 4.14) 90t" percentile rainfall 1.20 inches(Section 4.2) 1-year 24-hour rainfall 2.22 inches(NRCC and NRCS joint collaborative website Section 4.9) 2-year 24-hour rainfall 2.60 inches(NRCC and NRCS joint collaborative website Section 4.9) 10-year 24-hour rainfall 3.74 inches(NRCC and NRCS joint collaborative website Section 4.9) 100-year 24-hour rainfall 6.31 inches(NRCC and NRCS joint collaborative website Section 4.9) Chapter 7:Stormwater Management Design Examples 7-1 Part 1. Delineate the Pre-development and Post-development Subcatchment Boundaries The study area consists of an overall watershed that contains the project site. The overall watershed is broken down into smaller watershed, or subcatchments, to allow for analysis of runoff conditions at several locations throughout the study area. Each of these locations is defined as a Design Point in order to compare the effects resulting from stormwater management facilities proposed as part of the project. A Design Point may include but is not limited to a concentrated point(end section, catch basin, etc.), the entire perimeter of a waterbody or permanent pool (wetland, stream, etc.), the full length of an existing on-site channel that is not being disturbed, or the full length of a natural flow spreader. A subcatchment is a relatively homogeneous area of land, which produces a volume and rate of runoff unique to that area. The subcatchment boundaries are determined using existing (and proposed under post-development)topography. Subcatchment lines originate at high points on the topography and run perpendicular to the contour lines until reaching a design point. These lines do not intentionally originate or terminate at the project's property boundaries, as runoff may flow onto or off of the site. Areas that will remain undisturbed should be bypassed around proposed stormwater management practices to avoid capture and treatment, maintain existing hydrology and minimize the footprint of proposed practices. Some computer design programs have the capability to delineate subcatchments using established topographic data. The subcatchments generated by these programs are considered approximate and shall be verified by the design engineer for consistency with site conditions. In addition, it is highly recommended that site visits be performed to confirmed delineated watershed divides, drainage paths and design points. Under the example project the pre-development project site is covered predominately by existing woodlands, with an on- site federally regulated wetland. The pre-development watershed delineation map is provided as Figure 7.1 with the area highlighted in blue identified as subcatchment ES-1. `�. ti. i t _ - — - Figure 7.1 Pre-development Watershed Delineation Map Under the example project the post-development project site will preserve areas of existing woodlands and the on-site federally regulated wetland. The area within the limit of disturbance will be covered predominately by impervious cover from pavement and buildings. The post-development watershed delineation map is provided as Figure 7.2, with the area highlighted in blue is identified as subcatchment PS-4. Chapter 7:Stormwater Management Design Examples 7-2 F-717 - F - Figure 7.2 Post-development Watershed Delineation Map Part 2. Determine the Pre-development and Post-development Cover Statistics Each subcatchment uses a Curve Number(CN) to characterize the runoff properties for a particular Hydrologic Soil Group (HSG) and ground cover. Some of these ground cover types can be classified as "Poor', "Fair" and "Good". It is the intent when classifying cover that"Poor" represents less than 50% ground cover density, "Fair" represents 50%to 75% ground cover density, and "Good" represents greater than 75% ground cover density. When referring to wood cover, "Poor" represents forest litter, small trees and brush destroyed by heavy grazing or regular burning; "Fair" represents woods grazed but not burned, and some forest litter covering the soil; "Good" represents woods protected from grazing, and litter and brush adequately covering the soil. In addition, the "Woods and Grass" cover type designation is intended to represent areas such as orchards or tree farms. For additional information regarding runoff curve numbers, refer to TR-55 Chapter 2. Infiltration rates of soils vary widely and are affected by subsurface permeability as well as surface intake rates. Soils are classified into four HSG's (A,B,C and D) according to their minimum infiltration rate, which is obtained for bare soil after prolonged wetting. High CN values cause most of the rainfall to appear as runoff with minimal losses. Lower values correspond to an increased ability of the soil to retain rainfall and produce less runoff. Figure 7.3 and Figure 7.5, shown below, provide the overall cover statistics for the pre-development and post-development conditions. Figure 7.4 and Figure 7.6, shown below, provide the cover statistics specific to pre-development subcatchment ES-1 and post- development subcatchment PS-4. Chapter 7:Stormwater Management Design Examples 7-3 Area CN Description (acres) (subcatchment-numbers) 4.430 74 >75%Grass cover,Good,HSG C (ES-1) 0.603 98 Paved parking, HSG C (ES-1) 0.012 98 Paved parking, HSG D (ES-1) 0.053 98 Roofs, HSG C (ES-1) 0.177 98 Water Surface,0%imp,HSG C (ES-1) 0.111 98 Water Surface,0%imp,HSG D (ES-1) 35,377 70 Woods, Good,HSG C (ES-1,ES-2) 3.219 77 Woods, Good,HSG D (ES-1) 43.982 72 TOTAL AREA Figure 7.3 Overall Pre-development Cover Statistics Area sf CN Description 2,326 98 Roofs, HSG C 26,278 98 Paved parking, HSG C 7,728 98 Water Surface,0%imp, HSG C 4,817 98 Water Surface,0%imp, HSG D 192,975 74 >75%Grass cover, Good, HSG C 140,204 77 Woods, Good, HSG D 763,723 70 Woods, Good, HSG C 506 98 Paved parking, HSG D 1,138,557 73 Weighted Average 1,109,447 97.44% Pervious Area 29,110 2.56% Impervious Area Figure 7.4 ES-1 Pre-development Cover Statistics Area CN Description (acres) (subcatchment-numbers) 5.879 74 >75%Grass cover,Good, HSG C (ES-1 A,ES-16,ES-2,PS-10, PS-2, PS-3,PS-4, PS-6, PS-7,PS-8,PS-9) 0.769 80 >75%Grass cover,Good, HSG D (ES-1 A,PS-10, PS-3, PS-4,PS-7,PS-9) 0.260 96 Gravel surface,HSG C (ES-1 B, ES-1 C, PS-4, PS-6,PS-8) 0.009 96 Gravel surface,HSG D (ES-1 B) 1.281 98 Paved parking, HSG C (ES-1 B, PS-10, PS-2, PS-3, PS-4, PS-5, PS-7, PS-8,PS-9) 0.143 98 Paved parking, HSG D (ES-1 B, ES-1 C, PS-3, PS-4, PS-7) 1.704 98 Paved roads wlcurbs&sewers, HSG C (PS-1) 0.361 98 Paved roads wlcurbs&sewers, HSG D (PS-1) 1.571 98 Roofs,HSG C (ES-1 B, ES-1 C, PS-10,PS-3, PS-4, PS-7, PS-8, PS-9) 0.145 98 Roofs,HSG D (PS-4, PS-7) 0.419 98 Water Surface, 0% imp,HSG C (ES-1 B, PS-6) 0.111 98 Water Surface, 0% imp,HSG D (ES-1 B) 29.591 70 Woods,Good, HSG C (ES-1A, ES-1 B, ES-1 C,ES-2) 1.740 77 Woods,Good, HSG D (ES-1 B, ES-1 C) 43.982 75 TOTAL AREA Figure 7.5 Overall Post-development Cover Statistics Area sf CN Description 2,654 98 Roofs,HSG C 5,042 98 Roofs,HSG D 1,475 98 Paved parking,HSG C 702 98 Paved parking,HSG D 3,075 80 >75%Grass cover,Good, HSG D 22,392 74 >75%Grass cover,Good, HSG C 36 96 Gravel surface, HSG C 35,376 81 Weighted Average 25,503 72.09%Pervious Area 9,873 27.91%Impervious Area Figure 7.6 PS-4 Post-development Cover Statistics Chapter 7:Stormwater Management Design Examples 7-4 Part 3. Calculate the Time of Concentration A time of concentration (Tc) is the time for runoff to travel from the hydraulically most distant point of the watershed to a point of interest within the watershed. Tc is computed by summing all the travel times for consecutive components of the drainage conveyance system. Water moves through a watershed as sheet flow, shallow concentrated flow, open channel flow, or a combination of these. Sheet flow is unconcentrated flow over existing or finish surfaces. In accordance with Chapter 4,the length of sheet flow used in Tc calculations is limited to no more than 150 ft for pre-development conditions and no more than 100 ft for post- development conditions. On areas of extremely flat terrain (<1% average slope), this maximum distance is extended to 250 ft for pre-development conditions and 150 ft for post-development conditions. If the start of Tc flow path is unchanged from pre-to post-development conditions, then the sheet flow length shall be identical. The value n is the Manning's roughness coefficient, which represents the friction applied to the flow by the existing or finish surface. When selecting an n value, the value should be what most closely represents the surface cover as this is what would obstruct sheet flow. Figure 7.7 shows values for n, taken from TR-55 Chapter 3: Surface description a_v Smooth surfaces(concrete,asphalt, gravel,or bare soil).......................................... 0.011 Fallow(no residue).................................................. 0.05 Cultivated soils: Residue cover 520%......................................... 0.06 Residue cover>20%......................................... 0.17 Grass: Short grass prairie............................................ 0.15 Dense grasses?�................................................ 0.24 Bermudagrass.................................................. 0,41 Range(natural)......................................................... 0,13 Woods: Light underbrush.............................................. 0.40 Dense underbrush............................................ 0.80 1 The n values are a composite of information compiled by Engman (1984 2 Includes species such as weeping lovegrass,bluegrass,buffalo grass,blue gra,ma grass,and native grass mixtures. 3 When selecting n,consider cover to a height of about 0.1 ft.This is the only part of the plant cover that will obstruct sheet flow. Figure 7.7 Reference: TR-55 Table 3-1 Roughness coefficients(Manning's n)for sheet flow Tc influences the shape and peak of the runoff hydrograph. Urbanization usually decreases Tc, thereby increasing the peak discharge. Tc can be increased as a result of ponding behind small or inadequate drainage systems, including storm drain inlets and road culverts, or reduction of land slope through grading. Under the example project, the pre-development times of concentration were determined using hydrologic modeling software. The summarized times of concentration for the pre-development conditions and are provided below in Figure 7.8. Information regarding the time of concentration and flow path for ES-1 are provided in Figure 7.9 and Figure 7.10. SubcatchmentES-1: Runoff Area=1,138,557 sf 2.56%Impervious Runoff Depth=3.45" Flow Length=1,255' Tc=34.9 min CN=74 Runoff=58.34 cfs 7.509 of SubcatchmentES-2: Runoff Area=777.278 sf 0-00%Impervious Runoff Depth=3.25" Flow Length=1,561' Tc=48.5 min CN=72 Runoff=31.66 cfs 4.831 of Figure 7.8 Overall Pre-development Times of Concentration Chapter 7:Stormwater Management Design Examples 7-5 I � 1 Figure 7.9 ES-1 Pre-development Times of Concentration Flow Path Tc Length Slope Velocity Capacity Description min feet ftlft) (ftlsec) (cfs 13.5 100 0.0300 0.12 Sheet Flow, Grass: Dense n=0.240 P2=2.60" 3.4 275 0.0372 1.35 Shallow Concentrated Flow, Short Grass Pasture Kv-7.0 fps 12.7 535 0.0196 0.70 Shallow Concentrated Flow, Woodland Kv=5.0 fps 5.3 345 0.0239 1.08 Shallow Concentrated Flow, Short Grass Pasture Kv=7.ftl 34.9 1,255 Total Figure 7.10 ES-1 Pre-development Times of Concentration Under the example project, the post-development times of concentration were determined using hydrologic modeling software. The summarized times of concentration for the post-development conditions and are provided below in Figure 7.11. Information regarding the time of concentration and flow path for PS-4 are provided in Figure 7.12 and Figure 7.13. For times of concentration less than 6 minutes, the minimum Tc applied is 6 minutes (0.1 hours) per TR-55 Chapter 3. Chapter 7:Stormwater Management Design Examples 7-6 SubcatchmentES-IA: Runoff Area=112,641 sf 0.00010 Impervious Runoff Depth=325" Flow Length=655' Tc=34.3 min CN=72 Runoff=5,48 cfs 0.700 at Subcatchment ES-1 B: Runoff Area=193,636 sf 14.74%Impervious Runoff Depth=3.96" Flow Length=993' Tc=39.0 min CN=79 Runoff=10.77 Gfs 1.466 at Subcatchment ESI C: Runoff Area=368,899 sf 0.64%Impervious Runoff Depth=3.35" Flow Length=1,069' Tc=58.8 min CN=73 Runoff=13,94 cfs 2.362 of SubcatchmentES-2: Runoff Area=759,467 sf 0.00%Impervious Runoff Depth=3.25" Flow Length=1,561' Tc=48-5 min CN=72 Runoff=30.94 ifs 4.720 of Subcatchment P5-1:Roadway Runoff Area=89,947 st 100.00%Impervious Runoff Depth=6XT' Tc=6_0 min CN=98 Runoff-14.88 cfs 1.045 of Subcatchment PS-10:outer Lots Runoff Area=97.395 sf 26,06%Impervious Runoff Depth=4A6" Flow Length=382' Tc=17.1 min CN=80 Runoff=8.19 cfs 0.757 of Subcatchment PS-2:DioretentionArea& Runoff Area=11,790 si 29.59%Impervious Runoff Depth=4.17" Flow Length=114' Slope=0.0175'r 'rc=17.0 min CN=81 Runoff=1.02 cfs 0.094 of Subcatchment PS-3:South Lots Runoff Area=73,825$1 32.36%Impervious Runoff Depth=4.27" Flow Length=140' Tc=12.4 min CN=82 Runoff=7.44 cfs 0.604 of Subcatchment PS-4:North Lot Runoff Area=35,376 sf 27.91%Impervious Runoff Depth=4.17" Flow Length=79' Slope=o,0380? Tc=10.1 min CN=81 Runoff=3,78 cfs 0.282 of Subcatchment PS-5:Maintenance Access Runoff Area=2,144sf 100.00%impervinus Runoff Depth=6.07" Tc=6,0 min CN=98 Runoff=0,35 cfs 0.025 of Subcatchment PS-6:Wet Pond Runoff Area=39.346 sf 0A0%Impervious Runoff Depth=4.49" Tc--6,0 rain CN=84 Runoff=5,39 cfs 0.338 of Subcatchment PS-7:East Lots Runoff Area=41,428 sf 41.26%Impervious Runoff Depth=4.81" Flow Length=92' Slope=0.0500? Tc=10.3 min CN=87 Runoff=5.00 cfs 0.382 of Subcatchment PS-8:Northeastern Lot Runoff Area=9,306 sf 40.33%Impervious Runoff Depth=4.49" Flow Length=60' Slope=0.0300 T Tc=8.9 min CN=84 Runoff=1,12 cfs 0.080 of Subcatchment PS-9:Inner Lots Runoff Aream80,661 sf 25,10%Impervious Runoff Depth=4.06" Flow Length=99' Slope=0,0500 T Tc=10.9 min CN=80 Runoff=8,16 cfs 0.627 of Figure 7.11 Overall Post-development Times of Concentration Chapter 7:Stormwater Management Design Examples 7-7 F y ] I lt�j -- � Figure 7.12 PS-4 Post-development Times of Concentration Flow Path Tc Length Slope Velocity Capacity Description min feet ft/ft ft/sec cfs 10.1 79 0.0380 0.13 Sheet Flow, Grass:Dense n=0.240 P2=2.60" Figure 7.13 PS-4 Post-development Times of Concentration Part 4. Six Step Process Step 1 —Site Planning The project site is evaluated for implementation of the green infrastructure planning measures identified in Table 3.1, in order to preserve natural resources and reduce impervious cover. Table 7.2 provides a description of each green infrastructure planning measure, along with a project specific evaluation. Practice Description Applicable Project Specific Evaluation The proposed site layout has been designed Preservation Delineate and protect undisturbed forests, native to limit land disturbance to the greatest of Undisturbed vegetated areas, riparian corridors, water bodies, Yes extent practical. Approximately 9.86+/-Acres Areas wetlands, and natural terrain. of land will remain undisturbed, in its natural state, which accounts for 29%of the total project parcel. Delineate and protect naturally vegetated buffers There are no perennial streams, rivers, Preservation along perennial streams, rivers, shorelines, and N/A shorelines, or state regulated wetlands on or of Buffers wetlands. adjacent to the project site. As such, this green planning measure does not apply. Chapter 7:Stormwater Management Design Examples 7-8 Practice Description Applicable Project Specific Evaluation Clearing and grading will be limited to the area Limit clearing and grading to the minimum of disturbance and will be minimized to the Reduction of amount needed for roads, driveways, greatest extent practical. The limits of all Clearing and Yes proposed clearing will be demarcated in the field Grading foundations, utilities and with orange construction fencing, prior to management facilithies.ies. ater construction, to prevent unnecessary removal of trees. Locating Avoid sensitive resource areas such as The site layout has been designed to avoid Development floodplains, steep slopes, erodible soils, sensitive resource areas to the greatest extent in Less wetlands, mature forests and critical habitats by Yes practical. The site layout will avoid disturbance Sensitive locating development to fit the terrain in areas to federally regulated wetlands. Areas that will create the least impact. Use clustering, conservation design or open The site layout has been designed to maximize Open Space space design to reduce impervious cover, open space. Impervious surfaces have been Design preserve more open space and protect water Yes minimized to the greatest extent practical and resources. approximately 9.86+/-Acres will be maintained as vegetated open space. Restore the original properties and porosity of the soil by deep till and amendment with Full soil restoration is proposed for all areas of Soil compost to reduce the generation of runoff and disturbance that will not become hardscape.All Restoration enhance the runoff reduction performance of Yes areas will be stabilized with seed & mulch, and practices such as downspout disconnections, landscaped areas will be provided. grass channels, filter strips, and tree clusters. Minimize roadway widths and lengths, below Roadway widths and lengths have been Roadway local requirements, to reduce site impervious No minimized to the greatest extent practical while Reduction still meeting the municipal roadway area. specifications for dedication. Sidewalk Minimize sidewalk lengths and widths, below There are no sidewalks proposed as part of this Reduction local requirements, to reduce site impervious N/A project. As such,this green planning measure area. does not apply. Minimize driveway lengths and widths, below Driveway lengths have been minimized to the Driveway local requirements, to reduce site impervious Yes greatest extent practical. Proposed house Reduction locations have been placed at the minimum lot area. setback line to reduce driveway length. Cul-de-sac Minimize the number of cul-de-sacs and There are no cul-de-sacs proposed on the Reduction incorporate landscaped areas to reduce their No project site. impervious cover. Building Reduce the impervious footprint of residences The proposed houses shown on the plan are Footprint and commercial buildings by using alternate or N/A schematic to demonstrate intent. Building Reduction taller buildings while maintaining the same floor footprints will be determined per individual lot. to area ratio. Reduce imperviousness on parking lots by The number of parking stalls has been eliminating unneeded spaces providing minimized to provide adequate access to the Parking compact car spaces and efficient parking lanes, playground while reducing impervious cover to Reduction reducing stall dimensions below local Yes the greatest extent. In an effort to further reduce requirements, using porous pavement surfaces impervious area, the design proposes reducing in overflow parking areas, and using multi- the parking stall dimensions. storied parking decks where appropriate. Chapter 7:Stormwater Management Design Examples 7-9 Step 2 — Determine Water Quality Treatment Volume (WQv) Using the post-development subcatchments shown in Figure 7.2, the required WQv for new development is calculated per Chapter 4 and sized for the contributing area to the three SMPs being applied. Upland area, that currently drains onto the project site from the adjacent properties, is being bypassed, using diversion swales, around the SMPs to the Design Points. As such, these areas are excluded from the contributing area used in the required WQv calculation. This design example is for a residential subdivision that will utilize conservation of natural areas, filtration bioretention and a wet pond for treatment and attenuation of stormwater runoff. The required WQv calculation includes the contributing area for all three of these practices: 9.86 acres for conservation, 0.27 acres for bioretention and 10.78 acres for the wet pond. The remaining 5.64 acres of the watershed to Design Point 1 is not being modified from pre-to post-development conditions and is therefore being bypassed around the stormwater management practices directly to the design point. The contributing impervious area includes the impervious area tributary to the bioretention and wet pond. As impervious area is not permitted, per Chapter 5, to discharge to conservation areas, there is no contributing impervious area for the conservation. I = (LPA \I(100) ( 4.50 acres \ (100) I 20.91 acres) I = 21.5% RV = 0.05 + 0.0091 RV = 0.05 + (0.009)(21.5) RV = 0.24 P •RV•A WQv 12 (1.20 inches)(0.24)(2 0.91 acres) WQv 12 WQV = 0.502 of = 21,860 cf Step 3 —Apply Runoff Reduction Techniques & Standard SMPs with RRv Capacity to Reduce Total WQv Chapter 4 states that runoff reduction shall be achieved through infiltration, groundwater recharge, reuse, recycle, and/or evaporation/evapotranspiration of 100% of the post-development water quality volume to replicate pre-development hydrology. Runoff control techniques provide treatment in a distributed manner before runoff reaches the collection system, by maintaining pre-construction infiltration, peak runoff flow, discharge volume, as well as minimizing concentrated flow. This can be accomplished by applying a combination of Area Runoff Reduction Techniques, Volume Runoff Reduction Techniques and standard Stormwater Management Practices (SMPs)with RRv capacity. Chapter 7:Stormwater Management Design Examples 74 As highlighted in blue, in Figure 7.14 below, the project proposes placing 9.86-acres into permanent conservation. As such, the conserved area can be subtracted from the total area used in the required WQv calculation to achieve a reduced WQv. The difference between the required WQv and reduced WQv is the RRv provided by this practice. i Figure 7.14 Post-development Conservation of Natural Areas RV = 0.24(taken from WQv required calculation) Area Reduction WQv = (P)(Rv)(A — Conserved A) 12 Area Reduction WQV = (1.20 inches)(0.24)(20.91 acres —9.86 acres) 12 Area Reduction WQv = 0.265 of = 11,552 cf RRv Provided = Required WQv —Area Reduction WQv RRv Provided = 21,860 cf— 11,552 cf RRv Provided = 10,308 cf Since the RRv provided by Area Reduction Techniques is not equal to the required WQv, calculated in Step 2, a Standard SMP with RRv Capacity is proposed. As highlighted in blue, in Figure 7.15 below, the proposed bioretention will be pretreated with a pea gravel diaphragm and 25 ft grass filter strip. The bioretention design assumes a 2.5 ft media depth and 12 inches maximum of ponding during the WQv storm event. The provided filter area must be greater than or equal to the calculated required filter surface area shown below. Chapter 7:Stormwater Management Design Examples 74 1 f \ ti l 30 00, I' Figure 7.15 Post-development Filtration Bioretention Area The required WQv for the area tributary to the bioretention needs to be calculated to determine the required filter area: I = (A,A___p/I(100) acresI — (0.080 ) (100)0.271 acres I = 29.5% RV = 0.05 + 0.0091 RV = 0.05 + (0.009)(29.5) RV = 0.32 P •Rv•A W Qv 12 (1.20 inches)(0.32)(0.2 71 acres) W Qv 12 WQv = 0.009 of = 378 cf Chapter 7:Stormwater Management Design Examples 7-12 The required filter area is calculated using Darcy's Law: _ (WQv)(df) Af (k)(hf + df)(tf) (378 cf)(2.5 ft) Af (1 ft/day)(0.5 ft+ 2.5 ft)(2 days) Af = 158 sf The proposed bioretention is sized to provide 711 sf of filter area, which is greater than the required 158 sf filter area. Therefore, it is appropriately sized to capture, retain and filter the WQv storm event. Based on Section 4.4, for practices with underdrains that require sizing the surface area of the filter bed using Darcy's Law, the surface area of the filter bed can be oversized to provide additional storage volume and receive additional RRv credit up to 100% of the WQv required. The total RRv credit is the percentage, as noted in Tables 3.6 and 3.7, applied to the storage volume provided. The storage volume provided is considered the volume within the filter media and the volume of ponding occurring during the WQv event. The RRv credit provided by the bioretention area is calculated as shown below: RRv = (Volume of Filter Media + Volume of Ponding)(0.40) RRv = (1,778 cf+ 412 cf)(0.40) RRv = 876 cf However, because the total RRv credit cannot exceed 100% of the WQv required, the RRv provided by the bioretention area is 378 cf. Table 7.3 and Table 7.4 demonstrate a summary of the runoff reduction techniques being applied for this project, and both the water quality and runoff reduction volumes provided: TableA• • • RunoffTechnique Variant NYSDECVar DesignRRv Capacity Require d c Provided c Treated cf cf WV RRv Total Wv WQv Provided Conservation of RR-1 - - 10,308 - - Natural Areas CapacityTable 7.4 Summary of Volume Reduction Runoff Reduction Techniques and Standard SMPs with RRv being Applied Runoff Reduction NYSDEC Design WQv RRv WQv Treated2 Total Treatment Technique Variant RRv Capacity Required (cf) Pr(cf)ded (cf) Provided3(cf) Filtration Bioretention F-5 40% 378 378 0 378 Footnotes 'RRv Provided=RRv Capacity x WQv Required ZWQV Treated=WQv Required—RRv Provided 3TotalTreatment Provided=WQv Treated+RRv Provided Table 7.5 provides a summary of the RRv provided: Table RRv Required =WQv Required (cf) RRv Provided (cf) % RRv Provided' 21,860 10,686 49 Footnotes '%RRv Provided=(RRv Provided/RRv Required)x 100 Chapter 7:Stormwater Management Design Examples 7-13 As indicated in Table 7.5, the RRv provided is not greater than or equal to the RRv required for the project site. A good faith effort has been made to reduce runoff to the greatest extent practical. However, the project site has soils with an infiltration rate less than 0.5 inch/hr, which prevents reduction of the total WQv. Table 7.6 provides a project specific evaluation for each RR technique and standard SMP with RRv capacity, demonstrating why these practices are infeasible. StandardTable 7.6 Evaluation of Runoff Reduction Techniques and p. Design practice Description Applicable Project Specific Evaluation Variant Retain the pre-development hydrologic and water Approximately 9.68+/-Acres will quality characteristics of undisturbed natural remain undisturbed, in its natural Conservation areas by permanently conserving these areas on state, which accounts for 29%of the RR-1 of Natural a site. Undisturbed natural areas include: forest Yes total property. The pre-development Areas retention areas; reforestation areas; stream and hydrologic and water quality river corridors; shorelines; wetlands, vernal pools, characteristics of the undisturbed and associated vegetated buffers; and natural areas will be maintained. undisturbed open space. Undisturbed natural areas such as forested The project proposes Conservation Sheet Flow to conservation areas and stream buffers or of Natural Areas and treatment by RR-2 Riparian vegetated filter strips and riparian buffers can be No Standard SMPs with and without Buffers or used to treat and control stormwater runoff from RRv capacity. In addition, Riparian Filter Strips portions of development. Buffers are not present on the site. The project proposes the preservation of existing mature trees, Plant or conserve trees to reduce stormwater as well as the planting of numerous Tree Planting/ runoff, increase nutrient uptake, and provide bank trees throughout the site, in order to RR-3 Tree Pit/ stabilization. Trees can be used for applications No reduce stormwater runoff and Tree Trench such as landscaping, stormwater management increase nutrient uptake. However, practice areas, and conservation areas. credit for these trees will not be taken toward an area reduction in the RRv calculations. The building roof(s)will be directed to downspouts with splash blocks, Disconnection Direct runoff from residential rooftop areas and which will promote sheet flow and RR-4 of Rooftop upland overland runoff flow to designated No vegetative filtering. However, credit Runoff pervious areas to reduce runoff volumes and for rooftop disconnect will not be rates. taken toward an impervious area reduction in the RRv calculations. The natural drainage paths, or properly designed The project site has C and D type vegetated channels, can be used instead of soils and application of different RR RR-5 Vegetated constructing underground storm sewers or No techniques and Standard SMPs with Swale concrete open channels to increase time of RRv capacity would provide a greater concentration, reduce the peak discharge, and benefit. provide infiltration. Manage and treat small volumes of stormwater Due to the limited tributary area to runoff using a conditioned planting soil bed and rain gardens(<_ 1,000SF), a RR-6 Rain Garden planting materials to filter runoff stored within a N0 bioretention facility will be shallow depression. implemented instead of rain gardens. The stormwater management approach for this project is intended Small landscaped stormwater treatment devices to provide a more natural aesthetic that can be designed as infiltration or filtering that is consistent with the wooded RR-7 Stormwater practices. Stormwater planters use soil infiltration No surrounding. Since, stormwater Planters and biogeochemical processes to decrease planters have significant stormwater quantity and improve water quality. maintenance considerations and a more structured aesthetic, they have not been proposed for this project. Chapter 7:Stormwater Management Design Examples 7•14 Design practice Description Applicable Project Specific Evaluation Variant Rain Barrels/Cisterns are not proposed on-site due to the need for Capture and store stormwater runoff to be used active management/maintenance Rain Barrels/ capital cost. In addition, the i RR-8 Cisterns for irrigation systems or filtered and reused for No and initial ca p� non-contact activities. cold climate of the project area would require additional protection measures from freezing. Pervious types of pavements that provide an Porous pavement is not proposed as alternative to conventional paved surfaces, part of this project due to low Porous designed to infiltrate rainfall through the surface, permeability of on-site soils, as well RR-9 Pavement thereby reducing stormwater runoff from a site N0 as concerns regarding winter and providing some pollutant uptake in the maintenance. underlying soils. Capture runoff by a layer of vegetation and soil installed on top of a conventional flat or sloped A green roof is not proposed on-site RR-10 Green Roofs roof. The rooftop vegetation allows evaporation No due to significant structural, and evapotranspiration processes to reduce insurance, and maintenance volume and discharge rate of runoff entering considerations. conveyance system. Stream Daylight previously-culverted/piped streams to restore natural habitats, better RR-11 Stream attenuate runoff by increasing the storage size, N/A No stream da thing opportunities Daylighting promoting infiltration, and help reduce pollutant are present onn this site. loads. Excavated, stone-filled trenches designed to capture and temporarily store runoff in the stone Infiltration reservoir to promote infiltration. Can be No Infiltration is not proposed due to I-1 Trench constructed as sheet flow to a ground surface poor draining soils. depression or piped flow discharged directly into the trench. Vegetated excavations designed to capture and infiltrate the WQv. Can be designed off-line to I-2 Infiltration bypass larger flows to downstream flood control No Infiltration is not proposed due to Basin facilities or as combined infiltration/flood control poor draining soils. facilities by providing temporary detention ponding. Underground structures designed to capture, treat, and infiltrate runoff from small drainage Infiltration is not proposed due to 1-3 Dry Well areas(rooftop only)that have low sediment or No poor draining soils. pollutant loadings. Larger stormwater volumes can be bypassed directly to a flood control facility. Underground, proprietary systems designed to Underground capture and infiltrate the WQv, reduce runoff, No Infiltration is not proposed due to I-4 Infiltration remove fine sediment and associated pollutants, poor draining soils. recharge groundwater, and attenuate peak flows. Shallow landscaped depressions where Infiltration stormwater flows into the practice, ponds at the Infiltration is not proposed due to F-4 Bioretention surface, and gradually filters through the media to No poor draining soils. remove pollutants. Filtered runoff infiltrates into the surrounding soil. Chapter 7:Stormwater Management Design Examples 7-1 r Design practice Description Applicable Project Specific Evaluation Variant Shallow landscaped depressions where stormwater flows into the practice, ponds at the Filtration Bioretention has been Filtration surface, and gradually filters through the media applied to this project due to low F-5 Bioretention to remove pollutants. Filtered runoff is collected Yes infiltrating soils and the ability to use by an underdrain system and discharges to the storm sewer system or directly to receiving underdrains. waters. Specialized media filtration typically used in Due to the minimal size of the F-6 Bioslope longitudinal applications to treat stormwater No parking lot and wing curbs along the along an impervious area (road, parking lot, etc.) road, sheet flow to a bioslope is not practical on this project. Designed to temporarily hold the WQv in a pool or series of pools created by permanent check Due to the minimal size of the dams. The soil bed consists of native soils or 0-1 Dry Swale highly permeable fill material, underlain by an No parking lot and wing curbs along the underdrain system. Pollutants are removed road, sheet flow to a dry swale is through sedimentation, nutrient uptake, and not practical on this project. infiltration. Step 4— Determine the Minimum RRv Required Projects that cannot achieve 100% of the runoff reduction requirement due to site limitations, shall provide a minimum runoff reduction volume, per Chapter 4. The project has two different HSGs on site, therefore the Specific Reduction Factor(S)was calculated referencing Chapter 4 Section 4.4. The minimum RRv must be calculated for the impervious area proposed in each HSG: Rv = 0.05 + (0.009)(100) Rv = 0.95 S _ (Aic in HSG A)(0.55) + (Aic in HSG B)(0.40) + (Aic in HSG C)(0.30) + (Aic in HSG D)(0.20 acres) Aic S _ (0 acres)(0.55) + (0 acres)(0.40) + (3.40 acres)(0.30) + (1.10 acres)(0.20 acres) 4.50 acres S = 0.28 P •R„ •Aic •S RRvmin = 12 (1.20 inches)(0.95)(4.50 acres)(0.28) RRvmin = 12 RRvmin = 0.12 a f = 5,214 cf Table 7.7 Minimum RRv Summary, Minimum RRv Required (cf) RRv Provided (cf) '%of Minimum RRv Provided 5,214 10,686 205 Footnotes '%Min. RRv Provided=(RRv Provided/Min. RRv Required)x 100 As indicated in Table 7.7, the RRv provided is greater than the minimum RRv required for the project site. Therefore, the runoff reduction volume criteria have been met for the project. Chapter 7:Stormwater Management Design Examples 7-16 Step 5 —Apply Standard Stormwater Management Practices to Address Remaining WQv If the entire WQv is not treated through implementation of RR techniques and standard SMPs with RRv capacity, the design must achieve the remaining WQv through the standard SMPs listed in Table 3.3. 1111 e Mrs Technique Step 5-Reduced WQv to be Step 2—WQv Required (cf) Step Standa d SMPs with CapacityRRvR (cf)s 7TSeated by Standard SMPs(cf) 21,860 10,686 11,174 Based upon the results listed in Table 7.8, the entire WQv has not been treated by application of RR techniques and standard SMPs with RRv capacity. As such, a wet pond (Design Variant P-2), has been incorporated into the stormwater management plan for this project, to meet the WQv objective. I t .f 1 r r i 1 ' ! 1 ! I 1+ / � 1 ll Figure 7.16 Post-development Wet Pond Per Chapter 6 Section 6.1.1 the minimum contributing area for Design Variant P-2 is 25 acres. However, the minimum contributing area can be reduced to 10 acres if a water balance calculation is performed. The water balance calculation, as shown in Chapter 6 Section 6.1.4.2, provides a required minimum permanent pool depth to accommodate the reduced tributary area, as shown below: DP > ET+INF+RES DP > 5 inches + 10.1 inches + 36 inches DP > 51.1 inches DP > 4.3 f t Chapter 7:Stormwater Management Design Examples 7-17 The pond design proposes a permanent pool depth of 4.5 ft and, as such, meets the water balance requirement for reducing the contributing area to a minimum of 10 acres. Volume Invert Avail.Stora a Storage Description 41 305,00' 0 cf Permanent Pool(Forebay)(Prismatic�isted below(Recalc) 3,072 cf Overall x 0.0%Voids 42 303.00' 0 cf Permanent Pool(Pond)(Prismatic)Listed below(Recalc) 17,032 cf Overall x 0.0%Voids #3 309.50' 87,460 cf Extended Detention(Prismatic)Listed below Recalc 87,460 of Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 305.00 49 0 0 306.00 278 164 164 307.00 545 412 575 308.00 889 717 1,292 309.00 1,282 1,086 2,378 309.50 1,495 694 3,072 Volume#1 Elevation Surf Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 303.00 560 0 0 304.00 945 753 753 305.00 1,410 1,178 1,930 306.00 1,953 1,682 3,612 307,00 2,575 2,264 5,876 308.00 3,276 2,926 8,801 309,00 6,465 4,871 13,572 309.50 6,975 3,360 17,032 Volume#2 Elevation Surf Area Inc.Store Cum-Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 309.50 10,583 0 0 310.00 12,621 5,801 5,801 311.0 0 14,913 13,767 19,568 312.00 17,347 16,130 35,698 313.00 19,930 18,639 54,337 314,00 22,900 21,415 75,752 314.50 23,933 11.708 87,460 Figure 7.17 Wet Pond Volume Distribution Table 7.9 and Table 7.10 summarize both the WQv requirements and the treatment volumes provided in accordance with Table 6.4. Required WQv Distribution Provided WQv Distribution NYSDEC Step 5 - Permanent Extended Permanent Extended Design Variant Calculated Pool Detention Pool' Detention WQv(cf) (min%) (max%) cf % cf % P-2 11,174 100 0 20,104 100 0 0 Footnotes 'Permanent pool distribution includes pretreatment permeant volume and treatment permanent pool volume ZExtended detention distribution excludes extended detention above pretreatment Tablet Summary of e Calculated Pretreatment Treatment Volume Pretreatment Volume NYSDEC Design Step 5 -Ca Variant WQv lcucf) Volume Required Provided (cf) Provided (cf) (%of WQv)' P-2 11,174 10 8,102 3,072 Footnotes 'Refer to Section 6.1.3 ZAlthough 17,032 cf of volume is available after pretreatment,treatment provided cannot exceed 100%of the tributary required WQv. Chapter 7:Stormwater Management Design Examples 7.18 Step 6 —Apply Volume and Peak Rate Control Chapter 4 of the Design Manual requires that projects meet three separate stormwater quantity criteria: 1. The Channel Protection (CPv) requirement is designed to protect stream channels from erosion. This is accomplished by providing 24 hours of extended detention for the 1-year, 24-hour storm event. The CPv detention time is the center of mass detention time through each stormwater management practice. 2. The Overbank Flood Control (Qp) requirement is designed to prevent an increase in the frequency and magnitude of flow events that exceed the bank-full capacity of a channel, and therefore must spill over into the floodplain. This is accomplished by providing detention storage to ensure that, at each design point, the post-development 10-year 24-hour peak discharge rate does not exceed the corresponding pre-development rate. 3. The Extreme Flood Control (Qf) requirement is designed to prevent the increased risk of flood damage from large storm events, to maintain the boundaries of the pre-development 100-year floodplain, and to protect the physical integrity of stormwater management practices. This is accomplished by providing detention storage to ensure that, at each design point, the post-development 100-year 24-hour peak discharge rate does not exceed the corresponding pre-development rate. In order to demonstrate that the NYSDEC detention requirements are being met, a hydrologic and hydraulic analysis of the pre- and post-development conditions needs to be performed using the Natural Resources Conservation Service Technical Release 20 (TR-20) and Technical Release 55 (TR-55) methodologies. For the example project hydraulic and hydrologic modeling software, HydroCAD, developed by HydroCAD Software Solutions LLC of Tamworth, New Hampshire, was used. A comparison of the pre- and post-development watershed conditions was performed for all design points and storm events evaluated herein. For all design points and design storms, this comparison demonstrates that the peak rate of runoff will not be increased. Therefore, the project will not have a significant adverse impact on the adjacent or downstream properties or receiving water courses. Tableof • Post development Peak Dischar• Design Point 10-year 24-hour storm event 100-year 24-hour storm event Pre(cfs) Post(cfs) Pre(cfs) Post(cfs) 1 21.30 17.71 56.58 52.40 2 10.25 10.02 29.65 28.97 For each stormwater management facility that provides detention, Table 7.12 presents the center of mass detention time for the 1-year 24-hour storm event. As shown below, the wet pond does not meet the required 24-hour detention time. However, the project provides the minimum CPv orifice size allowed, per Chapter 4. As such the CPv requirement is waived. Table • Center of Mass Detention time Diameter of the CPv Orifice(inches) NYSDEC Design for the 1-year Storm(hours) Variant Minimum allowable to Required Provided achieve the required center Provided of mass detention time' P-2 24 13.7 3 3 Footnotes 'Per Chapter 4 where a CPv control orifice is provided,the minimum orifice size shall be 3 inches,with acceptable external trash rack or internal orifice protection. Chapter 7:Stormwater Management Design Examples 7-19 Summary for Pond P1:Wet Pond(wl Forebay&Outlet Control) Inflow Area= 10.777 ac, 40.97%impervious, Inflow Depth= 1.03' for 1-yr event Inflow - 10.52 cfs @ 12.06 hrs, Volume= 0.923 of outflow = 0.34 cfs @ 10.49 hrs, Volume= 0.923 of, Atten=97%, Lag=3063 min Primary = 0.34 cfs @ 18.49 hrs, Volume= 0,923 of Secondary= 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Flouting by Dyn-Stor-Ind method,Time Span=0.00-72,00 hrs,sit-0.01 hrs Peak Elav=311.30'@ 18.49 hrs Surf,Areo=26.237 sf Storage=24,219 of Flood Elev=314.50' Surf.Area=34,516 sf Storage=87,460 cf Plug-Flow detention time=(not calculated-outflow precedes inflow) Canter-of--Mass dot.time=822.3 min{1,658.7-836.4} Figure 7.18 Center of Mass Detention Time for the 1-year 24-hour Storm Device Ruutimq Invert Outlet Devices #1 Primary 309,16 74.0" Round Culvert L=36.U' CPP,+end-section conforming to fill, Ke=0,500 Intel f Outlet Invert=309.16'/307.25" S=0.0531 T Cc=0.900 n=0.012 Corrugated PE,smooth interior, Flow Area=3.14 sf #2 Device 1 309.16' 3.0"Vert.Primary Orifice C=0.600 Limited to weir flow at low heads #3 Device 1 311,30' 36.0"W x 12.0"H Vert.Secondary Orifice C=0.600 Limited to weir flow at low heads #4 Device 1 312.12' 4.0'long x 0.5'breadth Broad-Crested Rectangular Weir Head(feet) 0.20 0.40 0.60 0.90 1,00 Coef.(Engi*h) 2.00 2.92 5.08 3.30 3 32 #5 Secondat 313.59 12.0'long x 14.0'breadth Broad-Crested Rectangular Weir Head(feet) 0.20 UA0 0,50 0,80 1.00 1.20 1.40 1.60 Coef,(English) 2.54 2.67 2.70 265 2,64 2.65 2.65 2S3 Figure 7.19 Wet Pond Outlet Devices Chapter 7:Stormwater Management Design Examples 7-20 Section 7.2 Sizing Example — Filtration Bioretention & Infiltration Basin for Treatment of Stormwater Hotspot Figure 7.20 below shows a proposed commercial development including a parking lot and an associated garden center. The existing soils on the site are HSG A soils with an infiltration rate of 8.0 in/hr. The site stormwater is divided into two subcatchments as shown in the figure. Subcatchment 1 contains the proposed garden center and surrounding area. The stormwater from subcatchment 1 is treated by the proposed lined filtration bioretention before discharging by conveyance pipe to the proposed infiltration basin. Subcatchment 2 contains the proposed box store and parking lot. The stormwater from this subcatchment is conveyed via a closed storm sewer network to the proposed infiltration basin. 1 1 r, 1 fl r 1 61 fr 1 f c I ! rr I I I J r I Lr(.ffJ 1 f r J{ 11 J d rJl f I�Vlf f ! 1 ��nff 1 � ! ------ --- -------- 4- f+r 1 1 ! Figure 7.20 Proposed Development Site Plan Chapter 7:Stormwater Management Design Examples 7-21 Step 1 —Site Planning An example of site planning has been provided in Section 7.1. Step 2 —Calculate Water Quality Treatment Volume (WQv) The garden center is considered a level 1 stormwater hotspot, in accordance with Chapter 4 Table 4.3. As such, infiltration as treatment for this practice is prohibited. Per Chapter 6, runoff from designated stormwater hotspots shall not be directed to an infiltration practice, unless two treatment practices in series (i.e. non-infiltration SMP followed by an infiltration practice) are provided, both of which are sized to treat the entire WQv. Pretreatment for each practice in series is required and the amount of pretreatment shall conform to the practice specific requirements of Chapters 5 and 6. A lined filtration bioretention will be used to treat stormwater from the garden center before it is discharged into the infiltration basin. Per Chapter 4, when a development project includes an activity designated as a stormwater hotspot, consideration must be taken to isolate the hotspot from the remaining watershed. The hotspot will be isolated through appropriate site grading to divert stormwater from the upgradient surrounding areas away from the hotspot and towards the closed storm sewer network to be discharged directly to the infiltration basin. Additionally, the hotspot will be captured at the source and conveyed to the proposed lined filtration bioretention for treatment. Finally, all tributary area to the filtration bioretention will be subject to the same treatment requirements as the hotspot. Through these measures the criteria for isolating the stormwater hotspot have been met according to Section 4.14 of Chapter 4. Calculate the required WQv for the proposed filtration bioretention per Chapter 4: I = (A'A___p)(100) (0.72 acres)(100) I 1.69 acres I = 42.6% RT, = 0.05 + 0.0091 RT, = 0.05 + (0.009)(42.6) Rv = 0.43 P •Rv•A WQv 12 (1.20 inches)(0.43)(1.69 acres) WQv 12 WQv = 0.073 of = 3,166 cf Since the garden center is a stormwater hotspot, the stormwater runoff from PS-1 must be treated by a non-infiltration practice before being directed to the infiltration basin. Due to this, the required WQv for the infiltration basin must take into account the areas of both subcatchments PS-1 and PS-2. If there was not a hotspot in PS-1 then having two practices in series would not be required and the WQv for the infiltration basin would only take into account PS-2 even if the practices were proposed in series. Chapter 7:Stormwater Management Design Examples 7- 2 Calculate the required WQv for the proposed infiltration basin per Chapter 4: I = (A,A___p\I(100) ac/resI — (12.36 ) (100)19.20 acres I = 64.4% Rv = 0.05 + 0.0091 Rv = 0.05 + (0.009)(64.4) Rv = 0.63 P •Rv•A WQv 12 (1.20 inches)(0.63)(19.20 acres) W Qv 12 WQv = 1.210 of= 52,690 cf Step 3 —Apply RR Techniques and Standard SMPs with RRv Capacity to Reduce Total WQv Chapter 4 states that runoff reduction shall be achieved through infiltration, groundwater recharge, reuse, recycle, and/or evaporation/evapotranspiration of 100% of the post-development water quality volume to replicate pre-development hydrology. Runoff control techniques provide treatment in a distributed manner before runoff reaches the collection system, by maintaining pre-construction infiltration, peak runoff flow, discharge volume, as well as minimizing concentrated flow. This can be accomplished by applying a combination of Runoff Reduction Techniques, and standard Stormwater Management Practices (SMPs) with RRv capacity. Calculate the bioretention required filter area using Darcy's Law and the filtration bioretention WQv calculated in Step 2: _ (WQ,)(df) Af (k)(hf + df)(tf) (3,166 cf)(2.5 ft) Af (1 ft/day)(0.5 ft+ 2.5 ft)(2 days) Af = 1,319 sf As shown in Figure 7.21, the proposed lined bioretention is sized to provide 3,266 sf of filter area, which is greater than the required 1,319 sf filter area. Therefore, it is appropriately sized to capture, retain and filter the WQv storm event from the proposed hot spot. Based on Section 4.4, for practices with underdrains that require sizing the surface area of the filter bed using Darcy's Law, the surface area of the filter bed can be oversized to provide additional storage volume and receive additional RRv credit up to 100% of the WQv required. The total RRv credit is the percentage, as noted in Tables 3.6 and 3.7, applied to the storage volume provided. The storage volume provided is considered the volume within the filter media and the volume of ponding occurring during the WQv event. The RRv credit provided by the bioretention area is calculated as shown below: RRv = (Volume of Filter Media + Volume of Ponding)(0.40) RRv = (8,165 cf+ 5,460 cf)(0.40) RRv = 5,450 cf However, because the total RRv credit cannot exceed 100% of the WQv required, the RRv provided by the bioretention area is 3,166 cf. Chapter 7:Stormwater Management Design Examples 7- 3 As shown in Figure 7.21 below, the proposed infiltration basin has a proposed bottom area of 23,502 sf and will be pretreated with a forebay. The infiltration basin design assumes a 3 ft depth. Calculate the required infiltration basin bottom area using the infiltration basin WQv calculated in Step 2: _ WQv Ab d b 52,690 cf Ab 3 f t Ab = 17,563 sf The proposed bottom area is greater than required.As such,the infiltration basin meets the design criteria. ---------------- ----------------------- CIL- Figure 7.21 Proposed Bioretention and Infiltration Basin Table 7.13 demonstrates a summary of the RR techniques being applied for this project, and both the water quality and runoff reduction volumes provided: Standard10 Table 7.13 Summary of RR Techniques and p. Applied An NYSDEC Design WQv RRv WQv Treated2 Total Treatment RR Technique Variant RRv Capacity Required (cf) Provided (cf) Provided3(cf) Filtration Bioretention F-5 40% 3,166 3,166 0 3,166 Infiltration Basin 1-2 100% 52,690 52,690 0 52,690 Footnotes 'RRv Provided=RRv Capacity x WQv Required ZWQV Treated=WQv Required—RRv Provided 3TotalTreatment Provided=WQv Treated+RRv Provided Table 7.14 provides a summary of the RRv provided. It should be noted that because the filtration bioretention is tributary to the infiltration basin, RRv credit cannot be taken for the filtration bioretention since it is the first practice in series. Table 7.14 RRv Summary RR Required=WQv Required (cf) RRv Provided (cf) % RRv Provided' 52,690 52,690 100 Footnotes '%RRv Provided=(RRv Provided/RRv Required)x 100 Chapter 7:Stormwater Management Design Examples 7-24 Step 4—Calculate the Minimum RRv Required As previously discussed, the RRv provided is equal to the RRv required for this project. As such,the runoff reduction volume criteria has been met, and the minimum RRv is not applicable. Step 5 —Apply Standard SMPs to Address Remaining WQv As previously discussed, 100% of the required WQv is being provided and the minimum RRv is being reduced through RRv practices. As such, the water quality and runoff reduction volume criteria have been met and no other standard SMPs are required. Step 6 —Apply Volume and Peak Rate Control An example of applying volume and peak rate control has been provided in Section 7.1. Section 7.3 Sizing Example — Dry Swale As shown in Figure 7.22, this design example is for a residential subdivision that will utilize dry swales for treatment and conveyance of stormwater runoff. This example assumes a HSG B for the site, which allows for 40% RRv capacity in accordance with Table 3.7. The contributing area to the dry swales includes the residential road, driveways, homes, and lawn for a total of 11.05 acres, 3.62 acres of which is impervious cover. ( 5 Y � } y l - Figure 7.22 2-Year Flow Depth in Dry Swale Chapter 7:Stormwater Management Design Examples 7-25 Step 1 —Site Planning An example of site planning has been provided in Section 7.1. Step 2 —Calculate Water Quality Treatment Volume (WQv) Calculate the required WQv for new development per Chapter4: I = (LY-P\I(100) I - ( 3.62 acres l 11.05 acres) (100) I = 32.8% RT, = 0.05 + 0.0091 RT, = 0.05 + (0.009)(32.8) Rv = 0.345 P •Rv•A WQv 12 (1.20 inches)(0.345)(11.05 acres) W Qv 12 WQv = 16,616 cf = 0.381 of Step 3 —Apply RR Techniques and Standard SMPs with RRv Capacity to Reduce Total WQv Chapter 4 states that runoff reduction shall be achieved through infiltration, groundwater recharge, reuse, recycle, and/or evaporation/evapotranspiration of 100% of the post-development water quality volume to replicate pre-development hydrology. Runoff control techniques provide treatment in a distributed manner before runoff reaches the collection system, by maintaining pre-construction infiltration, peak runoff flow, discharge volume, as well as minimizing concentrated flow. This can be accomplished by applying a combination of Runoff Reduction Techniques, and standard Stormwater Management Practices (SMPs)with RRv capacity. The proposed dry swale has a 3 ft bottom, 3:1 side slopes, 2 ft swale depth, a WQv max. flow depth of 1 ft, 2.0% slope, a proposed length of 2,800 ft and will be pretreated by a grass filter strip and pea gravel diaphragm. in accordance with Chapter 6. Below are the calculations for the dry swale to determine the required length. The dry swale design needs to meet or exceed the minimum length required and provide enough storage behind the check dams to meet or exceed the required WQv. Calculate the top width of the WQv flow, using the maximum WQv flow depth (check dam height) as the height: WwQv = b + (2 x Side Slope)(d) WwQv = 3 ft+ (2)(3)(1 f t) WWQv = 9ft Calculate the area of the WQv flow, using the flow depth as the height: (d)(b + WwQv) AtvQv = 2 (1 f t)(3 ft+ 9 ft) AtvQv = 2 AwQv = 6 s f Chapter 7:Stormwater Management Design Examples 7-26 Calculate the required length of swale based on the required WQv and calculated area: L = WQv r AwQv 16,616 cf Lr = 6 sf Lr = 2,769 f t Verify that the proposed swale length is greater than or equal to the required swale length: LP Lr 2,800 f t > 2,769 f t Therefore,the dry swale design meets the required minimum length Calculate the channel volume using the calculated area and proposed swale length: Vc = LP •AwQv Vc = (2,800 ft)(6 sf) Vc = 16,800 cf Verify that the channel volume provided is greater than or equal to the required WQv: Vc > WQv 16,800 cf > 16,616 cf Therefore,the proposed dry swale meets the required WQv for this practice Calculate the required check dam spacing within the swale using the proposed check dam height and slope: CH CS S L 1 ft CS 0.02 ft/ft CS = 50ft Calculate the number of check dams required using the proposed swale length and calculated spacing: LP C = CS 2,800 f t C Soft C = 56 check dams required Chapter 7:Stormwater Management Design Examples 7- 7 Using computer modeling, as shown in Figure 7.23, the peak water surface elevation during the 2-year storm event is 0.54 ft above the bottom of dry swale. Inflow Area = 11.050 ac, 32.76% Impervious, Inflow Depth = 0.62 for 2-.,r e"Ient Inflow = 0.42 cfs @ 12.05 hrs, 'Volume= 0.573 of Outflow = 1.08 cfs @ 12.57 hrs, 'Volume= 0.573 af, Atten=78%, Lag= 31.6 min Routing by Dyn-Stor-Ind method,Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Max.'Velocity= 0.75 fps, Pin.Travel Time= 62.4 min Avg.'VeIocity= 0.19 fps, Avg.Travel Time= 24-3.7 min Peak Storage=7,030 cf @ 12.57 hrs Average Depth at Peak Storage=0.54', Surface:°didth= 6.26` Bank-Full Depth= 2.00' Flow Area= 18.0 sf, Capacity= 27.68 cfs 3.00' x 2.00' deep channel, n= 0.150 Side Slope Z-value= 3.0 'T Top:°didth= 15.00' Length= 2,800.0' Slope= 0.0200 T Inlet Invert= 100.00', Outlet Invert= 44.00' Figure 7.23 2-Year Flow Depth in Dry Swale Using the 2-year average flow depth, calculate the top width and flow area of the 2-year storm event. WZ = b + (2)(Side Slope)(d2) WZ = 3 f t+ (2)(3)(0.54 ft) WZ = 6.24ft (d2)(b +W2) AZ = 2 AZ _ (0.54 ft)(3 ft+ 6.24 ft) _ 2 AZ = 2.50 sf Chapter 7:Stormwater Management Design Examples 7-28 Using the graph from Appendix G, as shown in Figure 7.24, determine the Manning's number to be used in the 2-year velocity calculation based on the 2-year flow depth. L.1fi I I I i I I I i I I I I I I I I I I I I I I f I I I I I I I al■■■■■■■■11■■■■■■■■■i■■■■■■■■■11■00 C I I I • I I 1■ I I I ■ I `� I I I • I I ■ C 1 I I ■ I C I i I ■ I I � I I I • I I ■ --I I I I ■ I I I I I • I I I • I I ■ 0.04 --------------------+----------r----:----+----------+------ --- I I • I I I I I I I I t I I I I I i I I I I i ■ I I I ■ I I 0 0 2 4 6 8 10 12 Flow Depth[Inches] Figure 7.24 2-Year Manning's Number(Refer to Appendix G) Calculate the 2-yr velocity, using the Manning's number from Appendix G, the 2-year flow depth and channel slope: PWZ = b + (d22 + [(Side Slope)(d2)]2)1/2(2) PWZ = 3 ft+ ([0.54 ft]2 + [(3)(0.54 ft)]2)1/2(2) PWZ = 6.42 ft UZ _ (1.49n \ \P 2 2/3 (SJ1/2 J f 2/ UZ _ (149s20.11\ ( .5 s 1 (0.02 ft/ft)1/2 6.42 f t U2 = 1.02 fps Based on the above, the 2-yr velocity is less than 5 fps and meets the requirement for non-erosive conditions. Chapter 7:Stormwater Management Design Examples 7- 9 Using computer modeling, as shown in Figure 7.25, the peak water surface elevation during the 10-year storm event is 0.95 ft above the bottom of the dry swale. The swale configuration uses a 2 ft channel depth, therefore during the 10-year storm there is at least 6 inches of freeboard. InflowArea = 11.050 ac, 32.76% Impervious, Inflow Depth = 1.34" for 10-yr e-lent Inflow = 19.59 cfs @ 12.04 hrs, Volume= 1.237 of Outflow = 5.61 cfs @ 12.44 hrs, Volume= 1.237 af, .Atten=71%, Lag= 24.0 min Routing by Dyn-Star-Ind method,Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Max.Velocity= 1.01 fps, Min.Travel Time=46.0 min .Avg.Velocity= 0.22 fps, .Avg.Travel Time=214.2 min Peak Storage= 15,491 cf @ 12.44 hrs Average Depth at Peak Storage 0.95', Surface Width= 8.68' Bank-Full Depth= 2.00' Flow Area= 18.0 sf, Capacity= 27.68 cfs Figure 7.25 10-Year Flow Depth in Dry Swale As shown above, all design criteria for the dry swale have been met. Therefore, the proposed dry swale provides 40% of the required WQv toward runoff reduction, and the remaining volume has been treated to meet the water quality criteria. Table 7.15 demonstrates a summary of the RR techniques being applied for this project, and both the water quality and runoff reduction volumes provided: NYSDEC Design WQv RRv WQv Treated2 Total Treatment RR Technique Variant RRv Capacity Required (cf) Provided (cf) Provided3(cf) Dry Swale 0-1 40% 16,616 6,646 9,970 16,616 (HSG B) Footnotes 'RRv Provided=RRv Capacity x WQv Required 2NQv Treated=WQv Required-RRv Provided 3TotalTreatment Provided=WQv Treated+RRv Provided Table 7.16 provides a summary of the RRv provided: RR Required=WQv Required (cf) RRv Provided (cf) % RRv Provided' 16,616 6,646 40 Footnotes '%RRv Provided=(RRv Provided/RRv Required)x 100 Step 4—Calculate the Minimum RRv Required The proposed design does not meet 100% RRv provided, as such calculating the minimum RRv is required. An example of calculating the minimum RRv required is provided in Section 7.1. Step 5 —Apply Standard SMPs to Address Remaining WQv An example of applying standard SMPs to address the remaining WQv required is provided in Section 7.1. Step 6 —Apply Volume and Peak Rate Control An example of applying volume and peak rate control has been provided in Section 7.1. Chapter 7:Stormwater Management Design Examples 7-3 Section 7.4 Sizing Example — Multiple Dry Wells in Series As shown in Figure 7.26, this design example is for a portion of a residential subdivision that will utilize multiple dry wells in series for treatment of stormwater runoff. This example assumes a HSG B for the site and an underlying soil infiltration rate of 5.0 inch/hr. The contributing area to the dry wells includes a portion of the residential road, driveways, homes, and lawn for a total of 1.774 acres, 0.773 acres of which is impervious cover. r 1 r I Dry Well 'Y Figure 7.26 Dry Well Contributing Area Step 1 —Site Planning An example of site planning has been provided in Section 7.1. Step 2 —Calculate Water Quality Treatment Volume (WQv) Calculate the required WQv for new development per Chapter4: I = (A'A---p\I(100) ac/resI — (0.773 ) (100)1.774 acres I = 43.6% RT, = 0.05 + 0.0091 RT, = 0.05 + (0.009)(43.6) Rv = 0.442 P •Rv•A WQv 12 (1.20 inches)(0.442)(1.774 acres) WQv 12 WQv = 0.078 of = 3,416 cf Chapter 7:Stormwater Management Design Examples 7-31 Step 3 —Apply RR Techniques and Standard SMPs with RRv Capacity to Reduce Total WQv Chapter 4 states that runoff reduction shall be achieved through infiltration, groundwater recharge, reuse, recycle, and/or evaporation/evapotranspiration of 100% of the post-development water quality volume to replicate pre-development hydrology. Runoff control techniques provide treatment in a distributed manner before runoff reaches the collection system, by maintaining pre-construction infiltration, peak runoff flow, discharge volume, as well as minimizing concentrated flow. This can be accomplished by applying a combination of Runoff Reduction Techniques, and standard Stormwater Management Practices (SMPs) with RRv capacity. The contributing area is greater than 0.50 acre, therefore multiple dry wells in series will be used. For this example, the underlying soil infiltration rate is 5.0 inch/hr, therefore 25% of the required WQv must be provided for pretreatment. Pretreatment for the dry wells will be provided by a sedimentation chamber(catch basin with 2 ft deep sump), in accordance with Section 6.4.3. Calculate the required surface area for the pretreatment sedimentation chamber: AS = (0.066)(WQv) AS = (0.066)(3,416 cf) AS = 225 sf Calculate the maximum depth for the pretreatment sedimentation chamber: d = p -WQV s As d = (0.25)(3,416 cf) s 225 sf ds = 3.8ft If the proposed depth for the pretreatment sedimentation chamber is less than the maximum depth, calculate the new minimum surface area of sedimentation chamber: W Q„ AS ds proposed 3,416 cf AS = 2 f t As = 1,708 sf The example proposes multiple sedimentation chambers to meet the minimum surface area. The percentage of the surface area provided by each structure would correlate to the percentage of contributing impervious area to each structure. Each proposed dry well has an 8ft inside diameter, 8 ft height, 4 inch wall thickness, and a 1 ft stone reservoir thickness in accordance with Chapter 6. Below are the calculations for the dry well to determine the provided volume. The dry well design must meet or exceed the required WQv. Calculate the inside volume of the dry well: V = rc•r2 -H Vi = (7T)(4 f t)Z(8 f t) V = 402.2 cf Calculate the volume of the stone around the dry well: V = (7r. [(r+ t+ ts)Z — (r + t)Z]) •H •0.40 V = (rc• [(4ft+ 0.25ft+ 1ft)Z — (4ft+ 0.25ft)Z]) •8ft• 0.40 V = 95.5 cf Chapter 7:Stormwater Management Design Examples 7-32 Calculate the dry well volume provided using the calculated inside volume and volume of the stone: VW = Vi + V Vw = 402.2cf+ 95.5cf Vw = 497.7cf Calculate the WQv provided by multiplying the dry well volume by the number of dry wells proposed: WQv = N•Vw WQv = (7)(497.7 cf) WQv = 3,484 cf Verify that the WQv provided is greater than or equal to the required WQv: 3,484 cf > 3,416 cf Therefore,the dry well design meets the required WQv volume Table 7.17 demonstrates a summary of the RR techniques being applied for this project, and both the water quality and runoff reduction volumes provided: Table 7.17 Summary of RR Techniques and Standard SMPs with RRv Capacity being Applied NYSDEC Design WQv RRv WQv Treated' Total Treatment RR Technique Variant RRv Capacity Required(cf) Provided (cf) Provided'(cf) Dry Well 1-3 100% 3,416 3,416 0 3,416 Footnotes 'RRv Provided =RRv Capacity x WQv Required 'WQv Treated=WQv Required—RRv Provided 3TotalTreatment Provided=WQv Treated+RRv Provided Table 7.18 provides a summary of the RRv provided: RR Required =WQv Required (cf) RRv Provided(cf) % RRv Provided' 3,416 3,416 100 Footnotes '%RRv Provided=(RRv Provided/RRv Required)x 100 Step 4—Calculate the Minimum RRv Required As previously discussed, the RRv provided is equal to the RRv required for this project. As such, the runoff reduction volume criteria has been met, and the minimum RRv is not applicable. Step 5 —Apply Standard SMPs to Address Remaining WQv As previously discussed, 100% of the required WQv is being provided an the minimum RRv is being reduced through RRv practices. As such, the water quality and runoff reduction volume criteria have been met and no other standard SMPs are required. Step 6 —Apply Volume and Peak Rate Control An example of applying volume and peak rate control has been provided in Section 7.1. Chapter 7:Stormwater Management Design Examples 7-33 This Page is Left Intentionally Blank NEW Department of PORK STATE Environmental Conservation Chapter 8: Urban Stormwater Management This Chapter presents guidance for implementation of runoff reduction techniques and applicable SMPs, in both new development and redevelopment projects located in urban areas. Urbanization has altered the hydrologic cycle through increased development density. High quantities of impervious surfaces have led to reduced groundwater recharge, increased rates and volumes of runoff, higher potential for flooding, and increased pollutant loading. A key component of the urban environment is the roadway network, which constitutes a large percentage of impervious cover and produces significant quantities of polluted stormwater runoff. Consequently, application of runoff reduction techniques and applicable SMPs into roadway design or retrofit, presents a sizeable opportunity to improve stormwater quality and quantity by capturing, treating, and promoting groundwater recharge at the source. In this way, stormwater runoff is being integrated into urban roadway design as a resource, instead of a waste product requiring costly conveyance and/or downstream treatment by municipal facilities. Runoff reduction techniques and applicable SMPs, can also be applied as a retrofit to an existing urban roadway network to provide localized storage and reduce flows to existing conveyance systems that may be underperforming. Urban stormwater management can provide the added benefits of improved air quality, reduced urban heat island effect, and enhanced safety and walkability. Section 8.1 NYSDOT Urban Roadway Classification The New York State Department of Transportation (NYSDOT) has developed functional classifications for urban roadways statewide. The functional classifications categorize roadways by level of significance within the overall network, character of traffic flow (vehicle, bicycle, and/or pedestrian), and access provided to adjacent properties. Designated "Urban Areas" and urban roadway functional classifications can be easily identified using the NYSDOT Functional Class Viewer system (https://www.dot.ny.gov/gisapps/functional-class-maps). The "Urban Area" boundaries, as shown on the Functional Class Viewer, may not be inclusive of all qualifying urban areas. A summary of the NYSDOT Urban Roadway Functional Classifications can be found in Table 8.1. Table •T Urban Roadway • Type Description Urban Principal Encompasses interstates and other freeways and expressways. Design speeds typically range from Arterial (F11, F12, 50 to 70 mph. Due to the travel density and design speeds, traffic calming and speed reduction F14) measures are generally not applicable, and on-street parking is generally not allowed. Carry large traffic volumes within and through urban areas, but do not have the capacity or Urban Minor Arterial significance of Urban Principal Arterials. They serve major areas of activity, carrying a high (F-16) proportion of an area's traffic on a small proportion of the area's lane mileage. Design speeds typically range from 30 to 45 mph. Traffic calming and speed reduction measures are generally applicable, and on-street parking is generally allowed in commercial areas. Link neighborhoods or areas of homogeneous land use with Principal or Minor Arterials, serving the dual function of land access and traffic circulation. They are generally not intended to serve regional Urban Collector(F- trips and generally do not provide route continuity for more than a few miles. Design speeds typically 17, F-18) range from 30 to 45 mph. Traffic calming and speed reduction measures are generally applicable and on-street parking is generally allowed in commercial, industrial and some residential areas. On- street bicycle lanes may be provided with a dedicated preferential travel lane. Sidewalks can be included on both sides of the roadway and separated from vehicle lanes by a buffer strip. Designated local roadways that provide direct vehicle, bicycle, and pedestrian connections between adjacent neighborhoods, and between neighborhoods and commercial areas. They do not serve trans-regional trips and provide no route continuity beyond the areas they serve. Design speeds are Urban Local typically less than 30 mph. Traffic calming and speed reduction measures may be used as warranted (F-19) by adjacent land uses and traffic characteristics. On-street parking will generally be allowed where adequate roadway width is available. On-street bicycle lanes may be provided with a dedicated preferential travel lane. Sidewalks can be included on both sides of the road and separated from vehicle lanes by a buffer strip. Typically, a focal point of an urban environment, providing pedestrian and bicycle access only. Urban Access Vehicle access is generally prohibited,with the exception of emergency vehicles. This class is not included in the NYSDOT Functional Classifications; nor is it included on the Functional Class Viewer. Chapter 8: Urban Stormwater Management 8-1 Section 8.2 Urban Practice Suitability The Urban Practice Suitability Matrix (Table 8.2) allows the designer to perform an initial evaluation of practices most suitable for a given roadway classification. Practices listed below are not exhaustive of all types of runoff reduction techniques or applicable SMPs. Other runoff reduction techniques may be evaluated, designed and implemented depending on the need or context. Table 8.2 Urban Urban Urban Minor Urban Technique Principal Arterial Collector Urban Local Urban Access Arterial Tree Tree Pit Low High High High High Planting Tree Trench Low Medium High High High Rain Garden Low Low Low Medium High Stormwater Planter Low Medium High High High Porous Pavement/ Porous Concrete Low Low Low High High Porous Paver Roadway Low Low Low High High Porous Porous Paver/Flexible Pavement Porous Pavement Low Medium High High High Pedestrian Applications Porous Pavement/ Porous Concrete Gutter Low Medium High High Medium Bioretention Bumpout Low High High High High Bioslope High High Medium Low Low Underground Infiltration Systems Low Low Medium High High Chapter 8: Urban Stormwater Management -2 Section 8.3 Implementation of Urban Stormwater Management Practices Urban stormwater management practices must consider potential design constraints, interaction with vehicles, bicycles and pedestrians, and how they can be uniquely integrated into urban design. The following descriptions outline how runoff reduction techniques and applicable SMPs can be implemented in urban environments. In order to meet the water quality requirements, set forth in this Design Manual, the practices must conform to the sizing criteria presented in Chapter 4, or Chapter 9 (if applicable), and must be constructed in accordance with the performance criteria in Chapters 5 or 6. While considering the implementation of urban stormwater management practices, it is imperative to recognize potential constraints and considerations of practices and the interaction a practice may have with vehicles, bicycles and pedestrians. Figure 8.1 demonstrates the different zones identified in urban settings used for urban stormwater management practice: Building Use Zone: the area between the building front or property line and the pedestrian zone. This zone is intended to buffer pedestrians from doorways and appurtenances. Pedestrian Zone: the area primarily utilized for pedestrian travel. This zone shall be free of obstacles, protruding objects, and vertical obstructions for pedestrians. Buffer Zone: the area between the pedestrian zone and roadway. This zone is typically utilized for urban stormwater management, utilities, landscaping, public signage, transit stops, and streetscape amenities to keep the pedestrian zone free of obstacles. I, i B 4 Building Use Zone Pedestrian ufferZone Zone Figure 8.1 Urban Stormwater Management Implementation Zones(City of Albany Complete Streets Policy&Design Manual, 2016) Chapter 8: Urban Stormwater Management 8-3 Tree Planting: Tree Pit Tree pits can be applied as a volume reduction practice for urban stormwater management. This practice has the potential to enhance streetscapes, increase the overall urban forest canopy, improve air quality, reduce the urban heat island effect, and provide wildlife habitat. See Chapter 5 Section 5.3.3 for design requirements. Potential Constraints and Considerations : ;J Tree pits have a limited stormwater management capacity. Tree species shall be chosen based on: �, F Hardiness zone; i Allowable growth area for both canopy and root structure; Frequency and degree of maintenance; and Typical life expectancy and disease resistance. ' Trees shall not be planted in front of steps, doorways, or alleyways. Z. Trees with narrow canopies, that do not reduce intersection Figure 8.2 Tree Pit installed in Cohoes, NY visibility, shall be used in medians and near intersections. Interface between trees and utilities, both above and below ground. Volume of soil required to achieve treatment capacity and support mature tree growth. Non-compacted filter media shall be provided within the limits of the open surface area of the tree pit. Where space allows, structural soil shall be extended beyond the non-compacted filter media to allow for root growth into adjacent areas. Structural soil shall be designed with adequate bearing capacity to support sidewalks and other pedestrian amenities. Tree pits shall be located and designed to allow maintenance workers and equipment to safely navigate around the practice. Interaction with Vehicles, Bicycles and Pedestrians Street trees provide the benefit of shade and a physical separation between pedestrians and vehicle traffic. Tree pits must consider accessibility requirements: The pedestrian zone shall meet accessible minimum width requirements. The pedestrian zone shall meet the accessible changes in level requirements. Tree pits may protrude into the pedestrian zone when the surface of the pit (tree grate, flexible porous pavement, etc.) meets accessibility requirements. If the tree pit has a recessed elevation, then a protective barrier shall be provided to restrict pedestrian access. Urban Design Integration Tree pits are best suited for source control treatment of directly adjacent impervious surfaces. Typical applications include pedestrian hardscapes, road rights-of-way, and medians. Refer to Figure 8.3 for application examples. Chapter 8: Urban Stormwater Management 8 UTILITY POLE,STREET LIGHT OR HYDRANT 10'MIN VEHICLE EXIT --DRIVEWAY TREE SPACING 20'MIN VEHICLE APPROACH 15'-30'O.C.BASED O MATURE SIZEIFORM - > - Bl11Ll]i1VG BUILDING i m - r- i i i BUILDING nm x z BUILDING m UNDERGROUND UTILITY MAIN 5'MIN j fl - 1.5'MI �z z OVERHEAD UTILITY LINE UTILITY POLE,STREET LIGHT OR HYDRANT Oq UTILITY MANHOLE c7 5' MI >� 5' MI STORM INLET OR DRAIN c f NOTE:ALL DIMENSIONAL OFFSET REQUIREMENTS SHALL BE CONFIRMED WITH STATE AND LOCAL ENTITIES HAVING JURISDICTION. Figure 8.3 Tree Pit Configuration at Urban Intersection Chapter 8: Urban Stormwater Management 8-5 Tree Planting: Tree Trench Tree trenches can be applied as a volume reduction practice for urban stormwater management. This practice has the potential to enhance streetscapes, increase the overall urban forest canopy, improve air quality, attenuate noise, reduce the urban heat island effect, and provide wildlife habitat. See Chapter 5 Section 5.3.3 for design requirements. Potential Constraints and Considerations Tree species shall be chosen based on: Hardiness zone; Allowable growth area for both -- canopy and root structure; -- Frequency and degree of - maintenance; and Typical life expectancy and + - disease resistance. Interface between trees and utilities, e • ' both above and below ground. Volume of soil required to achieve - treatment capacity and support mature tree growth. In subsurface flow designs, non- compacted filter media shall be Figure 8.4 Tree Trench installed in Hudson Falls, NY provided within the limits of the open surface area of the tree trench only. Structural soil shall be extended within the remaining bounds of the tree trench to provide adequate bearing capacity to support sidewalks and other pedestrian amenities. In areas where soil and/or sidewalk settling is of concern, designs shall consider underground structural supports and/or soil compaction. In surface flow designs, non-compacted filter media shall be provided within the limits of the open surface area of the tree trench. Maintenance required may be outside the regular scope of municipal public works staff. Identifying a suitable maintenance plan and appropriate staff to manage is recommended. Tree trenches shall be located and designed to allow maintenance workers and equipment to safely navigate around the practice. Interaction with Vehicles, Bicycles and Pedestrians Tree trenches do not impede bicycle traffic. A break in the tree trench shall be provided every 40 ft, minimum, where sidewalks are not present between parking stalls and tree trenches. Trees provide the benefit of shade and a physical separation between pedestrians and vehicle traffic. Tree trenches must consider accessibility requirements: The pedestrian zone shall meet accessible minimum width requirements. The pedestrian zone shall meet the accessible changes in level requirements. In subsurface flow designs, tree trenches may protrude into the pedestrian zone when the surface of the trench (tree grate, flexible porous pavement, etc.) meets accessibility requirements. Chapter 8: Urban Stormwater Management 8.16 In surface flow designs, a protective barrier, such as curb or railings, shall be provided at the perimeter of the trench to restrict pedestrian access. Urban Design Integration Tree trenches are best suited for source control treatment of directly adjacent impervious surfaces. Typical applications include pedestrian hardscapes, road rights-of-way, and medians. Refer to Figure 8.5 for application examples. Runoff from adjacent building roofs can be captured and directed into right-of-way tree trenches. Roof drains shall discharge at the surface of the tree trench or connect to a storm sewer structure for flow dissipation, prior to entering the tree trench. Direct connections to the subsurface infiltration pipe are not permitted. Chapter 8: Urban Stormwater Management 8-7 CLEANOUT ROOF DRAIN CONNECTION TO I I CLEANOUT EQUALIZATION STRUCTURE SOLID CONVEYANCE PIPE ROOF DRAIN CONNECTION TO l EQUAIAZATION STRUCTURE ROADWAY CURB INLET(TYP) � � �' f� y ®_ ROADWAY CURB INLET(TYP)SIDEWALK CURB INLET(TYP) TREE TRENCH(SURFACE I I _ TRENCH DRAIN IN SIDEWALK(TYP) FLOW)5'MIN WIDTH AND SIDEWALK CURB INLET(TYP) LENGTH. .I PERFORATED INFILTRATION PIPE OFFSET FROM MIDDLE PROVIDE MINIMUM SIDEWALK I OF TREE TRENCH WIDTH PER CODE(TYP) j I TREE TRENCH(SURFACE FLOW). SOLID CONVEYANCE RIPE 5'MIN WIDTH AND LENGTH. 111 BUILDING BUILDING • c a i DRAINAGE „> MANHOLE(TYP) '} 4 INFLOW CATCH r I BASIN(TYP) BUILDING BUILDING L7— SOLID CONVEYANCE PIPE PERFORATED INFILTRATION j - I PIPE OFFSET FROM MIDDLE OF TREE TRENCH(SUBSURFACE FLOW)WITH— I TREE TRENCH FLUSH CURB TO COLLECT SIDEWALKE) + RUNOFF-5'MIN WIDTH AND LENGTH. I= I I TREE TRENCH(SUBSURFACE — FLOW)WITH FLUSH CURB TO I COLLECT SIDEWALK RUNOFF- 5 MIN WIDTH AND LENGTH- ROOF DRAIN CONNECTION TO EQUALIZATION STRUCTURE I, ROOF DRAIN CONNECTION TO EQUALIZATION STRUCTURE NOTE-ALL DIMENSIONAL OFFSET REQUIREMENTS SHALT.BE CONFIRMED WITH STATE AND LOCAL ENTITIES HAVING JURISDICTION. Figure 8.5 Tree Trench Configuration at Urban Intersection Chapter 8: Urban Stormwater Management 8-8 Rain Garden Rain gardens may be applied as filtration or infiltration practices, depending on site conditions, to provide volume reduction for urban stormwater management. This practice is designed to capture, temporarily store and treat stormwater runoff from adjacent impervious surfaces. In addition, rain gardens have the potential to reduce urban heat island effect and provide wildlife and pollinator habitat through dense, native vegetation. See Chapter 5 Section 5.3.6 for design requirements. Potential Constraints and Considerations Contributing drainage area is limited. May be installed in the building use zone or the buffer zone. Requires adequate space for pedestrian circulation around the rain garden. Surface area may need to be increased to limit the depth of ponding and ensure that ponding does not extend into pedestrian zones. Grading and landscaping placement must establish an appropriate transition zone from the elevation of the pedestrian zone to the elevation of the rain garden bottom _ area. Volume of soil required to achieve treatment capacity. Figure 8.6 Rain Garden installed in Lake George, NY Interface between the rain garden section and below ground utilities. Plant species shall be chosen based on: Hardiness zone; Frequency and degree of maintenance; and Typical life expectancy and disease resistance. Require maintenance which may be outside the regular scope of municipal public works staff. Identifying a suitable maintenance plan and appropriate staff to manage is recommended. Rain gardens shall be located and designed to allow maintenance workers and equipment to safely navigate around the practice. Interaction with Vehicles, Bicycles and Pedestrians Rain gardens may be used as a divide between the pedestrian zone and any recreational site areas or amenities (i.e. playgrounds, multi-use trails, seating areas, etc.) Rain gardens must consider accessibility requirements: The pedestrian zone shall meet ;< y accessible minimum width requirements. g Urban Design Integration Rain gardens are best suited for source control treatment of directly adjacent impervious Figure 8.7 Rain Gardens installed at SUNY Albany campus surfaces. Typical applications include pedestrian plazas, pedestrian medians, pocket parks, and multi-use trails. Chapter 8: Urban Stormwater Management 8-9 Stormwater Planter Stormwater planters may be applied as filtration or infiltration practices, depending on site conditions, to provide volume reduction for urban stormwater management. This practice allows designers to capture, temporarily store and treat rooftop runoff. In addition, stormwater planters have the potential to enhance streetscapes, reduce urban heat island effect, and provide wildlife habitat. See Chapter 5 Section 5.3.7 for design requirements. Potential Constraints and Considerations Stormwater planters shall be placed in the building use zone against building faces and used to capture and treat _ rooftop runoff only. — «a Volume of soil required to achieve treatment capacity. Interface between the stormwater planter section and T • � ' below ground utilities. - w �. Plant species shall be chosen based on: Hardiness zone; Frequency and degree of maintenance; and Typical life expectancy and disease resistance. Figure 8.8 Stormwater Planter installed in Tarrytown, NY Require maintenance which may be outside the regular scope of municipal public works staff. Identifying a suitable maintenance plan and appropriate staff to manage is recommended. Stormwater planters shall be located and designed to allow maintenance workers and equipment to safely navigate around the practice. Interaction with Vehicles, Bicycles and Pedestrians Stormwater planters must consider accessibility requirements: The pedestrian zone shall meet accessible minimum width requirements. Stormwater planters may protrude into the pedestrian zone; however, the pedestrian zone shall meet accessible width requirements. Recessed stormwater planters shall be designed with a protective barrier, such as curb or railings, at the perimeter of the planter to restrict pedestrian access. Urban Design Integration Stormwater planters are best suited for source control treatment of directly adjacent impervious surfaces. Typical applications include treatment of rooftop runoff. Chapter 8: Urban Stormwater Management • £ Porous Pavement Porous pavement may be applied as a volume reduction - practice for urban stormwater management. This practice R' has the potential to reduce local flooding, minimize ice i conditions, reduce the burden on closed storm or combined - ° sewer networks, and promote groundwater recharge. See 4.'.Z.:44 Chapter 5 Section 5.3.9 for design requirements. Potential Constraints and Considerations ; - Highly compacted impervious subbase under existing roadways or hardscapes may need to be ���� removed. Porous pavement designs shall consider traffic loading and volume conditions. Interface between the porous pavement section and below ground utilities. Requires maintenance (semiannually) which may be outside the regular scope of municipal public Figure 8.9 Porous Asphalt parking stalls installed in Cohoes, NY works staff. Identifying a suitable maintenance plan and appropriate staff to manage is recommended. Porous pavement gutters require more regular maintenance (minimum 4 times per year). Interaction with Vehicles, Bicycles and Pedestrians Porous pavement may be applied in the building use zone, pedestrian zone, buffer zone and roadways. Porous pavement within the pedestrian zone must consider accessibility requirements: The pedestrian zone shall meet accessible minimum width requirements. The pedestrian zone shall meet the accessible changes in level requirements. Porous pavements used within the pedestrian zone shall be a stable, firm, walkable surface. Porous pavements may be implemented in bike lanes to reduce the period of time required for pavement to dry. Urban Design Integration Porous pavements can be used in new and retrofit scenarios. Porous concrete may be a suitable replacement for conventional concrete in sidewalk applications. Porous asphalt may be a suitable alternative to conventional asphalt and can be used in a variety of applications such as low traffic roadways, bicycle lanes, shoulders, parking stalls, and multi-use trails. Porous pavers can be used in a variety of applications such as low traffic roadways, bicycle lanes, streetscapes, recreation areas, plazas and parking stalls. Flexible porous paving may be applied in areas such as the buffer zone, around street trees, playground or sporting surfaces, and lower impact multi-use trail surface. Alternating porous pavement types may be used to differentiate surfaces by modal use. Alternating porous pavement textures, colors or patterns may enhance overall street aesthetic. Chapter 8: Urban Stormwater Management •1 Bioretention Bumpout Bioretention bumpouts may be applied as filtration or infiltration practices, depending on site conditions, to provide volume reduction for urban stormwater management. This practice can be applied as a curb extension (bumpout), within the buffer zone, to capture, temporarily store and treat stormwater runoff from roadways and adjacent impervious surfaces. In addition, bumpouts reduce the burden on closed storm or combined sewer networks, promote groundwater recharge, enhance streetscapes, provide traffic calming by visually and physically narrowing the roadway, and create safer and shorter pedestrian crossings at intersections. Potential Constraints and Considerations AFL , Designers shall consider existing on-street parking conditions, road width, and vehicle turning radii. - Alteration of existing curb line may directly impact existing road drainage patterns and shall consider longitudinal and cross slope to bumpout inflow points. In a retrofit design, placement of bumpouts shall considers t location of existing catch basins and potential removal of catch basins to maximize the interception of stormwater runoff from roadways. .. Surface area may need to be increased to limit the depth of ponding and ensure that ponding does not extend into roadways or pedestrian zones. Volume of soil required to achieve treatment capacity. Figure 8.10 Bioretention Bumpout Vegetation shall accommodate adequate sight distance at (Millburn Environmental Commission) intersections. Plant species shall be chosen based on: Hardiness zone; Frequency and degree of maintenance; and Typical life expectancy and disease resistance. Considerations shall be taken for below grade utilities that may be present in the bioretention section. Pretreatment is required for bumpouts. Due to spatial constraints and runoff required to enter at the surface, pretreatment shall be provided in the form of gabion baskets or stone and curb check dams Refer to Figure 8.11. Bumpout design shall consider maneuverability of snow removal equipment. Maintenance may be outside the regular scope of municipal public works staff. Identifying a suitable maintenance plan and appropriate staff to manage is recommended. Bumpouts shall be located and designed to allow maintenance workers and equipment to safely navigate around the practice. Interaction with Vehicles, Bicycles and Pedestrians Where a designated bicycle lane is present, bumpout placement shall provide adequate space between the edges of curb extension and travel lane for bicycle movement. If placed near an intersection, bumpouts shall accommodate pedestrian passage through the curb extension. Mid-block bump outs shall not encourage undesired or unsafe mid-block pedestrian crossings. Allows for separation between pedestrian zones and travel lanes creating a safer and more walkable environment. Recessed bumpouts shall be designed with a protective barrier on the edge of the pedestrian zone, such as curb or railings, to restrict pedestrian access. As an alternative, grading and landscaping placement can be used to establish an appropriate transition zone from the elevation of the pedestrian zone to the elevation of the bioretention bottom area. Chapter 8: Urban Stormwater Management 8•12 Urban Design Integration Bumpouts are best suited for source control treatment of directly adjacent impervious surfaces. Typical applications include intersections and road rights-of-way. Refer to Figure 8.15 for application examples. CONCRETE SIDEWALK PEA GRAVEL O GABION BASKET PRETRE kTMENT MIN 4" MIN WIDTH CURB IIlLET GU IRS SET 4" IIN ABOVE 3` L NG k V WI E SPACED EVERY 8' (T } SID WALK GRA E A A ROADWAY CURB INLET ROADWAY PLAN VIEW ROADWAY CURB INLET EXISTING fi" MIN DEPTH PEA GRAVEL L—SHAPED EDGING NTH ROADWAY 9" MIN STAKES 3" MIN SHREDDED HARDWOOD MULCH 1 FILTER MEDIA REFER TO I BUMPOUT DETAILS FOR I'--� DEPTH 24" MIN DEPTH J j� NO 2 STONE FILTER GABION LAYER (WASHED, NO BASKET FILLED {-_— FINES). EXTEND STONE WITH NO 57 DEPTH TO BOTTOM OF STONE, BIORETENTION STONE WASHED FILTER LAYER \XUNDISTURBED EARTH "__DRAINAGE FILTER FABRIC WRAPPED AROUND GABION AND STONE FILTER LAYER SECTION A-A Figure 8.11 Pretreatment for Bioretention Bumpouts—Gabion Basket Chapter 8: Urban Stormwater Management 8-13 CONCRETE SIDEWALK TAPER FROM EXIISI ING URB SET MIN ABO AL NG BUMPP UT 4" MIN tDTH CURB SID ALK GRADNLET SPD EVERY 86 12" 10"12" 0" 12" Eli TING 4' 7` (TYP) B I A I I I A I I I TAPER ROADWAY TO ROADWAY 4' V-NOTCHESWCONCRETE TERIOR RIMETER CURB 8" REBAR DOWEL PEA GRAVEL PRETREATMENT PLAN VIEW 3" MIN SHREDDED EXISTING HARDWOOD MULCH ROADWAY PONDING DEPTH 6"-12" ,CONCRETE 12" APRON. 10% 15" 2"14 SLOPE EXISTING ROADWAY 6" CONCRETE (TYP} IDEWALK 6 12" 6 7 40 I _ r EXTERIOR i ► UNDISTURBED I PERIMETER CURB EARTH r UNDISTURBED EARTH INTERIOR I I DRAINAGE NO. 2 STONE FILTER LAYER PERIMETER CURB _FILTER FABRIC (WASHED, NO FINES). PEA GRAVEL I EXTEND STONE DEPTH TO BOTTOM OF BIORETENTION N0. 2 STONE FILTER STONE FILTER LAYER LAYER (WASHED, NO PEA GRAVEL PRETREATMENT FINES). EXTEND STONE DRAINAGE FILTER FABRIC DEPTH TO BOTTOM OF L-SHAPED EDGING WITH 9" MIN STAKES BrORETENTION STONE FILTER MEDIA REFER TO FILTER LAYER BUMPOUT DETAILS FOR DEPTH SECTION A-A SECTION S-B Figure 8.12 Pretreatment for Bioretention Bumpouts—Stone and Curb Check Dam Chapter 8: Urban Stormwater Management 8-14 12" MIN PERFORATED INFILTRATION PIPE A CONCRETE SIDEWALK 1 1 1 ! 1 1 1 -- i STABILIZED PRETREATMENT A OPTION 1: GABION BASKET DROP CURB INLET WITH ROADWAY DOME OR FLUSH WHEEL GUARD OVERFLOW GRATE PLAN VIEW CONCRETE DOME OR FLUSH INLET SIDEWALK BEYOND OVERFLOW GRATE 3" MIN SHREDDED FINISH GRADE HARDWOOD MULCH AT ROADWAY FILTER MEDIA i 36" MIN DEPTH ----------- ______________ __________ 24" MIN NO. 2 STONE j FILTER LAYER (WASHED, -----__—__-_r__—__— «____— -- NO FINES) 0 12" MIN PERFORATE DD PROFILE VIEW INFILTRATION PIPE 24- MIN SEPARATION TO DRAINAGE FILTER SEASONAL HIGH FABRIC WATER TABLE/BEDROCK REFER TO APPENDIX H 3" MIN SHREDDED HARDWOOD MULCH SUGGESTED PLANT LIST DOME OR FLUSH OVERFLOW GRATE FINISH GRADE AT ROADWAY CONCRETE SIDEWALK r �1 u _ FILTER MEDIA STABILIZED PRETREATMENT 0 36" MIN DEPTH OPTION 1: GABION BASKET 24" MIN NO. 2 STONE FILTER LAYER (WASHED, DRAINAGE FILTER FABRIC -- NO FINES) 24" MIN 12" MIN. PERFORATED SEPARATION TO INFILTRATION PIPE SEASONAL HIGH WATER TABLE/BEDROCK SECTION A-A VIEW Figure 8.13 Bioretention Filter Island Bumpout Chapter 8: Urban Stormwater Management 8-15 12" MIN PERFORATED DOME OR FLUSH INFILTRATION PIPE OVERFLOW GRATE pNCRETE S:aE WALK - r - r r � L E r r r r r r r --------- ROADWAY— STABILIZED PRETREATMENT CATCH BASIN INLET OPTION 2: STONE & CURB CHECK DAM PLAN VIEW STABILIZED PRETREATMENT OPTION 2: STONE & CURB PONDING DEPTH = 6"-12" 3- MIN SHREDDED HARDWOOD MULCH CHECK DAM [DOME OR FLUSH INLET GRATE CONCRETE SIDEWALK r _ i r r r FILTER MEDIA r r r r { 36" MIN DEPTH r a-* .,.�..,. �.,.�.4. ----- 24" MIN NO. 2 STONE i r _ _ r FILTER LAYER (WASHED, r �ii-----ii��ii .,...�...�.---. --- -.���,. NO FINES DRAINAGE FILTER y ] 12' MIN PERFORATED FABRIC R MIN SEPARATION TO INFILTRATION PIPE PROFILE VIEW SEASONAL HIGH WATER TABLE/BEDROCK 3' MIN SHREDDED REFER TO APPENDIX H HARDWOOD MULCH SUGGESTED PLANT LIST DOME OR FLUSH OVERFLOW GRATE FINISH GRADE CONCRETE SIDEWALK AT ROADWAY FILTER MEDIA r 36" MIN DEPTH r �---- 24" MIN NO, 2 STONE DRAINAGE r r FILTER LAYER (WASHED, FILTER FABRIC NO FINES) — 24" MIN 12" MIN SECTION A-A VIEW SEPARATION TO PERFORATED PIPE SEASONAL HIGH WATER TABLE/BEDROCK Figure 8.14 Bioretention Corner Bumpout Chapter 8: Urban Stormwater Management 8-16 CURB INLET WITH STABILIZED OVERFLOW GRATE(TYP) PRETREATMENT(TYP) UNDERDRAIN(IF REQUIRED) BIORETENTION FILTER(ISLAND BUMPOUT)WITH FLUSH CURB AT SIDEWALK TO COLLECT RUNOFF 1� PROVIDE MINIMUM _ SIDEWALK WIDTH PER CODE BUILDING BUILDING -- I I I I I I I OVERFLOW GRATE(TYP) I i 1 1 - .I SIEMENS SEEMED UNDERDRAIN CURB INLET WITH (IF REQUIRED) r� STABILIZED SENSE* TY PRETREATMENT( P) "`�~ � rr CURB INLET WITH STABILIZED - - PRETREATMENT(TYP) BIORETENTION FILTER BUILDING (CORNER BUMPOUT)WITH BUILDING FLUSH CURB AT SIDEWALK T', BIORETENTION FILTER(CORNER TO COLLECT RUNOFF BUMPOUT)WITH FLUSH CURB AT SIDEWALK TO COLLECT RUNOFF PROVIDE MINIMUM SIDEWALK WIDTH - - PER CODE PROVIDE MINIMUM SIDEWALK WIDTH PER CORE^ Al NOTE.ALL DIMENSIONAL OFFSET REQUIREMENTS SHALL BE CONFIRMED WITH STATE AND LOCAL ENTITIES HAVING JURISDICTION.. Figure 8.15 Bioretention Bumpout Configuration at Urban Intersection Chapter 8: Urban Stormwater Management 8-17 Bioslope Bioslopes can be applied as a volume reduction practice for urban stormwater management. This practice is best suited for linear applications to treat stormwater along impervious areas, such as medium to high volume roadways with minimal pedestrian interaction, linear utility projects, low volume access drives, and multi-use trails. See Chapter 6 Section 6.4 for design requirements. Potential Constraints and Considerations Limited to sheet flow applications only. Adequate space must exist to provide all components of the bioslope, including pretreatment. .. "� Require maintenance which may be outside the regular scope of municipal public works staff. Identifying a suitable maintenance plan and appropriate staff to manage is recommended. Interaction with Vehicles, Bicycles and Pedestrians Applicable where curb and gutters are not utilized. Roadway must provide adequate space for vehicle stopping, such that the vehicle does not �'f interact with the pretreatment and treatment Figure 8.16 Bioslope Application zones. (Georgia Stormwater Management Manual, 2016 Edition) Bicycle travel and pedestrian zone, if applicable, must be provided with adequate space outside of the pretreatment and treatment zones. Urban Design Integration Require a relatively small amount of space to function effectively and can be applied in rights-of-way where availability is limited. Chapter 8: Urban Stormwater Management • Underground Infiltration Underground Infiltration can be applied as a volume reduction practice for urban stormwater management. This practice can be used to capture, temporarily store and treat stormwater runoff, reduce the burden on closed storm or combined sewer networks, and promote groundwater recharge in areas where space is constrained. See Chapter 6 Section 6.3 for design requirements. Potential Constraints and Considerations Adequate cover shall be provided, based on manufacturer's recommendations, to protect the structural integrity of the system. Urban fill soils shall not be used in areas of underground A Tk infiltration practices. Urban fill in considered soil that � � ^ includes unsuitable materials such as brick, cement, asphalt, demolition debris, etc. Figure 8.17 Underground infiltration system installed in Maintenance required may be outside the regular scope Mahopac, NY of municipal public works staff. Identifying a suitable maintenance plan and appropriate staff to manage is recommended. Interaction with Vehicles, Bicycles and Pedestrians Proposed grates, covers and inspection ports associated with the system shall be selected and placed with the anticipated traffic above the system in mind to avoid interfering with traffic. Proposed grates, covers and inspection ports associated with the system, within the pedestrian zone, shall not impede pedestrian movements and shall meet the accessible changes in level requirements. Inlet grates within the pedestrian zone shall meet accessibility requirement. Inlet grates within the bicycle travel lane shall meet bicycle safety requirements. Urban Design Integration Ideal for highly urbanized areas where soil permeability is high and space is constrained. Systems have little to no surface footprint and can be integrated within the building use zone, pedestrian zone, or buffer zone. Chapter 8: Urban Stormwater Management •1 This Page is Left Intentionally Blank NEW Department of PORK STATE Environmental Conservation Chapter 9: Redevelopment Activity This Chapter outlines alternative approaches for addressing stormwater management at projects that include the disturbance and reconstruction of existing impervious surfaces (i.e. redevelopment activity). The approaches set forth in this Chapter comply with the Department's technical standards. Section 9.1 Introduction Redevelopment of previously developed sites is encouraged from a watershed protection standpoint because it often provides an opportunity to conserve natural resources in less impacted areas by targeting development to areas with existing services and infrastructure. At the same time, redevelopment provides an opportunity to correct existing problems and reduce pollutant discharges from older developed areas that were constructed without effective stormwater pollution controls. Redevelopment activities can range from large-scale redevelopment (e.g. reconstruction of a box store, mall, etc.), to much smaller building, parking lot or road reconstruction projects. The proposed density of the large-scale projects can be high, resulting in space constraints to implement on-site stormwater controls. Added to this basic space constraint is the need to tie into the existing drainage infrastructure, which may be at an elevation that does not provide enough head for certain stormwater management practices (SMPs). Other problems encountered in redevelopment include the presence of underground utilities, incompatible surrounding land uses, highly compacted soils that are not suitable for infiltration, and contaminated soils that require mitigation and can drive up project costs. Because the technical standards contained elsewhere in this Manual were primarily intended for new development projects, compliance with the sizing criteria in full may present a challenge on projects that include redevelopment activities. Therefore, this Chapter sets forth alternative sizing criteria for redevelopment activities. Implementation of this alternative sizing criteria will result in pollutant reductions over existing conditions where no practices are currently in place, particularly when considering the cumulative effect of multiple projects. For redevelopment activities located in critical environmental areas (see http://www.dec.ny.gov/permits/6184.html) and other sensitive environmental or regulated areas, all attempts should be made to seek compliance with the sizing criteria set elsewhere in this manual. Section 9.2 Scope and Applicability The provision of stormwater management practices during redevelopment activities should follow an approach to balance between 1) maximizing improvements in site design that can reduce the impacts of stormwater runoff, and 2) providing a maximum level of on-site treatment that is feasible given the site constraints present where the redevelopment activities are occurring. Under conditions where onsite treatment is not practicable, an appropriate off-site watershed improvement to offset the required level of control may be applied, in the presence of a regulated/permitted municipal stormwater management program. The off-site stormwater management approach is subject to applicable local agency approval for banking and trading of credits. This approach may not be an acceptable option in all cases. In addition, a SWPPP that incorporates this approach is considered to be not in conformance with the State's technical standards. Requirements for installation of post construction controls set forth in current stormwater regulations do apply to construction projects that include redevelopment activities. The sizing criteria described in this Chapter apply to redevelopment activities only. If a construction project includes both new development and redevelopment activities, the stormwater management practices for the new development portion of the project must be designed in accordance with the sizing criteria in Chapter 4, and the redevelopment activities portion of the project is subject to the sizing criteria in Section 9.2.1. If runoff from the reconstructed impervious area (i.e. redevelopment activity) was being treated by an existing stormwater management practice that generally meets the criteria of one of the practices included in this manual, the final design must include WQv treatment equal to the treatment that was provided by the existing practice or the treatment options defined in Section 9.2.1 of this Chapter, whichever treatment volume is greater. Chapter 9: Redevelopment Activity _1 9.2.1 Sizing Criteria Note: The following sizing criteria apply to redevelopment activities only. A. Water Quality treatment objective shall be achieved using the following options. If there is an existing stormwater management practice located on the site that captures and treats runoff from the impervious area that is being disturbed, the water quality volume treatment option selected must, at a minimum, provide treatment equal to the treatment that was being provided by the existing practice(s) if that treatment is greater than the treatment required by options I - V: The plan proposes a reduction of existing impervious cover by a minimum of 25% of the total disturbed, impervious area. A reduction in site imperviousness will reduce the volume of stormwater runoff, thereby achieving, at least in part, stormwater criteria for both water quality and quantity. The final grading of the site should be planned to minimize runoff contribution from new pervious area onto the impervious cover. Effective implementation of this option requires restoration of soil properties in the newly created pervious areas. Soil restoration is achieved by practices such as soil amendment, deep-ripping, and de- compaction (See Section 5.1.6 Soil Restoration). The plan proposes that 100% WQv is captured and treated, for a minimum of 25% of the disturbed, redevelopment impervious area, by implementation of standard SMP or reduced by application of runoff reduction techniques (see Chapter 5 of this Manual). The SWPPP must clearly document the 25% redevelopment area that is being treated. The remaining 75% can flow to the design point untreated so long as the water quantity control requirements are met. For all sites that utilize structural SMPs, these practices should be targeted to treat areas with the greatest pollutant generation potential (e.g. parking areas, service stations, etc.). If the construction project includes both new development and redevelopment activities, 100% WQv treatment is required for, at minimum, 25% of the existing disturbed impervious area; however, in accordance with Chapter 4, 100% of the WQv must be provided for any increases in impervious cover to a given design point. In cases where treatment of the redeveloped area is infeasible, due to site constraints, designers may choose to treat an equivalent or greater existing impervious area that is tributary to the same design point as the redeveloped area. As with design of any practice, sizing of structures shall be based on all contributing areas to the SMP. Construction projects that involve the redevelopment of a portion of the site, may choose diversion or flow splitters to be able to size the control structures for the reconstructed area only. For all sites that utilize runoff reduction techniques (See Table 3.1), a proposed plan is effective when runoff is controlled near the source and managed by infiltration, reuse, and evapotranspiration. The plan proposes that 100% WQv is captured and treated, for a minimum of 75% of the disturbed, redevelopment impervious area, by implementation of a volume-based alternative SMP, as defined in Section 9.4. However, in accordance with Chapter 4, 100% of the WQv must be provided for any increases in impervious cover to a given design point using runoff reduction techniques and/or standard SMPs. If an alternative SMP is proposed for the new development portion of a project, then that practice must be approved by the Department for conformance with the new development design criteria. As with design of any practice, sizing of practices should be based on all areas contributing to the SMP. The plan proposes that 100% WQv is captured and treated, for a minimum of 75% of the disturbed, redevelopment impervious area, by implementation of a flow-through alternative SMP sized to treat the peak rate of runoff from the WQv design storm, as defined in Chapters 4 and 10. As with design of any practice, sizing of practices should be based on all areas contributing to the SMP. For guidance, the Water Quality Peak Flow Calculation is provided in Section 9.3. The flow capacity identified in the verification process for the specific alternative practice must be greater than or equal to the calculated peak runoff rate from the WQv design storm. For off-line practices, the installation must include flow diversion that protects the practice from exceeding the design criteria. However, in accordance with Chapter 4, 100% of the WQv must be provided for any increases in impervious cover to a given design point using runoff reduction techniques and/or standard SMPs. If an alternative SMP is proposed for the new development portion of a project, then that practice must be approved by the Department for conformance with the new development design criteria. Chapter 9: Redevelopment Activity _ The plan proposes a combination of techniques, such as impervious cover reduction (ICRED), standard SMPs, runoff reduction or alternative SMPs that provide a weighted average of at least two of the above methods. The plan may provide a combination of the above options using the following calculation. In accordance with Chapter 4, 100% of the WQv must be provided for any increase in impervious cover to a given design point. If an alternative SMP is proposed for the new development portion of a project, then that practice must be approved by the Department for conformance with the new development design criteria. %ALT = [25 — (%ICRED +%SMP +%RR)](3) Where: %ALT= Percent of redevelopment impervious area treated by alternative SMP(s) %ICRED= Percent reduction in existing disturbed impervious area %SMP = Percent of redevelopment impervious area treated by standard SMP(s) %RR = Percent of redevelopment impervious area treated by runoff reduction technique(s) For example, water quality volume for the alternative practice for the following scenarios shall be computed as follows: Example 1: Combination of impervious area reduction and standard SMP 0%ALT = [25 — (5%ICRED +20%SMP + 0%RR)](3) Example 2: Combination of impervious area reduction and alternative practice 60%ALT = [25 — (5%ICRED + 0%SMP + 0%RR)](3) Example 3: Combination of standard SMP, runoff reduction and alternative practice 45%ALT = [25 — (0%ICRED + 5%SMP + 5%RR)](3) Example 4: Combination of impervious area reduction, standard SMP, runoff reduction and alternative Practice 30%ALT = [25 — (5%ICRED + 5%SMP + 5%RR)](3) B. Runoff Reduction Volume, although encouraged, meeting the RRv sizing criteria is not required for the redevelopment activity portion of a project. The need to provide RRv shall be considered separately for each design point. For design points with a net increase in impervious area, RRv is required for the increase in impervious area only. For urban redevelopment projects requiring RRv refer to Chapter 8 for urban design considerations. For design points with a net decrease in impervious area, RRv is not required for that design point. C. Water Quantity controls shall be sized using the following options: VI. Channel Protection for redevelopment activities is not required if there is 0% change to hydrology that increases the discharge rate and volume from the project site. Evaluation of the change to hydrology shall include the redevelopment activity portion of a project, and if applicable any new development tributary to the same design point as the redevelopment, in the analysis. This criterion, as defined in Chapter 4 of this Manual, is not based on a pre-versus post-development comparison. However, for redevelopment activities this requirement is relaxed. If the hydrology and hydraulic analysis for the project site shows that the post-construction 1-year 24-hour discharge rate and volume are less than or equal to the pre- construction discharge rate and volume, providing 24-hour detention of the 1-year storm to meet the channel protection criteria is not required. VII. Overbank Flood and Extreme Flood Control for redevelopment activities is not required if there is 0% change to hydrology that increases the discharge rate from the project site. Evaluation of the change to hydrology shall include the redevelopment activity portion of a project, and if applicable, any new development that is tributary to the same design point as the redevelopment in the analysis. This is true because the calculated discharge of pre-development versus post-development flows results in zero net increase. This consideration does not mean that existing quantity controls may be neglected in planned designs. Existing quantity controls must be maintained for post-development flow discharge control. Any new, replacement quantity controls shall be designed to provide equivalent control as the existing. Chapter 9: Redevelopment Activity -3 9.2.2 Performance Criteria The performance criteria of selected SMPs for redevelopment activities fall under three categories: Performance criteria for standard stormwater management practices as defined in Chapter 6 of this Manual must be applied in the design of the practices. Performance criteria for runoff reduction techniques as defined in Chapter 5 of this Manual must be applied to the design of the practices, and; 3. The alternative SMPs discussed in this Chapter are to be used for redevelopment activities only, unless approved for use on new development activities. The performance criteria for alternative SMPs are based on the testing protocols and procedure set for verification of manufactured system by regulatory agencies. Section 9.3 Water Quality Peak Flow Calculation The peak rate of discharge for the water quality design storm is needed for the sizing of diversion structures for off-line practices, such as flow-through Alternative SMPs. An arbitrary storm would need to be chosen using the Rational Method, and conventional SCS methods have been found to underestimate the volume and rate of runoff for rainfall events less than 2 inches. This discrepancy in estimating runoff and discharge rates can lead to situations where a significant amount of runoff bypasses the filtering treatment practice due to an inadequately sized diversion structure and leads to the design of undersized bypass channels. The procedure outlined in Appendix B shall be used to estimate peak discharges for small storm events. Section 9.4 Alternative Stormwater Management Practices Proprietary Practices Proprietary practices encompass a broad range of manufactured structural control systems available from commercial vendors designed to treat stormwater runoff and/or provide water quantity control. Manufactured treatment systems are often attractive during redevelopment activities because they tend to take up less space, often installed underground, and can usually be retrofitted to existing infrastructure. The NYSDEC provides criteria for Proprietary Practices for Stormwater Management that can be applied for new development, redevelopment, and pretreatment: (https://www.dec.ny.gov/chemica1/29089.htm1). ProprietaryTable 9.1 Common g. Category Description Treatment Type Hydrodynamic Devices that move water in a circular, centrifugal manner to accelerate Flow Based Separators the separation and deposition of primarily sediment from the water. Water-tight structures that include a permanent pool and promote Wet Vaults settling of particulates through detention and use of internal baffles and Volume Based other proprietary modifications. Surface or subsurface practices that contain filter beds containing Media Filters absorptive filter media that promotes settling of particulates as well as Flow Based adsorption and absorption of other pollutants attracted to the characteristics of the proprietary filter media. 9.4.1 Evaluation of Alternative Practices As a group, the performance of proprietary SMPs has been verified thus far only to a limited extent, through laboratory testing and long-term field monitoring. Where verification data does exist, they generally indicate that these practices do not meet both the 80% total suspended solids (TSS) and 40% total phosphorus (TP) removal efficiency target that is specified in Chapter 3 of this Manual. However, proprietary practices that have been certified by specific verification sources and demonstrate that they provide some level of water quality treatment, are allowed for redevelopment activities in New York State. This allowance is conditioned upon the system being operated at the specific tested design flow rate, defined based on the verified performance of each specific system. Based on the conclusions of the verification sources, it is believed that these treatment systems have the capability of achieving an acceptable TSS removal efficiency in field applications. Chapter 9: Redevelopment Activity 9-4 NYSDEC's evaluation of proprietary practices for demonstration of minimum removal efficiency for redevelopment activities shall be based on one of the following stormwater management practice evaluation systems: New Jersey Corporation for Advanced Technology (NJCAT) verified and New Jersey Department of Environmental Protection (NJDEP) certified, for inclusion in NJCAT Verification Database or NJDEP list of approved Manufactured Treatment Devices (MTD's). The NJCAT"Archived List" shall not be referenced for device approvals. Washington State Technology Assessment Protocol - Ecology (TAPE), list of"Approved Technologies." Practice must be approved at the "General Use Level" use designation for"Basic", "Enhanced," and/or"Phosphorus" treatment types. The proposed manufactured treatment systems that are verified or certified through the above systems and meet the criteria stated above are allowed for redevelopment activities in New York State. Proposed manufactured treatment systems that are not verified yet may be considered for acceptance in New York State if verified at any time through one of these verification sources. All the manufactured treatment systems must be sized appropriately to provide treatment for the water quality volume or the runoff from the entire contributing area. Due to the proprietary nature of the practices, designers are responsible to ensure that manufacturer's recommendations are followed for all design details, such as structural integrity, configuration, assembly, installation, operation, and maintenance of the units. Designers are also responsible to address, at minimum, all the relevant requirements set by New York State standards such as pretreatment, bypass, quantity controls, overflow, head configuration, inflow/outflow rates, maintenance, separation distance, accessibility, and safety issues concerning the selected practice. 9.4.2 Recommended Application of Practice Many proprietary practices are useful on small sites and space-limited areas where there is not enough land or room for other structural control alternatives. Proprietary practices can also be reasonable alternatives where there is a need to tie into the existing drainage infrastructure, where site elevations limit the head for certain stormwater management practices (SMPs). Hydrodynamic separators are generally more effective on sites with potential loading of coarse particulates. Specific media filters may be suitable in most conditions. 9.4.3 Benefits The benefits of using proprietary practices will vary depending on the type of practice, but may include: Reduced space requirements for practices located below grade. Reduced engineering and design due to prefabricated nature of systems and design support and tools provided by manufacturer. Spill containment and control capabilities. 9.4.4 Feasibility/Limitations Depending on the proprietary practice, the following factors may be considered as a limitation: Limited performance data. Data that does exist suggest these practices don't perform at the same level as the suite of standard practices in Chapters 3 and 6 of this Manual, particularly with regard to nutrient load reduction. Application constraints such as limits to area draining to a practice, due to pre-manufactured nature of products. High maintenance requirements (e.g., need for specialized equipment, confined space entry training, frequency of recommended maintenance, and cost of replacement components)that often are ignored or forgotten because many practices are underground and out of sight. Higher costs per treated area than other structural control alternatives, but this can be offset by value of land not needed due to subsurface nature of many proprietary practices. Concern over mosquito breeding habitat being provided by practices that have wet sumps as design components. Chapter 9: Redevelopment Activity - 9.4.5 Sizing and Design Guidance Sizing and design guidance will vary based on the product being used. Since sizing criteria is integral to the verified performance of manufactured practices, designers should refer to the capacities and flow rates associated with the models (sizes) of the manufactured SMPs identified by the verification source. The New York State design standards calls for small storm hydrology and the use of Simple Method for hydrology calculation. For practices with volume-based sizing approaches, sizing shall be performed to meet the water quality volume as defined in Section 4.2 of this Manual. For rate or flow-based sizing approaches, sizing shall be performed based on the peak rate of discharge for the water quality design storm, as described in Section 9.3. Proprietary practices are designed as on-line or off-line practices. On-line practices typically have built-in bypass capabilities. Flow through systems, that do not have built-in bypass must be designed as off-line systems It is important for designers to specify proprietary practices based on their treatment capacities (CASQA, 2003). Since hydraulic capacity can be as much as ten times that of the treatment capacity, designer must ensure that hydraulic load does not exceed the performance rate defined in the verification process. The above applies to all design elements that affect the performance rate. Some examples of such design elements are head, orifice sizing, oil storage or sediment storage capacities, baffle configuration, or screen size. Practices with a volume-based sizing approach must be sized to capture and treat 75 % of the WQv as defined in Chapter 4 of the Manual. Flow through practices must be sized to the peak rate of runoff from the WQv design storm, as defined in Chapter 4 and Chapter 10, and Section 9.3. For off-line practices, the installation must include flow diversion that protects the practice from exceeding design criteria. 9.4.6 Environmental/Landscape Elements There are few or no environmental or landscaping elements that designers can consider with most proprietary treatment practices. They are frequently absent or predetermined by the manufacturer. The use of land area above the facility needs to be selective and manufacturer design specifications must be strictly followed. 9.4.7 Maintenance Maintenance is a critical component to ensure proper functioning of proprietary practices. Most manufacturers provide maintenance recommendations. When these schedules are not followed, proprietary practices can be expected to fail. Most proprietary practices require a minimum of quarterly inspections and cleanouts. In addition, specialized equipment (e.g., vacuum excavator trucks and boom trucks) may be required for maintaining certain proprietary practices. Refer to maintenance requirements defined in Section 3.5 of this Design Manual. Links New Jersey Corporation for Advanced Technology, Technology Verification Database, http://www.nocat.org/verification- process/technology-verification-database.html New Jersey Department of Environmental Protection (NJDEP) —Stormwater Manufactured Treatment Devices, https://www.n'.qov/dep/stormwater/treatment.html Washington State Department of Ecology— Emerging Stormwater Treatment Technologies (TAPE), http://www.ecy.wa.gov/programs/wg/stormwater/newtech/technologies.htmI Chapter 9: Redevelopment Activity 9-6 Chapter 10: Addressing Stormwater Pollutants of Concern Section 10.1 Introduction and Overview The chapter presents a discussion of five categories of common pollutants of concern that are found in stormwater runoff during the WQv design storm. The following sections provide common pollutant sources, environmental fate and transport characteristics, an overview of SMP pollutant removal capabilities, and recommended SMP design modifications to further reduce specific pollutants of concern. Common sources of origin for pollutants of concern are listed in Table 10.1. I Table 10.1 Common Sources for Pollutants of Concern Pollutant of Concern Common Sources Solids JSS) Road and vehicle wear, soil erosion, dust, litter, organic debris. Phosphorus Fertilizers, farm-animal waste, detergents, flame-retardants in many applications(including lubricants), corrosion inhibitors, and plasticizers. Fertilizers, farm-animal waste, and faulty septic systems. Naturally occurring Nitrogen from vegetation decomposition. Metals(typically include copper, Industrial and domestic waste, mining, mineral leaching, automobile parts and lead, zinc, and cadmium) fluids, roof runoff, paints. Can occur naturally in soil. Pathogens(including bacteria such Domestic sewage, animal waste, combined sewer overflows(CSOs), biofilms. as fecal coliform and E. coli) Naturally occurring in plant or soil material. rl A Natural Industrial car Urban Ewn Agricultural Residentimiki : al Figure 10.1 Common Sources of Pollutants of Concern in a Watershed Chapter 10:Addressing Stormwater Pollutants of Concern 10-1 10.1.1 Description and Properties of Pollutants of Concern Solids (TSS) Solids in stormwater can consist of sediment, trash, and other forms of organic materials and debris. Total suspended solids (TSS) is the measure used to commonly describe the particulates of various origin that are suspended in a body of water. Sediment is naturally present to varying degrees in receiving waters and runoff; however, both urban and agricultural human activities can increase sediment loads to levels that impact aquatic life and other beneficial uses of waterbodies. Solids contribute to many water quality, habitat and aesthetic problems in urban waterways. Elevated levels of solids increase turbidity, thereby reducing the penetration of light at depth within the water column and limiting the growth of desirable aquatic plants. Solids that settle out as bottom deposits contribute to sedimentation and can alter and eventually destroy habitat for fish and bottom-dwelling organisms. Solids also provide a medium for the accumulation, transport, and storage of other pollutants such as nutrients and metals. In the context of stormwater, the primary concern has traditionally been the fine solids fraction. As particles decrease in size, they have a higher ratio of surface area to mass, so smaller particles generally have a higher capacity for carrying heavy metals and nonpolar organics. Pollutants such as phosphorus, pesticides, non-polar organics, and metals such as copper, zinc, cadmium, and lead, may adsorb onto the surface of sediment, especially to clay and organic particles in runoff. Phosphorus Phosphorus in stormwater occurs in dissolved and particulate forms. Dissolved forms typically are more than 90% bioavailable, while particulate forms are typically less than 25% bioavailable. Orthophosphate is the most readily bioavailable form of phosphorus and can move from sediment into the water column by diffusive processes, and can also bind to metals, such as iron and aluminum to form solid complexes. Due to its tendency to sorb to soil particles and organic matter, phosphorus is primarily transported in surface runoff with eroded sediments. In areas with high phosphorus content in soils, deposition of sediment due to construction or other land disturbance activities or areas with fertilizer can represent a significant source. Phosphorus is typically the limiting nutrient in most freshwater systems, resulting in stormwater discharge of phosphorus having the potential to cause significant water quality impairment to receiving waters. Dissolved phosphorus has the greatest impact on receiving waters and minimizing or treating for dissolved phosphorus in runoff should be a priority for protecting receiving waters. While phosphorus is an essential nutrient for all life forms, increased amounts of bioavailable phosphorus in surface waters can stimulate excessive algae growth and result in numerous water quality problems (WERF, 2005). Nitrogen Nitrogen predominantly exists in stormwater as nitrogenous organic solids, nitrate, and ammonia. Nitrogen generally does not sorb strongly to soil particles and can be transported in surface runoff in both particulate and dissolved phases. Most forms of nitrogen can transform into nitrate in the nitrogen cycle. Nitrate is totally soluble in water, readily available for biological uptake, and moves freely through most soils. As a result, nitrate is the primary form of nitrogen that is leached into groundwater and can commonly cause surface water degradation that leads to eutrophication. Ammonium nitrogen sorbs to surfaces of clays and finer-grained soils or organic soil matter, making it less likely to enter groundwater. However, under the right soil conditions, ammonium can readily transform into the more mobile form of nitrate. Movement of nitrogen into surface water can take several pathways. It can enter water directly through direct discharges from municipal and industrial waste sources or can be dissolved in runoff water or attached to soil particles. Depending on the soil characteristics, the movement of nitrogen is variable. Nitrogen moves well through non-cohesive soils with high groundwater, however less so for cohesive soils. Nitrogen can also be emitted into the atmosphere and then deposited to surface waters and land through precipitation and dry deposition. Metals Metals typically have low solubility and are not mobile in soil. Metals of primary concern in stormwater include cadmium, copper, lead, and zinc. Most are readily adsorbed within typical pH ranges found in soil. Leaching of metals may also increase under certain environmental conditions as mobility typically increases for most metals as pH decreases. Metals may also form complexes with organic matter, which may increase their mobility as well. Chapter 10:Addressing Stormwater Pollutants of Concern 10-2 Metals are found in either a dissolved state or bound to suspended solids in stormwater, with most of the metal mass bound to suspended solids. As such, metals can be easily filtered out in soil and engineered media. However, metals are not easily biodegraded, which results in their ability to accumulate and persist for long periods of time, until they are disposed of(Weiss et al., 2008). At trace concentrations, several of these metals are essential to human life; at higher concentrations they can be toxic. Pathogens Pathogens, or disease-causing organisms, can be broken down into three categories: bacteria, protozoa, and viruses. Many of these pathogens are commonly found in runoff and may pose a threat to human health. Fecal coliform and Escherichia coli(E. coli) bacteria are the most commonly used indicators of pathogen presence. Fecal indicator bacteria in urban stormwater originate from feces of warm-blooded animals deposited on pervious and impervious surfaces. Pet waste, leaking septic systems, and urban wildlife are primary sources. These bacteria may be directly deposited into the receiving water or transported in stormwater flows. Additionally, bacteria may persist for extended periods of time in sediments, biofilms, and organic litter within stormwater facilities, pipes, and media. Bacteria are living organisms and their primary effect on stormwater quality results from their life status rather than their simple presence. Bacteria can be controlled (i.e. inactivated)without being removed, but concentrations can also increase without further bacterial loading when conditions are conducive to natural population growth within stormwater conveyances, treatment facilities, and receiving waters. While sediment and organic litter represents a sink for most pollutants, bacteria may survive longer in sediments/organic litter than in the water column. Therefore, sediment or organic litter, if mobilized, could actually be a significant source of bacteria, and removal of water column particulate- bound or free bacteria may not constitute a reliable permanent removal mechanism in some cases. 10.1.2 Summary of Pollutant Characteristics Table 10.2 summarizes the typical fate and transport characteristics and behavior of pollutants within the environment. Table 10.2 Pollutant Characteristics Characteristic Solids(TSS) Phosphorus Nitrogen Metals Pathogens Mobility Moderate Moderate High Very low/Moderate Moderate/High Solubility Low Low/High for High Low Low dissolved forms Abundance in High Moderate/High Low/Moderate Low/High Likely present stormwater Low. Primary Toxicity Variable Low concern is for Variable Variable infants less than 6 months in age High in anaerobic Degradation Low High for particulate environments; low Low Low Potential form in aerobic environments Adsorption/ High High for dissolved Low High High Absorption form Plant uptake Low High for dissolved High Low Low form Low/Moderate based on high Potential risk to Low Low/Moderate mobility but Low, except Low/Moderate groundwater relatively low possibly for zinc concentrations in urban stormwater Chapter 10:Addressing Stormwater Pollutants of Concern 10-3 Section 10.2 Pollutant Removals in Stormwater Management Practices Pollutant removals highly vary among stormwater management practices. Generally, practices that utilize filtration and sedimentation as their primary removal mechanism are effective at decreasing the presence of solids, metals, and pathogens. Infiltration practices are preferred for phosphorus removal, and practices that promote settling, filtration, and biological activity are recommended for nitrogen removal. The matrices shown in Table 10.3 and Table 10.4 examine the pollutant removal capabilities of standard stormwater management practices (SMP) and runoff reduction techniques. • 1 • . • • • •. • • l• • • Pollutant of Concern SMP Group SMP Design Solids(TSS) Phosphorus (TP) Nitrogen (TN) Metals Pathogens Micropool ED Pond Wet Pond Pond Good Good Good Fair Fair Wet ED Pond Multiple Pond Shallow Wetland ED Shallow Wetland Good Good Good Fair Fair Wetland Pond/Wetland System Pocket Wetland Gravel Wetland Good Good Fair Fair Fair Infiltration Trench Infiltration Basin Infiltration Good Good Good Good Good Dry Well Underground Infiltration Surface Sand Filter Underground Sand Filter Good Good Good Good Fair Perimeter Sand Filter Filters Infiltration Bioretention Good Good Good Good Good Filtration Bioretention Good Good Fair Good Good Bioslope Good Good Fair Good Fair Open Dry Swale Good Good Fair Fair Poor Channels Wet Swale Good Good Fair Fair Poor Ratings based on pollutant removal efficiencies: Good pollutant removal(>80%TSS, >40%TP, >30%TN, >60% Metals, >70% Pathogens) Fair pollutant removal (30-80%TSS, 15-40%TP, 15-30%TN, 30-60% Metals, 35-70% Pathogens) Poor pollutant removal (<30%TSS, <15%TP, <15%TN, <30% Metals, <35% Pathogens) Chapter 10:Addressing Stormwater Pollutants of Concern 10-4 Table 10.4 • • •n Technique Pollutant • • . •ility Matrix for WQv • • IL Pollutant of Concern GI Design Solids(TSS) Phosphorus(TP) Nitrogen (TN) Metals Pathogens Sheet Flow to Riparian Good Good Fair Poor Poor Buffers or Filter Strips Vegetated Swale Fair Fair Fair Fair Poor Tree Planting/Tree Good Good Fair Good Good Pit/Tree Trench Disconnection of Rooftop Good N/Az N/A N/A N/A Runoff Runoff Reduction Infiltration Rain Garden Good Good Good Good Good Technique Filtration Rain Garden Good Good Fair Good Good Green Roof Good Poor3 Fair Good Good Infiltration Stormwater Good Good Good N/A N/A Planter Filtration Stormwater Good Good Fair N/A N/A Planter Rain Barrels &Cisterns Good N/A N/A N/A N/A Porous Pavement Good Fair Fair' Good Good Ratings based on pollutant removal efficiencies. Good pollutant removal(>80%TSS, >40%TP, >30%TN, >60% Metals, >70% Pathogens) Fair pollutant removal (30-80%TSS, 15-40%TP, 15-30%TN, 30-60% Metals, 35-70% Pathogens) Poor pollutant removal (<30%TSS, <15%TP <15%TN, <30% Metals, <35% Pathogens) 2 Not enough data available. More research needs to be performed. May provide partial benefits. 3 Typically leach phosphorous in first years after construction if built with media having high organic content. 'Pervious concrete or permeable interlocking concrete pavement have highest nitrogen removal capabilities. Chapter 10:Addressing Stormwater Pollutants of Concern 10- Section 10.3 Recommended SMP Design Modifications to Enhance Pollutant Removal Generally, all pollutants experience enhanced removal rates when SMPs are implemented within a treatment train and are maintained appropriately and consistently. Proper maintenance involving removing sediments and harvesting vegetation is crucial to avoid clogging and reduced practice efficiency. However, certain design aspects of practices can be modified to improve pollutant reductions. Performance enhancing mechanisms include selecting appropriate plant species for a specific pollutant and application of iron-enhanced check dams. 10.3.1 Plant Species Selection A combination of plants is necessary for optimal water quality and hydraulic performance. Plants with thick roots create macropores and help prevent clogging of filter media, while finer root systems prove to be best for nutrient removal performance. Plant traits that benefit pollutant removal efficiency and decrease nutrient effluent concentration include: High plant biomass Rapid growth rate of>10mg/g/day Long roots and a large total root length of a root system (-1000 m) Large total root mass and dense fine root patterns (>40% dense roots) Table 10.5 presents specific plants that have been tested to be effective at reducing pollutant levels in stormwater effluent. Table 10.5 Recommended Plant Species to Maximize Pollutant Removal Pollutant Plant Species Alfalfa (Medicago sativa), Big Muhly Grass(Muhlenbergia lindheimeri), Blue Grama(Bouteloua gracilis), Buffalo Grass(Buchloe dactyloides), Curl-Leaf Nitrogen Mountain Mahogany(Cercocarpus ledifolius), Indian Grass(Sorghastrum nutansv), Little Bluestem(Schizachyrium scoparium), Silver Sagebrush (Artemisia cana), Swamp Sunflower(Helianthus angustfolius), Utah Serviceberry (Amelanchier utahensis) Big Muhly Grass (Muhlenbergia lindheimeri), Buffalo Grass (Buchloe dactyloides), Phosphorus Evergreen Azalea (Rhododendron indicum), Purple Joe-Pye Weed (Eutrochium purpureum), River Birch (Betula nigra), Swamp Sunflower(Helianthus angustfolius), Tall Sedge(Carex appressa) Clustered Field Sedge (Carex praegracilils), Creeping Juniper(Juniperus Metals horizontalis), Kentucky-31 (Poa pratensis), Smallwing sedge(Carex microptera), Switch Grass (Pancium virgatum), Tall Sedge(Carex appressa), Yellow Marsh Marigold (Caltha palustris) Pathogens Palmetto Buffalo (Bouteloua dactyloides), Scarlet Honey Myrtle(Melaleuca fulgens), Wooly Tea-Tree(Leptospermum lanigerum) Chapter 10:Addressing Stormwater Pollutants of Concern 10- 10.3.2 Iron-Enhanced Check Dams Research being performed by the Minnesota Department of Transportation indicates that implementing an iron-enhanced check dam within swales can help enhance the removal of dissolved phosphorus and metals from stormwater. Iron- enhanced check dams, as shown in Figure 10.2, are low permeable mounds consisting of sand and iron filings installed horizontally across a swale. IRON-ENHANCED FILTER BERM TE` A1111 FIFtFAi' (SEE NOTE 1) A- -12" MAX 10 MAX P F I) MAX TCPSUL -& �A1 SLOPE TOP CF FLTER BERL �v p --- IR0f4-ENHAN0ED� FILTER 8_RU Oa NOTE 1) EXTEND L WER 6" MIN� -- --- _ BEVOM FILTEF EEFLI 'i'ERIwEROLE uNL' -Lsr;rl:rl Cr D REICTL7 9E"CATH FILTER BERM EOTTCU WIDTH + 12" eaxraM or FILTER B1_RM Figure 10.2 Profile view and cross-sectional view of an Iron-Enhanced Swale Check Dam Design considerations for employing iron-enhanced check dams in swales include the following: Filter berm shall consist of a metal cage to meet dimensional requirements. Cage shall be tightly packed with filter media that is encapsulated within a single woven geotextile enclosure (i.e. filter log or filter sock). Filter media shall consist of 95% sand (coarser than ASTM C-33) and 5% iron shavings (by weight). The filter berm must be buried into the ground at least 6 inches below the normal swale bottom to prevent flow- bypass underneath the filter media. An impermeable liner shall be placed directly beneath the filter log. Acceptable impermeable liner options include: 12 to 24 inches of clay soil (min. 50% passing the#200 sieve and max. permeability of 1 x 10-5 cm/sec); or 40 mil HDPE geomembrane. Riprap, selected in accordance with NYSDOT gradation requirements, shall be placed, extending to the top of bank, of the filter log to form the check dam. Since the bottom of the filter is subject to receiving stormwater more frequently, iron filings shall be mixed every other year to redistribute the filter media to the bottom, restore sorption capacity, and eliminate macropores. The entire filter media, approximately every six years, shall be replaced (Minnesota Department of Transportation, 2019). 10.3.3 Enhanced Bioretention Media Refer to Chapter 6 Section 6.4.4.1. Chapter 10:Addressing Stormwater Pollutants of Concern 10-7 This Page is Left Intentionally Blank NEW Department of PORK STATE Environmental Conservation Chapter 11 : Planting Guidance for Stormwater Management Practices Facilities Section 11 .1 Introduction This Chapter serves as guidance for selection of plants for stormwater management practices, in order to maximize the runoff reduction and water quality benefits. Plants serve imperative roles in the environment, such as: Producing oxygen through photosynthesis; Creating food energy for the ecosystem; Providing shelter for a wide range of organisms; Improve aesthetics and property values; Providing soil stabilization; Supporting biological uptake through root systems; Promoting evapotranspiration; Filter both water and air; Soil nutrient management; Reducing heat island effect; and Benefit to human health and wellbeing. This Chapter outlines several general considerations when incorporating plantings into SMPs including: Site constraints; Confined sites; Snow storage; Water availability; Plant origin; Planting location; Plant growth patterns; Plant installation; and Material availability. In addition, this Chapter outlines several practice specific considerations when incorporating plantings into SMPs including: Plant form; Plant installation categories; Plant scale; Rooting depth; Rooting volume; Inundation tolerance; and Maintenance requirements. Chapter 11: Planting Guidance for Stormwater Management Practices 11-1 Section 11 .2 Landscape Planning Plantings are considered an integral part of the function and success of most stormwater management practices. It is highly recommended to engage a registered landscape architect, with specific experience in stormwater management planning early in the process and throughout the design and installation phases. Stormwater management plantings consist of interactions between hydrology, plants, and soils. These plantings should collectively create a high-performing system that meets multiple goals and objectives for function and aesthetics. As such, landscape architects should be brought in as early as possible, no later than Step 3 of the Six Step Process for Stormwater Site Planning and Practice Selection, refer to Section 3.6. While a registered landscape architect can perform most of the requirements, the figure below outlines the landscape architect's role in the Six Step Process and where they should be specifically consulted. Step 1: Site Planning Consult Landscape Architect for recommendations to preserve natural resources and reduce impervious cover Step 2: Determine Water Quality Volume (WQv) Step 3: Runoff Reduction by Applying Runoff Reduction Techniques and SMPs with RRv Capacity (Refer to Chapters 5 & 6) Consult Landscape Architect on practice selection and planting schematic for Green Infrastructure Techniques and SMPs with RRv Capacity being Step 4: Determine minimum RRv required Step 5: Apply SMPs to address remaining WQv (Refer to Chapter 6) Consult Landscape Architect on practice selection and planting schematic for Standard SMPs being applied Refine stormwater management cross section, layout and plant Step 6: Apply volume and peak rate control practices Finalize plant selection and complete plan Figure 11.1 Incorporating Landscape Planning in the Six Step Process Chapter 11: Planting Guidance for Stormwater Management Practices 11-2 During the SMP selection in Steps 3 and 5, it is important to review the functional role plants can play in meeting runoff reduction and water quality requirements, as follows: Water uptake: Stormwater is immediately slowed through contact with plant stems. Stormwater management and volume control are provided through plant uptake and used by the plant (depending on the species and the climatic conditions this can be a significant amount of water). Ponded stormwater filters through the practice filter media (where applicable) Plant roots help maintain soil integrity and porosity to facilitate stormwater flow through the media. Processing of pollutants: Filtering of particulates and pollutants through the leaf canopy, filter media (where applicable), and root structure Plants provide mechanical filtration and aid in sediment removal by slowing water and allowing sediment to drop out of flowing water. Pollutant remediation through phytoremediation. Habitat development and support: Increased biodiversity. Support pollinators and other species through food sources, nesting, and reproductive sites. Habitat goals can be matched with plant species selections. Create microclimates for flora and fauna in mixed planting or buffer areas. Local effects: Evapotranspiration, the process of water vapor being released through plant leaves; conditions the air. Energy expenditure reduction from shading, reduction of heat island effect, and wind exposure mitigation. Glare reduction from reflections off sidewalks, buildings, and other surfaces. Provide visual interest thereby softening architecture and infrastructure. Regional effects: Many small SMPs in proximity to one another when viewed collectively, can become important ecological links between larger regional environmental conservation areas (e.g., parks, recreation areas, and protected lands) by providing supporting and linking habitats between systems. Chapter 11: Planting Guidance for Stormwater Management Practices 11 e3 Section 11 .3 General Plant Considerations 11.3.1 Site Constraints Prior to plant selection, a thorough site assessment should be performed to determine the site's physical capacity. Additionally, the vision for the project, regulatory requirements, and the project's specific goals, should be considered. The following table provides a series of physical criteria for analysis prior to plant selection. Table 11.1 Site Assessment Existing soil conditions Physical capabilities Localized hydrologic patterns Property lines and easements Existing structures that cannot be moved Surface spatial constraints Limits of hard and softscapes, overhead utilities Proximity to concrete leaching sources from new concrete construction Depth of bedrock Depth to seasonal high water table Underground constraints Proximity to foundations Extents of existing tree roots Underground utility routing Urban Suburban Location/User Rural Projected user group (memory care, children, pets) Solar exposure Climatic considerations Wind exposure Temperatures and microclimates Snow removal Seasonal care practices Deicing practices Salt runoff patterns Owner capacity and capability to maintain Owner participation Programmatic agreement Commitment to planting establishment Chapter 11: Planting Guidance for Stormwater Management Practices 11- Figure 11.2 Parking Lot Bioretention (Photo Source: NYSEFC) 11.3.2 Confined Sites Development in urban areas or those with limited space for SMPs may consider several options including tree pits, tree trenches, rain gardens, stormwater planters, green roofs and bioretention. Due to the limited space available for these practices, plant selection should be focused on their ability to mature and thrive within a limited filter media footprint, while the practice is still sized appropriately for the contributing area (refer to Chapter 5 and 6). In urban environments, the planting selection should also account for heavy vehicle and/or pedestrian traffic as well as the potential for higher pollutant concentrations. In areas with concern of compaction of underlying soils, modular proprietary practices may be used to protect and maintain uncompacted filter media and allow for additional space for root growth. However, the modular proprietary practice shall still meet the criteria outlined in Chapters 5 and 6. 11.3.3 Snow Storage It is recommended that SMPs not be used for snow storage. Where unavoidable, practices used for snow storage need to consider the structure of plants and their ability to handle snow load. In these situations, herbaceous plants may work best. In addition, the practice is likely to receive a higher concentration of salt or sand laden snow which can be problematic for many species and overall practice performance. 11.3.4 Water Availability It is important that the designer understands the intent of the project to utilize irrigation and that there be water available during establishment, or first three plant growing seasons. At a minimum, temporary tanks, water trucks or hose access points should be available to allow for necessary watering during establishment. A temporary irrigation system may be utilized during the establishment period and then removed or abandoned afterward. The decision to use irrigation will significantly impact the plant selection. 11.3.5 Plant Origin Consideration should be given to using native plants, as they are typically well suited to local environments (e.g., climate, soils, rainfall, etc.). For example, in coastal settings, where conditions are hot, dry, and occasionally salty due to winter deicing, pair plants from a list of naturally occurring exposed, dry, and high salinity habitat where conditions may be similar. Reference documents for plant selection include: DEC's New York Natural Heritage Program guide "Ecological Communities of New York State"; The New York Natural Heritage Program's website; or New York Flora Atlas website. Chapter 11: Planting Guidance for Stormwater Management Practices 11 e When selecting plants (native or non-native) it is necessary to ensure plants are well suited to the climate and microclimate conditions of the site, as well as being ecologically suited for the location. Plants that show continued and robust growth without extended care and do not take over the plant bed should be prioritized over plants that are considered less vigorous and/or maintenance heavy. Plants with vigorous tendencies should be used with caution. Vigorous tendencies can be advantageous to a project in that they can quickly establish themselves, especially in monoculture settings, but can be ruinous if they allowed to overrun an intented mixed planting. Care should also be taken when working in sensitive habitat areas with neighboring rare or endangered species. On these sites, consultation with a biologist regarding species selection and plant provenance issues (genetic source and lineage) is recommended. 11.3.5.1 Native Native plants can include those growing in local settings or specific plant communities within a county, state, or region. When the project goals broaden the native definition to include plants native to the Northeast, the plant palette widens considerably, and can include species native to several growing conditions (e.g., coastal plant communities tolerant of sandy soils, exposed conditions, and saline spray). The nursery industry continues to expand access to natives. It is important to check plant availability to confirm that they are available for purchase. Some resources include: Finger Lakes Native Plant Society; Long Island Native Plant Initiative; NYS Adirondack Park Agency Native Plant List; PlantNative.org; or The Lyceum at Silo City. 11.3.5.2 Non-native In addition to natives, the micro-climates of New York State have long supported many non-native and non-invasive plant varieties. A non-native plant is introduced, with human help (intentionally or accidentally), to a new place or new type of habitat where it was not previously found. Not all non-native plants are invasive. Many non-native, non-invasive species are also suitable and complementary to stormwater practices and may have different characteristics than native plants under certain conditions. 11.3.5.3 Invasive New York State has made significant strides and efforts to eliminate the use of invasive species. When selecting stormwater plantings, it is important that invasive species, both native and non-native, are not chosen. Consultation with the NYSDEC Invasive Species Regulation (6 NYCRR Part 575) is critical and must be evaluated for applicable information. In addition, for information on plants known to be invasive but not yet included in the NYSDEC Invasive Species Regulation, consult the New York Invasive Species Information Partnerships for Regional Invasive Species Management (PRISMs). 11.3.6 Planting Location 11.3.6.1 Plant Hardiness Zones A hardiness zone is the standard that determines which plants are most likely to thrive at a location. USDA has an interactive Plant Hardiness Zone Map available to designers for use. The map is based on the average annual minimum winter temperature, divided into 10-degree Fahrenheit zones. New York includes a wide range of growing conditions that are represented by USDA plant hardiness zones, which generally range from Zone 3b to Zone 7b. The temperatures established by the hardiness zones are affected by topography, elevation, and hydrology, which create varied moisture regimes, solar access, and wind exposure. 11.3.6.2 Macroclimate and Microclimate Macroclimate refers to the general climate of the overall region. The four climate conditions include temperature, humidity, wind, and precipitation, which are affected by site latitude, site elevation, prevailing winds, proximity to water, proximity to mountains, and topography. Microclimate refers to the specific local conditions of a site which are affected by vegetation, elevation, slope, built structures, as well as water, wind, and sun exposure. As such, plantings should be selected according to the macroclimate and microclimate constraints of the site location. Chapter 11: Planting Guidance for Stormwater Management Practices 11- Strategic plant selections and placement can help control climatic conditions in several ways: Grass areas have low albedo and high conductivity; Trees and vegetation can be used to screen or direct wind; Trees and vegetation absorb sunlight and add humidity to the air; Planted areas typically are cooler during hot days and have less heat loss during the night; Trees can be used to shade the south and west facing portions of the site; and Deciduous trees filter direct sunlight in the summer while allowing it to pass through in the winter. 11.3.7 Plant Growth Patterns 11.3.7.1 Growth Rate Most plants undergo a shock period when initially planted and may remain at their planted size for up to 2 years before springing forth new growth. Overall growth rate can be impacted by available growing medium, nutrients and water availability and maintenance practices such as pruning. 11.3.7.2 Longevity In nature and cultivated environments some plants germinate quickly, grow fast, and provide a community for other plants to establish. This may be partially due to their tolerance for outside factors, like air pollution or compacted soils. These are sometimes known as pioneer plants. Plants are impacted by many outside factors, some have a natural shortened life expectancy while others are affected by insects or pathogens that shorten their life expectancy. It is important for designers to stay current on trends in plant diseases. 11.3.7.3 Sunlight Tolerance - � -71 = Figure 11.3 Hudson Headwaters Healing Rain Garden (Photo Source: HHHN) 11.3.8 Plant Installation Considerations 11.3.8.1 Planting Season Stormwater planting generally occurs throughout the construction season, however given construction sequencing and timing there may be constraints. Some species of plants may be unavailable or held at a nursery during fall due to digging season limitations and provisions for procurement. In addition, some evergreen species, as well as those with thin bark, abundant small twigs, or coarse roots may have difficulty establishing new roots during fall planting and the trees may desiccate over winter due to lack of moisture. For fall planting it is recommended that trees be watered for a period prior to being removed from the nursery as well as additional watering after they are installed on site, generally through to heavy frost. Temperatures and rainfall should be monitored throughout the project construction schedule, as the late spring and early fall months can see less precipitation and temperature spikes or drops requiring additional watering for new plantings. Chapter 11:Planting Guidance for Stormwater Management Practices 11-7 11.3.8.2 Diversity The variety of plants selected for a design should be considered from both an ecological and aesthetic perspective. Ecologically designs that utilize only one plant species, also known as a monoculture, may face struggles with insects, disease, and extremes in weather conditions. A planting palette with greater diversity mimics more natural systems, and has inherent resilience against environmental changes, pests, and diseases, as not all species will be impacted equally. When a uniform aesthetic is the project goal, a selection of 4-7 plants that have similar structure, form, height, bloom color, etc. may be used to create the impression that the practice is comprised of a singular species, while offering plant diversity to avoid the issues created by monoculture. 11.3.8.3 Predation Protection New plantings, particularly those in stormwater wetlands, are often targets for predation by deer, muskrats, rabbits, mice, birds, and other wildlife. To prevent this and assist in establishment, fencing around plantings and netting overtop may be necessary. Style, type, and duration of these enclosures varies with the predatory animal. As such, consulting with an ecologist may be helpful in determining which measures will be most effective. .-W -_ _ , loft Jl- r Figure 11.4 Mattituck-South hold Wildlife Screen (Photo Source: Nanci Bateman, RLA, NYSDEC) 11.3.8.4 Mulch Mulch is useful as a surface layer to help minimize weed growth, moderate soil temperatures and moisture, and provide an aesthetic finish. Organic mulches help with silt and sediment capture, as well as absorbing hydrocarbons, to help reduce pollution. For organic mulches, it is recommended that shredded hardwood mulch be used. Overtime the need for mulch should be reduced as the groundcover and shrub layers cover the planting areas. Where clogging and/or floating mulch is a concern, beehive drainage grates should be used for overflow structures. Consideration should be given to erosion and sediment control measures throughout the design and construction phase, as well as post installation of stormwater plantings. Erosion and sediment control measures should be maintained around the system until the entire drainage area has stabilized to keep sedimentation out of stormwater systems. 11.3.8.5 Staking Staking is not universally recommended as studies have shown that trees develop better trunk taper, and therefore stronger trunk support, when not staked at planting. Staking is recommended only in spaces where trees are subject to high winds, trees are of significant size, or when planted in loose soils and only for the first year. Staking should be removed after the first growing season. 11.3.9. Material Availability Plants should be readily available, and sources confirmed during the design process, to the greatest extent practical. In addition to the standard nursery wholesalers, several quality niche nurseries exist for native species, as well national and state sponsored nurseries. Contract growing; where a nursery is engaged during design to grow specific quantities and varieties may be possible. This method typically requires extended lead time of a year or more. When considering appropriateness of plant substitutions, it is important to discern if the change will achieve the overall goals of both the SMP, as well as the larger project goals. The substitutions should be reviewed to determine if the substitution will meet all specifications of the originally selected plants. Chapter 11: Planting Guidance for Stormwater Management Practices 11- Section 11 .4 Practice Specific Plant Considerations 11.4.1 Plant Form It is useful in the early stages of planting design to consider plant form rather than plant species. Several plant forms are more conducive to application in specific SMPs. The following table lists key strengths and limitations of each plant form. Table 11.2 Key Strengths and Limitations by Plant Form P Plant Form Strengths Limitations Living mulch Weed-suppression Tender structure—more prone to damage Groundcover Aesthetics Water retention Limited habitat benefit Soil stabilization Provide shade Require larger planting area Trees Large water uptake Heavy or difficult to move Disperse rain Often hard to establish Broad root structure Varied size and shape Vigorous Shrubs Defines stormwater area Dwarf is relative Provide four season interest Subject to breakage due to snow loading Diverse scale and texture Herbaceous Plants Varied bloom times Winter die back and Native Grasses Can be planted small Requires more regular maintenance Improved biodiversity Generally tolerant of some standing water Heavier maintenance Turf grass Generally quick to establish Fertilizer, pesticides may be required Good for erosion control Chapter 11: Planting Guidance for Stormwater Management Practices 11-9 11.4.2 Plant Installation Categories Plant materials can be professionally grown, or field collected. At professional nurseries, plant propagation is typically divided into several categories as follows: � . Plant Installation Categories Category Description Most large trees and some shrubs are commercially grown in the ground at the nursery are typically harvested in the spring prior to leaf-out. Keeping the root In ground—ball and burlap ball intact is key for plant survival. The harvesting can be done mechanically with a tree spade or the plant can be dug by hand. The root ball is typically wrapped in burlap and can be either placed in a wire basket or hand tied with jute rope for delivery. Containers are used for larger perennials, ornamental grasses, shrubs, and small trees.. Containers should utilize a potting mix closely matching the filter Containerized media(refer to Chapter 5 and Chapter 6)as containers utilizing mineral soils may not support healthy plant growth. In addition, larger containerized plants may require more frequent watering and physical support if root bound prior to becoming established. Plugs are small plants, such as sedums, perennials, and ornamental grasses, often arriving to the site in trays. These plants have initial root systems with a small amount of growing media and can typically adapt quickly. They must be Plugs manually placed directly in the soil media. Utilizing plugs allows for more control in terms of plant placement. However, given their relative size, many plants are usually needed to complete the project. The scale of the plant and root makes plugs a good option for semi-intensive or intensive roofs, or areas where a diverse meadow or herbaceous wetland is desired. Cuttings are taken from a"parent' plant capable of rooting from their stems . They are typically broadcast over the soil media and lightly tamped or raked into the soil media, or pushed into the ground (woody stem cuttings). The cuttings method is particularly effective with sedum varieties, as the plant can Cuttings root easily when in direct contact with the soil media. However, the types of plants available in cutting form is limited and with cast cuttings it is difficult to be exact with spacing or location of plants. Often the design effect is "meadowlike" if several species are mixed or a monoculture effect if only one species is selected. Vegetated mats or carpets are pre-grown plantings containing the plant, root and soil media surrounding the root. The mat is rolled out over the surface and pinned in place, similar to sod. This method is effective with sedum varieties Mats, Carpets and Trays and is less labor intensive than container or plug planting. However,the variety of plants is minimal, with limited offering of pre-planted mat selections available. The layout and installation can be a monoculture for ease of installation, or a more intricate design can be developed where the mat is cut and placed in specific patterns. 11.4.3 Plant Scale The scale of plants should correlate to the scale of the stormwater practice and its surrounding context. Plant species should be selected, such that they will not outgrow their available space. Additionally, line of sight should be considered near vehicular intersections and pedestrian walkways. Chapter 11: Planting Guidance for Stormwater Management Practices 11-10 11.4.4 Rooting Depth The typical rooting depth of each plant form should be consistent with the depth of the filter media or planting soil provided within the practice. Stormwater management practice filter media or planting soil depth shall meet the design criteria outlined in Chapters 5 and 6. The following table shows minimum depths of filter media or planting soil that can support each plant form in typical growing conditions. Table • • • Filter Media • • Forms Minimum Recommended Plant Forms Filter Media Depth Drought tolerant herbaceous perennials, groundcovers, and turf 6 inches Drought tolerant small ornamental grasses 8 inches Groundcovers, herbaceous perennials, and small ornamental grasses tolerant of dry conditions, turfgrass Herbaceous perennials 12 inches Small to medium ornamental grasses, Drought tolerant small shrubs Small to medium woody shrubs, 18 inches Larger ornamental grasses 24 inches Larger woody shrubs Winches Small trees Winches Medium to Large Trees 11.4.5 Rooting Volume Available volume for rooting should be matched to plant needs, particularly for large trees. The following table shows recommended rooting volumes, given the ultimate diameter at breast height (DBH) and soil volume required. This volume includes both the filter media within the stormwater practice as well as the soil rooting areas outside the practice, so long as roots can grow out of the stormwater practice. Table • • • rooting volumes per •iameter(Adopted from Urban, 1 1 DBH at Maturity Recommended Rooting Volume 4" 200 cu. ft. 8" 450 cu. ft. 12" 750 cu. ft. 16" 1,000 cu. ft. 20" 1,250 cu. Ft. 24" 1,500 cu. Ft. Particularly in urban contexts linking planting areas and filter media for long runs below grade allows plants and trees to have substantial rooting volumes, without the construction complexities of starting and stopping the materials, and additional holding capacity. Chapter 11: Planting Guidance for Stormwater Management Practices 11-11 11.4.6 Inundation Tolerance Inundation or flooding impacts plant selection because excess water can deprive them of certain basic needs, notably oxygen carbon dioxide exchange . As a majority of runoff reduction techniques, and some standard practices, result in temporary inundation or permanent ponding of areas of the stormwater practice (i.e. plunge pool = permanent ponding) the proper selection of plant material is key to a successful system. Plants should be selected based on their ability to survive standing or fluctuating water levels as well as drought conditions. 11.4.7 Maintenance Requirements Plants' growth needs (e.g., water levels, nutrients, pH, etc.) should be matched to the characteristics of the filter media or natural soil, in which they are planted, in order to reduce the level of additional maintenance beyond what is normally required for the practice. To reduce energy, resources, and pollution, selecting plant materials that do not require long term irrigation, fertilization, etc. should be considered. A plant identification guide or application should be utilized to identify specific plant species within practices and their individual maintenance requirements. Some resources include: Naturalist application; PlantNet Plant Identification application; USDA PLANTS Database; Cornell University Woody Plants Database; Dirr's Encyclopedia of Trees and Shrubs by Michael Dirr; or Native Plants of the Northeast by Donald Leopold. 11.4.8 Plant Considerations — Practice Specific Summaries Urban, suburban, and rural sites have widely differing needs and options for stormwater management landscaping and plantings. Therefore, it is important to consider how the selected landscaping and plantings will impact the practice, existing environment, hydrology, outflow or infiltration opportunities, as well as the construction of adjacent surfaces and features. It is important to select plant types and scales that are appropriate for the given practice and the adjacent site conditions. A large tree may quickly outgrow a small urban stormwater planter. As such, planting choices should consider the future maturity that will match the scale of the area in which the practice is placed. With the varying climates and environments across New York State, there is no singular plant palette for a stormwater design. The following sections provide a series of criteria that should be considered during stormwater management plant selection. Chapter 11: Planting Guidance for Stormwater Management Practices 11-1 11.4.8.1 Tree Plantings/Tree Pits/ Tree Trenches �, Table 11.6 Plant Considerations for Tree Plantings/Tree Pits/Tree Trenches Plant Considerations Practice Specific Considerations Plant Form Non-invasive trees, with other suitable plant materials layered into the practice depending on size and location. In-ground ball and burlap: Applicable. Containerized: Applicable. Plant Installation Categories Shrubs : Applicable. Plugs and Cuttings: Not applicable: Mats, Carpets and Trays: Not applicable. Scale of tree(s)should be correlated to the available space and surrounding context, including overhead and underground utilities. Tree species should be Plant Scale selected such that it will not outgrow its space. Additionally, line of sight and branching height should be considered near intersections and pedestrian walkways. The recommended rooting depth of each plant form should match the filter media Rooting Depth depth provided. Where the recommended depth is greater than the requirement outlined in Chapter 5,the larger of the two should be applied. Available volume for rooting should be matched to plant needs, given the ultimate Rooting Volume diameter at breast height(DBH)and soil volume required. This volume can be within the stormwater practice itself or in combination with soil rooting areas outside the practice, so long as roots can grow out of the stormwater practice. Inundation Tolerance Species should be selected based on the practice specific ponding depth outlined in Chapter 5 and the plant tolerance for drought and/or temporary flooding. Maintenance Refer to Chapter 12. f f AR Figure 11.5 Locust Street/ Paris Park Tree Trench (Photo Source: Village of Hudson Falls/NYSEFC) Chapter 11: Planting Guidance for Stormwater Management Practices 11-13 11.4.8.2 Vegetated Swales Table 11.7 Plant Considerations for Vegetated Swales Plant Considerations Practice Specific Considerations Turf grass: Choose the appropriate mix for the soil, soil exposure,velocity factors and temperature of the project site. Example Mixes Include: Mix A: Perennial ryegrass (Lolium perenne): 30 lbs. per acre or 0.68 lbs. per 1,000 sf Tall fescue or smooth bromegrass (Festuca arundinacea or Bromus inermis): 20 lbs. per acre or 0.45 lbs. per 1,000 sf Redtop(Agrostis gigantea): 2 lbs. per acre or 0.05 lbs. per 1,000 sf Mix B': Kentucky bluegrass(Poa pratensis): 25 lbs. per acre or 0.60 lbs. per Plant Form 1,000 sf Creeping red fescue (Festuca rubra):: 20 lbs. per acre or 0.50 lbs. per 1,000 sf Perennial ryegrass (Lolium perenne): 10 lbs. per acre or 0.20 lbs. per 1,000 sf This mixture should be used in areas that are mowed frequently. Common white clover may be added at a rate of 8lbs. per acre or 0.2 lbs. per 1,000 sf. Mix C: Hardwood Fescue, 'Beacon' (Festuca brevipila, 'Beacon'): 4 lbs. per 1,000 sf Sheep Fescue (Festuca ovina): 4 lbs. per 1,000 sf Creeping Red Fescue(Festuca rubra): 4 lbs. per 1,000 sf In-ground ball and burlap trees or shrubs: Not applicable. Containerized Perennials: Applicable. Plant Installation Categories Plugs: Applicable. Cuttings: Not applicable: Mats, Carpets and Trays: Not applicable. Plant Scale Capable of being mowed to 6" height Rooting Depth Not applicable. Rooting Volume Not applicable. Inundation Tolerance Species should be selected based on the ponding depth outlined in Chapter 5 and tolerance for both drought and temporary flood conditions. Maintenance Mow as required during the growing season to maintain grass heights of 4 to 6 inches. Refer to Chapter 12. Chapter 11: Planting Guidance for Stormwater Management Practices 11-14 11.4.8.3 Rain Gardens Plant Considerations Practice Specific Considerations Plant Form Non-invasive trees, shrubs and/or herbaceous plants with other suitable plant materials positioned within the practice depending on size and location. In-ground ball and burlap: Applicable. Containerized: Applicable. Plant Installation Categories Plugs: Applicable Cuttings: Not applicable: Mats, Carpets and Trays: Not applicable. Scale of tree(s)should be correlated to the available space and surrounding context, including overhead and underground utilities. Tree species should be Plant Scale selected such that it will not outgrow its space. Additionally, line of sight and branching height should be considered near intersections and pedestrian walkways. Rooting Depth The recommended rooting depth of each plant form should match the filter media depth provided. Available volume for rooting should be matched to plant needs, given the ultimate diameter at breast height(DBH), location and depth of geotextile fabric within the Rooting Volume practice cross section, and soil volume required. This volume can be within the stormwater practice itself or in combination with soil rooting areas outside the practice, so long as roots can grow out of the stormwater practice. Inundation Tolerance Species should be selected based on the ponding depth outlined in Chapter 5 and tolerance for both drought and temporary flood conditions. Maintenance Refer to Chapter 12. .. f yy � Figure 11.6 Canal Square Park Rain Garden (Photo Source: City of Cohoes/NYSEFC) Chapter 11: Planting Guidance for Stormwater Management Practices 11-15 11.4.8.4 Stormwater Planters Table 11.9 Plant Considerations for Stormwater Planters Plant Considerations Practice Specific Considerations Plant Form Non-invasive trees, shrubs and/or herbaceous plants with other suitable plant materials layered into the practice depending on size and location. In-ground ball and burlap: Applicable. Containerized: Applicable. Plant Installation Categories Plugs: Applicable Cuttings: Not applicable: Mats, Carpets and Trays: Not applicable. Scale of tree(s)should be correlated to the available space and surrounding context, including overhead and underground utilities. Tree species should be Plant Scale selected such that it will not outgrow its space. Additionally, line of sight and branching height should be considered near intersections and pedestrian walkways. Rooting Depth The recommended rooting depth of each plant form should match the filter media depth provided. Available volume for rooting should be matched to plant needs, given the ultimate diameter at breast height(DBH), location and depth of geotextile fabric within the Rooting Volume practice cross section, and soil volume required. This volume can be within the stormwater practice itself or in combination with soil rooting areas outside the practice, so long as roots can grow out of the stormwater practice. Inundation Tolerance Species should be selected based on the ponding depth outlined in Chapter 5 and tolerance for both drought and temporary flood conditions. Maintenance Refer to Chapter 12. Chapter 11: Planting Guidance for Stormwater Management Practices 11-16 11.4.8.5 Green Roofs Table 11.10 Plant Considerations for Green Roofs Practice Specific Considerations Plant Considerations Extensive Intensive Non-invasive small herbaceous plants, Non-invasive small trees, shrubs, bulbs, turf, and groundcover with other herbaceous plants, bulbs,turf, and Plant Form suitable plant materials layered into the groundcover with other suitable plant practice depending on size and materials layered into the practice location. depending on size and location. In-ground ball and burlap: Not Small In-ground ball and burlap: applicable. Applicable Plant Installation Categories Containerized: Applicable. Containerized:Applicable. Plugs: Applicable Plugs: Applicable Cuttings: Applicable Cuttings: Applicable Mats, Carpets and Trays: Applicable Mats, Carpets and Trays: Applicable Layout and massing of plants should always consider views to and from the green Plant Scale roof, as well as views from adjacent buildings. In addition, the layout should consider if the green roof is meant to remain static, or if the natural dynamics of the plants will be allowed. Rooting Depth The recommended rooting depth of each plant form should match the filter media depth provided. Available volume for rooting should be Available volume for rooting should be matched to plant needs, given the matched to plant needs and soil ultimate diameter at breast height Rooting Volume volume required. The rooting volume is (DBH)where applicable and soil within the filter media of the stormwater volume required. This volume is within practice itself. the filter media of the stormwater practice itself. Inundation Tolerance Species should be selected based on the ponding depth outlined in Chapter 5 and tolerance for both drought and temporary flood conditions. Plant patterning is important to facilitate maintenance and inspections. Larger Maintenance blocks of plants in clear arrangements will help highlight weed species and facilitate their removal by maintenance crews. Dried stalks and leaves should be removed in the spring. Refer to Chapter 12. Figure 11.7 SUNY ESF Gateway Center Green Roof(Photo Source: Tim Toland) Chapter 11: Planting Guidance for Stormwater Management Practices 11-17 11.4.8.6 Stormwater Ponds/Wetlands Stormwater ponds and wetlands have specific hydrological regimes. Ponds and wetlands are designed with a permanent pool that will be wet year-round, as well as storage above the permanent pool that will be wet periodically from storm events. In addition, they typically have varying topography and therefore varying soil moisture levels. `•r r. Figure 11.8 Wet Pond at Westbrook Conservation Initiative (Photo Source: Lake George Association) Pond and Wetland Hydrologic Zones and Plants For stormwater pond and wetland plantings it is necessary to determine which of the hydrologic zones will be established within the practice. The hydrologic zones designate the degree of tolerance the plant exhibits to differing degrees of inundation, although a practice may not include all hydrologic zones. Each zone has its own set of plant selection criteria based on the hydrology of the zone, the stormwater functions required of the plant and the desired landscape effect. These zones create a distinctive form within the practice and the plant communities grow in patterns that respond to these zones. The following table outlines the six possible hydrologic zones. HydrologicTable 11.11 Zone# Zone Description Hydrologic Conditions Zone 1 Deep Water Pool Permanent pool deeper than 18 inches Zone 2 Shallow Water Bench 6 to 18 inches deep Zone 3 Shoreline Fringe Regularly inundated Zone 4 Riparian Fringe Periodically inundated Zone 5 Floodplain Terrace Infrequently inundated Zone 6 Upland Slopes Seldom or never inundated Chapter 11: Planting Guidance for Stormwater Management Practices 11-1 Zone 1: Deep Water Area (Permanent Pool Deeper than 18 inches) Ponds and wetlands have deep pool areas that comprise Zone 1, which are best colonized by submergent plants. This zone is not routinely planted for several reasons. The availability of plant materials that can survive and grow in this zone is limited, and plants may clog the stormwater facility outlet structure. In many cases, these plants will gradually become established through natural recolonization. If submerged plant material becomes more commercially available and clogging concerns are addressed, this area can be planted. The function of the planting is to reduce resedimentation and improve oxidation while creating a greater aquatic habitat. The following should be considered when plantings are proposed within Zone 1: Should be able to withstand constant inundation deeper than 18 inches. Should be able to enhance pollutant uptake. May provide food and cover for waterfowl, insects, and other aquatic life. Zone 2: Shallow Water Bench (6 to 18 inches deep) Zone 2 includes all areas (i.e., aquatic bench, low marsh, high marsh)that are inundated below the permanent pool, to a depth of 18 inches, and is best colonized by emergent species. Plants will stabilize the edges of the permanent pool, absorb wave impacts and reduce erosion, when water level fluctuates. Plants also slow water velocities, increase sediment deposition rates and reduce resuspension of sediments caused by wind. Zone 2 can be an important habitat for many aquatic and nonaquatic animals, creating a diverse food chain. The following should be considered when plantings are proposed within Zone 2: Should be able to withstand constant inundation to depths between six and 18 inches. Should be able to enhance pollutant uptake. May provide food and cover for waterfowl, insects, and other aquatic life. Zone 3: Shoreline Fringe (Regularly inundated) Zone 3 encompasses the shoreline of a pond or wetland and extends vertically from the top of permanent pool to the peak water surface elevation of the water quality extended detention volume. This zone may include the safety bench of the practice and may be regularly inundated by the water quality storm event. This zone can be the most difficult to establish since plants must be able to withstand inundation during storms or drought during the summer. The following should be considered when plantings are proposed within Zone 3: Should have vigorous cover to stabilize the soil and minimize erosion caused by waves and wind action or water fluctuation. Should be able to withstand occasional inundation of water. Should shade the permanent pool, especially the southern exposure, to reduce the water temperature. Should be able to enhance pollutant uptake. May provide food and cover for waterfowl, songbirds, and wildlife. Should be selected and located to control overpopulation of waterfowl. Should be located to reduce human access, where there are potential hazards, but should not block the maintenance access. Should have very low maintenance requirements since they may be difficult or impossible to reach. Should be resistant to disease and other problems which require chemical applications. Chapter 11: Planting Guidance for Stormwater Management Practices 11-1 Zone 4: Riparian Fringe (Periodically Inundated) Zone 4 extends vertically from the peak water surface elevation of the water quality extended detention volume to the peak water surface elevation of the channel protection volume. Plants in this zone are subject to periodic inundation after storms and may experience saturated or partly saturated soil conditions. The following should be considered when plantings are proposed within Zone 4: Should be able to withstand periodic inundation after storms, as well as occasional drought during the summer months. Should stabilize the ground from erosion caused by runoff. Should shade the permanent pool, especially the southern exposure, to reduce the water temperature. Should be able to enhance pollutant uptake. Should have very low maintenance since they may be difficult or impossible to access. May provide food and cover for waterfowl, songbirds, and wildlife. Should be selected and located to control overpopulation of waterfowl. Should be located to reduce pedestrian access to the permanent pool. Zone 5: Floodplain Terrace (Infrequently Inundated) Zone 5 is infrequently inundated by flood waters that quickly recede in a day or less. Operationally, Zone 5 extends from the peak water surface elevation of the channel protection volume up to the extreme flood water surface elevation. Key landscaping objectives for Zone 5 are to stabilize the steep slopes characteristic of this zone, and establish a low maintenance, natural vegetation. The following should be considered when plantings are proposed within Zone 5: Should be able to withstand infrequent but brief inundation during storms. However, should be tolerant of varied moisture conditions during dry weather periods. Should stabilize the practice side slopes from erosion. Ground cover should be very low maintenance, as they may be difficult to access on steep slopes or if frequency of mowing is limited. May provide food and cover for waterfowl, songbirds, and wildlife. Placement should provide structure and shade to accommodate a greater variety of plants. Zone 6: Upland Slopes (Seldom or Never Inundated) The last zone extends above the extreme flood water surface elevation and includes the outer buffer of a pond or wetland. Unlike other zones, this upland area may have sidewalks, bike paths, retaining walls, and maintenance access roads. The following should be considered when plantings are proposed within Zone 6: Care should be taken to locate plants so they will not overgrow pedestrian/vehicle routes or limit visibility. Capable of surviving the site specific constraints, including soil condition, light, and function within the landscape. Ground covers should emphasize infrequent mowing to minimize maintenance. In pedestrian related areas, placement should be aesthetically pleasing, serve as a buffer and provide shade to accommodate a greater variety of plants. Particular attention should be paid to seasonal color and texture. Chapter 11: Planting Guidance for Stormwater Management Practices 11-20 Wetland Indicator Status Wetland plant species are given a wetland indicator status that indicates the probability of their occurrence within specific zones of the wetlands. Indicator categories are used to indicate a plant's likelihood for occurrence in wetlands versus non- wetlands. Wetland biologists typically use wetland indicator status to categorize and understand a plant's location on the gradient from permanent pool to upland condition. CategoriesTable 11.12 Wetland Plant Indicator Status Indicator Code Indicator Status Comment UPL Upland Almost never occur in wetlands FACU (FAC-) Facultative Upland Usually occur in non-wetlands, but may occur in wetlands FAC Facultative Occur in wetlands and non- wetlands FACW(FAC+) Facultative Wetland Usually occur in wetlands, but may occur in non-wetlands OBL Obligate Wetland Almost always occur in wetlands Pond/Wetland Plant Installation Site preparation, accurate grading, and specification of appropriate soils will help ensure successful establishment of the plants. Planting schedules may be grouped by hydrologic zones that consider minimum/maximum inundation tolerance. Select native plants suitable to the region from nurseries that specialize in wetland species, from regional plant catalogs, or from native seed distributors. • . Plant Type Description Plant Example Submergent Roots and plant below the Pondweeds, eelgrass permanent pool Emergent Plants with leaves that grow Cattails, sedges, and rushes through the permanent pool Floating May root on practice bottom, leaf Water lilies, duckweed floats on the permanent pool Chapter 11: Planting Guidance for Stormwater Management Practices 11-21 Wetland Filter Media Installation Proper installation of wetland filter media is critical to ensuring that the vegetation will benefit from the air, water, nutrients, and physical support provided by the media. The following table outlines installation considerations for wetland filter media. Fil Table 11.14 Wetland ter Media Installation Considerations Sequencing excavation Protect Soils from Over Compaction Use floatation of low ground pressure equipment Decompaction of the soils may be required prior to planting Heavy Equipment Considerations Disking, ripping, plowing, or tilling Final soil bed planting areas should be finished by hand Pond/Wetland Planting Maintenance The maintenance plan should include detailed monitoring protocols for wetland plantings that align with permit requirements, to include plant establishment and removal of invasive species. Where plants are slow to establish, biodegradable erosion control mats and blankets may be used to secure soils. The maintenance plan should also include annual mowing of the pond buffer along maintenance rights-of-way and the embankment with the remaining buffer should be managed as a meadow (mowing every other year). Refer to Chapter 12. 11.4.8.8 Surface Sand Filter Table 11.15 Plant Considerations for Surface Sand Filters Plant Considerations Practice Specific Considerations Plant Form Non-invasive grass species selected based on specific site and soil conditions present within the practice. In-ground ball and burlap: Not applicable. Containerized: Not applicable. Plant Installation Categories Plugs: Applicable. Cuttings: Applicable. Mats, Carpets and Trays: Applicable. Plant Scale Not applicable. Rooting Depth Not applicable. Rooting Volume Not applicable. Inundation Tolerance Species should be selected based on the ponding depth outlined in Chapter 6 and tolerance for both drought and temporary flood conditions. Maintenance Mowing during the growing season to maintain grass heights of 4 to 6 inches. Refer to Chapter 12. Chapter 11: Planting Guidance for Stormwater Management Practices 11-22 11.4.8.9 Bioretention Plant Considerations Practice Specific Considerations Non-invasive trees, shrubs and/or herbaceous plants with other suitable plant Plant Form materials layered into the practice depending on size and location. Woody non- herbaceous shrubs and trees shall not be specified at inflow locations. Trees shall be planted primarily along the perimeter of the facility. In-ground ball and burlap: Applicable. Containerized: Applicable. Plant Installation Categories Plugs: Applicable Cuttings: Applicable Mats, Carpets and Trays: Not applicable. Scale of tree(s)should be correlated to the available space and surrounding context, including overhead and underground utilities. Tree species should be Plant Scale selected such that it will not outgrow its space. Additionally, line of sight and branching height should be considered near intersections and pedestrian walkways. Rooting Depth The recommended rooting depth of each plant form should match the filter media depth provided. Available volume for rooting should be matched to plant needs, given the ultimate diameter at breast height(DBH), location and depth of geotextile fabric within the Rooting Volume practice cross section, and soil volume required. This volume can be within the stormwater practice itself or in combination with soil rooting areas outside the practice, so long as roots can grow out of the stormwater practice. Inundation Tolerance Species should be selected based on the ponding depth outlined in Chapter 6 and tolerance for both drought and temporary flood conditions. Maintenance Refer to Chapter 12. ' Mi� v Kin , � �. •. `'r 5 * t iv b PrJ, r: Figure 11.9 Albany Housing Authority Development Bioretention Filter(Photo Source: AHA/NYSEFC) Chapter 11: Planting Guidance for Stormwater Management Practices 11-23 11.4.8.10 Bioslope Table 11.17 Plant Considerations for Bioslopes Plant Considerations Practice Specific Considerations Plantings are not required. However, if surface stabilization is necessary, then Plant Form non-invasive grass species or sod can be selected based on specific site and soil conditions present along the slope. Surface stabilization must be selected to preserve the infiltration rate of the filter media. In-ground ball and burlap: Not applicable. Containerized: Applicable. Plant Installation Categories Plugs: Applicable. Cuttings: Not applicable. Mats, Carpets and Trays: Not applicable. Plant Scale Ground cover, grass, short perennial Rooting Depth Not applicable. Rooting Volume Not applicable. Inundation Tolerance Not applicable. Maintenance Mowing during the growing season to maintain grass heights of 6 to 15 inches. Refer to Chapter 12. Chapter 11: Planting Guidance for Stormwater Management Practices 11-24 11.4.8.11 Dry Swales Table • • • for Plant Considerations Practice Specific Considerations Non-invasive grass species selected based on specific site and soil conditions Plant Form present along the channel. Refer to Appendix G for non-erosive velocities of vegetated channels. In-ground ball and burlap: Not applicable. Containerized:Applicable. Plant Installation Categories Plugs: Applicable Cuttings: Not applicable Mats, Carpets and Trays: Not applicable. Plant Scale ground cover or grass. Rooting Depth Not applicable. Rooting Volume Not applicable. Inundation Tolerance Species should be selected based on the ponding depth outlined in Chapter 6 and tolerance for both drought and temporary flood conditions. Maintenance Mowing during the growing season to maintain grass heights of 4 to 6 inches. Refer to Chapter 12. 11.4.8.12 Wet Swales • Plant Considerations Practice Specific Considerations Non-invasive grass species and wetland plants selected based on specific site, Plant Form soil and hydric conditions present along the channel. Refer to Appendix G for non-erosive velocities of vegetated channels. In-ground ball and burlap: Not applicable. Containerized: Not applicable. Plant Installation Categories Plugs: Applicable Cuttings: Applicable Mats, Carpets and Trays: Not applicable. Plant Scale Wetland plants should be installed below the WQv maximum ponding depth. Rooting Depth Not applicable. Rooting Volume Not applicable. Inundation Tolerance Species should be selected based on the ponding depth outlined in Chapter 6 and tolerance for both drought and temporary flood conditions. Maintenance Regular observation for invasive species. Refer to Chapter 12. Chapter 11: Planting Guidance for Stormwater Management Practices 11-25 Section 11 .5 Plant Maintenance A critical component of plant selection is understanding the installation process, duration of plant establishment, and necessary maintenance to ensure longevity of plantings and function of the practice. Plantings should be designed with the understanding that they will change overtime and that their maintenance and care will change as well. It is recommended for all stormwater management projects to have a long-term maintenance plan with a specific focus on the first three years. This should indicate which elements are imperative to inspect seasonally, watering suggestions, pruning, weeding, fertilizing, replenishment of mulch, maintenance of protective fencing, and policy regarding replacement of plantings. Owners or the entity responsible for implementing the maintenance program should be collaborative partners during the design and understand the importance of having a quality maintenance component. Plants should be chosen that match the maintenance capabilities of the project owner. Horticulturally intensive plants (e.g., those requiring require regular dividing, pruning, winterization, annual fertilizing, etc.) should generally be avoided unless the owner provides commitments for their care. Plants that require regular dividing, pruning, or other intensive maintenance practices should also be avoided. Refer to Chapter 12 for Maintenance Guidance. 11.5.1 First Year Maintenance A regular maintenance plan shall be put in place following installation. Traditionally, this is performed by the Contractor until the site is turned over to the Owner. Primarily in the first-year watering is the key care required. Watering rates should be established and are contingent on the species and on the rainfall, planting media. The watering regime should be designed to transition toward natural rainfall patterns and make plants less reliant on supplemental watering. A specified level of water should be provided either via supplemental irrigation or natural rainfall. Other care includes observing for invasive species, and general observation of plant growth (e.g., evaluating vigor, color, dieback, etc.) 11.5.2 Second Year Maintenance Maintenance performed by the site owner shall include: occasional watering as needed due to climatic conditions, periodic weeding, and leaf cleanup from fall/winter season. A visual inspection of planting is important to determine if plant loss has occurred between the first and second growing season. If plant loss has occurred replacement is recommended. If the practice is mulched an additional thin top dressing can be applied to exposed bed areas (Note: mulch should not be placed at the base (trunk flare) of any tree or shrub. It is important to determine the causes of erosion, if observed, and remedy the issue. Special consideration should be given to the type and size of any maintenance equipment that is utilized within a green infrastructure practice to reduce the threat of over compaction. 11.5.3 Third Year Maintenance The third year of planting maintenance should require less supplemental watering as plants should be established. Maintenance should include periodic weeding and leaf removal. Caution must be exercised to ensure that mulch layers do not become too thick. Preferred mulch depth is 3"to 4". 11.5.4 Long Term Maintenance Beginning in the third-year plantings should be well established (cannot be pulled by hand from the ground) and pushing new growth in their respective growth season. At this time supplemental water can be reduced to extended dry periods or removed. The on-going maintenance should include weeding of undesirable plants, replacement of dead, dying, or non- established plants, pruning of broken branches, leaf litter removal and inspection for signs of decay, disease, or insect damage. Plants should be replaced in kind or with suitable substitutes that meet the original objective of the planting. Planting bed areas should be edged and re-mulched annually to reduce weed growth and support moisture retention. Caution must be exercised to ensure that mulch layers do not become too thick or crowd against the root flair. The preferred mulch depth is 3"to 4". Chapter 11: Planting Guidance for Stormwater Management Practices 11•-2 11.5.5 Invasive Control During all phases of maintenance invasive species monitoring is important. Eradication of invasive or other undesirable plant species is essential and should be conducted as early as possible. Site selection and sizing of practices should be mindful of nearby areas (including those outside of project limits) where invasives may exist, as these may provide sources that can establish within new stormwater areas. Coordination with NYS Invasive Species staff(Bureau of Invasive Species and Ecosystem Health)throughout the project is recommended. A wide range of methods for their elimination exists, falling generally into three categories: Chemical: a pre-emergent or a foliar herbicide for emergent plants. Biological: a biocontrol species, host-specific to the non-native exotic plant. Mechanical: using tools to remove the plant including the root. Disposal of removed invasive materials requires specific treatment. Consult the DEC Invasive Species staff(Bureau of Invasive Species and Ecosystem Health) for proper disposal protocol. The use of herbicides to control invasive species must be applied by a certified pesticide applicator or someone working under their supervision. Chapter 11: Planting Guidance for Stormwater Management Practices 11-27 This Page is Left Intentionally Blank NEW Department of PORK STATE Environmental Conservation Chapter 12: Maintenance Guidance SMPs will not function to protect water resources without proper attention to operation and maintenance (O&M). In order to ensure long-term performance, it's critical that O&M tasks and responsibilities are identified, clearly outlined in an inspection and maintenance plan, and assigned to various stakeholders. This Chapter was developed to address the need for maintenance guidance, and is structured in the following sections: Section 12.1 introduces the 10 SMP groups used in this Chapter, establishes the 3 level hierarchy for inspection and maintenance responsibilities and procedures, and provides an overview of planning and budgeting for maintenance. Section 12.2 outlines the key components to be inspected, the Level 1 inspection and maintenance procedures, and common triggers for Level 2 and Level 3 inspections, for each of the 10 SMP groups. Section 12.3 includes diagnostic measures for specific problems, as well as guidance for performing repair activities. Section 12.1 Introduction 12.1.1 Stormwater Management Practice (SMP) Groups For the purpose of this Chapter, the standard SMPs and Runoff Reduction Techniques have been clustered into ten SMP groups (Table 12.1), containing practices that share common inspection components and maintenance concerns. This grouping has been applied to the detailed inspection guidance provided in Section 12.2, as well as the fillable Level 1 and Level 2 Inspection Checklists that are available for download on the NYSDEC Construction Stormwater Toolbox website (www.dec.ny.gov). The checklists identify common problems with key components of the SMPs, recommend follow-up actions to correct them, and outline triggers for Level 2 and Level 3 inspections. These checklists have been developed as a guideline to assist responsible parties with efficient and thorough O&M. Table 12.1 Practices Discussed in this Chapter, by Group SMP Group Practices Included Sheet Flow to Filter Sheet Flow to Riparian 1. Sheet Flow and Disconnection Strip Buffers • Rooftop Disconnection 2. Tree Planting • Tree Planting 3. Swales • Vegetated Swale Wet Swale • Tree Pit Infiltration Bioretention 4. Bioretention • Tree Trench • Filtration Bioretention • Rain Garden Bioslope • Stormwater Planter Dry Swale 5. Rainwater Harvesting • Rain Barrel Cistern 6. Porous Pavements • Porous Asphalt Porous Concrete Porous Paver Stabilized Grid/Cell 7. Green Roofs Extensive Green Roof Intensive Green Roof 8. Ponds and Wetlands Stormwater Ponds Stormwater Wetlands 9. Infiltration Infiltration Trench Dry Well Infiltration Basin Underground Infiltration 10. Sand Filters • Surface Sand Filters Underground Sand Filters • Perimeter Sand Filters Chapter 12:Maintenance Guidance 12-1 12.1.2 Maintenance Hierarchy This Chapter is structured around a hierarchy concept, where the severity of the problem directly correlates to the level of experience needed to perform the inspection and identify corrective maintenance measures. Many SMP maintenance problems start out as minor and can be easily identified by individuals with limited experience (Level 1). As long as these issues are detected early, through regular inspections, they can typically be addressed in an expedient and Level 3: cost-effective manner. Qualified �rofessft�na�s However, in some cases, issues may arise that require additional technical knowledge or capabilities to diagnose the problem and identify the appropriate remedy (Level 2). At this point, Level 2' assistance from an individual with training in SMP inspection, Trained Municipal staff operation and maintenance, may be necessary. Similarly, some problems escalate to the point where a Qualified Professional or specialized expert is needed to return the SMP to Level 1, proper functioning condition (Level 3). Property owners, property managers, and municipal rn aintenance staff The step-wise approach of the Maintenance Hierarchy (Figure 12.1) was developed to ensure long-term performance of SMPS, Figure 12.1 The SMP Maintenance Hierarchy through cost-effective implementation of inspection and maintenance. Level 1: Individuals with Limited or No Training Level 1 includes routine inspection and maintenance activities conducted by: Property owners, property managers, or HOA representatives, for privately owned SMPs. Municipal maintenance staff/interns or volunteers, for municipally owned SMPS. These individuals typically have very limited training in stormwater operation, inspection, and maintenance, but can use available guidance to quickly identify and rectify common or minor issues with SMP performance. For most SMPs, the majority of inspection and maintenance activities can be conducted at this skill level, thus Level 1 forms the base of the Maintenance Hierarchy pyramid. Many well-functioning SMPs can be adequately maintained for long periods of time using Level 1 capabilities. Some issues may arise that require a higher level of resources and expertise. Such issues are referred to in this Chapter and the Inspection Checklists as "kick-outs to Level 2." Level 2: Trained Individuals Level 2 includes inspection and maintenance activities conducted by municipal employees or landscape contractors who have completed training on SMP operation, inspection, and maintenance. Level 2 inspections can occur in response to two circumstances: As part of an ongoing, municipal inspection program whereby SMPs are visited on a rotating basis at a frequency of once every five years, or a frequency established by the local program; or In response to a "kick-out"from a Level 1 Inspector. Circumstance#2 requires coordination and communication between the Level 1 and Level 2 Inspectors, with documentation and background provided by the Level 1 Inspector. This is essential to make the hierarchy approach successful. As with kick-outs from Level 1 to Level 2, the same can exist from Level 2 to Level 3. If the Level 2 Inspector encounters a problem where a Qualified Professional is needed to re-design certain components of the SMP, and/or a Qualified Contractor is needed to undertake a more serious repair, then Level 3 is activated. Chapter 12: Maintenance Guidance 12-2 Level 3: Qualified Professionals Level 3 includes inspection and maintenance conducted by Qualified professionals, including professional engineers and landscape architects, that can revisit design issues associated with chronic or serious problems. For repair and maintenance of the SMPs at this level, individuals with specific skills and certifications, such as a certified plumber with experience working with rainwater harvesting systems or a horticulturalist with knowledge on proper plantings, may need to be called in by the Qualified Professional. Table 12.2 describes how SMP inspection and maintenance activities differ at each level of the Maintenance Hierarchy. Table 12.2 SMIP Ins ection and Maintenance Hierarchy Levels Level 1: Individuals with Level 2: Trained Individuals Level 3: Qualified Professionals Limited or No Training Qualifications/ No special training, but person is On-the-job training and/or Professional License, such as a Training of provided educational materials workshops PE or RLA Inspectors Frequency of Routine as determined by the local Only as needed from Inspection At least annually program OR as kick-out from Level Level 2 inspection 1 inspection Inspection guidance is included in Guidance on diagnosing common Section 12.2. Refer to the Refer to the NYSDEC Construction problems is included in Section Inspection NYSDEC Construction Stormwater Stormwater Toolbox website 12.3. Refer to the NYSDEC Guidance Toolbox website (www.dec.ny.goy) (www.dec.ny.gov)for Level 2 Construction Stormwater Toolbox for Level 1 Inspection Inspection Checklists. website(www.dec.ny.goy)for a Checklists. Level 3 Inspection Form. Routine mowing. Trash removal. Removal of larger amounts of Redesign an improperly Typical Plant care and upkeep. Mulching sediment. Structural damage functioning practice, to include: Maintenance as needed. Removal of small repair. Minor regrading and regrading the contributing Activities amounts of sediment from scarification of soil surface to drainage area, replacing filter pretreatment areas of the practice. restore permeability. media or plantings, modifying conveyance structures, etc. Triggers for Common triggers for Level 2 Common triggers for Level 3 Inspection or Regular inspection inspection are included in inspection are included in Maintenance (no trigger) Section 12.2. Section 12.2. by this Level 12.1.3 Level 1, 2 and 3 Inspections 12.1.3.1 General Guidance for Level 1 Inspections Read through this guidance before performing an inspection and use the specific guidance in Section 12.2 for the SMP Group that includes the practice being inspected. Refer to Chapter 11 for guidance on plant maintenance, as well as control of invasive species. When to Conduct a Level 1 Inspection Level 1 Inspections are the most common and are intended to identify minor maintenance issues early and keep up with routine maintenance tasks. They should be conducted at least annually for all practices and supplemented with additional visits after large storms, winter salting and sanding, or other seasonal changes. In addition, it is recommended that inspections take place more frequently during the first few years after installation of an SMP. Many issues can be identified and corrected during this early period, so that they do not lead to larger problems in subsequent years. Once the SMP is stable and seems to be functioning properly, the inspections can become less frequent. Chapter 12:Maintenance Guidance 12- What to Take into the Field The Level 1 Inspection is simple, and it is assumed that very little measurement is needed. However, the Inspector should take pictures to document findings and keep a record of all inspections. The following items may be needed during a Level 1 Inspection: 1. Letter of permission to access property if the Inspector is from an outside agency 2. Clipboard and pencils (if using paper forms), or Tablet or smartphone (if using digital forms) 3. Level 1 Inspection Checklists (paper or digital copies) 4. Notes or records from past inspections 6. Approved Site Plan, Planting Plan (includes planting/seed mixes), and/or details for SMP's 6. Digital camera or smartphone 7. Engineer's scale 8. Flagging/stakes and waterproof marker(to mark problem areas that need to be revisited) 9. 25-ft Measuring Tape (optional, to measure pipe sizes and SMP dimensions) 10. Safety equipment: safety vest, steel-toe shoes, traffic cones, etc. (if SMP is located near traffic) 11. Bug spray (if needed) 12. Sun block (if needed) Level 1 Checklists The Level 1 Inspection Checklists are available for download on the NYSDEC Construction Stormwater Toolbox website (www.dec.ny.gov). These checklists outline common problems with key components of the SMPs and describe follow-up actions for each observed condition. Refer to Figure 12.2, for an example checklist. The Checklists are intended to be used as follows: Check the box in the LEFT column if the problem is present at the site. Check the appropriate follow-up action(s) in the RIGHT column, or add an action as needed to fix the problem. Record all your actions. Keep copies of the Level 1 Inspection Checklists, plus notes, photos, or other documentation of corrective measures to fix problems. Record dates of actions and any follow-up inspections. This will be important for communicating with Level 2 Inspectors and/or the local maintenance program. Activate a Level 2 Inspection using the blue cells to identify conditions when a more detailed inspection is necessary to further diagnose a problem. Refer to Section 12.2 for common triggers of Level 2 Inspection for each of the SMP Groups. Consult the local stormwater program authority for the most appropriate Level 2 inspection option. Porous Pavement 1. Drainage Area Problem (Check if Present) Follow-Up Actions Seed and mulch areas of bare soil to get vegetation established. . 0 Fill in erosion areas with soil, compact, and seed straw to get vegetation established. Wft 7 If a rill or small channel is forming, try to redirect water flowing to this area by creating a small bern or adding topsoil to area by creating a small berm or adding topsoil to areas k ' f- that are heavily compacted. Kick-Out to Level 2 Inspection: Large areas of soil have been eroded, or larger channels Bare soil, erosion of the ground are forming. May require rerouting of flow paths. (rills washing out the dirt) Figure 12.2 Example Level 1 Inspection Checklist, with Follow-Up Actions. Note "Kick-Out to Level 2"highlighted in light blue. Chapter 12:Maintenance Guidance 12-14 12.1.3.2 General Guidance for Level 2 and 3 Inspections Read through this guidance before performing an inspection, and use the specific guidance in Section 12.2 for the SMP Group that includes the practice being inspected, or Section 12.3 for the specific problem encountered. When to Conduct a Level 2 Inspection Level 2 Inspections occur as routine inspections for compliance with local stormwater regulations or when triggered by a Level 1 Inspector to address or diagnose specific problems. In this situation, the Level 2 Inspector should confer with the Level 1 Inspector about problems they have identified and then conduct a follow-up inspection that focuses on diagnosing the causes of the problems and possible solutions. The frequency of Level 2 Inspections is typically defined by the municipality, but shall occur at least once every five years. As with Level 1 inspections, the frequency may change with the age of the SMP, with higher inspection frequency the first couple of years after installation. Notifying the Owner/Operator Consult the project files and maintenance agreement to ascertain the Owner/Operator. Confirm that there is right of access through the local code, signed maintenance agreement, or other means. Contact the Owner/Operator at least three business days in advance of the proposed inspection. If the Owner/Operator cannot be found or contacted, make a reasonable effort through file research to contact a property representative, and document those efforts in writing. If the inspection is in response to a Level 1 inspection and referral to your agency, speak with the person who conducted the Level 1 inspection and get any documentation they may have. For publicly owned and managed SMPs, the municipality or other regulated MS4 is responsible for long-term operation and maintenance. What to Take in the Field Level 2 inspections may require authorized access to private property. Therefore, additional identification shall be provided for these inspections. It is recommended that the following items be taken into the field during a Level 2 Inspection: Letter on municipal letterhead granting access to property and/or agency photo badge Clipboard and pencils (if using paper forms), or Tablet or smartphone (if using digital forms) Level 2 Inspection Checklists (paper or digital copies) Dry erase board and marker (optional) to include in photos to keep track of SMP tracking#in municipal database (see Figure 12.3 as example) 5. Notes or records from past inspections 6. Approved Site Plan, Planting Plan (includes planting/seed mixes), and/or details for SMP's 7. SMP As-Built Plan (if available) 8. Digital camera or smartphone 9. Engineer's scale 10. Flagging/stakes and waterproof marker(to mark problem areas that need to be revisited) 11. 100-ft Measuring Tape 12. Hand level and pocket rod (if needed to measure relative elevations) 13. Pipe wrench (to open underdrain clean-out caps) 14. Flashlight (to look into underdrain cleanouts and/or manholes) 16. Manhole cover puller 16. Soil probe, auger, and/or shovel 17. Safety equipment: safety vest, steel-toe shoes, traffic cones, etc. (if SMP is located near traffic) 18. Bug spray (if needed) 19. Sun block (if needed) Chapter 12:Maintenance Guidance 12- The Level 2 Inspection Checklists are available for download on the NYSDEC Construction Stormwater Toolbox website (www.dec.nv.qov). These checklists outline recommended repairs for common problems with key SMP components, and common triggers for Level 3 Inspection. In general, the inspection should follow a consistent, logical approach, such as outlined below. Conduct a quick tour of the practice to identify any obvious issues and important components: inlets (number, location), surface area, outlet structures, ` berms or impoundments, outfalls, downstream - conveyance channels or receiving waters. Check these - components against the approved design plan or as- built drawing (if available). Starting at the upland area, use the Level 2 Checklist to Figure 12.3 Use a white board and digital camera to evaluate the practice. The inspection will proceed from note SMP tracking#, date of inspection, and other the upland drainage area to inlets, side slopes, berms, forms of documentation. Alternatively, tag treatment area, and outlets/outfalls. Make sure to fill in photographs using a smartphone key information on the inspection form, such as SMP identifier number, site name, Inspector name, date, and weather conditions. Take photos of key practice components or maintenance concerns. Mark photo locations and orientation on a sketch Site Plan. Review the Inspection Checklists before leaving the site to make sure that all necessary information has been collected. Upon completion of an inspection, complete these follow-up actions as soon as possible: Enter the inspection information in the appropriate database or hard copy file Download and label photos Communicate problems and corrective measures to the Owner/Operator(private or public). This may involve the Level 2 Inspector making a judgement call as to whether observed problems warrant a Level 3 investigation, providing a timeframe for correcting simpler issues, and coordinating with the Owner/Operator to pursue such an investigation, if required. Many local programs have existing protocols for sending letters, activating a compliance procedure, or verifying that repairs and corrections are completed by the Owner/Operator. The Level 2 Inspection Checklists summarize follow-up actions and recommended repairs associated with various observations of SMP condition (blue cells) and highlight specific conditions that would trigger Level 3 Inspection (grey cells). Level 3 Inspections are conducted in response to more complex issues identified during a Level 2 inspection, with the goal of developing specific repairs to resolve the issues. Therefore, the inspection primarily focuses on the problematic components of the SMP, but it is good practice to perform a cursory review of all system components. Section 12.3 identifies twelve problems that are typically addressed in Level 3 inspections and discusses how to diagnose the cause of each problem, as well as repairs needed to address them. It should be noted that the problems addressed in each subsection can occur in a variety of SMPs. As a result, each subsection identifies the SMPs where the problem most commonly occurs and, in some cases, an SMP-specific diagnosis procedure. Chapter 12: Maintenance Guidance 12-6 12.1.4 Planning for Stormwater Maintenance This section outlines key elements of stormwater maintenance planning, including: 1. Program models for stormwater maintenance 2. Inspection and maintenance checklists 3. Planning for the costs of stormwater maintenance 4. Identifying the need for infrequent maintenance items 12.1.4.1 Program Models for Stormwater Maintenance The Maintenance Hierarchy concept (See Section 12.1.2 ) is discussed throughout this Chapter, but the individuals who will conduct the Level 1, Level 2 and Level 3 inspections and maintenance will vary depending on how the local program is administered. While this Chapter does not focus on program elements, it is important to note that the local program requirements will influence who performs ongoing maintenance. A legally binding and enforceable maintenance agreement shall be established between the property owner and local reviewing authorities to assign maintenance responsibilities to the responsible parties. This will play an important role in how to develop a comprehensive maintenance plan.All required maintenance elements shall be included in the maintenance plan. Stormwater maintenance plans can generally be designated in three categories: 1) Private; 2) Local Government; and 3) Hybrid Approach. Understanding the program and regulations in the local community will influence the best techniques for developing the maintenance plan (Table 12.3). Option 1: Private Maintenance In this option, maintenance is the responsibility of the private landowner. In regulated MS4s, however, the landowner will periodically report to the local government. In this model, it is important to ensure that the maintenance plan is very easy to understand. Option 2: Local Government Maintenance In this option, the local government takes over maintenance responsibility for all stormwater practices. While it is still important to develop a clear and simple plan, the designer can assume some level of training or supervision for the individuals conducting inspections and maintenance. Maintenance access should be made available to local government staff through official easements. Option 3: Hybrid Approach In the hybrid approach to stormwater maintenance, larger practices or practices on public land are maintained by the local government, and smaller practices on private property are maintained by the landowner. Alternatively, the local government may take responsibility for inspections, but leave the landowner responsible for maintenance items identified during the inspection. Table 12.3 Maintenance Considerations for Three Program Options Program Option Inspection/Maintenance Performed By: Key Considerations for the Designer Level 1: Property owner or HOA Make the plan very simple and graphic intensive. Option 1: Private Level 2: Trained Individual Make a landscape/seed plan very simple and graphic intensive Level 3: Qualified Professional/Contractor Include a list of contractors if applicable. Provide links to educational materials. Option 2: Local Level 1: Interns or Untrained Staff Learn about the resources the local program has at its disposal. Government Level 2: Trained Local Staff If government staff are being trained, develop a maintenance plan Program Level 3: City/Town/Village Engineer or that is consistent with their knowledge and understanding. other individual hired by the municipality Be aware of equipment and materials on hand in this community. Option 3: Hybrid Inspection and maintenance Understand how the responsibilities are divided and develop a plan Approach responsibilities are divided between the that is consistent with this arrangement. local government and private landowner. Chapter 12: Maintenance Guidance 1 -7 12.1.4.2 Inspection and Maintenance Checklists and Documentation The NYSDEC Construction Stormwater Toolbox website (www.dec.ny.gov) includes inspection checklists specific to each level of the maintenance hierarchy. The maintenance plan should include the inspection checklists for each level for the SMP Group(s) being constructed. The checklists include blank sections under each of the practice key components, to input project specific information. All materials developed as a part of the maintenance plan should be provided to the practice owner and local government. (See Table 12.4) Table 12.4 Customizing Checklists and Guidance Attach photographs of the practice(once installed), and a simple aerial photograph of the site to locate the practice. Include key local Level 1 Section 12.2 includes guidance. government contacts and contractors along with the checklist. Modify to add other problems, as they are identified during inspections. Attach site specific photographs of each problem identified. Section 12.2 includes triggers for Level 2 and Modify to add other observed conditions and recommended Level 2 Level 3 Inspection. repairs, as they are identified during inspections. Attach site specific photographs of each observed condition identified. Section 12.2 and Section 12.3 include Attach site specific photographs of each observed condition Level 3 guidance. identified. Develop plans, details, and/or written narrative of recommended. 12.1.4.3 Budgeting for Maintenance A maintenance plan should include a budget for annual maintenance. In the Local Government Maintenance model, a single entity (the local government)will be responsible for maintenance of many practices, so the cost of maintenance for an individual practice may not be as important as estimating the average cost of maintenance across all practices. For privately maintained practices, on the other hand, it is very helpful to develop a cost estimate that is as accurate as possible for the specific location. As a result, two options for estimating costs are presented here, including: Option 1: Average or Unit Costs Generalized cost data are used to estimate an annual cost. This option may be used for a municipality or other institution that manages a large number of practices. Option 2: Detailed Individual Practice Budget Annual costs are estimated using more detailed practice information, as well as more detailed estimates of labor and material costs. Option 1: Average or Unit Costs In this option, annual maintenance costs are estimated on a per-acre basis or as a percentage of the total construction costs. These prices typically range from about 1% to 4% of the construction costs (King and Hagan, 2011; Table 12.6 Typical Maintenance Costs). Table 12.6 Typical Maintenance Costs (Source: King and Hagan, Practice Annual Maintenance Cost Annual Maintenance Cost (%of Construction) ($/cf of water quality volume treated) Buffers 4% $0.25-$0.35 Tree Planting 4% $0.35 Ponds and Wetlands 4% $0.22-$0.35 Infiltration Trench/Basin 2% $0.25 Filtering Practices 4% $0.41 -$0.47 Bioretention 4% $0.44 Swales 3% $0.18-$0.26 Porous Pavement 1% $0.64-$0.89 Chapter 12:Maintenance Guidance 12_ While the costs in Table 12.5 may be a reasonable starting point, it is important to note that the actual data will vary greatly, depending on labor rates and material costs. For example, the hourly"Open Shop" labor rate for rough grading is approximately$27/hour in Elmira and $38/hour in New York City (Means, 2015). In addition, costs for labor, materials and equipment will vary depending on the maintenance arrangement (Table 12.6). Table 12.6 Variability in Maintenance Costs Based on Maintenance Arrangement P Maintenance Labor Materials Equipment Arrangement Public Level 1: Intern Wage Level 2: Staff Salary Low: Typically owned by Public Maintenance Level 3: Professional Staff or Low: Materials bought in bulk. Works or similar department. (Municipality) Contractor Level 1: Homeowner(Free)or Private Contractor High: Materials purchased in small High: Specialized equipment Maintenance Level 2: Private Landscaper or quantities. needs to be rented if needed. (Homeowner) Contractor Level 3: Professional Contractor Private Level 1: Free(with HOA volunteers) or Contracted Labor Rate Varies: Materials may be bought in Maintenance Level 2: Private Landscaper or bulk or on a small scale, depending High: Specialized equipment (Commercial Contractor on the size of the private entity. needs to be rented if needed. or HOA) Level 3: Professional Contractor Option 2: Site-Based Costs Because the unit costs of labor and materials, and the average annual costs of maintenance can be highly variable, more detailed data will be needed to estimate costs at a particular site. One approach for estimating costs is to generate a list of routine maintenance items, along with associated unit costs for labor, materials, and equipment. This approach requires the user to enter basic design data for the practice, as well as information regarding local labor rates and other general costs. In the bioretention example below, unit costs are used to estimate routine maintenance costs, including regular inspections and maintenance. Example Annual Cost Estimation: Bioretention An example cost estimation for a bioretention filter follows below, which demonstrates how the unit cost and typical frequency data can be used to estimate average annual maintenance costs. Table 12.7 summarizes the characteristics of the example bioretention practice, as well as the unit cost assumptions for typical inspection and maintenance activities. Table 12.8 then summarizes routine inspection and maintenance activities, their frequency and extent, and associated labor costs. Using the assumptions for this example, the annual costs for routine inspection and maintenance would be $1,828 ($1.15/cfof Water Quality Volume) in the first year, and $1,468 ($0.90/cf WQ ) in subsequent years. These values are much higher than the $0.44/cf estimated using general cost data (Table 12.5). However, significant cost savings could be realized by using volunteer or intern-level labor for Level 1 inspections and routine maintenance. Chapter 12: Maintenance Guidance 1 - Table 12.7 Bioretention Example: Assumed Practice Characteristics and Unit Costs- Practice Design Unit Costs Water Quality Volume (cf) 1,600 Level 1 Labor($/hr) $15 Forebay Volume(cf) 400 Level 2 Labor($/hr) $35 Total Practice Area(sf) 2,000 Mulch ($/cy) $10 Filter Area(sf) 1,000 Plants ($/plant) $1 Ponding Area(sf) 1,500 Trash Tipping Fee $25 Slope Area (sf) 500 Seed/Mulch for a small area $10 Turf Area(sf) No Turf Average Cost for a PVC Replacement $100 Part(Planning Level) Inlets(#) 1 Chapter 12: Maintenance Guidance 12-10 RoutineTable 12.8 Bioretention Example: Annual Costs Frequency Materials and Task (x/year, Typical Extent Extent Hours (Unit) Hours/yr Level Eui Materials Decimal) qpment Labor and Total Equipment Level 1 Inspection - 1 to 5- 1 Practice 1 1 per inspection 1 1 $15 $15 acre drainage Level 2 Inspection - 1 to 5- 0.2 Practice 1 2 per inspection 0.4 2 $14 $14 acre drainage Weekly for first Watering -grass and 16 growing season, over 1,000 0.5 per 400 sf area 24 1 Assume minimal plants: Year 1 cost for water $360 $360 filter surface area Trash and Debris 1 per 400 sf Assume$25 Removal 4 Ponding area 1,500 practice surface 15 1 Tipping Fee for $225 $100 $325 area Each Trip Assume 50%of 4 per 400 sf Weeding 2 practice area 1,000 practice surface 20 1 $300 $300 area Bark mulch; Mulching 1 Ponding area 1,500 4 per 400 sf area 15 1 assume 15 $225 $150 $375 cy/application Sediment Removal Assume one small (minor, less than 2") 1 area per inlet 1 1 per small area 1 1 $15 $15 Erosion Repair(minor) 1 Inlets; assume 25 25 1 per 25 sf 1 1 Seed, mulch, and $15 $10 $25 sf/practice topsoil Erosion Repair(minor) 1 10%of slope area 50 1 per 25 sf 2 1 Seed, mulch, and $30 $20 $40 topsoil Minor Regrading 0.5 1 spot per 400 sf of 5 1 per repair 2.5 2 Assume done by $88 $88 practice area hand Planting (plants) 0.2 Assume 50%of 1,000 8 perL00 sf 8 1 Assume 500 $120 $100 $220 practice area plants/planting Minor PVC or Metal Repairs(observation well Assume about a cap, PVC outlet Control, 0.2 1 per practice 1 1 per repair 0.2 2 $100 piece of $7 $20 $27 equipment grates) Sediment Removal 0.2 per forebay 1 2 per forebay 0.4 2 Assume removal $14 $14 (small forebay) by hand Total Costs -Year 1 $1,428 $400 $1,828 Total Costs -Subsequent Years $1,068 $400 $1,468 Chapter 12: Maintenance Guidance 1 _11 12.1.4.4 Planning for "Non-Routine" Maintenance If the guidance provided in this Chapter is followed and practices are designed properly, the routine maintenance (and budget guidance in Section 12.1.4.3) should be sufficient to keep a practice functioning indefinitely. However, planning is needed for infrequent maintenance items. In the initial maintenance plan, identify a few of the most likely infrequent items. If initial routine inspections start to identify a more serious problem, develop a plan and budget for performing the repairs. To be more conservative, another option is to provide a contingency budget to plan for non-routine repairs over the life of the practice. Note: Maintenance and repairs that rise to a Level 3 inspection may require permits from the NYSDEC and/or US Army Corps of Engineers, if they are undertaken within or adjacent to regulated wetlands or other waters of the U.S. Chapter 12: Maintenance Guidance 12-12 Section 12.2 Inspections by SMP Group 12.2.1 Sheet Flow and Disconnection Includes: Sheet Flow to Riparian Buffers/Filter Strips (RR-2) and Disconnection of Rooftop Runoff(RR-4) Components The intent of sheet Flow and disconnection is for runoff from small areas of impervious cover to spread out evenly and dissipate in a grassy, vegetated, riparian, or reforestation area. It is a low-technology practice intended to reduce runoff at its source. Key components to inspect for Sheet Flow and Disconnection include the following: S&D-1 Drainage Area: The drainage area consists of rooftops and/or impervious surfaces such as parking lots, driveways, or sidewalks. S&D-3 Treatment Area Pervious areas such as lawns or forests may also be part of the drainage area. S&D-2 Level Spreader/Energy Dissipator: Some sheet flow and disconnection practices -_ have a mechanism in place to dissipate concentrated runoff and return it to sheet flow. _- S&D-2 Level SpreaderlEnergy After runoff is Dissipator dissipated as sheet flow, it enters the treatment ' area. - S&D-1 Drainage Area _ Level 1 Inspections Frequency: 2 times per year in early spring and fall. Figure 12.4 Key Areas for Level 1 Inspection of Sheet Flow Recommend an additional inspection during a storm to and Disconnection with filter strip shown. (R.Winston,NCsu) better see any active blockages, bypassing, or other problems. Triggers for Level 2 Inspection The most likely triggers for Level 2 Inspection of S&D practices are: Widespread sediment accumulation in paved tributary area Deterioration at pavement edge Deterioration of level spreader/energy dissipator Erosion in the treatment area Triggers for Level 3 Inspection The most likely triggers for Level 3 Inspection of S&D practices are: Major sediment or erosion caused by uphill issue Significant damage to level spreader/energy dissipator Chapter 12: Maintenance Guidance 12-13 12.2.2 Tree Plantings Includes: Tree Plantings (RR-3) J, Components Key components to inspect for tree planting include the following: * + r �r TP-1 Surface Area: The tree planting surface area is the , mulched area where water accumulates and is absorbed during a storm. :' * .. • :� TP-2 Vegetation: The vegetation of a tree planting is comprised of the tree itself. The health of the tree is one of the most critical maintenance items for tree plantings. Note: This is a simple, "non-structural' practice and, as such, maintenance tasks are similar to any landscape maintenance. Tree planting can involve individual trees or multiple trees, such as ` „ -- reforesting a riparian buffer. - Level1 Inspections -• - ` Frequency: Annually in early spring. Recommend every 3 months, within 1 week of ice storms and within 1 week of high wind events (>20 Figure 12.5 Key Areas for Level 1 mph) until the trees reach maturity. Inspection of Tree Plantings The Level 1 inspection goes hand in hand with active maintenance and includes inspection of the surface area (TP-1) and Vegetation (TP-2) of the tree planting. Watering, mulching, and pruning are common maintenance activities. During the first three years, mulching, watering, and protection of young trees may be necessary, see Chapter 11 for additional maintenance guidance. Watering should occur during the growing season. Mulching and pruning occurs once a year in the spring and early spring, respectively. At a minimum, inspections shall include an assessment of tree health and determination of survival rates. Any dead trees shall be replaced, and remaining trees shall be inspected for evidence of insect, disease, or other physical damage. Triggers for Level 2 Inspection The most likely triggers for Level 2 Inspection of TP practices are: Appearance of fungus or pest damage to vegetation Triggers for Level 3 Inspection The most likely triggers for Level 3 Inspection of TP practices are: Uncertainty about how to address the infestation or disease Chapter 12: Maintenance Guidance 1 .14 12.2.3 Swales Includes: Vegetated Swales (RR-5) and Wet Swales (0-2) Components Key components to inspect for swales include the following: SWA Drainage Area: The drainage area sends runoff to and is uphill from the swale. When it rains, water runs off and flows to and along the swale. SW-2 Inlets: The inlets to a swale are where water flows in. Depending on the design, water can flow in through: a ditch, pipe, or curb opening at top of swale or as sheet flow along the entire length of swale. SW-3 Surface Area: The swale surface area is the vegetated bottom area and side slopes where water flows during a storm. Depending on the design, the swale may also contain check dams, which are small dams of earth, stone, wood, or other materials that slow down and temporarily pond water as it flows down the swale. SW-4 Vegetation,- The health of vegetation within the swale is perhaps the most critical maintenance item for the property owner or responsible party. SW-5 Outlets: These are where water leaves the swale when it fills up or where water reaches the downstream end of the swale. There may be a small stone apron or rock dam here or even an outlet grate. Level 1 Inspections SW1.Drainage Area SWS.Outlet Frequency:Annually in early Spring. Recommend an additional inspection during the growing season or in the early fall to assess the health of vegetation. Triggers for Level 2 Inspection f The most likely triggers for Level 2 Inspection of SW SW3.Swale SurfaceArea practices are: Water ponding on the surface for more than 72 hours following a storm event Vegetation being replaced by weeds and SW4.Vegetation invasive species SW2.Inlets Erosion of check dams, inlets, swale surface area or side slopes Significant sediment accumulation Figure 12.6 Key Areas for Level 1 Inspection of Swales Triggers for Level 3 Inspection The most likely triggers for Level 3 Inspection of SW practices are: Standing water caused by over compacted or clogged soil media Severe erosion around or under check dams Large area of vegetation overrun with weeds and/or invasive species Problem requires practice redesign or modification to solve Severe sediment accumulation that appears to be getting worse overtime Chapter 12: Maintenance Guidance 12-15 12.2.4 Bioretention Includes: Tree Pits (RR-3), Tree Trench (RR-3), Rain Gardens (RR-6), Stormwater Planters (RR-7), Infiltration Bioretention (F-4), Filtration Bioretention (F-5), Bioslope (F-6), Dry Swales (0-1) Note: For the purposes of this Chapter, the term 00,�,■; "Bioretention"will be used to generally describe all of � these practices. n _ Components ' �" BR-5 Outlet Key components to inspect for Bioretention BR-3 Ponding Area �A•1 include the following: «• ���,: BRA Drainage Area: The drainage area sends '= runoff to and is uphill from the Bioretention. When 11 BR-2 Inlet BR-4Vegetation it rains, water runs off and flows to the Bioretention and ponds within the filter temporarily (usually for no more than 48 hours). Sometimes, BR-1 Drainage Area the runoff will contain dirt, grit, grass clippings, oil, or other substances that SHOULD NOT be directed to the practice. BR-2 Inlets: The inlets to a Bioretention are Figure 12.7 Key Areas for Level 1 Inspection of Bioretention where water flows into the filter. Depending on the design,water can flow in through: curb cuts, pipes, ditches, or sheet flow. BR-3 Ponding Area: The ponding area fills up with water during a rainstorm. If you picture the Bioretention as a bathtub, there is the bottom (usually flat surface), side slopes (areas that slope down to the bottom from the surrounding ground), and berms or structures that control the depth to which water ponds. BR-4 Vegetation: The health of vegetation within the Bioretention is perhaps the most critical maintenance item for the Owner/Operator. Many Bioretention become overgrown, and "desirable"vegetation becomes choked out by weeds and invasive plants. Weeding and watering are essential the first year and can be minimized with the use of a weed-free mulch layer. It is important to know what the practice is supposed to look like, and what plants seem to be thriving or doing poorly. BR-5 Outlets: Outlets are where water leaves the Bioretention when stormwater exceeds the storage capacity. Level 1 Inspections Inspection Frequency: 4 times per year during the growing season. During the first 6 months of operation, it is recommended that bioretention practices be inspected at least twice, and after each storm event greater than 0.5". Maintenance Frequency:At least 4 times during the growing season, bioretention should be pruned, weeded, and mowed around;have sediment, trash, and debris removed;and have dead and damaged plants replaced, as needed. In the spring and fall, the practices should have rills, gullies, dead or diseased trees and shrubs repaired or replaced;have bare areas reseeded if applicable;and have mulch replenished to required depth. In the winter months, planting material should be trimmed, and the practice should be inspected for snow accumulation. Once per year, soils should be tested for appropriate pH levels. Finally, every 2 to 3 years, damaged or compromised structures within the practice should be replaced, perennials should be trimmed and divided, and infiltration rates should be checked to ensure proper drainage. Maintenance Frequency(Design F-6):In addition to the above, Bioslopes should be inspected after snow events to ensure that the added weight from accumulated snow did not compact the filter media. On a monthly basis, stabilize eroded areas, ensure that flow is not bypassing the facility, and mow the slope using a retractable arm mower to a height of 6 to 15 inches. Recommend performing a flow test on the cleanouts annually to check for clogging, and to remove accumulated sediment that exceeds three inches in depth. Chapter 12: Maintenance Guidance 12-16 Curb Inlet#1: flow enters through curb channel. Curb Inlet#2: flow enters through drop curb. L r -- Pea Gravel Diaphragm: sheet flow enters and Grass filter strip: sheet flow enters and is is evenly distributed along the practice length. evenly distributed along the practice length. Figure 12.8 Bioretention Filter Inlets Triggers for Level 2 Inspection The most likely triggers for Level 2 Inspection of BR practices are: Water ponding on surface of practice for more than 72 hours after a storm event Bioslope does not drain properly Sparse or out of control vegetation Practice deviates from original design Erosion of inlets, filter bed or outlets Significant sediment accumulation Triggers for Level 3 Inspection The most likely triggers for Level 3 Inspection of BR practices are: Standing water caused by clogged or over compacted media Vegetation management needed Bioretention does not conform to original design plan in surface area or storage. Severe erosion especially when caused by subsurface defect Widespread significant and persistent sediment accumulation Chapter 12: Maintenance Guidance 12-17 12.2.5 Rainwater Harvesting RWH-1 Conveyance System Includes: Rain Barrels and Cisterns (RR-8) &Filter Components r � Key components to inspect for Rainwater Harvesting systems include the following: RWH-1 Conveyance System and Filter: The conveyance system is �^ all the components that collect and convey runoff from the roof ���� toward the storage tank. This typically consists of gutters and RWH-2 Storage Tank Zi downspouts, and sometimes additional drainage pipes. These �"►:��! components must be kept clear of debris in order to avoid blockages and spilling of runoff out of the gutters. The system should also be equipped with one or more ways of filtering water coming in from the conveyance system, such as screens, first-flush diverters, and/or ; vortex filters. RWH-3 Outlet RWH-2 Storage Tank: Many different types and sizes of tanks can _ --- -- be used for rainwater harvesting. They can be situated underground, Figure 12.9 Key Areas for Level 1 Inspection above ground, or even partially buried. The tank body has an inlet of Rainwater Harvesting Systems (and/or cover) and one or more outlet points for water to leave the tank. Advanced rainwater harvesting systems usually also have a - y� pump and a filter inside or outside the tank to further clean the stored - water and pump it to the point of use. n . RWH-3 Outlets: An above-ground rainwater harvesting tank usually has at least two outlets—one at the top of the tank where water overflows when the tank is full, and one near the bottom of the tank ti for delivering the stored water by gravity feed. Many filters also have an outlet pipe to divert the first flush of roof runoff away from the tank. , Level 1 Inspections Frequency: 2 times per year in early spring and fall prior to the tank being Figure 12.10 Inspecting the conveyance taken offline. Recommend two additional intermediate inspections per year, system, vortex-style filter. during or immediately following a storm. Triggers for Level 2 Inspection The most likely triggers for Level 2 Inspection of RWH practices are: - Tank not filling properly or water level drops quickly ~ " Tank is sinking, leaking or at risk of collapse Severe erosion at outlet Triggers for Level 3 Inspection The most likely triggers for Level 3 Inspection of RWH practices are: Structural or mechanical problems Problem requires practice redesign or modification Figure 12.11 Inspecting the RWH system top access port. Accumulation of debris in the tank that cannot be easily removed by hand Severe reoccurring erosion at the outlet or downstream drainage concerns Chapter 12: Maintenance Guidance 12-18 12.2.6 Porous Pavement Includes: Porous Pavements (RR-9), which covers porous versions of asphalt, concrete, pavers, concrete block, stabilized grid/cell systems, etc. Components Key components to inspect for porous pavement include the following: = PP-1 Drainage Area: The drainage area sends runoff to the Porous pavement area and is uphill from the Porous PP-2 Surface pavement. PP-2 Surface: The surface of the porous pavement should be r; ' relatively clean (not a lot of dirt and grit on the surface), free of cracks and broken pavement, and should NOT hold water after „ r a rainstorm for more than a few hours. : ,: - ',raw►�<, ��'- Level 1 Inspections Figure 12.12 Key Areas for Level 1 Inspection of Porous Pavement Frequency: 2 times per year in early spring and fall, to inspect for surface deterioration, spalling, etc. In addition, the surface should be ' inspected monthly to ensure that it is clear of debris and sediments and that it dewaters between storms(or after storms >0.5 inches). Triggers for Level 2 Inspection The most likely triggers for Level 2 Inspection of PP practices are: Extensive bare soil and erosion in the drainage area Sediment accumulating on the surface - �- Damage to the pavement surface 4111' Ponding water following storm events Triggers for Level 3 Inspection Figure 12.13 Winter salting, sanding, plowing, and snow storage can cause problems for porous The most likely triggers for Level 3 Inspection of PP practices are: pavement surfaces,which may trigger a Severe erosion in drainage area Level 3 Inspection. Subsurface water conveyance or soil stabilization issues Highly clogged pavement Solving the problem would require practice redesign or �� extensive regrading of the drainage area. _ w Figure 12.14 A Level 3 Inspection is warranted if more than 25%of the porous pavement surface appears to be clogged,joints are filled in, or vegetation is not growing (as shown in photo). Chapter 12: Maintenance Guidance 12-19 12.2.7 Green Roof r . i Includes: Green Roofs (RR-10), which covers extensive and intensive systems. Note: Green Roofs are unique in that they are often '�irF GR-1 Vegetation and Surface �� covered by a professional ongoing maintenance contract, and their design is highly variable depending on the system specified. ' vx , Components Key components to inspect for green roofs include - GR-2 Overflows the following: &Drains GRA Vegetation and Surface: The green roof ' vegetation usually consists of succulent plants, such as sedums, and should form a dense cover over the course of several growing seasons. Figure 12.15 Key Areas for Level 1 Inspection of Green Roofs GR-2 Overflows and Drains: Green roofs typically drain through a network of underdrains to outlet at roof drainage infrastructure. These drainage structures need to be inspected and cleaned periodically to ensure that the media drains properly. Level 1 Inspections Inspection Frequency: 2 times per year in early spring and fall. Maintenance Frequency: In the first 2 years of operation, green roofs shall receive routine maintenance on at least a monthly basis, to include watering, fertilizing, and weeding, see Chapter 11 for additional maintenance guidance. Once plants have become established, maintenance can be reduced to a frequency necessary to weed, remove invasive species, replace dying vegetation and maintain system components. It is also recommended that inspections occur during periods of drought, to water and ensure that vegetation is surviving. Triggers for Level 2 Inspection The most likely triggers for Level 2 Inspection of GR practices are: Unhealthy or dying vegetation Ponding caused by clogged outflow pipes or underdrains Minor damage to overflows Triggers for Level 3 Inspection The most likely triggers for Level 3 Inspection of GR practices are: Standing water caused by soil media or underdrain system Significant vegetation die-off requiring management Severe structural damage Roof is leaking Chapter 12: Maintenance Guidance 12-20 12.2.8 Ponds and Wetlands Includes: Micropool Extended Detention (P-1), Wet Pond (P-2), Wet Extended Detention Pond (P-3), Multiple Pond Systems (P-4), Shallow Wetland (W-1), Extended Detention Wetland (W-2), Pond/Wetland System (W-3), Pocket Wetland (W-4), Gravel Wetland (W-5) Note: It is strongly recommended to have as-built drawings and copies of previous inspections at hand, if available. Aerial photos may be needed to help direct the Inspector to the pond or wetland location if it is obscured by vegetation. Components Key components to inspect for ponds and wetlands PW-3 Ponding Area an d ' A include the following: Embankments PWA PWA Drainage Area: The drainage area conveys runoff to and is uphill from the inlet. f outlet r w TY P When it rains, water runs off through roof drains, yard drains, parking lots, roadways, and underdrains to the ponds. Flow is through underground piping systems, overland via swales, or across the ground as sheet flow. PW-1 Drainage ar PW-2 Inlets: Free, unobstructed flow from the F 4 : drainage area to stormwater ponds and , a��-, wetlands is necessary to prevent shallow .'Fi°''' v' flooding and even structural damage from PW-2 flooding. Inlets can consist of pipes, ditches, inlets swales, or other means to convey stormwater Figure 12.16 Key Areas for Level 1 Inspection of Ponds to the pond or wetland. PW-3 Ponding Area and Embankments: The ponding area and embankment can consist of the following elements: forebays, safety/aquatic benches, side slopes and permanent pools of water. PW-4 Outlets: The outlet enables the ponded water to discharge to downstream drainage systems or stream channels. The outlet is often at the base of the dam/embankment on the downstream side. Level 1 Inspections Inspection Frequency: 1 time per year in early spring. Recommend additional inspections following major storm events. Inspect the permanent pool and safety elements during every inspection. Maintenance Frequency:At least 2 times per year, the emergency spillway should be mowed and cleared of obstructions. Remove buildup of trash, vegetation, or sediment during every inspection. Triggers for Level 2 Inspection The most likely triggers for Level 2 Inspection of PW practices are: Extensive bare soil and erosion in the drainage area Manholes or inlet pipes buried or covered with vegetation Excessive sediment buildup or overgrown vegetation Triggers for Level 3 Inspection The most likely triggers for Level 3 Inspection of PW practices are: Severe erosion of the drainage area Buried or submerged manholes, pipes or other structures need to be located Excessive algae or aquatic plants Pipe or headwall settlement, erosion, corrosion, or failure Major sediment buildup Solving the problem would require practice redesign or extensive regrading of the drainage area Chapter 12: Maintenance Guidance 12-21 12.2.9 Infiltration Includes: Infiltration Trench (1-1), Infiltration Basin (1-2), Dry Well (1-3), Underground Infiltration System (1-4) Components Key components to inspect for Infiltration include the following: - INA Drainage Area The drainage area INA outlet - �~ conveys runoff to and is uphill from the infiltration cell. When it rains, water runs off and flows to the infiltration cell and soaks ^" into its underlying layers. r - IN-3 Infiltration Area IN-2 Inlets: The inlets are where water flows into the practice. Depending on the IN-2 Inlet design, inlets can include curb cuts, openings in a parking lot or roadway, downspouts, pipes, or ditches. Water can also enter the practice directly as sheet flow. Figure 12.17 Key Areas for Level 1 Inspection of Infiltration Practices IN-3 Infiltration Area. The area that collects water and allows it to seep into the underlying soil. IN-4 Outlets: Outlets are where water exits the surface of the infiltration area during larger storms when the underground infiltration reservoir fills up and the excess water needs somewhere to go. Note that not all infiltration practices will have an identifiable outlet if the design is for all the water to infiltrate into the ground. Outlets may be a berm, stone weir, or pipe. Level 1 Inspections Frequency:At least 2 times a year, especially in early spring, to ensure that the practice has survived the winter. Debris cleanout and dewatering inspection should occur monthly. Inspection of sediment traps, forebays, inlets and outlets should occur at least 1 time per year along with sediment cleanout and aggregate repairs. Triggers for Level 2 Inspection The most likely triggers for Level 2 Inspection of IN practices are: Water stands on the surface for more than 72 hours after a storm event Erosion of inlets, infiltration area or outlets Excessive sediment buildup Triggers for Level 3 Inspection The most likely triggers for Level 3 Inspection of IN practices are: Standing water caused by clogged media Severe erosion of infiltration area, inlets, or around outlets Reoccurring significant sediment accumulation that is getting worse with time Solving the problem would require practice redesign or modification Chapter 12: Maintenance Guidance 12-22 12.2.10 Sand Filters Includes: Surface Sand Filter(F-1), Underground Sand Filter SF-i Di;3iiti;ti�e Areti (F-2), Perimeter Sand Filter(F-3) SF-?inset Components - Key areas to inspect for these types of practices include ' the following: SF-1 Drainage Area: The drainage area conveys runoff to and is uphill from the filter. sF Filter Area SF-2 Inlets: Inlets to a filter are where water flows into the filter, such as curb cuts, downspouts, Figure 12.18 Key Areas for Level 1 Inspection of Sand Filters pipes, or ditches that carry water into the filter from the drainage area. Water can enter the practice directly through sheet flow. -- SF-3 Filter Area: The Filter Area is the area that collects water and allows it to seep into the filter media. Level 1 Inspections Inspection Frequency:All system components shall be inspected at least 1 time per year in early spring. Recommend an additional inspection in the fall to look for debris, vegetation, and water retention. Maintenance Frequency:Any grass cover should be mowed a minimum of 3 times per growing season, to Figure 12.19 Example Perimeter Sand Filter maintain a maximum grass height of 12 inches. Triggers for Level 2 Inspection 4% The most likely triggers for Level 2 Inspection of SF R 0'. tr practices are: Ponding water more than 72 hours after storm event Erosion of inlets, filter bed or outlets Excessive sediment buildup Triggers for Level 3 Inspection The most likely triggers for Level 3 Inspection of SF practices are: - " Figure 12.20 Example Concrete Perimeter Sand Filter(photo Standing water caused by clogged filter media shows the filter with the grate top off as the filter is being Need to pump out sedimentation chamber maintained. Sedimentation chamber filled with water is on the Severe erosion right, and the sand filter chamber is on the left. Severe sedimentation Response to fuel or other spills that make it into the filter Subsurface defects with underlying soil Solving the problem will require practice redesign or modification Chapter 12: Maintenance Guidance 12-23 Section 12.3 Diagnostics and Maintenance Measures This Section summarizes the most common problems found in SMPs, as well as typical maintenance or repair solutions. The guidance provided in this section has some similarities to Section 12.2, but differs in the following ways: 1. The primary audience of this Section is the Level 3 Inspector, who is tasked with diagnosing and repairing SMPs that are not working properly. However, this information may also be useful for a Level 2 Inspector seeking to diagnose a particular problem. The maintenance measures described in this Section are more detailed and focus on repairs to specific problems rather than on routine maintenance, such as weeding or minor sediment removal. Because the problems described in this section can be applied to several different practices, this section is organized by the problem type rather than the practice type. Common problems addressed during Level 3 inspection/maintenance are summarized in Table 12.9. This list is not exhaustive but does address SMP issues that require some advanced knowledge and skill to inspect and diagnose solutions. Each problem category is discussed in a separate subsection. Table 12.9 Common Level 3 Inspection/Maintenance Issues Subsection/Category Description Contributing Drainage Area—Pollutant Sediment or pollution sources in the Drainage Area Sources Physical Obstructions Physical obstructions to maintenance access, overflow, or emergency spillway Erosion Erosion on side slopes, practice bottom, at inlet or outlets. Rills and gullies forming where there should be sheet flow Departure from Design Dimensions Practice dimensions have been altered, either due to filling with sediment, redesign or filling in, or improper implementation. 12.: Improper Flow Paths Flow is short-circuiting the practice, or drainage flow paths have been otherwise modified. 12. Sediment Buildup Sediment has accumulated in a pool, practice bottom, pretreatment area, or vault. 12.3.7 Clogging The filter media or other components are clogged, and there may be standing gg g water for longer than intended. 12.3.8 Vegetation Excessive, inadequate, and/or unhealthy vegetation to support a practice 12.3.9 Embankment and Overflow Condition Issues with an embankment or overflow weir or channel 12.3.1C Structural Damage SMP infrastructure, such as concrete or metal elements, have been damaged. 12.3.11 Pool Stability Permanent pool of water is at the improper elevation. 12.3.12 Pool Quality Permanent pool of water suffers from poor quality due to algal growth or other issues. Chapter 12:Maintenance Guidance 12-2 12.3.1 Contributing Drainage Area — Pollutant Sources Applies Most Commonly To: Sheet Flow/Disconnection, Swales, Bioretention, Porous Pavement, Ponds/Wetlands, Infiltration, and Sand Filters. Problem General Approach for All Practices: Identify the specific source(s)of sediment in the drainage area by tracking sediment flow during a rainfall or looking for a track of sediment staining during dry weather. For an active sedimentation event, attempt to filter incoming runoff if conditions allow(e.g., enough space upstream of the practice for temporary ponding). Consider installing a silt fence, silt socks(at curb inlets), staked straw bales, or other filtering material at the inlets of the SMP. This will keep at least some of the sediment from getting into the practice. Runoff from active construction should not enter the SMP; divert to a temporary and approved sediment control practice. For areas of bare soil not due to active construction (bottom photo), prep the soil and re-seed/plant with grass species or other thick ground cover appropriate for the region. May also need starter fertilizer,topsoil, and/or compost. 4 For steep slopes with bare soil, consider also installing erosion-control matting to hold soil, seed, and straw in place until the vegetation becomes well established. For fill and topsoil stockpiles in the drainage area, provide temporary or permanent cover as soon as possible. Alternatively, surround the base of the stockpile with silt fence, or equivalent,to prevent the transport of sediment-laden runoff. r,. tirrt. .a .. .... Helpful Skills: Erosion and sediment control knowledge and skills Landscaping knowledge to understand appropriate ground cover species for re-vegetating bare areas Equipment Typically Used for Fixing Sediment Sources: Silt fencing and other sediment barriers Erosion-control matting and/or straw Rakes and shovels Light excavation or grading equipment for largerjobs Equipment to deliver topsoil or compost as needed Plants and/or seed mix, plus a way to move and store plant stock without damaging it or drying it out Starter fertilizer, topsoil, and/or compost Chapter 12: Maintenance Guidance 12-2 Problem #2: Other pollution sources in the drainage area General Approach for All Practices: Pollutants may include: road salt, oils, fuels, food grease, wash water, paints and solvents, trash, and many others. Identify the source(s)of pollution. —Jf For pollutants spilled on the ground, remove by hand or use absorbents to I ,. soak up wet material. Absorbents and other waste materials shall be disposed of properly. ` For materials stored outside, move them to a covered area or build/add cover over the materials. Provide secondary containment, if possible. 41�� Make sure all waste containers have lids and fix any leaks(see improper If practice in photo at right). For sites prone to frequent oil leaks and staining (e.g., vehicle maintenance "� - yards), consider installing an oil/water separator to pre-treat runoff that k - enters the SMP. For routine dumping of wash water, grease, paints, or other pollutants, enforce behavior change and explain good housekeeping practices. Develop a pollution prevention plan for the site to ensure that hazardous materials and other potential pollutants are not stored where they are exposed to rainfall. For areas that receive a heavy salt and/or sand load during the winter, consider diverting upslope runoff, especially for practices such as porous pavement. Some monitoring of winter road or parking lot clearing activities may also be warranted. Helpful Skills: Knowledge of good housekeeping and pollution prevention practices Good communication with employees and managers at site (e.g., for correcting bad site operations) Equipment Typically Used for Correcting Other Pollutant Sources: Tarps to cover stockpiles Absorbents to soak up spills Secondary containment barriers that will hold back any liquids or solids that may leak out of their primary container Storage barns, sheds, pole barns and other permanent cover for potential pollutants Chapter 12: Maintenance Guidance 12-26 12.3.2 Physical Obstructions Applies Most Commonly To: Sheet Flow/Disconnection, Swales, Bioretention, Rainwater Harvesting, Green Roofs, Ponds/Wetlands, Infiltration, and Sand Filters Problemobstructeff Ground-Level SMPs: Where a path for vehicles and construction equipment to access the practice was established during construction but is now overgrown, remove woody vegetation and any other tall vegetation. This path should i be bush hogged once or twice a year. If the SMP needs a large quantity of trash and/or sediment removed in areas where access is limited due to steep grades, overgrown vegetation, etc., it will be necessary to establish safe vehicular access by _ clearing and possibly re-grading the area. It is advisable to have a maintained, all-weather surface to critical parts of the SMP. • It is most important to provide access nearest to parts of the practice where sediment and trash tend to accumulate the most: forebay and outlet control structure. For an SMP blocked by fences(photo at right), install a gate that is wide enough for vehicles to enter for any current or future maintenance. Sometimes access is blocked by unauthorized structures, such as sheds, property fences, retaining walls, etc. Confer with the local stormwater authority on the presence of any maintenance easements and means to gain access to the practice. The solutions above should also provide for safe foot access for routine inspection and maintenance. Rainwater Harvesting: Ensure that no structures are covering the filter or the tank's access/inspection port. Green Roofs Ensure that individuals can safely reach the roof with tools in hand (e.g., buckets, pruners, hoses). If the roof cannot be accessed via a walk-through door, this may require installing a wide ladder or fire escape-style stairs on the inside or outside of the building. If there is a concern of getting too close to the roofs edge while doing maintenance, install a railing around the edge for safety. Alternatively, for sloped roofs, workers may need to use harnesses during maintenance activities. Helpful Skills: Use of motorized landscaping equipment Chainsaw skills Use of grading equipment for larger jobs Note: OSHA safety requirements and certifications may apply to green roof maintenance. Equipment Typically Used to Regain Proper Access: Mower, trimmer For very overgrown areas, chainsaw and/or bush hog For areas that need to be regraded, excavator, skid steer, or other grading equipment Chapter 12: Maintenance Guidance 1 -27 Problemobstructed General Approach for All Practices: tr r Flow can bypass an SMP when there is too much sediment/debris buildup near the inlets or due to grading changes in the drainage area(e.g., repaving of parking lot).If the cause of blockage or bypass is not obvious, inspect the practice during rainfall to watch the flow paths. (See Section 12.3.5 for additional guidance.) Obstruction of overflow or emergency spillway structures is most often due to buildup of debris, such as trees, sticks, trash. It is very important to keep these structures clear of such blockages in order to avoid flooding or a dam breach (avoid conditions caused by beaver activity -top photo). Where debris cannot easily be cleared by hand, special equipment and skills may be needed. An obstructed outlet control structure in a wet pond may need to be accessed by boat(bottom photo). In cases where large sticks, tree branches, trash, or other debris obstruct the overflow or n, �,k j,`- spillway, they may need to be cut up by chainsaw. Large ;t debris will usually need to be hauled away with a truck. ' "` - - Helpful Skills: Chainsaw skills Muscle strength to haul large debris Boating capabilities Equipment Typically Used to Clear Obstructions: Gloves, shovels, pruners, rakes, and other hand tools Waders for wetlands Chainsaw for large sticks and branches Cable puller(come-along)to remove large branches that cannot be pulled out by hand Boat and personal floatation device for outlet control structures in wet ponds Truck to haul away debris Chapter 12: Maintenance Guidance 12-2 12.3.3 Erosion Applies Most Commonly To: Sheet Flow/Disconnection, Swales, Bioretention, and Ponds/Wetlands Problem: outlets General Approach for All Practices: See Section 12.3.9 for how to repair erosion on side-slope embankments. Rill and gully erosion occur when runoff flow is concentrated. Deep rills and gully erosion on the practice surface (top photo)will require the surface to be regraded to make uniform again. Use the lightest equipment possible in order to minimize soil compaction during excavation. {At After excavation, reseed/plant the area with ground cover that is appropriate for the moisture conditions of the practice. Amend or enhance soil as needed according to a soil test-, soil may need more organic material to support plants. • To prevent further erosion on the surface of the practice, ensure that flow from the inlets can spread out adequately and has enhanced energy dissipation features. This may require installing or enhancing a stone apron outlet protection that flares out and down to the level of the practice to slow and spread out the flow. Other options include check dams, energy dissipation devices, or an armored low-flow channel. A stilling basin (bottom photo)can also dissipate flow as it comes out of an inlet or outlet !pipe. Apply similar treatments to any outlets that are experiencing erosion. Any sloped soils that are disturbed during excavation will likely need erosion-control matting to hold it in place while vegetation becomes established. Helpful Skills: Landscaping/Gardening Consult with Cooperative Extension Office or independent laboratory for soil testing Skills with excavation equipment Knowledge of sediment and erosion control practices and resources appropriate for the area Equipment Typically Used for Fixing Erosion: Rakes, shovels, wheelbarrows, and other"landscaping"equipment Light excavation or grading equipment for largerjobs Equipment to deliver, unload, and move stone and other materials around Plants and/or seed mix, plus a way to move and store plant stock without damaging it or drying it out Chapter 12: Maintenance Guidance 12-29 12.3.4 Departure from Design Dimensions Applies Most Commonly To: Swales, Bioretention, Ponds/Wetlands, Infiltration, and Sand Filters Problem: General Approach for All Practices: Once constructed, the dimensions of an SMP may become altered from the original design for a variety of reasons. These reasons can include: The SMP was not constructed to the proper dimensions at initial ` installation. F Sediment accumulation in the SMP reduces the intended storage volume of the practice (top photo). . z Redevelopment or regrading of the site encroaches into the footprint of the SMP. • Dumping of leaves, trash, or other debris into the SMP reduces the intended storage volume of the practice. • If it appears that the dimensions of an SMP have been altered, proceed as follows: Consult the original design or as-built plans and sizing computations for the SMP to identify the intended dimensions and storage volume of the - practice. Measure the length,width, and depth of the practice to estimate the current storage volume. Calculate the difference in volume to determine whether it is significant enough to warrant restoring the practice to its original dimensions. If the loss in volume is greater than about 10%, this likely warrants action. If the SMP's original storage volume cannot practically be restored because of current site conditions, an additional SMP may need to be built elsewhere on the site in order to regain adequate storage and treatment volume for the site. For problems of dumping by individuals on or near the site, install"No Dumping" or similar signage to inform people that this is not an appropriate place to dispose of debris. Any debris that has already been dumped should be removed from the practice either by hand or with equipment. Helpful Skills: Basic surveying Understanding stormwater design plans and sizing computations • Stormwater management design Skills with excavation equipment and erosion and sediment control Equipment Typically Used to Investigate and Fix Dimensions: Simple level or survey equipment, tape measure, and other tools to measure SMP dimensions Light excavation or grading equipment for larger jobs Rakes, shovels, wheelbarrows, and other"landscaping"equipment for small jobs Soil stabilization materials Chapter 12: Maintenance Guidance 1 -30 12.3.5 Improper Flow Paths Applies Most Commonly To: Sheet Flow/Disconnection, Swales, Bioretention, Rainwater Harvesting, Infiltration, and Sand Filters Problemg• into a practice is diverted by debris or grit buildup or capacity Bioretention,Swales, Infiltration,Sand Filters: • Grit, sediment, leaves, and other debris builds up at curb inlets or other inlets, sometimes to the point where flow is diverted completely around the practice(photos above). This is a common issue for practices that rely on curb cuts or other small inlet structures to get water into the practice for treatment. A minor amount of debris may be OK and not affect the ability of water to enter the practice. However, be aware of conditions where flow that is supposed to be treated is diverted to a downgradient storm drain or other structures in such a way that the stormwater treatment is entirely or partially bypassed. • In many cases, correcting the problem may simply involve removing debris or unclogging the inlet. • However, this problem can be chronic if the inlet design is susceptible to clogging. This can occur if the slope from the inlet into the practice is flat and/or there are controllable sources of sediment and debris in the drainage area. • For chronic problems, consider redesigning inlets to be more clog proof. One solution is to build in a 2 to 3"drop from the curb inlet onto a gravel or stone diaphragm along the edge of the practice(see example in photo at right). ` • Inlets that are undersized for the flow coming to them should be enlarged and armored with an appropriate erosion-resistant lining. Rainwater Harvesting: • Water intended to be collected in rainwater harvesting systems is sometimes a not delivered to the tank or cistern if the system of gutters, downspouts, pipes, - etc. is not sized properly or if the first-flush diverter or vortex filter is not functioning correctly and diverting too much water away from the tank. • As with inlets, this may simply be a matter of routine cleaning of gutters, downspouts, vortex filters, etc. • It may also be a design or capacity issue, in which case, installing larger gutters or a more robust piping system may be in order. Source: Rainwater Management Solutions 1 Example of enhancing the gutter and piping system leading to a rainwater harvesting system Helpful Skills: Basic surveying Typical landscaping skills using materials such as soil, rock/stone, edging material, mulch, etc. Light construction of gutters, downspouts, piping Some knowledge of first-flush diverter and vortex filter products Chapter 12: Maintenance Guidance 1 -31 Problem Bioretention,Swales, Infiltration,Sheet Flow and Disconnection,Sand Filters: Improper flow path issues in this category include: These three issues are illustrated below: Water forming channels or rills through the treatment bed of bioretention, swales, infiltration, or surface sand filters, and thus not spreading out across the treatment area surface Water ponding only at one end of the treatment area because the surface is not level Water piping through weak spots to an outlet or underdrain, such as where filter media meets a concrete structure Water from the inlet at top of photo is channeling See Section 12.3.3 for issues of channeling or erosion on the through the bioretention area. treatment surface. For uneven treatment area and preferential ponding, assess they,. v , severity of the problem. Compare the relative elevations of the "high" part of the treatment area(the area where water does not ? seem to pond)and any overflow structure or weir where high water flows will leave the practice. If there is still some freeboard __ �•;;, ,,, (such that the overflow structure is higher than all of the treatment bed surface), then there will still be some ponding for larger rainfall events. Try some minor raking or moving filterir media and mulch around to even out the filter bed. However, the problem is more serious if parts of the treatment area are higher than the overflow structure. These areas will never be valuable for treatment purposes. The treatment area is [" supposed to fill up like a bathtub, so some regrading is needed to Water is preferentially ponding only at one end of level out the treatment area. the bioretention because the surface is not flat. • If water is piping or short-circuiting through the soil or filter medial forming sinkholes, or otherwise bypassing the intended treatment mechanism, it will be necessary to repair these spots. Around ti . concrete or metal overflow structures, use soil material right around the structure that can be compacted (bioretention filter media tends to be light, sandy, and fluffy and won't compact very well). Another option is to"ramp up"the soil layer to the lip of the structure so that there won't be a hydraulic jump at this potentially weak point. See the figure below. *`* -3 4 Water is "piping"down to the underdrain at the weak spot where the filter media meets the concrete overflow structure. Chapter 12: Maintenance Guidance 12-32 PROVIDE MINIMUM OF 1'OF FREEBOARD FROM DI TOP TO RAMP SOIL LAYER UP TO TOP OF BERM.STRUCTURE MUST LIP OF STRUCTURE OR PASS IQ-YEAR STORM WITHOUT PROVIDE STONE PROTECTION TOPPING BERM TRASH RAC3C AROUND STRUCTURE SEE NOTE UP Ram u soil layer the lip of the structure to address this �;�,�.,,�••'�-ass ,•���-i=�.,, ;� p p Y ,• �. y� •'�,.X being a weak interface where water can work down and create bypassing. Source: Virginia 2013 Stormwater BMP tit.., „ Yp 9� ( 9� _44 s_r" ; Specifications, Specification#9, Bioretention, Figure 9.13.) NOTE! AS AN ALTERNATIVE TO THE TRASH RACK,AN OVERFLOW STRUCTURE MAY BE A DROP INLET WITH A BAR GRATE. Impervious Disconnection: The most likely flow path issues with Impervious Disconnection are: (1)owners intentionally diverting downspouts away from pervious area and onto impervious area(left photo below), and (2)slight grading issues diverting the water away from the intended pervious receiving area (right photo below). I� Both issues are fairly straightforward to address but involve communicating and working with property owners to explain the purpose of disconnection and how to properly maintain it. The second issue may involve some minor regrading or building low-profile berms to get water to flow to the intended disconnection area. Helpful Skills: Rudimentary surveying Typical landscaping skills—using materials such as soil, rock/stone, edging material, mulch, etc. Equipment Typically Used for Inspecting and Fixing Flow Paths Surveying equipment(i.e. Site level or total station)to get relative elevations among different parts of treatment area, inlets, overflow structures, etc. Small, simple tools—flat shovels, wheelbarrows, rakes, other common landscape/gardening tools Large, more complicated equipment—small excavators to move material around or do regrading. Always work from the side of the practice and NOT within the practice itself. Chapter 12: Maintenance Guidance 12-33 12.3.6 Sediment Buildup Applies Most Commonly To: Swales, Bioretention, Porous Pavement, Ponds/Wetlands, Infiltration, and Sand Filters Problem: Bioretention,Swales: • Determine the source(s)of sediment. The most likely sources are: (1) premature installation of the practice during the construction process and discharge of construction site sediment loads; (2)erosion in the contributing drainage area after construction is complete; and (3)erosion along the practice side slope or within the practice itself. If it is an ongoing source, it must be abated (see Section 12.3.1, and Section 12.3.3). • Use a soil auger to auger holes in various places across the Bioretention or Swale surface area, especially in areas where sediment is accumulating. Determine how deep the sediment is penetrating into the filter media layer. Usually, it will be the top 2 to 3"that are most affected. Note that for swales without an engineered filter media, the sediment layer will likely be confined to the surface. • Remove the"fouled"filter media to the affected depth (using flat shovels or small excavators and working from the side)and replac( with clean material from an approved vendor(bioretention filter media or equivalent). If no vendors are available in your area, use the filter media specifications from the Design Manual to replicate the right mix of sand, topsoil, and composted organic material. • Check to ensure that the practice is filtering at the proper rate after the next several storm events. Infiltration: • For infiltration practices excavated to a suitable infiltrating soil layer(e.g., not stone reservoir layer), use the same procedures as for Bioretention/Swales above. • For infiltration trenches and basins that have a stone reservoir layer, use similar procedures, but use a shovel to dig into the stone layer to ascertain how deep the sediment incursion is into the stone. Remove down to this layer and replace with clean material. • If the infiltration practice is clogged, see Section 12.3.7. • As with Bioretention, check for controllable sources of sediment in the Drainage Area(Section 12.3.1). Porous Pavement: • NOTE: Routine sweeping with a regenerative air vacuum(max. power 2,500 rpm) is important to avoid more costly repairs that result from deferred maintenance. It is best to sweep the pavement surface in early spring after winter sanding/salting materials or snow piles have led to sediment or winter slag accumulation. If the area is surrounded by tree canopy, fall cleanup is essential, as vegetative debris is broken up by vehicle traffic and ground into the pavement surface. • Observe the pavement surface during a storm event to see whether the sediment is clogging the pavement(i.e., standing water on the surface after the storm stops). If so, see Section 12.3.7. • Remove several of the paver blocks in different parts of the structure to ascertain how deep the sediment is penetrating into the bedding and reservoir layers. Most ` of the time, sediment incursion will be limited to the top 1 or 2" of the pavement bedding layer(for porous interlocking concrete pavers and concrete grid pavers). Infiltration test using ASTM C-1781 • Based on the above observations, it may be worthwhile to quantify the infiltration rate using ASTM C-1701 and ASTM C1781. This is most useful in conducting the test in the same place within the pavement surface through the course of several years to document reduction in infiltration rates. Repair or restorative sweeping is warranted when infiltration rates drop below around 10" per hour. NOTE: As stated above, this can likely be avoided if routine annual sweeping is conducted. • If sediment covers more than 25%of the surface, is deeper than 2", or vegetation is starting to grow where sediment has accumulated, consult a street-sweeping vendor about restorative sweeping. In this case, it will be necessary to use a higher RPM sweeper or vacuum sweeper to suck out more of the bedding pea gravel that has been fouled,then replace with clean material. • Vegetation growing in pavement joints should be removed either manually or with a water-safe herbicide (e.g., glysophate without surfactants). It is important to not let weeds proliferate in the pavement surface because pulling them out by the roots may damage the pavement structure. (Note: The application of herbicides Pulling grass and weeds from the joints can within wetlands or other waters of the U.S. may require an Aquatic Pesticide damage parking surface if roots are firmly Permit from the NYSDEC) established in the bedding layer. Chapter 12: Maintenance Guidance 12-34 • Check the pavement surface after a storm event to ensure that it is draining - properly. The North Carolina State University(NCSU)Stormwater Engineering Group has an informative Urban Waterways publication, Maintaining Permeable Pavements(2011). • Routine, air-vacuum sweeping in the early spring and fall is the best approach for porous pavement maintenance(Photo source: Toronto and Region Conservation) Ponds and Wetlands: • Sedimentation is an inevitable process in ponds and wetlands. NOTE that upstream erosion, especially along stream channels or ditches leading to the practice will accelerate the sedimentation process and lead to more frequent and costly sediment removal operations. Whenever possible, it is important to mitigate any upstream erosion issues. • Forebays and/or pre-treatment areas should be cleaned out when they reach 50%of their design capacity. Once cleanout is complete, it will be worthwhile to install a graduated rod into the forebay with a clear marking of future sediment clean-out levels. • The main body of a pond or wetland may need to be dredged on an infrequent basis or when sediment has replaced 50%of the design capacity. There are many dredging methods available. Excavators with long arms can handle most small or moderate-sized ponds. Other methods may be necessary for larger facilities. Dredging can be a complicated operation involving dewatering,storage of wet sediment, and possibly hauling to on-site or off-site disposal or refuse areas. Consult a qualified contractor to explore available methods and costs for the particular application. Once again, installation of a graduated rod can help mark future clean-out levels. Note: The dredging of accumulated sediment within regulated wetlands, ponds or at outlet structure may require permits from NYS DEC and/or USACE. In addition, removed sediment should be properly disposed of in a regulated solid waste management facility or in an upland area that is at least 100 ft from regulated wetlands or streams. Sediment managed in upland disposal areas shall be graded, seeded, and mulched. Sand Filters: • See the section above on Bioretention/Swales as some of the procedures will be similar, especially for above-ground filters. It is important to determine whether the �"M! drainage area is generating a controllable source of sediment that can be abated. • Underground trench or vault filters will require routine maintenance to: (1) remove ` accumulated sediment, trash, and floatables from the sedimentation chamber, usually with a vac truck; and (2) remove sediment, grit, and sludge from the top layer of the filter media and replace with clean material. NOTE: Depending on the configuration of the underground filter, confined-space procedures may apply. For a normally operating practice, these maintenance tasks should be conducted every two to three years. If the filter is treating a stormwater hotspot or a particularly dirty drainage area(e.g.,vehicle maintenance, washing, repair), the mammal, frequency may increase to annually or more often, as dictated by Level 2 Routine cleaning of a perimeter or inspections. Also, in these cases, it may be warranted to test the material to "Delaware"sand filter. This can be done ensure proper disposal. from the surface, but deeper, vault-type • Some proprietary filters require replacement of special cartridges or filter material. filters will require confined-space entry Consult the vendor or manufacturer for special maintenance procedures. procedures. Chapter 12: Maintenance Guidance 1 -3 Helpful Skills: • Most common contracting skills • Excavation, dewatering, and sediment disposal in some cases • Knowledge of maintenance equipment, such as vac trucks, street sweepers, etc. • Knowledge of preferred conditions for bioretention filter media • Soil testing in some cases where sediment is being removed from stormwater hotspots Equipment Typically Used for Sediment Removal Activities: • Small, simple tools—flat shovels, wheelbarrows, rakes, other common tools • Larger jobs—small or large excavators, loaders, dewatering equipment(pumps, dirt bags, etc.),trucks to haul material to on-site or off-site disposal or reuse areas, erosion and sediment-control supplies. 12.3.7 Clogging Applies Most Commonly To: Bioretention, Porous Pavement, Infiltration, and Sand Filters Problem: clogged; storm Bioretention: Standing water on the bioretention surface 48 to 72 hours after a storm event is a sure indication of clogging (top photo). Clogging of bioretention practices can be tricky to diagnose as there are several probable causes: a. Clogged underdrain b. Filter fabric between filter media and underdrain stone c. Sediment/grit buildup at surface d. Erosion of contributing drainage area e. Improper filter media k. The following procedure can be used to work through diagnosing the most f common causes, beginning with the simplest and easiest to fix and progressing through more complex remedies: 1. Look for a thin, crusty layer of sediment that covers some or all of the filter media. It is often grayish in color. This thin layer can sometimes be enough to cause slow drainage. Scrape this crust off and ascertain sources of sediment in the drainage area(see Section 12.3.1). Often, this problem can - be caused by the bioretention filter media being installed too early in the F construction process, but other chronic sediment sources should also be checked. 2. Open the underdrain cleanout and pour water in to verify that the - underdrains are functioning and not clogged or otherwise in need of repair. The purpose of this check is to see whether there is standing water all the way down through the soil. If there is standing water on the surface, but not in the underdrain, then there is clogging somewhere in the soil layer. If the underdrain and cleanout have standing water and there is not water coming out the other end (outlet)of the underdrain pipe,then the underdrain is - clogged and will need to be rooted out. 3. Use a soil auger to auger several holes down through the filter media to the underdrain layer(if present)or underlying soil. Check to see whether there is a layer of filter fabric at the bottom of the soil layer. The auger will pierce through any filter fabric that is present, and pieces of fabric in the auger bucket should be removed. Notice if the fabric is"blinded" or clogged with sediment. This is a common issue with older bioretention practices. If the practice has a clogged the filter fabric layer, go to step#6, install wick drain. 4. While checking for filter fabric in auger holes, also note whether there is a layer of saturated filter media or bad filter media(e.g., too much clay content)that may be on top of a good media layer. This will be fairly obvious as the top 3 or 4"will be mucky and saturated,with dry and sandy media below. If this is the case, it will be necessary to remove the bad material and replace with good, clean bioretention filter media in accordance with the design specifications. Till or incorporate the good material into the underlying existing filter media to establish a good contact. 5. If the entire profile of filter media is bad, has too much clay content, or does not appear to meet the specifications for filter media, it will be worthwhile to test the soil and compare against the recommended specifications(e.g., clay content, particle sizes, etc.). If the soil does not meet specifications, see steps#6 and#9 below. Chapter 12: Maintenance Guidance 12-36 6. If the problem appears to be filter fabric or bad filter media(steps#3 or#5 above), there is a critical decision to be made. It is an expensive proposition to dig up the entire facility to either remove the filter fabric or replace the entire soil layer. If the clogging problem is not severe in nature, an intermediate(and much cheaper)option may be to install wick drains. Using a 6" auger bucket, auger numerous vertical holes around the practice surface area, making sure to auger all the way down to the underdrain stone or underlying soil (if there is no underdrain). Hammer 6" perforated PVC or other type of pipe into these holes. Perforations should be about 3/8" diameter. Fill the pipes with clean underdrain gravel (#57 stone)mixed in with coarse construction sand. These drains will serve to wick fines from the surrounding filter media and will provide alternative drainage. Check after the next several storm events to see whether the wick drains improve drainage. 7. Sometimes the cause of saturated filter media is springs or -_ some type of baseflow coming into the practice. This is a more W71h r difficult problem as bioretention is not supposed to receive this type of constant flow. It will be necessary to identify and reroute springs or baseflow or perhaps replace the bioretention practice with a different type of practice. 8. Another possible source of poor drainage or clogging is that there can be too much water on top of the filter media when the bioretention practice fills up. Most specifications call for a maximum ponding depth of 12", but sometimes the ponding 1 ? depth can be 18 or even 24".While this increases the amount of head pushing water down through the filter media, it can also lead to compaction or too much sediment building up. If the bioretention practice has a ponding depth greater than 12", consider configuring the outlet or large storm overflow to reduce the ponding depth to 12" or less. Check with the local stormwater authority to ensure that doing this will not compromise the required treatment volume of the practice. Adding sand to a wick drain. The vertical perforated PVC pipe has already been placed in the auger hole. 9. If clogging is too severe to be fixed with wick drains or other remedies listed above, it may be necessary to rebuild the bioretention practice by digging up the existing soil, taking out any filter fabric that is between the filter media and underdrain stone, and rebuilding and replanting according to the design specifications. 10. Whatever the chosen remedy, check to ensure that the practice is filtering at the proper rate after the next several storm events. The Chesapeake Stormwater Network(CSN)has produced an excellent reference guide for inspecting and diagnosing Bioretention issues, Technical Bulletin #10, Bioretention Illustrated. This tool can be used as an additional reference and can be downloaded using this link: http://chesapeakestormwater.net/catego[y/publications/ Infiltration: • Clogging of infiltration practices can be simple to resolve or fatal: • On the simple side, clogging (or poor drainage) may arise from sediment, vegetative debris, parking lot grit, or other debris clogging the top few inches of soil or stone. • With luck, the practice will have an observation well (vertical perforated PVC pipe with cap that extends through the stone reservoir in an infiltration trench or basin). Check the observation well three days after a storm event of/2" or more. If water is standing in the observation well to the surface, then the whole profile may be clogged (see below under fatal). If the observation well has only a few inches or no water and there is still water standing on the surface, then surface clogging is a likely culprit. • For infiltration practices in soil(no stone reservoir), auger several holes around the infiltration surface area. If saturated soil seems to be on top of good, clean, dry soil,then surface clogging seems likely. • For infiltration trenches and basins with a gravel reservoir, dig several holes around the surface to determine, again, whether there seems to be a layer of gravel clogged with sediment, leaves, vegetative debris, parking lot grit, etc. If possible, dig down to where the gravel meets the underlying soil to see whether a layer of filter fabric is present(which may be common with older practices). If this is the case, blinding of the filter fabric may be a cause of the clogging. • For surface clogging, remove the affected material down to the level where the soil or gravel seems clean, and replace with clean material. If filter fabric seems to be a problem, it will be necessary to dig up the gravel, remove the filter fabric, and rebuild the reservoir layer in accordance with the current design specifications. In either case, check after a storm event to ensure that this has resolved the issue. • On the fatal side,the underlying soil may not be suitable for infiltration, either due to soil characteristics,compaction during construction, or other causes. Check the original design package to see whether any soil testing was done at the time. It may be worthwhile to auger down to the infiltration interface layer(e.g.,where stone reservoir meets the underlying soil and then another several inch es below this interface), and take several soil samples for lab analysis to compare to current soil specifications(see information below about infiltration soil analysis). • It may be that a geotechnical analysis would reveal that there is a good infiltration soil layer, but it is lower than the existing Chapter 12: Maintenance Guidance 12-37 interface. This would still require a complete rebuild and excavation down to the suitable soil layer. Restoring porosity at the designed elevation would require replacing soil above this suitable layer and avoiding compaction. • Another option would be to convert the practice to a bioretention practice with an underdrain. Check with the local stormwater authority to see whether this would require any site plan or stormwater plan amendments or other permits. • Many updated state stormwater manuals and specifications include protocols for infiltration soil testing and analysis that reference various ASTM standards. For example, see: Virginia 2013 BMP Standards &Specifications, Specification #8:Infiltration, Appendix 8-A, Infiltration and Soil Testing. Porous Pavement: • As noted in Section 12.3.6, routine sweeping with a regenerative air vacuum (maximum power 2,500 rpm) is important to avoid more costly repairs that result from deferred maintenance. Preventative maintenance is the best and most cost-effective way to prevent clogging in the first place. • If there is standing water on the pavement surface 48 to 72 hours after a storm event of/2' or more, then the pavement surface is clogged. • Check the design plan or as-built plan to see whether the porous pavement design includes an underdrain. There may also be underdrain cleanouts at the edge of the porous pavement. • If there is an underdrain, the first thing to check is whether the underdrain is clogged, crushed, or broken. Check to see whether there is standing water in Water standing on the parking surface 48 to 72 the underdrain cleanout 48 to 72 hours after a storm event. If the underdrain is hours after a storm is an indication of clogging. dry, pour water into the underdrain with a hose and see whether it comes out Snow piles at the edge of the photo point to the other end. If the underdrain is clogged, snake it out, as this is the first and possible clogging from winter sanding or easiest thing to try. plowing. • If the underdrain is working, then clogging may be due to: (1)clogged surface or bedding layer; or(2)underlying soil is not suitable for infiltration for designs with no underdrain. First, refer to the guidance in Section 12.3.6, and then proceed as follows: • If there is no underdrain and the design is based on soil infiltration under the pavement, it will be worthwhile to check the soil because unclogging the surface layer will likely not fix the problem. Check the original design package for any soil infiltration testing. It is likely worthwhile to remove the entire pavement section in several places down to the soil layer and to do a geotechnical investigation of the soil profile. See: ASTM C-1701/1701M and/or Virginia 2013 BMP Standards&Specifications, Specification #8:Infiltration, Appendix 8-A, Infiltration and Soil Testing for examples of soil infiltration protocols(URL above). • If the soil is not suitable for an infiltration design, it will probably be necessary to rebuild the pavement using an underdrain design or possibly adding subsurface drainage along the perimeter of the parking area. • If there is an underdrain or the soil is suitable for infiltration, the best approach to try to unclog the pavement is restorative sweeping with a vacuum sweeper. Regenerative air sweepers may not have enough suction to relieve the clogging. • If vacuum sweeping is not successful, it may be necessary to rebuild any layers fouled with sediment and fines. It is likely that this will be confined to the bedding layer and gravel used in the paver stone joints, but some clogging can possibly move down into the underlying stone reservoir layer. • The North Carolina State University(NCSU)Stormwater Engineering Group has an informative Urban Waterways publication, Maintaining Permeable Pavements(2011). Chapter 12: Maintenance Guidance 12-38 Sand Filters: See the section above on Bioretention/Swales as some of the procedures will f - be similar, especially for above-ground filters. Also see Section 12.3.6 for guidance on routine maintenance of the r, F sedimentation and filter chambers. As with Bioretention,there can be various causes for clogged filters: Filter fabric layer under the filter media that has blinded or clogged Clogging of the surface of the filter layer or filter cartridges ' Bad filter media(e.g., sand media) "Plumbing" issues with configuration of overflow and underdrain pipes Fortunately, filters are usually confined within concrete vaults or manholes, so Standing water on the parking lot is evidence diagnosing and rectifying clogging problems should be more straightforward. that this perimeter sand filter(under the Check the original design or as-built plans. Some of the following guidance may sidewalk)is clogged. also be helpful: For proprietary cartridge or special filter media structures, consult the vendor or manufacturer for recommended solutions. See Section 12.3.6 for guidance on removing the top layer of filter media and replacing with clean material, as well as vacuuming out any sedimentation chambers. If it is suspected that overflow or outlet pipes are not configured correctly, check against the design plans and also standard drawings from the manufacturer. Chronic clogging problems are likely due to excessively dirty drainage areas, including uncontrolled sources of sediment, oil and grease wash off,vegetative debris from surrounding trees or shrubs, or other sources. It will be important to check and resolve any controllable sources of clogging in the drainage area (see Section 12.3.1). Helpful Skills: Soil infiltration analysis techniques as per ASTM and/or current BMP design specifications Excavation, dewatering, and sediment disposal in some cases Knowledge of maintenance equipment, such as vac trucks, street sweepers, etc. Knowledge of preferred conditions for bioretention, sand filter media, or standard porous pavement types and bedding layers General practice of trying easier or less expensive strategies before jumping right to wholesale reconstruction of a practice Equipment Typically Used for Unclogging Activities: Soil infiltration testing or geotechnical equipment Small or large excavators, loaders, dewatering equipment(pumps, dirt bags, etc.), trucks to haul material to on-site or off-site disposal or reuse areas, erosion and sediment control supplies Pavement demolition and repair equipment Mulch, plants, filter media, and other materials needed to rebuild practices Chapter 12: Maintenance Guidance 1 -3 12.3.8 Vegetation Applies Most Commonly To: Tree Planting, Swales, Bioretention, Green Roofs, and Ponds/Wetlands Problem Tree Planting,Swales, Bioretention: Test soil/media to ensure proper conditions exist for plant survival. Check water drawdown after a storm to make sure that wet/saturated conditions are not the cause of plant failure. If this IS an issue, see Section 12.3.7. Amend or enhance soil as needed-, soil may need more organic material to support plants, but do not use uncomposted organic material or animal waste, as it will likely export undesirable nutrients to the stormwater system. 3 If plants have continued to die, consider a different species or entire planting palette or revised planting plan (photo to right shows the need for a whole new planting plan). Also consider using an appropriate bioretention or swale native seed mix to supplement use of plugs or other nursery stock. Consult a horticulturalist or plant nursery if there is evidence of disease or pests. . Replant and add mulch or ground cover as needed. Ponds and Wetlands: See Section 12.3.12 for general guidance on pond and wetland vegetation maintenance, as well as the following. For emergent vegetation, determine whether water depths are too deep or shallow for survival (i.e., depths are different from design depths, or original design included improper vegetation). If a small amount of supplemental vegetation is needed, plant wetland plugs per nursery guidance. For large-scale plantings, drain the permanent pool and plant during the early spring. Green Roof: Consult with a green roof plant vendor about possible causes of plant failure. Lack of watering during initial establishment could be the main culprit. Work with a qualified vendor to develop and install a new planting plan. Speak with building facilities maintenance personnel to ensure they understand need for watering and caring for new plants after they are installed. Helpful Skills: Landscaping/gardening Consult with Cooperative Extension Office or independent laboratory for soil testing If original planting plan is deemed inadequate, consult a landscape architect or horticulturalist to determine whether a revised planting plan is needed. Knowledge of native plant and/or wetland plant nurseries in general region Chapter 12: Maintenance Guidance 1 -40 Problem . . much vegetation, overgrown (with invasive species), not maintained General Approach for All Practices: Determine which invasive plants are present. For a list of regulated and prohibited invasive plants in New York State, see New York State Prohibited and Regulated Plants(NYS DEC, NYS Agriculture and Markets, 2014)at: , http://www.dec.ny.aov/docs/lands forests pdf/isprohibitedplants2.pdf. Invasive plants shall be properly disposed of in a manner that renders them non-living and non-viable to prevent the establishment, introduction or spread of disposed species. ' Review whether the original planting plan relied on these plants; for example, some wetland plans may rely on"aggressive colonizers" such as cattails. For more detailed information regarding appropriate control measures for each species, consult the Cornell Cooperative Extension Invasive Species Program at the following link: http://ccetompkins.org/environment/invasive-nuisance- species/invasive-plants. If invasive species have taken over the facility, wholesale removal and replanting with desirable species may be necessary. If(non-invasive)plants are overgrown, (example in photo to right), remove, thin, or trim back excessive vegetation. r. If an entire new planting plan is deemed necessary, use SMP-Specific ` '" � Guidance in the remainder of this manual, along with landscaping goals for the site location, to devise a plan that allows for adequate growth over a long r period of time. A simple, clear planting design (example in photo below)with * '� � P _ , a long-term plan has the best chance of being maintained through time. x � ' Maintenance crews need to know which plants are part of the design versus weeds and how the practice should look from year to year. ' , Develop a plan to ensure proper weeding, pruning,trimming, and replanting to o,--g.� F-• maintain the plan overtime. See Section 12.3.12 for general guidance on pond and wetland vegetation maintenance, as well as the following. Helpful Skills: Knowledge of exotic and invasive species is needed. Consult a local Cooperative Extension Office. Specific measures may include mechanical hand pulling, regrading (requires construction equipment), or herbicide/pesticide application by a certified pesticide applicator. See DEC webpage for"Pesticide Applicator/Technician Guidance". Landscape architect Knowledge of wetland plants(for ponds/wetlands) Knowledge of SMP design (to understand hydrologic regime for plant selection) Equipment Typically Used for Vegetation Maintenance Activities Soil auger to diagnose issues of soil drainage that may affect vegetation health Rakes, shovels, wheelbarrows, and other"landscaping"equipment Light excavation or grading equipment for Iargerjobs Equipment to deliver, unload, and move filter media, mulch, and other materials Plants and/or seed mix, plus a way to move and store plant stock without damaging it or drying it out Planting bars, soil drills, etc. For planting in standing water(e.g., ponds, wetlands), pumps or pump-around systems and dirt bags or other ways to temporarily dewater planting area Chapter 12: Maintenance Guidance 1 •41 12.3.9 Embankment and Overflow Condition Applies Most Commonly To: Swales, Bioretention, and especially Ponds/Wetlands Problembare dirt areas of embankments Swales, Bioretention: Erosion and areas of bare dirt indicate two basic issues: 1)soils and moisture levels are not suitable for the plants or turf used; and 2)vegetation cannot take hold because of concentrated flow, physical wear, or poor soil conditions. ' Address these issues first with a soil/media test to ensure proper conditions exist for plant survival. High salt content from winter deicing of pavement is a common culprit of poor soil conditions for roadside plants. If this is the case, restore area with plant species that can tolerate salt levels, or replace edge plants with a stone diaphragm to intercept runoff from road. Amend or enhance soil as needed; soil may need more organic material to support dense ground cover. For concentrated flow and physical wear, redirect concentrated flow so that it disperses in mulched and vegetated areas. Anchor mulch and replant with vigorous plants recommended through the soils test. If plants have continued to die, consider a different species or entire planting palette or a revised planting plan (see Section 12.3.8 and photo to right). � E Also consider using an appropriate bioretention or swale native seed mix to supplement use of plugs or other nursery stock. 4" Consult a horticulturalist or plant nursery if there is evidence of disease or pests. Replant and add mulch or ground cover as needed. Ponds and Wetlands: Where erosion has deposited soil within the pond or wetland water line, remove this material and reshape the slope. If a small amount of supplemental vegetation is needed, plant wetland plugs per nursery guidance. x ' To address rill and channel erosion, first obtain a soil sample test _ to get soil amendment recommendations. Undercut the eroded _ sections and replace with clean amended soil, based on the soil test, and reseed as appropriate for the season. It may be necessary to stake in seed blankets or erosion- resistant lining (e.g., erosion-control matting or even rock in extreme situations)to stabilize eroded areas. Again, choose seed types appropriate for the season. Based on soil test guidance, reseed bare areas to prevent further erosion. For persistent problems, reroute the flow to more stable receiving areas using berms, diversions, etc. Helpful Skills: Landscaping/gardening Consult with Cooperative Extension Office or independent laboratory for soil testing. If original planting plan is deemed inadequate, consult a landscape architect or horticulturalist to determine whether a revised planting plan is needed. Knowledge of sediment and erosion control practices and resources appropriate for the area Chapter 12: Maintenance Guidance 12• 2 Problemoverflow General Approach for All Practices: • Settlement, loss of armoring material, erosion and accumulated debris can affect the dimension, water velocity or capacity of the emergency overflow such that embankment failure could occur in flood events (photos below). Inspect for exposure of soil or geotextile base material in the overflow and re-armor areas of exposure. In cases of settlement, a qualified engineer should be sought to assess its capacity and impact on pond capacity. • Erosion of spillways should be repaired and revegetated as described for embankments. Helpful Skills: Knowledge of sediment and erosion control practices for the area Completion of self-guided training on dam safety through Association of State Dam Safety Officials: http://www.damsafetV.org Problem #3: Impounding structure (embankment or dam) integrity issues due to tunneling or digging animals, 0 woody vegetation, or seepage Ponds/Wetlands: Impounding structure stability is a serious concern, especially where trees have become established on the slopes, or there's evidence of animal burrows or seepage. The best approach for trees on the crest, slopes, and adjacent to an impounding structure or embankment is to cut them down before they reach significant size. If large trees have been cut down but their root systems not removed, carefully monitor the area around the remaining stumps for signs of seepage. Exercise judgement for trees on the surrounding side slopes that are NOT impounding structures (not designed to hold back water in the pool). Sometimes a forested edge can enhance the appeal of a pond, but access for maintenance must also be available, and some trees can drop debris into ponds, leading to quality issues. • Animal burrows can be dangerous to the structural integrity of the embankment because they weaken it and can create pathways for seepage. Professional exterminators may be needed to trap and remove animal pests. Seepage as water flow or boiling sand on the lower portion of the exterior slope or toe area of an impounding structure should be brought to the attention of a qualified engineer. Leakage around conveyance structures such as barrel pipes or spillways should be monitored for increase since the last inspection. A qualified engineer is needed to resolve issues of piping or seepage along the barrel pipe through a dam. Turbidity or cloudiness in seepage should also be brought to the attention of a qualified engineer. Helpful Skills: Completion of self-guided training on dam safety through the Association of State Dam Safety Officials: http://www.damsafety.org Equipment Typically Used for Embankment and Overflow Maintenance Activities Excavation or grading equipment for larger jobs Equipment to deliver, unload, and move filter media, mulch, and other materials Plants and/or seed mix, seed blanket and erosion control materials Rod and level for settlement measurements Clear glass bottle for seepage visual test Chapter 12: Maintenance Guidance 12-43 12.3.10 Structural Damage Applies Most Commonly To: Any Practice Problem: other components0 structural Structural components are necessary for water to flow into and out of stormwater practices as intended. This is a broad category that involves components composed of concrete, metal, plastic, and other materials. Some common examples include: Deteriorated or broken curbs that allow water to bypass a practice Slumping or sinkholes where soil meets a concrete drop inlet or outlet structure Broken or collapsed inlets Connections in an inlet or manhole structure that are not parged and are leaky Collapsed or crushed pipes(especially corrugated metal) Missing or broken steps or other safety features in a manhole or outlet control structure Root penetration and clogging of underdrain or other pipes Broken check dams There are too many particular instances to mention here, but the general idea is to inspect and repair any structural components that are affecting the performance of a practice or leading to a potential health or safety issue. Helpful Skills: General contracting skills—concrete work, metal, properjoint sealing Routing out clogged pipes Perhaps CCTV experience to look for broken or clogged pipes Equipment Typically Used for Fixing Erosion: General contracting CCTV Chapter 12: Maintenance Guidance 12- 4 12.3.11 Pool Stability Applies Most Commonly To: Ponds/Wetlands Problem: • •d pond outlet General Approach for Ponds and Wetlands: Note high-water marks on structures or pond banks and compare with outlet structure weir. If the outlet weir is submerged, investigate downstream for plugs such as beaver dams, woody debris or sediment bars. Refer to Section 12.3.2 for removal of obstructions. • If the pond is retaining more water than it is supposed to and there is no r flow from the outlet with no visible blockages in the outlet pipe, look for obstructions above the weir or outlet pipe. Woody debris, vegetation and silt can plug outfall weirs or blind rock outfall protection. Removal of such blockages tends to be a hand exercise. Ajet/vacuum truck or other heavy equipment may be needed to clear excessive or precarious blockages (photo on right). r If the pond is too low and not holding water in the designated pool,the outlet structure should be closely inspected to see whether it has settled � � from the original construction or there is leakage through joints or cracks. Finding no deficiencies with the structure, investigate the pond embankment as described in Section 12.3.9 for evidence of seepage. If there is no evidence of seepage and the outlet structure has no apparent structural defects, an engineer should be consulted to review the pond design and determine the proper outlet elevation. f Helpful Skills: The ability to navigate uneven surfaces, to follow ditch banks and to sight drainage obstructions is implicit with this task. Ability to use a level to sight adequate elevation fall is helpful. Equipment Typically Used for Pool Stability Evaluations Bright flashlight for pipe inspection Manhole hook for manhole cover access Brush hook to clear debris and walking surfaces Rod and level to check elevation differentials Chapter 12: Maintenance Guidance 12•4 12.3.12 Pool Quality Applies Most Commonly To: Ponds/Wetlands Problempond edge: plants a have taken over Ponds and Wetlands: If there is not enough vegetation or no vegetation, determine whether maintenance practices have killed the plants. If so, work with the owner to educate those responsible for pond maintenance on correct methods. Consult plans for original planting and replant. For emergent vegetation, determine whether water depths are too deep or shallow for survival(i.e., depths are different from design depths, or original design included improper vegetation). 6 If a small amount of supplemental vegetation is needed, plant wetland plugs "A per nursery guidance. + 'i For large-scale plantings, drain the permanent pool and plant during the early spring. If ponds are overgrown so that less than 25%of the surface area is visible, the pond water level should be lowered to enable selective plant removal. • Invasive plants, such as phragmites or common reed, should be removed with their roots. Be sure to restore areas that have been disturbed with replacement vegetation because root removal exposes soil to erosion. Invasive plants shall be properly disposed of in a manner that renders them non-living and non-viable to prevent the establishment, introduction or spread of disposed species. • Native plants selected based on environmental conditions have the greatest chance for survival. • Consult a horticulturalist or plant nursery if there is evidence of disease or pests. Helpful Skills: • Landscaping/gardening If original planting plan is deemed inadequate, consult a landscape architect or horticulturalist to determine whether a revised planting plan is needed. Knowledge of native plants and/or wetland plant nurseries in general region • Familiarity with New York invasive terrestrial and wetland plants and their control: http://nyis.infoProblem #2: Pond color, scum, odor, algae, and plant overgrowth • Ponds that have algae covering more than 20%of the surface should have maintenance to remove it. Raking or mechanical harvesting of filamentous algae offers short-term control, but feasible long-term strategies should be considered. Pond maintenance companies should be relied on to identify the algae and appropriately control them. Pond specialists can control the algae growth in ponds, but its growth and reproduction are dependent on nutrients. When nutrients are in abundance, so will be the algae or vegetation. Plants can be used in shallow shelfs at inlets to take up nutrients. However, they must be maintained, and cuttings shall be removed to take nutrients out of the pond system. If(non-invasive)plants are overgrown, remove or trim back excessive 0 0, 0 0- vegetation. Remove cuttings and trimmings. Do not allow vegetative debris to remain in the pond. Pond clarity and color can be impacted by excessive sediment discharge or flow shortcircuiting. For issues of clarity and color, follow the recommendations in Section 12.3.6. If invasive aquatic plants are identified, follow DEC guidelines for reporting and controlling invasives(see Section 12.3.8). Some color, odor, and pond quality issues can be caused by leaks, spills, and other releases in the drainage area. Any petroleum odor or oily sheen (aside from natural rainbow sheen associated with decomposition of organic matter)should be reported to the appropriate state or local response agency. Other peculiar colors or odors can be investigated in collaboration with relevant agencies. Common issues are grease, paint, or other substances poured into storm drains, dumpster management, and stockpiles of various materials exposed to rainfall. Chapter 12: Maintenance Guidance 1 •46 Helpful Skills: Ability to recognize invasive aquatic plants Specific measures may include mechanical hand pulling, regrading (requires construction equipment), or herbicide/pesticide application by a certified pesticide applicator. See DEC webpage for"Pesticide Applicator/Technician Guidance". Knowledge of wetland plants and common types of algae and aquatic weeds Knowledge of types of pond maintenance practices Equipment Typically Used for Pool Quality Investigations High-top rubber boots Canoes or small boats Brush hook to clear vegetation and access pond bank Secchi disk to check and compare pond color and clarity Large-mouth bottle to collect algae and water quality samples Various materials to control aquatic weeds and algae Chapter 12: Maintenance Guidance 12-47 This Page is Left Intentionally Blank NEW Department of PORK STATE Environmental Conservation ��K Department of STATE Environmental Conservation This Page is Left Intentionally Blank NEW Department of PORK STATE Environmental Conservation New York State DEC Division of Water Guidelines for Design of Dams January 1985 Revised January 1989 New York State Department of Environmental Conservation George E. Pataki, Governor John P. Cahill, Commissioner GUIDELINES FOR DESIGN OF DAMS NEW YORK STATE DEPARTMENT OF ENVIRONMENTAL CONSERVATION DIVISION OF WATER BUREAU OF FLOOD PROTECTION DAM SAFETY SECTION 50 WOLF ROAD ALBANY, NEW YORK 12233-3507 GUIDELINES FOR DESIGN OF DAMS TABLE OF CONTENTS SECTION TITLE PAGE Preface to the January 1 1989 Edition 1 Introduction 2 2 Definitions 3 3 Hazard Classification 5 4 Design and Construction Documents 5 5 Hydrologic Criteria 7 6 Hydraulics of Spillways 10 6A Flashboard Policy 12 7 Outlet Works and Conduits 15 8 Geotechnical Investigations 16 9 Earth Dams 18 10 Structural Stability Criteria for 21 Gravity Dams 11 Existing Dams : Rehabilitation and 25 Modification 12 Cofferdams 26 13 Miscellaneous 27 14 Emergency Action Plan 27 15 Approval to Fill Reservoir 28 16 References 29 17 DEC - Regional Directory 31 PREFACE TO THE JANUARY 1988 EDITION The January 1988 revision involves : Page Item 2 Introduction 4 Corrected definition for the Service Spillway Design Flood (SSDF) 6 Construction Inspection 11 Insertion of Section 6A, Flashboard Policy 14 Filter and drainage diaphragm replacing antiseep collars for pipe conduits 19 Vegetation Control 22 Insertion of Loading Condition 3A 25 Cofferdams 28 The addition of references 3 , 4 , 5 and 6 PREFACE TO THE JANUARY 1989 EDITION The January 1989 revision involves : Page Item 7 Hydrology Investigations 7 Existing Dams - Service Spillway Design Flood Criteria 1.0 INTRODUCTION 1.1 General The Department of Environmental Conservation receives many requests for detailed information about designs for dams requiring a permit under Article 15, Section 0503 of the Environmental Conservation law. This brochure has been developed by the department for the general guidance of design engineers. These guidelines represent professional judgment of the Dam Safety Section's staff engineers. The guidelines convey sound engineering practices in an average situation. Where unusual conditions exist and the guidelines are not applicable, it is the duty of the design engineer to notify the department which will then consider deviation from the guidelines. Since these are only general guidelines for small dam construction in an average situation, compliance will not necessarily result in approval of the application. The determination by the department of the acceptability of the design and adequacy of the plans and specifications will be made on a case-by-case basis. The primary responsibility of proper dam design shall continue to be that of the applicant. In the administration of this law, the department is concerned with the protection of both the health, safety and welfare of the people and the conservation and protection of the natural resources of the State. (See Reference 1 and 2) . Water stored behind a dam represents potential energy which can create a hazard to life and property located downstream of the dam. At all times the risks associated with the storage of water must be minimized. This document deals with the engineering guidelines for the proper design of a dam. In order for a dam to safely fulfill its intended function, the dam must also be constructed, operated and maintained properly. Supervision of construction or reconstruction of the dam by a licensed professional engineer is required to insure that the dam will be built according to the approved plans. See Article 15-0503, Item 5 of the New York State, Environmental Conservation Law (Reference 1) . For the proper operation and maintenance of a dam, see "An Owners Guidance Manual for the Inspection and Maintenance of Dams in New York State" (Reference 6) . 1.2 Application A permit is required if the dam: is at least 10 feet high or stores 1 million gallons (3 .07 acre feet) or has a drainage area of 1 square mile. Waste surface impoundments which are large enough to meet the above mentioned criteria shall not require an Article 15 dam permit. Hazardous waste surface impoundments will continue to be regulated by the Bureau of Hazardous Waste Technology, Division of Hazardous Substances 2 Regulation of the Department of Environmental Conservation, under 6NYCRR-Part 373, Hazardous Waste Management Regulation. Surface impoundments which are part of an approved waste water treatment process will be regulated within a SPDES permit issued by the Division of Water. 1.3 Application Forms Applications, including the Supplement D-1 (hydrological, hydraulic and soils information) , can be obtained from and should be submitted to the Regional Permit Administrator. The addresses of the Regional Permit Administrators are shown on page 31. Detailed information on application procedures is contained in the Uniform Procedures Regulations, Part 621. Information on all pertinent items should be given. Construction plans and specifications should be prepared in sufficient detail to enable review engineers to determine if the proposed design and construction is in compliance with department guidelines. Thorough engineering review will be given each application. The time for this review and any additional time if revisions are necessary should be a consideration in each application. 2 .0 DEFINITIONS Appurtenant works are structures or materials built and maintained in connection with dams. These can be spillways, low-level outlet works and conduits. Auxiliary spillway is a secondary spillway designed to operate only during large floods. Cofferdam is a temporary structure enclosing all or part of the construction area so that construction can proceed in the dry. Conduit is an enclosed channel used to convey flows through or under a dam. Dam is any artificial barrier and its appurtenant works constructed for the purpose of holding water or any other fluid. Department is the Department of Environmental Conservation (DEC) . Detention/Retention Basin is any structure that functions as a dam. Earth Dam is made by compacting excavated earth obtained from a borrow area. Energy Dissipator is a structure constructed in a waterway which reduces the energy of fast-flowing water. 3 Flood Routing is the computation which is used to evaluate the interrelated effects of the inflow hydrograph, reservoir storage and spillway discharge from the reservoir. Freeboard is the vertical distance between the design high water level and the top of the dam. Gravity Dam is constructed of concrete and/or masonry and/or laid-up stone that relies upon its weight for stability. Height is the vertical dimension from the downstream toe of the dam at its lowest point to the top of the dam. Low-Level Outlet is an opening at a low level used to drain or lower the water. Major Size Dam is at least 25 feet high and holds at least 15 acre feet of water or is at least 6 feet high and holds at least 50 acre feet of water. Maximum Impoundment Capacity is the volume of water held when the water surface is at the top of the dam. Probable Maximum Flood (PMF) is the flood that can be expected from the severest combination of critical meteorologic and hydrologic conditions possible for the particular region. It is the flow resulting from the PMP. Probable Maximum Precipitation (PMP) is the maximum amount of precipitation that can be expected over a drainage basin. Seepage Collar is built around the outside of a pipe or conduit under an embankment dam to lengthen the seepage path along the outer surface of the conduit. Service Spillway is the principal or first-used spillway during flood flows. Service Spillway Design Flood(SSDF) is the flow discharged through the service spillway. Spillway is a structure which discharges flows. Spillway Design Flood(SDF) is the largest flow that a given project is designed to pass safely. Toe of Dam is the junction of the downstream face of a dam and the natural ground surface, also referred to as downstream toe. For an earth dam the junction of the upstream face with the ground surface is called the upstream toe. 4 3 .0 HAZARD CLASSIFICATION 3 .1 General The height of the dam, its maximum impoundment capacity, the physical characteristics of the dam site and the location of downstream facilities should be assessed to determine the appropriate hazard classification. Applications should include the design engineer's description of downstream conditions and his judgment of potential downstream hazards presented in the form of a letter designation and a written description. 3 .2 Letter Designation Class "A" : dam failure will damage nothing more than isolated farm buildings, undeveloped lands or township or country roads. Class "B" : dam failure can damage homes, main highways, minor railroads, or interrupt use or service of relatively important public utilities. Class "C" : dam failure can cause loss of life, serious damage to homes, industrial or commercial buildings, important public utilities, main highways, and railroads. 3 .3 Written Description The written description is an elaboration of the letter designation. It includes descriptions of the effect upon human life, residences, buildings, roads and highways, utilities and other facilities if the dam should fail. 4 .0 DESIGN AND CONSTRUCTION DOCUMENTS 4.1 Engineer Qualifications The design, preparation of construction plans, estimates and specifications and supervision of the construction, reconstruction or repair of all structures must be done under the direction of a professional engineer licensed to practice in New York State. (See References 1 and 7) . 4.2 Design Report A design report, submitted with the application, should include an evaluation of the foundation conditions, the hydrologic and hydraulic design and a structural stability analysis of the dam. The report should include calculations and be sufficiently detailed to accurately define the final design and proposed work as represented on the construction plans. Any deviations from the guidelines should be fully explained. 5 4 .3 Construction Plans Construction plans should be sufficiently detailed for department evaluation of the safety aspects of the dam. The cover sheet should include a vicinity map showing the location of the dam. The size of the plans should be not less than 18 x 24 inches and no more than 30 x 48 inches. As-built plans of the project are required upon completion of construction. 4.4 Construction Inspection The dam' s performance will largely be controlled by the care and thoroughness exercised during its construction. Undisclosed subsurface conditions way be encountered which may materially affect the design of the dam. To ensure a safe design, the designer must be able to confirm design assumptions and revise the dam design if unanticipated conditions are encountered. Construction inspection is required in order to ensure that the construction work complies with the plans mid specifications and meets standards of good workmanship. Therefore, construction inspection of a dam is required by a licensed professional engineer to monitor and evaluate conditions as they are disclosed and to observe material placement and workmanship as construction progresses. The engineer involved in the construction of the dam work will be required to submit a periodic construction report to the Department covering the critical inspection activities for the dam's construction/reconstruction. Prior to permit issuance the applicant shall submit, for review and approval, a proposed schedule of construction inspection activities to be performed by the applicant' s engineer. Upon permit issuance, the approved schedule shall be part of the required work. 4.5 Specifications Materials specifications will be required for items incorporated in the dam project. Materials specifications including format found acceptable are those issued by the following agencies and organizations. State: New York State Department of Transportation Federal: COE - Corps of Engineers SCS - Soil Conservation Service Industry: ASTM - American Society for Testing and Materials ACI - American Concrete Institute AWWA - American Water Works Association CSI - Construction Specifications Institute 6 5.0 HYDROLOGIC CRITERIA 5.1 Hydrologic Design Criteria A table of hydrologic design criteria giving the spillway design flood, the service spillway design flood and minimum freeboards for various hazard classifications can be found in Table 1. 5.2 Design Flood The National Weather Service has published data for estimating hypothetical storms ranging from the frequency-based storm to the Probable Maximum Precipitation event. For the frequency-based storms Technical Paper TP-40 (Ref 17) and TP-49 (Ref 18) will be used to determine rainfall . For the Probable Maximum Precipitation event, Hydrometeorological Report HMR-51 (Ref 16) will be used. When using the above mentioned TP's and HMR's, the minimum storm duration will be six hours. For large drainage areas in which the time of concentration exceeds six hours, the precipitation amounts must be increased by the applicable duration adjustment. The Soil Conservation Service (SCS) has developed Technical Release 55 (TR-55) "Urban Hydrology for Small Watersheds" . TR-55 presents simplified procedures for estimating runoff and peak discharge and is an acceptable procedure for designing spillways for small watersheds. In developing TR-55 the SCS uses a storm period of 24 hours for the synthetic rainfall distribution. Although the "rational method" (Q=CIA) is used for estimating design flows for storm drains and road culverts, it normally is not an acceptable method for determining peak discharge for the design of a dam spillway. The rational method should not be used for watershed areas larger than 200 acres because of its inaccuracy above that range. The greatest weakness of the "rational method" for predicting peak discharges lies in the difficulty of estimating the duration of storms that will produce peak flow. The greatest probability for error, both as to magnitude and understanding relates to the term "intensity" or "rate of rainfall" . Although the units are inches per hour, the term does not mean the total inches of rain falling in a period of one hour. "Intensity" should be related to the time of concentration. "Intensities" would be higher for storms of short duration and would be lower for storms of longer duration. Table I indicates that the appropriate Spillway Design Flood will be a percentage of the 100 year flood or the PMF. Therefore, in order to correctly determine the peak flow, the rainfall values used will be for the 100 year flood or the PMF and the appropriate peak discharge will be computed. After the peak discharge has been found, this value will then be multiplied by the appropriate percentages. For example a small dam in the Class "B" hazard category will have the discharge based on the 7 rainfall from a 100 year flood and this discharge will then be multiplied by 2 .25 to obtain the peak discharge. The percentages should be applied to the discharge vllues in the final step of the calculations. It is incorrect to apply the percentages to the rainfall values. 5.3 Existing Dams - Design Flood Existing dams that are being rehabilitated should have adequate spillway capacity to pass the following floods without overtopping: Hazard Classification Spillway Design Flood (SDF) A 100 year B 150% of 100 year C 50% of PMF The Service Spillway Design Flood (SSDF) for existing dams is the same as shown for the new dams on Table 1. 8 e w 0 < o . / \ \ \ / \ = o \ \ \ \ K m B e m e m e m w w / \ w w o < = w e o / ® / w e < w , o / / \ / / / — w w w w w \ o e \ \ \ \ \ \ \ \ \ / ) z o z o z / G / / m e m e m z m e t o z / / / / \ / B ^ / \ ® « / ® / w z 4-4 \ / \ e \ \ \ \ / o = = t 7 \ \ j\ / / / \ \ / e \ § \ ) / 4-4 \ \ \ \ m o & w c o o _ _ e 2 m / / ® / / / \ / / ® g J n z m ® ' e / H ~ / { / n \ / \ e m \ CD / / \ o z G m e } \ } \ 43\ \ 43 ) / § // / / / / ro m o ® / w q o / / / / © w G \ \ \ = u 0 � \ \ \ 0 0 4-4 \ co \ \ « \ 1 \ l \ / \ ^ / ® / / / / 6 .0 HYDRAULICS OF SPILLWAYS 6 .1 Spillways Spillways protect the dam from overtopping. Consideration must be given to dams and reservoirs upstream of the dam in question when designing the spillway. A dam should be provided with either a single spillway or a service spillway-auxiliary spillway combination. 6.2 Single Spillway For a single spillway, the structure should have the capacity and the durability to handle sustained flows as well as extreme floods and be non-erodible and of a permanent-type construction. Free overall spillways, ogee spillways, drop inlet or morning glory spillways, and chute spillways are common types. An earth or grass-lined spillway is not durable under sustained flow and should not be used as a single spillway. 6.3 Criteria for a single spillway are as follows: 6.3 .1 Sufficient spillway capacity should be provided to safely pass the spillway design flood with flood routing through the reservoir. (See Table 1 for spillway design flood) . 6.3 .2 Assuming no inflow, the spillway should have sufficient discharge capacity to evacuate 75% of the storage between the maximum design high water and the spillway crest within 48 hours. 6.3 .3 The spillway will have an energy dissipater at its terminus. 6.3 .4 A drop inlet or morning glory spillway, as a single spillway, is only acceptable on a Hazard Class "A" structure with a drainage area of less than 50 acres. In this case, sufficient storage capacity should be provided between the spillway crest and top of dam to contain 150% of the entire spillway design flood runoff volume. 6.4 Service Spillway - Auxiliary Spillway Combination: In the case of the service spillway - auxiliary spillway combination, the service spillway discharges normal flows and the more frequent floods, while the auxiliary spillway functions only during extreme floods. Service spillways must be durable under conditions of sustained flows; whereas auxiliary spillways do not. Service spillways should have sufficient capacity to pass frequent floods and thus reduce the frequency of use of the auxiliary spillway. The service spillway usually does not have sufficient capacity to pass the entire spillway design flood. Drop inlet or morning glory spillways are common types of service spillways. This type of structure will consist of a vertical inlet riser connected to a service spillway conduit with an energy 10 dissipator at the outlet. An auxiliary spillway is capable of handling high but short duration flows. It may be an excavated grass-lined channel if the designer is able to limit velocities to the non-erodible range for grass. It cannot carry prolonged flows because of eventual deterioration of the grass linings. For spillways which will be required to discharge flows at a high velocity, a more permanent type of material such as concrete will be required. An auxiliary spillway may be located adjacent to a dam abutment or anywhere around the rim of the reservoir. It should be located sufficiently apart from the dam to prevent erosion of any embankment materials. A spillway over the dam is not acceptable. It may either discharge back into the natural watercourse below the dam, or so long as a flood hazard is not created, into a watercourse within an adjacent drainage basin. 6.5 Criteria for an auxiliary spillway-service spillway combination are as follows: 6.5 .1 Sufficient service spillway capacity should be provided to safely pass the service spillway design flood with flood routing through the reservoir. (See Table 1 for service spillway design flood) . 6.5 .2 The service spillway normally should be provided with an energy dissipater at its outlet end. 6.5 .3 The auxiliary spillway crest must be placed at or above the service spillway design high water, and not less than 1 foot above the service spillway crest. 6.5 .4 The auxiliary spillway-service spillway combination must provide sufficient discharge capacity to safely pass the spillway design flood with flood routing through the reservoir (See Table 1 for spillway design flood) . 6.5 .5 Assuming no inflow, the auxiliary spillway-service spillway combination should have sufficient capacity to evacuate the storage between the maximum design high water and the auxiliary spillway crest within 12 hours. 6.5 .6 Assuming no inflow, the service spillway should have sufficient capacity to evacuate 75% of the storage between the auxiliary spillway crest and the service spillway crest within 7 days. 6.5 .7 Auxiliary spillways shall not be placed on fill. 6.5 .8 Velocities in auxiliary spillways should not exceed the maximum permissible velocities (non-erodible velocities) of the spillway materials. 11 6.5 .9 If an auxiliary spillway is located near an embankment,it should be located so as not to endanger the stability of the embankment. The following criteria will help guard against damage to the embankment: a. Discharge leaving the exit channel should be directed away from the embankment and should be returned to a natural watercourse far enough downstream as to have no erosive effect on the embankment toe. b. The spillway exit channel, from the spillway crest to a section beyond the downstream toe of dam, should be uniform in cross-section, contain no bends, and be longitudinally perpendicular to the spillway crest. Curvature may be introduced below the toe of dam if it is certain that the flowing water will not impinge on the toe of dam. 6.0 A FLASHBOARD POLICY Background Flashboards are used to raise the water surface of an impoundment. However, the installation of flashboards along the crest of a spillway may permanently reduce the size of the spillway opening. Our records indicate that in some instances the reduction of spillway capacity with the installation of flashboards has resulted in overtopping and subsequent dam failure. Two examples are the Tillson Lake Dam (#1942420) in Ulster County and the Lake Algonquin Dam (#171-2700) in Hamilton County. In 1939 flashboards were placed across the spillway of the 40 foot high Tillson Lake Dam in such a manner as to greatly reduce the spillway opening. Storm flow caused dam overtopping which eroded the earth slope in front of the 100 foot wide, 30 foot high concrete core wall. Failure of the core wall resulted in a tremendous amount of erosion to farm land, loss of farm machinery, chickens, several local bridges and basement flooding. The dam was rebuilt and failed in 1955 because flashboards were again in place and did not fail during storm flow. In 1949 the Lake Algonquin Dam failed because flashboards were not removed for the winter. A January storm caused overtopping and subsequent dam failure at the right abutment. The dam failure resulted in the loss of a home, several farm buildings and a road. When wood flashboards are installed properly they will be 12 supported by steel pins. These steel pins will be designed to fail when the depth of flow over the top of the flashboards reaches a certain level. Critical to the design of the flashboard system are the diameter of the steel pin, the ultimate strength of the steel and the spacing of the pins. In very few cases is the Consulting Engineer or Contractor who designed the flashboards able to provide sufficient quality control to ascertain that the as-built condition is similar to the design proposal. Many field maintenance personnel do not understand the need for flashboards to fail when the depth of flow over the flashboards reaches a certain level. Therefore, there is a tendency to insert the flashboards in such a manner so that they will never fail, thus permanently reducing spillway capacity and increasing the possibility of dam failure by overtopping. This is what nearly happened at the Gore Mountain Dam at North Creek. During the period of 1977-1980 DEC operations personnel installed wide flange beams to support the wood flashboards. The approved design for the flashboard supports were one inch diameter steel pins. However, operations personnel decided they would have less maintenance problems if they permanently secured the wood flashboards between the six inch wide flange beams. Under this support the flashboards would never fail. Around February 15, 1981 a sudden thaw and rain caused the water level at Gore Mountain Dam to rise within eight inches of the top of dam. This level was about two feet, four inches over the top of the flashboards. The extra sturdy wide flange beam support system precluded any chance of flashboard failure. Fortunately this abnormally high level was reported to the DEC by a local resident while he was snowmobiling. During the fall of 1981, DEC revised the flashboard support system so that the flashboards were properly supported by one inch diameter steel pins and the steel pins would fail in bending when the depth of flow over the top of the flashboards reached one foot. For the foregoing reasons the Dam Safety Section has developed the following policy regarding the installation of flashboards on dams. New Dams Flashboards shall not be installed on any new dams. The dam owner or hydroelectric developer shall determine the normal pool elevation for the proposed impoundment and provide a permanently fixed spillway crest at the selected elevation. If pool elevation fluctuations are desired, they should be achieved by means of adequately sized gates, drains, siphons or other acceptable methods. 13 Existing Dams A permanently fixed spillway crest is the preferred method of establishing normal pool elevation. The installation or continued use of flashboards on existing dams will be considered on a case by case basis. Flashboards on existing dams will only be acceptable if the dam is able to satisfy the hydraulic and structural stability criteria contained in the Guidelines for Design of Dams. If the flashboards are designed to fail in order to satisfy either criterion, detailed failure calculations must be submitted for Department review and approval. The maximum pool elevation the flashboards are designed to fail at shall be the lower of: 1. Two times the height of the flashboards measured from the bottom of the flashboards, or 2 . Two times the freeboard specified in Table 1 of these Guidelines, for a dam of the pertinent size and hazard classification, measured downward from the top of dam. The maximum pool elevation that would be reached under Spillway Design Flood conditions, without the flashboards failing, shall also be determined. Flashboards shall be installed, operated and maintained as intended in their design and in accordance with the terms and/or conditions of any permits or approvals. The approved flashboard configuration (pin spacing, pin size, board height, board size, etc. ) shall not be modified without prior Department approval . _ ,TOP OF,DAM MINIM MU FOR SMALL] DAM MINIMUM' FOR, LARGE: DAMS, MAXIMUM 2X' X=FLAlSH BOARDI HEIGHT FIXED CREST 14 7.0 OUTLET WORKS AND CONDUITS 7.1 Outlet Works A low-level outlet conduit or drain is required for emptying or lowering the water in case of emergency; for inspection and maintenance of the dam, reservoir, and appurtenances; and for releasing waters to meet downstream water requirements. The outlet conduit may be an independent pipe or it may be connected to the service spillway conduit. The low level drain is required to have sufficient capacity to discharge 90% of the storage below the lowest spillway crest within 14 days, assuming no inflow into the reservoir. 7.2 Control Outlet conduits shall have an upstream control device (gate or valve) capable of controlling the discharge for all ranges of flow. 7.3 Conduits Only two types of conduits are permitted on Hazard Class "B" and "C" structures; precast reinforced concrete pipe and cast-in-place reinforced concrete. On Hazard Class "A" structures, welded steel pipe or corrugated metal pipe may be used providing the depth of fill over the pipe does not exceed 15 feet and the pipe diameter does not exceed 24 inches. All outlet conduits shall be designed for internal pressure equal to the full reservoir head and for the superimposed embankment loads, acting separately. The minimum size diameter conduit used as the barrel of a drop inlet service spillway shall be 12 inches. The joints of all pipe conduits shall be made watertight. Any pipe or conduit passing through an embankment shall have features constructed into the embankment whereby seepage occurring along the pipe or conduit is collected and safely conveyed to the downstream toe of the embankment. This can be accomplished by using a properly designed and constructed filter and drainage diaphragm. The filter and drainage diaphragm will be required unless it can be shown that antiseep collars will adequately serve the purpose. Antiseep collars will not be permitted for dams with a height in excess of 20 feet. If antiseep, collars are used in lieu of a 15 drainage diaphragm, they shall have a watertight connection to the pipe. Collar material shall be compatible with pipe materials. The antiseep collars shall increase the seepage path along the pipe by at least 15%. A means of dissipating energy shall be provided at the outlet end of all conduits 12 inches or more in diameter. If a plunge pool is used, the conduit should be cantilevered 8 feet over a concrete, steel or treated timber support located near or at the downstream toe of the embankment. The plunge pool should be riprap-lined if a conduit 18 inches or more in diameter is used. The foregoing may apply to smaller pipes if the embankment's downstream slope is steep and the soil erodible. 8.0 GEOTECHNICAL INVESTIGATION 8.1 Foundations 8.1.1 Subsurface explorations (drill holes, test pits and/or auger holes) should be located along the centerline of the dam, at the proposed service and auxiliary spillway locations, and in other critical areas. The depth of the subsurface explorations should be sufficient to locate and determine the extent and properties of all soil and rock strata that could affect the performance of the dam, the reservoir and appurtenant structures. Referring to information such as geologic bulletins, soil survey maps, groundwater resources bulletins, etc. , may aid the designer in determining the scope of the exploration program needed and interpreting the results of the program. For even the smallest low hazard dams, at least three explorations should be made along the centerline of the dam, one in the deepest part of the depression across which the dam will be built and one on each side. At least one exploration should be made at the proposed auxiliary spillway location. For small low-hazard dams, to be built on a foundation known from the geology of the area to be essentially incompressible and impervious to a great depth, the minimum depth of explorations should be 5 feet unless bedrock is encountered above this depth. In other cases the minimum depth of explorations should be 10 feet, with one or more borings extending to a depth equal to the proposed height of the dam. If it is proposed to excavate in the reservoir area, the possibility of exposing pervious foundation layers should be investigated by explorations or a review of the geology of the area. If rock is encountered in explorations, acceptable procedures, such as coring, test pits, or geologic information, should be used to verify whether or not it is bedrock. 8.1.2 Sufficient subsurface explorations should be made to verify the suitability of encountered rock for use as a foundation 16 and/or construction material . Testing of the rock materials shall ascertain its strength, compressibility, and resistance to degradation, and its ability to safely withstand the loads expected to be imposed upon it by the proposed project. 8.1.3 Soils encountered in explorations should be described accurately and preferably classified in accordance with the Unified Soil Classification System. 8.1.4 For Hazard Class "C" dams, appropriate field and/or laboratory tests should be performed in order to aid in evaluating the strength, compressibility, permeability, and erosion resistance of the foundation soils. Also, appropriate laboratory tests should be performed on samples of the proposed embankment materials in order to ascertain their suitability for use in the dam. Field and/or laboratory tests may be required also for dams of lower hazard classification in the case of critical foundation strength or permeability conditions. 8.1.5 Stability of the foundation under all operating conditions should be evaluated. 8.1.6 Settlement of the dam and appurtenant works should be evaluated and provisions made in the design to counteract the effects of any anticipated settlements. 8.1.7 Whenever feasible, seepage under the dam should be controlled by means of a complete cutoff trench extending through all pervious foundation soils into a relatively impervious soil layer. If the dam is to be built on an impervious foundation, the cutoff or key trench should be excavated to a depth of at least 3 feet into the foundation soils and backfilled with compacted embankment material. Where the final depth of cutoff cannot be established with certainty during design, a note should appear on the plans stating that the final depth of the cutoff trench will be determined by the engineer during the time of construction. Backfilling of the cutoff or key trench should be performed in the dry, unless special construction procedures are used. The bottom width of the trench should be at least 8 feet and should be increased in the case of dams more than 20 feet high. The widths of complete cutoffs my be made considerably less if the cutoff is extended vertically a minimum distance of 4 feet into impervious material. In the case of a cutoff or key trench extending to bedrock, the trench does not have to extend into rock. However, all shattered and disintegrated rock should be removed and surface fissures filled with cement grout. The need for pressure grouting rock foundations should be evaluated and, if necessary, adequately provided for. 17 8.2 Borrow Sources for Embankment Materials Sufficient subsurface explorations should be made in borrow areas to verify the suitability and availability of an adequate supply of borrow materials. Logs of explorations should be included for review with the plans and specifications. Exposure of pervious soils and fissured rock below normal water surface of the proposed pond, at borrow areas located in or connected to the reservoir area, should be avoided. If pervious soils or fissured rock conditions are encountered during borrow operations these exposed areas should be sealed with a sufficient thickness of compacted impervious material . In no case should this seal be less than two feet thick and consideration should be given to utilizing a greater thickness where site conditions and hazard classifications dictate. Borrow areas should be located with due consideration to the future safety of the dam and should be shown on the plans. In general, no borrow should be taken within a distance measured from the upstream toe of the dam equal to twice the height of the dam or 25 feet, whichever is greater. 9.0 EARTH DAMS 9.1 Geometry 9.1 .1 The downstream slope of earth dams without seepage control measures should be no steeper than 1 vertical on 3 horizontal. If seepage control measures are provided, the downstream slope should be no steeper than 1 vertical on 2 horizontal. 9.1.2 The upstream slope of earth dams should be no steeper than 1 vertical on 3 horizontal. 9.1.3 The side slopes of homogenous earth dams may have to be made flatter based on the results of design analyses or if the embankment material consists of fine grained plastic soils such as CL, MH or CH soils as described by the Unified Soil Classification System. 9.1.4 The minimum allowable top width (W) of the embankment shall be the greater dimension of 10 feet or W, as calculated by the following formula: W = 0.2H + 7; where H is the height of the embankment (in feet) 18 9.1.5 The top of the dam should be sloped to promote drainage and minimize surface infiltrations and should be cambered so that the design freeboard is maintained after post-construction settlement takes place. 9.2 Slope Stability Where warranted and especially for new Hazard Class "C" dams, the department may require that slope stability analyses be provided for review. The method of analyses and appropriate factors of safety for the applicable loading conditions shall be as indicated by U. S. Army Corps of Engineers publications (latest edition) (Ref. 11) . Earth dams, in general, should have seepage control measures, such as interior drainage trenches, downstream pervious zones, or drainage blankets in order to keep the line of seepage from emerging on the downstream slope, and to control foundation seepage. Hazard Class "A" dams less than 20 feet in height and Hazard Class "B" dams less than 10 feet in height, if constructed on and of erosion-resistant materials, do not require special measures to control seepage. In zoned embankments, consideration should be given to the relative permeability and gradation of embankment materials. No particle greater in size than six inches in maximum dimension should be allowed to be placed in the impervious zone of the dam. 9.3 Compaction Control and Specifications Before compaction begins, the embankment material should be spread in lifts or layers having a thickness appropriate to the type of compaction equipment used. The maximum permissible layer thickness should be specified in the plans or specifications. Specifications should require that the ground surface under the proposed dam be stripped of all vegetation, organic and otherwise objectionable materials. After stripping, the earth foundation should be moistened, if dry, and be compacted before placement of the first layer of embankment material . Inclusion of vegetation, organic material, or frozen soil in the embankment, as well as placing of embankment material on a frozen surface is prohibited and should be so stated in the specifications. For all dams, compaction shall be accomplished by appropriate equipment designed specifically for compaction. The type of compaction equipment should be specified in the plans or specifications. 19 The degree of compaction should be specified either as a minimum number of complete coverages of each layer by the compaction equipment or, in the case of higher or more critical dams, based on standard ASTM test methods. When the degree of compaction is specified as a number of complete coverages or passes, the final number of passes required shall be determined by the engineer during construction. In order to insure that the embankment material is compacted at an appropriate moisture content, a method of moisture content control should be specified. For Hazard Class "A" dams less than 20 feet high, the moisture content may be controlled visually by a qualified inspector. Hand tamping should be permitted only in bedding pipes passing through the dam. All other compaction adjacent to structures should be accomplished by means of manually directed power tampers. Backfill around conduits should be placed in layers not thicker than 4 inches before compaction with particle size limited to 3 inches in greatest dimension and compacted to a density equal to that of the adjacent portion of the dam embankment regardless of compaction equipment used. Care should be exercised in placing and compacting fill adjacent to structures to allow the structures to assume the loads from the fill gradually and uniformly. Fill adjacent to structures shall be increased at approximately the same rate on all sides of the structures. The engineer in charge of construction is required to provide thorough and continuous testing to insure that the specified density is achieved. 9.4 VEGETATION CONTROL - TREES AND BRUSH 9.4 .1 Trees and Brush Trees and brush are not permitted on earth dams because: a. Extensive root systems can provide seepage paths for water. b. Trees that blow down or fall over can leave large holes in the embankment surface that will weaken the embankment and can lead to increased erosion. 20 c. Brush obscures the surface limiting visual inspection, provides a haven for burrowing animals and retards growth for grass vegetation. Stumps of cut trees should be removed so grass vegetation can be established and the surface mowed. Stumps should be removed either by pulling or with machines that grind them down. All woody material should be removed to about 6 inches below the ground surface. The cavity should be filled with well compacted soil and grass vegetation established. 9.4 .2 Grass Vegetation Grass vegetation is an effective and inexpensive way to prevent erosion of embankment surfaces. It also enhances the appearance of the dam and provides a surface that can be easily inspected. 10. 0 STRUCTURAL STABILITY CRITERIA FOR GRAVITY DAMS 10.1 Application These guidelines are to be used for the structural stability analysis of concrete and/or masonry sections which form the spillway or non-overflow section of gravity dams. These guidelines are based on the "Gravity Method of Stress and Stability Analysis" as indicated in Reference 13 . If the gravity dam has keyed or grouted transverse contraction joints, then the "Trial-Load Twist Method of Analysis" (Reference 13) may be used for the stability analysis. Elastic techniques, such as the finite element method, my be used to investigate areas of maximum stress in the gravity dam or the foundation. However, the finite element method will only be permitted as a supplement to the Gravity Method. The Gravity Method will be required for the investigation of sliding and overturning of the structure. 10.2 Non-Gravity Dams For non-gravity structures such as arch dams, the designer is required to present calculations based on appropriate elastic techniques as approved by the Dam Safety Section. 21 10.3 Loads Loads to be considered in stability analyses are those due to: external water pressure, internal water pressure (pore pressure or uplift) in the dam and foundation, silt pressure, ice pressure, earthquake, weight of the structure. 10.4 Uplift Hydrostatic uplift pressure from reservoir water and tailwater act on the dam. The distribution of pressure through a section of the dam is assumed to vary linearly from full hydrostatic head at the upstream face of the dam to tailwater pressure at the downstream face or zero if there is no tailwater. Reduction in the uplift pressures might be allowed in the following instances: 10.4.1 When foundation drains are in place. The efficiency of the drains will have to be verified through piezometer readings. 10.4.2 When a detailed flow net analysis has been performed and indicates that a reduction in uplift pressures is appropriate. Any reduction of pressure of more than 20% must be verified by borings and piezometer readings. 10.4.3 When a sufficient number of borings have been progressed and piezometer readings support the fact that actual uplift pressures are less than the theoretical uplift pressures. 10.5 Loading Conditions Loading Conditions to be analyzed. Case 1 - Normal loading condition; water surface at normal reservoir level. Case 2 - Normal loading condition; water surface at normal reservoir level plus an ice load of 5, 000 pounds per linear foot, where ice load is applicable. Dams located in more northerly climates, may require a greater ice load. Case 3 - Design loading condition; water surface at spillway design flood level. 22 Case 3A- Maximum hydrostatic loading condition; maximum differential head between headwater and tailwater levels as determined by storms smaller in magnitude than the spillway design flood. This loading condition will only be considered when the is submerged under Case 3 loading condition. Case 4 - Seismic loading condition; water surface at normal reservoir level plus a seismic coefficient applicable to the location. 10.6 Stability Analysis for New Dams 10.6.1 Field Investigation Subsurface investigations should be conducted for new dams. Borings should be made along the axis of the dam to determine the depth to bedrock as well as the character of the rock and soils under the dam. The number and depth of holes required should be determined by the design engineer based on the complexity of geological conditions. The depth of holes should be at least equal to the height of the dam. Soil samples and rock cores should be collected to permit laboratory testing. The values of cohesion and internal friction of the foundation material should be determined by laboratory testing. On proposed sites where the foundation bedrock is exposed, the requirements for borings may be waived in some cases. An engineering geologist's professional opinion of the rock quality and the acceptability of the design assumptions will be required in those cases. 10.6.2 Overturning The resultant force from an overturning analysis should be in the middle third of the base for all loading conditions, except for the seismic analysis (Case 4) , where the resultant shall fall within the limits of the base. 10.6.3 Cracking The resultant force falling outside the middle third of the base and its resulting tension cracks will not be accepted in the design of new dams, except for the seismic loading condition (Case 4) . 23 10.6.4 Sliding Sliding safety factors may be computed using the Shear-Friction method of analysis when shear values are based on either the results of laboratory testing or an engineering geologist's professional opinion. When the Shear-Friction method is used, the structure should have a minimum safety factor of 2 .0 for all loading conditions except for Case 4 (seismic loading) where the minimum acceptable sliding safety factor shall be 1.5. Designs which are not based on laboratory testing or an engineering geologist's professional opinion must be analyzed using the Friction Factor of Safety. This analysis assumes that the value of shear or cohesion is zero. The minimum safety factor using this method should be 1.5 for all loading conditions except Case 4 where the minimum safety factor shall be 1.25. 10.7 Stability Analysis for Existing Dams 10.7.1 Field Investigations Subsurface investigations should normally be conducted as part of a detailed structural stability investigation for an existing dam and should provide information regarding the materials of the dam and its foundation. The number and depth of holes required should be determined by the engineer based on the complexity of the composition of the dam and foundation. Samples should be collected and tested to determine the material properties. The program should also measure the uplift pressures at several locations along the base of the dam. In cases where no subsurface investigations are conducted conservative assumptions regarding material properties and uplift pressures will be required. 10.7.2 Overturning The resultant force from an overturning analysis should be in the middle third of the base for normal loading conditions (Case 1) and within the middle half of the base for the ice loading condition (Case 2) and the spillway design flood loading condition (Case 3) . For the seismic loading condition (Case 4) , the resultant force should fall within the limits of the base. 24 10.7.3 Cracking If the overturning analysis indicates that the resultant force is outside the middle third, then tension exists at the heel of the dam which may result in the cracking of the concrete. For existing dams cracking will be permitted for all loading conditions except the normal loading condition (Case 1) . If the criteria specified above in Overturning for the location of the resultant force are not satisfied, further study and/or remedial work will be required. The Bureau of Reclamation's Cracked Section Method of analysis is acceptable for investigating the stability of the dam for the above mentioned loading conditions. When the Cracked Section Method of analysis is used, the criteria for the minimum sliding factor of safety will have to be satisfied. 10.7.4 Sliding Sliding safety factors may be computed using the Shear-Friction method of analysis when shear values are based on the results of laboratory testing of samples from subsurface investigations. When the Shear- Friction method is used, the structure should have a minimum safety factor of 2 . 0 for Case 1 and Case 2; a value of 1.5 for Case 3 and a value of 1.25 for Case 4. If no subsurface explorations are performed, the sliding safety factors must be computed using the Friction Factor of Safety. The minimum safety factor using this method should be 1.5 for Case 1; a value of 1.25 for Case 2 and Case 3; and a value of 1.0 for Case 4 . 11.0 EXISTING DAMS: REHABILITATION AND MODIFICATION Additional data should be submitted for dam rehabilitations or dam modifications, including a report by a professional engineer describing the performance and maintenance history of the existing dam. In addition, all data regarding construction, such as existing subsurface explorations, construction materials used for the dam, and plans and specifications should be submitted. If this information is not available, the engineer should inspect and evaluate the structure as to its condition, performance, maintenance history and other information regarding foundation soils and existing conditions. The engineer should also assess the safety and adequacy of the existing structure against those criteria for spillway capacity and structural stability, indicated in the appropriate sections of these guidelines. 25 Where a new embankment is to be constructed against an existing dam embankment, the existing slope shall be benched as the new fill is spread and compacted in layers as described in the plans and specifications. This benching is done to provide an interlock between the existing and new embankments. Benching shall not be done in the upstream-downstream direction. All topsoil and sod shall be stripped from the surface of the existing embankment before placing new material within the area of reconstruction. Remove or seal all existing drainage structures which are not to be operative in the proposed design, in order to prevent a plane of seepage from developing through the dam. 12 . 0 COFFERDAMS A cofferdam in most cases is a temporary structure enclosing all or part of the construction area. The purpose of the cofferdam is to provide protection so that construction can proceed in the dry. 12 .1 When using a cofferdam the following criteria must be met: 12 .1.1 Flood Plain Management A hydraulic analysis must be performed to determine the backwater effect of the cofferdam. A range of flood discharges up to and including the 100 year return frequency flood shall be evaluated to determine the potential flood damages to lands and improvements upstream of the cofferdam not owned or otherwise controlled by the applicant. The analysis shall focus on determining if the project meets the flood plain management criteria of 6NYCRR-Part 500, if applicable, or regulations adopted by the local jurisdiction for participation in the National Flood Insurance Program. 12 .1.2 Dam Safety The applicant will have to demonstrate that cofferdam failure will not adversely impact lives and property. The evaluation will focus on the potential for flooding, loss of life and damage to properties downstream of the cofferdam not owned or otherwise controlled by the applicant. 26 If cofferdam failure could adversely impact properties downstream of the cofferdam, not controlled by the applicant, or if the cofferdam failure could adversely impact lives, then more specific information regarding the geotechnical, structural and hydraulic aspects of the cofferdam design will be required. The determination by the department of the acceptability of the cofferdam design will be made on a case-by-case basis. 13 .0 MISCELLANEOUS The earth embankment, earth spillways, and all disturbed earth adjacent to the embankment or other appurtenances should be seeded, except where riprap or other slope protective materials are specified. Where destructive wave action is expected, the upstream slope of the embankment should be protected with rock riprap or other suitable material for effective erosion control . A trash rack designed to prevent debris from entering and obstructing flow in the conduit should be provided on the vertical riser for any drop inlet spillway. An anti-vortex device is required on the vertical riser for any drop inlet spillway with riser diameter greater than 12 inches. Instrumentation 1.Piezometers - All earth dams 40 feet high or higher shall have at least two piezometers on the downstream slope of the embankment to measure saturation levels and hydrostatic pressures. All concrete dams 40 feet or higher should have at least two piezometers along the crest of the dam. 2 .Weirs - on all dams with toe drains, weirs are required at the downstream end of the drain. The weirs measure the amount of seepage water through the embankment. Measurements of the seepage should be documented and correlated with the reservoir surface elevation. See Reference 6, pages 55-56. 14. 0 EMERGENCY ACTION PLAN An emergency action plan (EAP) should be developed by the owner of a high hazard dam (Class "C") . 27 A copy of this EAP is to be provided to the Dam Safety Section of the department during the initial permit review period for new dams and for existing dams, if a copy of the EAP has not been previously submitted. See Reference 6, pages 69-73 . 15. 0 APPROVAL TO FILL RESERVOIR OF A NEW DAM Before any water can be impounded by the dam, the dam owner shall adhere to the following: 15.1 For all Hazard Class "C" and [major size] Hazard Class "B" dams. Within two weeks after completion of dam construction the permittee shall notify the Regional Permit Administrator in writing by certified mail of its completion and shall include a notarized statement from the owner's engineer that the project has been completely constructed under his care and supervision in accordance with plans and specifications as approved by the department. Any changes in the construction of the dam from the approved plans will be reflected in the "As-Built" plans. The department will inspect the completed dam with the owner's engineer. During the inspection, the owner' s engineer will submit "As Built" drawings and other construction records for review, such as foundation data and geological features, properties of embankment and foundation materials, concrete properties and construction history. Upon review of the data and the determination of the adequacy of the structure the "Approval to Fill" letter will be issued, permitting the owner to store water. 15.2 For all Hazard Class "A" and [Below Major Size] Hazard Class "B" dams. Within two weeks after completion of dam construction the permittee shall notify the Regional Permit Administrator in writing by certified mail of its completion and shall include a notarized statement from the owner's engineer stating that the project has been completely constructed under his care and supervision in accordance with plans and specifications as approved by the department. Any changes in the construction of the dam from the approved plans will be reflected in the "As-Built" plans that will be submitted to the Department. No water shall be impounded for at least 15 days subsequent to the notification to the Regional Permit Administrator. 28 REFERENCES 1. New York State Environmental Conservation Law "Article 15-0503" . 2 . New York Code of Rules and Regulations (6NYCRR) "Part 621 - Uniform Procedures" . 3 . New York Code of Rules and Regulations (6NYCRR) "Part 673 - Dam Safety Regulations" 4 . New York Code of Rules and Regulations (6NYCRR) "Part 500 - Flood Plain Development Permits" 5. New York Code of Rules and Regulations (6NYCRR) "Part 373 - Hazardous Waste Management" 6. An Owners Guidance Manual For the Inspection and Maintenance of Dams in New York State. 7. New York State Education Law "Article 55" . 8. Soil Conservation Service; U. S. Department of Agriculture SCS National Engineering Handbook; August, 1972 "Section 4 -Hydrology Corps of Engineers; U. S. Army 9. Hydrologic Engineering Center 11HEC-1 Flood Hydrograph Package" ; 1981 10. ETL 1110-2-256; June 1981 "Sliding Stability for Concrete Structures" . 11. EM 1110-2-1902; April 1970 "Stability of Earth and Rock-Fill Dams" Bureau of Reclamation; U. S. Department of the Interior 12 . "Design of Small Dams" , 1977 Revised Reprint 13 . "Design of Gravity Dams" , 1976 14 . "Earth Manual" 29 National Oceanic and Atmospheric Administration National Weather Service; U.S. Department of Commerce 15. Hydrometeorological Report 33; April 1956 "Seasonal Variation of the Probable Maximum Precipitation East of the 105th Meridian for Areas from 10 to 1000 Square Miles and Durations of 6, 12, 24 and 48 Hours" 16. Hydrometeorological Report 51; June 1978 "Probable Maximum Precipitation Estimates, United States East of the 105th Meridian" 17. Technical Paper 40; May 1961 "Rainfall Frequency Atlas of the United States for Durations from 30 Minutes to 24 Hours and Return Periods from 1 to 100 Years" 18. Technical Paper 49; 1964 "Two-to-Ten-Day Precipitation for Return Periods of 2 to 100 Years in the Contiguous United States" 30 New York State Department of Environmental Conservation Division of Environmental Permits REGION 5 REGION 6 296 State Office Building CLINTON Route PO Box 317 Washington Street FRANKLIN Ray Brook, 3 12977- 7-0296 Watertown,NY 13601-3787 (518) 897-124 s LAwAENCE _ Sub-Office (315) 785-2245 PO Box 220 Sub-Offices Ask REGION 9 �i Warrensburg. NY 12II85-0220 270 Michigan Avenue State Office BuildingA (51$) 623-3671 Buffalo,NY 14203-2999 Utica, Genesee Street SON (716)851-7165 Utica. NY 13501-2885 � b Sub-Offices (315) 793 2555 LEWIS l IIA MILiON \ tt t 128 South St Olean, NY 14760-0645 wYR EYE N� ' ('716)372-6242 oswlco i EID` `\, \""- , / NIAGA4A ORLEANS MONROE O v.. ._'� \ `` ``¢ rULT Nay; SA�Ai�A SIT t W AYNE *vv \\ GENESE! —�O' -- t Lt ONTAAIO ONONDAGA \. ` \ MONIGOMERY REGION 4 V l} o MADISON 1150 North Wwstcott Rd — WTOMING 2 YATES 0 _ \ °T5°O\ Se w Schenectady,NY 12306 4498 I� CHFIIANG ` \ SL'a\�� ALepNY ' (518)382-0680 \ A � Sub-Office \ \ `\ � SCHUYLE r ` \ 1 `\, GREFNE Route 10.4 CR1 Box 3A C�TTAR ANUS ALL[ N STEu8FN CHIMuNO \ �f�� \"\ 1 0 Stamford, NY 12167-9503 CNAU``ll 7 TIOG� (1R000QQQME \ ' (607)652-7364 REGION 8 REGION 7 SULE,YpN REGION 3 6274 E.Avon-Lima Road 615 Erie Boulevard West o 21 South Putt Corners Road Avon, NY 1 44 1 4-951 9 Syracuse,NY 13204-2400 New Paltz,NY 12561-1696 (716)226-2466 (315)426-7438 GF pU1NAM (914)256-3054 OA PN Sub-Offices 1285,Fisher Ave Cortland.NY 13045-1090 3 (607)753-3095 , r� _I ION 1 REGION 2 Building 40,SUNY at Stony Brook 1 Hunters Point Plaza Stony Brook, NY 11790-2356 47-40 21 St Street (631)751-0365 Long Island City, NY 1 1 1 01-5407 (718)482-4997 LEGEND AWk Regional Headquarters Regional Sub-office (Sub-office responsible for areas printed in blue cross-hatch.) January 2000 ��K Department of STATE Environmental Conservation Water Quality Peak Flow APPENDIX B - This Page is Left Intentionally Blank NEW Department of PORK STATE Environmental Conservation Appendix B: Water Quality Peak Flow Rate The peak flow rate for the water quality design storm is needed for sizing flow-based practices and off-line practices. The conventional SCS methods have been found to underestimate the volume and rate of runoff for rainfall events less than two (2) inches. This discrepancy can lead to practices that are inadequately sized for the required Water Quality Volume (WQv), calculated using Chapter 4. This Appendix presents the steps taken to convert the required Water Quality Volume (WQv), calculated using Chapter 4, to the equivalent Water Quality Peak Flow Rate (WQF). The equivalent WQF is calculated through hydraulic and hydrologic modeling software utilizing the rainfall distribution generated in Section 4.9. It is important to note that a calculated rainfall value, different from the 90th percentile rainfall value in Chapter 4, is utilized to generate a runoff volume equivalent to the required WQv. The following provides the step-by-step process to convert the required WQv to the equivalent WQF using the NRCC and NRCS website and HydroCAD. For purposes of this example,the project site is taken to be in Queens, NY. Step 1 Create the Distribution Curve Using the steps provided in Section 4.9, create the synthetic rainfall distribution curve specific to the project site. Step 2 Determine the Water Quality Treatment Volume (WQv) Calculate the required WQv per Chapter 4 and/or Chapter 9. The example outlined below is for redevelopment activities, with a 15% reduction in impervious cover that will utilize a hydrodynamic separator. The required WQv is calculated using Section 9.2.1.A criteria II, where 100% WQv is captured and treated, for a minimum of 25% of the disturbed redevelopment impervious area. The subcatchment includes 1.18 acres contributing to the practice, of which the designer is required to treat 0.94 acres of impervious. As such, the required WQv is calculated to be 0.112 of or 4,887 cf. Step 3 — Solve for the Calculated "P9o" Value First, calculate the weighted Curve Number(CNw) for the contributing drainage area to the practice. In this example, two (2) subcatchments are tributary to the hydrodynamic separator. Therefore, CNw is the weighted average of the two (2) subcatchments: Appendix B.Water Quality leak Flays Date 13_1 o Edit Subcat ES-1-Queens X Edit Subcat ES-2-Queens X General Area ,To I Notes I General Area I To I Notes Line Area facresl CN Description A Line,Area lacre!sl ICN I Description A 1 0.555 98 Existinq impervious surface,HSG B 1 0.381 98 Existing impervious surface,HSG B 2 0.156 61 >75%Grass cover,Good,HSG B 2 0.089 61 >75%Grass cover,Good,HSG B 3 3 4 4 5 5 6 6 7 7 8 8 a rea: (acres) Weighted C rea: (acres) Weighted CN: 0.711 90 Lookup CN... 0.470 91 >ookup CN... areas automatically areas matically OK Cancel j Apply Help OK Cancel Apply Help (A1xCN1) + (A2xCN2) + "'(ANxCNN) CN1,t, = A Where: AN = Subcatchment Area CNN = Curve Number for Subcatchment (0.711 acres x 90) + (0.470 acres x 91) CN1i = 1.181 acres CNw = 90 Then, calculate the maximum basin retention (S) in inches, using CNw 1,000 S C — 10 N W 1,000 S 9 — 10 0 S = 1.11 inches Next, calculate the runoff(Q), in inches, generated over the contributing area given the required WQv: Required WQv Q A 0.112 of Q 1.181 acres Q = 0.09 f t(1.14 inches) Finally, using the runoff(Q) in inches and maximum basin retention (S), determine the calculated rainfall value (P9o): S+2.5Q + (6.25Q2 + 25SQ)o.s P90 5 1.11 inches + (2.5 x 1.14 inches) + (6.25 x 1.14 inches2 +25 x 1.11 inches x 1.14 inches)0.9 P90 5 P90 = 2.05 inches Appendix B:Water Quality Peak Flow Rate B- Step 4 — Input the Calculated Rainfall Value in the Model In the stormwater model, enter the "Calculation Settings" and click on the "Rainfall'tab. Ensure that in the rainfall tab, the "Storm Type" shown as the distribution curve created under Step 1 and the "Storm Curve" corresponds to the "Rainfall Event"shown. 'alculr Ge Rainfall pan I Reports I Unit Hydro I Advanced 5tormype: form Curve: View Storm 11 NY-Q ueens 24-hr S 1 1-yr More Storms Northeast New York -73.72640.7460 Duration Mode: Storm Duration: [hours] �Back-to-Back Storms: Default 24.00 I' Depth: [inches] ainfall Even 2.64 Name: 1-yr 211Save Delete Sort by: (' Manual r Name f Depth A�MC: I` Import Events From ...--:, . I Del All UiewAll OK Cancel _Apply J Help Type the rainfall depth, in inches, calculated under Step 3 in the "Depth" box and change the "Rainfall Event Name"to be 90% WQv. Ensure that the "Storm Curve" is the 1-yr, then click"Save" and click"OK". 0 General Rainfall 1 Time Span_ Reports Unit Hydro_Advanced Storm Type Storm Curve: View Storm NY-Queens 24-hr S171 1-yr More Storms Northeast New York -73.726 40.746 0 Duration Mode: Storm Duration: [hours] Back-to-Back Storms: Default 24.00 _epth: (inches Rainf 2.05 Name: 90_WQv Save Sort by: r Manual ' Name C Depth AMC: --J _Import Events From... Del All View All OK I Cancel Apply Help I In the ribbon, select"90% WQv" as the rainfall event. The value output in the model is the WQF corresponding to the required WQv for the practice. Appendix B.Water Quality leak Flays mate B-3 Project Diagram Node Vim Print Settings Help 0011MOTTM11i 0,10,1011M 941 x I a I balgLml—MJ—MJ -2J sums o Pond HYD-1:Hydrodynamic#1 Queens 0 X Summary FT9raPh Discharge Events I-Sing Hpdrograph Pr—ryLink 7 TOXL LL 2D Print Ep,,l G 5 10 15 20 25 30 35 4{I 45 4 5S 60 ES 74 Edit Thaw lihours) - -2-111 A final check is to compare the WQv required (0.112 af) to the inflow volume at the practice. Inflow Area 1.181 ac. 79.25%Impervious. inflow for 90�.--i event Inflow = 1.85 cfs P_, 12.04 hrs, Volume= 0.112 of Primary = 1.85 cfs @ 12.04 hrs, Volume= en=0%, Lag=0.0 min Routing by Dyn-Star-Ind method,Time Span=0.00-72.00 hrs.dt=0.01 hrs Appendix B:Water Quality Peak Flow Rate B-4 ��K Department of STATE Environmental Conservation APPENDIX C Miscellaneous Details This Page is Left Intentionally Blank NEW Department of PORK STATE Environmental Conservation Appendix C: Miscellaneous Details Miscellaneous Design Schematics for Compliance with Performance Criteria Figure CA Trash Rack Protection for Low Flow Orifice Figure C.2 Expanded Trash Rack Protection for Low Flow Orifice Figure C.3 Observation Well for Infiltration Practices Figure C.4 On-line Versus Off-line Schematic Figure C.5 Isolation/Diversion Structure Figure C.6 Half Round CMP Hood Figure C.7 Half Round CMP Weir Figure C.8 Concrete Level Spreader Figure C.9 Baffle Weir for Cold Climates Figure C.10 Hooded Outlet with Hood Below Ice Layer Figure C.11 Shallow Angle Trash Rack to Prevent Icing Figure C.12 Upturned Elbow Appendix C: Miscellaneous Details C-1 Figure CA Trash Rack Protection for Low Flow Orifice ,.Il ar — WELD (TYP.) 2"x 1/4" STEEL STOCK ALL AROUND 1/2" DIAMETER HOLES r §24"0/C MAX_(TYP_) LC3 3 LBIFT 2 EXPANDED STEEL GRATE ON TOP, BOTTOM, AND SIDES WELD 1"x1"x1/8"ANGLE OVER ALL EDGES (TYP.) NOTES FOR TRASH RACK 1. TRASH RACK TO BE CENTERED OVER OPENING. 2. STEEL TO CONFORM TO ASTM A-3+6. 3.ALL SURFACES TO BE COATED WITH ZRC COLD GALVANIZING COMPOUND AFTER WELDING. Appendix C: Miscellaneous Details C-2 Figure C.2 Expanded Trash Rack Protection for Low Flow Orifice EXPANDED STEEL GRATE PRE-CAST 3 LBSTr WELDED INSIDE RISER STRUCTURE ANGLES,TOP AND BOTH SIDES. #3.0 GRATING (SEE DETAIL) a * V4'x 4"STEEL ALL AROUND 0 � O 1 r2"DIAI MIR HOLE (TYP.) i 1"x 1"ANGLES ALONG TOP EDGES CAST4N-PLACE 1 LAYER B"x B"414 TRASH RACK BASE WOVEN WIRE FABRIC (3'-8"x3'-2'x8") CENTERED IN SLAS Appendix C: Miscellaneous Details C-3 Figure C.3 Observation Well for Infiltration Practices -SCREW TOP LID* FINISHED GRADE m=1 PANELLA TYPE CLEANOUT WITH COUNTERSUNK HEAD R PIPE SEAL GASKET 6" P.V.C. SOIL PIPE •ABOVE DETAIL PROVIDED AS SCHEMATIC SCREW TOP P.V.C.WELL CAP ONLY EACH OBSERVATION WELL 1 CLEANOUT SHALL INCLUDE THE FOLLOWING; 1. FOR AN UNDERGROUND FLUSH 'MOUNTED OBSERVATION WELL l CLEANOUT, PROVIDE A TUBE MADE OF NON-CORROSIVE MATERIAL, SCHEDULE 40 OR EQUAL,AT LEAST THREE FEET LONG WITH AN INSIDE DIAMETER OF AT LEAST 6 INCHES. 2.THE TUBE SHALL HAVE A FACTORY ATTACHED CAST IRON OR HIGH IMPACT PLASTIC COLLAR WITH RIBS TO PREVENT ROTATION WHEN REMOVING SCREW TOP LID. THE SCREW TOP LID SHALL BE CAST IRON OR HIGH OMPACT PLASTIC THAT WILL WITHSTAND ULTRA-VIOLET RAYS. Appendix C: Miscellaneous Details C-4 Figure CA On-Line Versus Off-Line Schematic -: W iy �V V W iF y i. . V, F_ * 1V iV ab � 1 PLAN VIEW PLAN VIEW SECTION SECTION OFF-LINE ON-LINE Appendix C: Miscellaneous Details C-5 Figure C.5 Isolation Diversion Structure STANDARD MAM40LE TOP OF TRASH CRATING t ��r PIPE AT OUTLET PIKE INVERT INVERT OF INFLOW ���Y r 4 QL��T��-OVY PIPE , - MAMA*1OLF WALL PER D Mm ETAIL MANHOLE CFLANNI - =�-ram.=,- TIRST FLLIW OUTLET PIPE {TO BMP FAON.M PRECAST MANHOLE BASE NOTE ALUMINUM TRASH GRATE KMO SEMICIRCULAR SECTIONS Appendix C: Miscellaneous Details C-6 Figure C.6 Half Round CMP Hood RISER r TOP PLATE LOW FLOW ORIFICE (IN RISER WALL) IQ ROUND CMP HOOD 12'-18'BEL W ` ORIFICE INVERT �- Appendix C: Miscellaneous Details C-7 Figure C.7 Half Round CMP Weir OPEN TOP , � 1W o- o a o- 0 e 0 c 1/2 ROUND CMP PIPE—WEIR PLATE WELDED TO BOTTOM Appendix C: Miscellaneous Details C-8 Figure C.8 Concrete Level Spreader 0%CHANNEL GRADE C CONCCENTRATESHEET F OW LOW (SPREADER CHANNEL) -__ _••�"•.=' - _-: =j. ..,•r.�} __y7m - V MINIMUM LEVEL PLAN VIEW CONCRETE ORKWNAL GROUND LIP`PROTECTION 4 LEVEL LIP .... _................... t,196 GRADE 2:1 OR FLATT 6"MIN. 3' ir PROFILE Appendix C: Miscellaneous Details C-9 Figure C.9 Baffle Weir for Cold Climates NZ K7 G' AYE Figure C.10 Hooded Outlet with Hood Below Ice Layer RISER w r 1 /CE •L YE.y7 �^ i dA�rFCOW Figure C.11 Shallow Angle Trash Rack to Prevent Icing r x f i � 4 ORIGINAL' $HALLOW AAIGLE Appendix C: Miscellaneous Details C-10 Figure C.12 Upturned Elbow � I�I�I��III���I El =111=111A 11 1ll=1 I -Jll-I 1 LL _S 11-111-11 I l I h :M=I_m-1 I F-TI _ I—I 11=1 I I—I 11=f I I- a - -- - - - - - - - - - - _ — IIIIIIe 10" ? a 6- 6N PVC PERFOR:ATEC UNDErRDRAI N-+ C" SOLID CONVEYANCE PIPEJ 900` BEN[] Appendix C: Miscellaneous Details C-11 This Page is Left Intentionally Blank NEW Department of PORK STATE Environmental Conservation ��K Department of STATE Environmental Conservation InfiltrationAPPENDIX D - • Requirements This Page is Left Intentionally Blank NEW Department of PORK STATE Environmental Conservation Appendix D: Testing Requirements for SMPs General Notes Pertinent to All Testing 1. Refer to practice specific"Feasibility"sections, in Chapter 5 &Chapter 6, for underlying soil infiltration rate requirements. 2. Number of required test pits/borings and permeability tests are based on the size of the proposed practice. Testing is done in two phases: Feasibility and Design Testing. 3. Testing shall be performed under the supervision of a qualified professional. This professional shall be either a registered Professional Engineer in the State of New York, Soil Scientist, or Geologist that is licensed in the State of New York. Feasibility Testing Feasibility Testing is conducted to determine whether full-scale testing is necessary and is meant to screen unsuitable sites and reduce testing costs. Permeability testing and test pits/borings are not required at this stage. However, the designer or landowner may choose to skip Feasibility Testing, and proceed directly to Design Testing, per Table D.1. Feasibility Testing requires, at minimum, one percolation test for each proposed practice, or previous testing data, such as the following: Septic percolation testing on-site, within 200 ft of the proposed SMP location, and on the same contour. Previously written reporting on the site location as prepared by a registered Professional Engineer in the State of New York, Soil Scientist, or Geologist licensed in the State of New York. NRCS County Soil Mapping showing an unsuitable soil group, such as a hydrologic group"D" soil, in a low-lying area, or a Marlboro Clay. If Feasibility Testing results in a percolation rate of less than or equal to 20 min/inch, then it is probable that the infiltration rate is sufficient to support infiltration practices and Design Testing is required per Table D.1. If Feasibility Testing results in a percolation rate greater than 20 min/inch, then it is probable that the infiltration rate is insufficient to support infiltration practices. The designer may choose to proceed with the design of non-infiltration practices or may choose to proceed with Design Testing. Non-infiltration practices may require infiltration testing to determine the need for an impermeable liner(see Chapter 6). Feasibility Testing Requirements Excavate each hole with vertical sides approximately 12 inches in diameter. The hole depth shall be at or as close to the projected bottom of practice as possible, with a 24-inch minimum depth. The sides of the percolation holes shall be scraped to remove smearing. Optional, place washed aggregate in the lower two inches of each test hole to reduce scouring and silting action when water is poured into the hole. b. Presoak the test holes by continually filling the hole with clean water, for a minimum of four hours, and allowing the water to seep into the subgrade. Feasibility tests shall take place one day after the presoak. After the water from the final presoaking has fully seeped into the subgrade, remove any sloughed soil from the bottom of the hole. As an exception, feasibility tests may occur the same day if all water has infiltrated, following completion of the four hour presoak. c. Pour clean water into the hole, with as little splashing as possible, to a depth of six inches above the bottom of the test hole. d. Observe and record the time in minutes for the water to drop from the six-inch depth to the five-inch depth. Appendix D:Infiltration Testing Requirements 01 Repeat test until the time for the water to drop from six inches to five inches, for two successive tests, is approximately equal. The test shall be repeated a minimum of three times. The longest time interval to drop one inch will be taken as the stabilized rate of percolation. If different results are obtained for multiple holes within the same proposed practice, the slowest stabilized rate shall be used for practice feasibility. Design Testing Requirements The goals of Design Testing are to establish detailed information about seasonal high water table conditions, boundary conditions such as bedrock, and physical characteristics of the soil to determine the suitability of the soil for a stormwater infiltration practice. Design Testing shall include the minimum quantity of test pits/borings and permeability tests, identified in Table D.1. --& Table DA Minimum Design Testing Re uirem, Area of Practice #of Test Pits/Boring #of Permeability Tests <2,500 sf 2 2 2,500 sf to<5,000 sf 2 3 5,000 sf to<7,500 sf 3 4 7,500 sf to 10,000 sf 3 5 > 10,000 sf Add 1 test pit/boring for each additional 5,000 sf of practice Add 1 permeability test for each additional 2,500 sf of practice Linear Practice 1 test pit/boring for each 250 linear feet of practice 1 permeability test for each 250 linear feet of practice The required minimum quantity of design tests shall be equally spaced across the footprint of each practice. When four or more permeability tests are performed within the footprint of a single practice, the stabilized rates of the lowest and highest permeability tests shall be discarded. An average shall be taken of the remaining rates. The soil profile recorded in each test pit/boring, and the infiltration rate recorded in each permeability test, shall be compared to the adjacent tests to confirm consistency. Where soil properties, infiltration rates, and/or depth to seasonal high water table or bedrock vary significantly, additional test pits/borings and/or permeability tests shall be conducted to resolve differences and accurately characterize the soils in the area of interest. If additional testing is not performed, then the more conservative value(s) shall be applied in the design. Documentation A legible site plan, drawn to an accurate scale, shall be provided and include all test locations, and SMP(s). All required documentation shall be included in the Stormwater Pollution Prevention Plan. The documentation of soil profiles shall include a soil profile log prepared for each test pit/boring and a description of all soil horizons encountered according to the USDA textural classification. The soil profile log shall, at a minimum, include the following: Test number; Total depth of test; Depth and thickness of each soil horizon (each stratum) and depth to restrictive layer(if encountered); Appropriate textural class as shown on the USDA textural triangle; Soil moisture condition, using standard USDA classification terminology; Depth to seasonal high water table, either perched or regional; and Appendix D:Infiltration Testing Requirements D-2 Any observed seepage, saturation, or mottling. Photos of each test pit/boring shall be provided with the soil profile log Test Pit/Boring Requirements a. Excavate a test pit or drill a boring to a depth of at least four feet below the proposed practice bottom, to the depth of bedrock, or to the seasonal high water table, whichever is less. Test pits should be of adequate size, depth, and construction to allow a person to enter and exit the pit and complete a soil profile description. If borings are drilled, continuous soil borings shall be taken using an auger, probe, or split-spoon sampler. Samples shall have a minimum two inch diameter. A minimum number of test pits and/or borings should be provided for each practice as designated in Table D.1. Determine depth to seasonal high water table (if potentially within four feet below the base of the practice). Determine USDA or USC System soil textures at the proposed bottom of practice and to four feet below the bottom of the practice. Describe soil horizons and depth to bedrock (if within four feet of proposed bottom of practice). The location of the test pit or boring shall correspond to the practice bottom; test pit/soil boring stakes shall be clearly labeled and left in the field for inspection and surveyed location. Field Permeability Tests Permeability tests shall be conducted at a depth of two feet below the bottom of the proposed SMP. Where stormwater practices are in proximity to fractured bedrock, the practice shall meet the separation requirements outlined in Chapter 5 or Chapter 6. For stormwater ponds and wetlands that do not provide a liner, the maximum allowable infiltration rate is 0.014 inch/hr (see Chapter 6). This can be proven with a permeability test that results in no measurable drop in water level over four hours. Field Permeability Testing Requirements Excavate to the proposed bottom depth of practice using a backhoe or other machinery. Dig a smaller excavation at the bottom depth of the practice approximately 12 inches in diameter to a depth of 24 inches. Firmly seat casing (solid 4 to 6 inch diameter, 30 inch length) in small excavation. Remove all loose material from the casing. Fill soil around the pipe and hydrate to seal the pipe in place. Fill casing with clean water to a depth of 24 inches and allow to presoak for 24 hours or until all water in the casing has infiltrated, whichever is earlier. Following completion of the presoak, refill casing with another 24 inches of clean water and monitor water level (measure drop from the top of casing) for one hour. Repeat this procedure (filling the casing each time) a minimum of three additional times, until the permeability rate stabilizes. A rate is considered stabilized when two successive tests are approximately equal. All results from permeability testing shall be reported utilizing the lowest reported stabilized rate per test. Testing units shall be in inches/hour. Upon completion of the testing, the casings should be immediately pulled, and the test pit shall be backfilled. Appendix D:Infiltration Testing Requirements D-3 EXISTING GRADE l EXCAVATE WITH SACKHOE OR USE SOIL BORING n CASING = FILL CASING 24 INCHES WITH CLEAN WATER FOR PRESOAK AND TEST _I BOTTOM ELEVATION OF PROPOSED STORMWATER MANAGEMENT PRACTICE 6"s3 SOLID PIPE f I l - 1 Figure D.1 Permeability Testing Requirements Alternate: Laboratory Permeability Testing The Ksat should be measured with test methods described in ASTM D2434 (Standard Test Method for Permeability of Granular Soils (Constant Head)) or ASTM D 5856 (Standard Test Methods for Measurement of Hydraulic Conductivity of Porous Material Using a Rigid-Wall, Compaction Mold Permeameter). Apply a minimum factor of safety by dividing the representative Ksat by 2.0 and use the result as the design infiltration rate. Once the fill is in place, the soil shall be field tested to confirm the design rate. To confirm the rate, run the field test in accordance with Field Permeability Testing Requirements. Appendix D:Infiltration Testing Requirements D-4 ��K Department of STATE Environmental Conservation This Page is Left Intentionally Blank NEW Department of PORK STATE Environmental Conservation Appendix E: Plan Review Checklists Example Checklist for Preliminary/Concept Stormwater Management Plan Preparation and Review Applicant information Name, legal address, and telephone number Common address and legal description of site Vicinity map Existing and proposed mapping and plans (recommended scale of 1" = 50ft.) which illustrate at a minimum: Existing and proposed topography (minimum of 2-ft contours recommended) Perennial and intermittent streams Mapping of predominant soils from USDA soil surveys Boundaries of existing predominant vegetation and proposed limits of clearing Location and boundaries of resource protection areas such as wetlands, lakes, ponds, and other setbacks (e.g., stream buffers, drinking water well setbacks, septic setbacks) Location of existing and proposed roads, buildings, and other structures Existing and proposed utilities (e.g., water, sewer, gas, electric) and easements Location of existing and proposed conveyance systems such as grass channels, swales, and storm drains Flow paths Location of floodplain/floodway limits and relationship of site to upstream and downstream properties and drainages Preliminary location and dimensions of proposed channel modifications, such as bridge or culvert crossings Preliminary location, size, and limits of disturbance of proposed stormwater treatment practices Hydrologic and hydraulic analysis including: Existing condition analysis for runoff rates, volumes, and velocities presented showing methodologies used and supporting calculations Proposed condition analysis for runoff rates, volumes, and velocities showing the methodologies used and supporting calculations Preliminary analysis of potential downstream impact/effects of project, where necessary Preliminary selection and rationale for structural stormwater management practices Preliminary sizing calculations for stormwater treatment practices including contributing drainage area, storage, and outlet configuration Preliminary landscaping plans for stormwater treatment practices and any site reforestation or revegetation Preliminary erosion and sediment control plan that at a minimum meets the requirements outlined in New York State Standards and Specifications for Erosion and Sediment Control (latest version) and any local Erosion and Sediment Control guidelines (if applicable) Identification of preliminary waiver requests Appendix E: Plan Review Checklists E-1 Example Checklist for Final Stormwater Management Plan Preparation and Review Applicant information Name, legal address, and telephone number Common address and legal description of site Signature and stamp of registered engineer/surveyor and design/owner certification Vicinity map Existing and proposed mapping and plans (recommended scale of 1" = 50ft or greater detail)which illustrate at a minimum: Existing and proposed topography (minimum of 2-ft contours recommended) Perennial and intermittent streams Mapping of predominant soils from USDA soil surveys as well as location of any site-specific borehole investigations that may have been performed. Boundaries of existing predominant vegetation and proposed limits of clearing Location and boundaries of resource protection areas such as wetlands, lakes, ponds, and other setbacks (e.g., stream buffers, drinking water well setbacks, septic setbacks) Location of existing and proposed roads, buildings, and other structures Location of existing and proposed utilities (e.g., water, sewer, gas, electric) and easements Location of existing and proposed conveyance systems such as grass channels, swales, and storm drains Flow paths Location of floodplain/floodway limits and relationship of site to upstream and downstream properties and drainages Location and dimensions of proposed channel modifications, such as bridge or culvert crossings Location, size, maintenance access, and limits of disturbance of proposed structural stormwater Management practices Representative cross-section and profile drawings and details of structural stormwater Management practices and conveyances (i.e., storm drains, open channels, swales, etc.)which include: Existing and proposed structural elevations (e.g., invert of pipes, manholes, etc.) Design water surface elevations Structural details of outlet structures, embankments, spillways, stilling basins, grade control structures, conveyance channels, etc. Logs of borehole investigations that may have been performed along with supporting geotechnical report. Appendix E: Plan Review Checklists E-2 Hydrologic and hydraulic analysis for all structural components of stormwater system (e.g., storm drains, open channels, swales, Management practices, etc.) for applicable design storms including: Existing condition analysis for times of concentration, runoff rates, volumes, velocities, and water surface elevations showing methodologies used and supporting calculations Proposed condition analysis for times of concentration, runoff rates, volumes, velocities, water surface elevations, and routing showing the methodologies used and supporting calculations Final sizing calculations for structural stormwater Management practices including, contributing drainage area, storage, and outlet configuration Stage-discharge or outlet rating curves and inflow and outflow hydrographs for storage facilities (e.g., stormwater ponds and wetlands) Final analysis of potential downstream impact/effects of project, where necessary Dam breach analysis, where necessary Final landscaping plans for structural stormwater Management practices and any site reforestation or revegetation Structural calculations, where necessary Applicable construction specifications Erosion and sediment control plan that at a minimum meets the requirements of the local Erosion and Sediment Control Guidelines Sequence of construction Maintenance plan which will include: Name, address, and phone number of responsible parties for maintenance. Description of annual maintenance tasks Description of applicable easements Description of funding source Minimum vegetative cover requirements Access and safety issues Testing and disposal of sediments that will likely be necessary Evidence of acquisition of all applicable local and non-local permits Evidence of acquisition of all necessary legal agreements (e.g., easements, covenants, land trusts) Waiver requests Review agency should have inspector's checklist identifying potential features to be inspected on site visits Appendix E: Plan Review Checklists E-3 This Page is Left Intentionally Blank NEW Department of PORK STATE Environmental Conservation ��K Department of STATE Environmental Conservation This Page is Left Intentionally Blank NEW Department of PORK STATE Environmental Conservation Appendix F: Construction Inspection Checklists Stormwater/Wetland Pond Construction Inspection Checklist Project: Location: Site Status: Date: Time: Inspector: CONSTRUCTION SEQUENCE SATISFACTORY/ COMMENTS UNSATISFACTORY Pre-Construction/Materials and Equipment Pre-construction meeting Pipe and appurtenances on-site prior to construction and dimensions checked 1. Material (including protective coating, if specified) 2. Diameter 3. Dimensions of metal riser or pre-cast concrete outlet structure 4. Required dimensions between water control structures (orifices, weirs, etc.) are in accordance with approved plans 5. Barrel stub for prefabricated pipe structures at proper angle for design barrel slope 6. Number and dimensions of prefabricated anti-seep collars 7. Watertight connectors and gaskets 8. Outlet drain valve Project benchmark near pond site Equipment for temporary de-watering Appendix F:Construction Inspection Checklists F-1 CONSTRUCTION SEQUENCE SATISFACTORY/ COMMENTS UNSATISFACTORY 2. Subgrade Preparation Area beneath embankment stripped of all vegetation, topsoil, and organic matter 3. Pipe Spillway Installation Method of installation detailed on plans A. Bed preparation Installation trench excavated with specified side slopes Stable, uniform, dry subgrade of relatively impervious material (If subgrade is wet, contractor shall have defined steps before proceeding with installation) Invert at proper elevation and grade _T B. Pipe placement Metal / plastic pipe 1. Watertight connectors and gaskets properly installed 2. Anti-seep collars properly spaced and having watertight connections to pipe 3. Backfill placed and tamped by hand under"haunches" of pipe 4. Remaining backfill placed in max. 8" lifts using small power tamping equipment until 2 ft cover over pipe is reached Appendix F:Construction Inspection Checklists F-2 CONSTRUCTION SEQUENCE SATISFACTORY/ COMMENTS UNSATISFACTORY 3. Pipe Spillway Installation Concrete pipe 1. Pipe set on blocks or concrete slab for pouring of low cradle 2. Pipe installed with rubber gasket joints with no spalling in gasket interface area 3. Excavation for lower half of anti-seep collar(s) with reinforcing steel set 4. Entire area where anti-seep collar(s) will come in contact with pipe coated with mastic or other approved waterproof sealant 5. Low cradle and bottom half of anti-seep collar installed as monolithic pour and of an approved mix 6. Upper half of anti-seep collar(s) formed with reinforcing steel set 7. Concrete for collar of an approved mix and vibrated into place (protected from freezing while curing, if necessary) 8. Forms stripped and collar inspected for honeycomb prior to backfilling. Parge if necessary. C. Backfilling Fill placed in maximum 8" lifts Backfill taken minimum 2 ft above top of anti-seep collar elevation before traversing with heavy equipment Appendix F:Construction Inspection Checklists F-3 CONSTRUCTION SEQUENCE SATISFACTORY/ COMMENTS UNSATISFACTORY 4. Riser/Outlet Structure Installation Riser located within embankment A. Metal riser Riser base excavated or formed on stable subgrade to design dimensions Set on blocks to design elevations and plumbed Reinforcing bars placed at right angles and projecting into sides of riser Concrete poured so as to fill inside of riser to invert of barrel B. Pre-cast concrete structure Dry and stable subgrade Riser base set to design elevation If more than one section, no spalling in gasket interface area; gasket or approved caulking material placed securely Watertight and structurally sound collar or gasket joint where structure connects to pipe spillway C. Poured concrete structure Footing excavated or formed on stable subgrade, to design dimensions with reinforcing steel set Structure formed to design dimensions, with reinforcing steel set as per plan Concrete of an approved mix and vibrated into place (protected from freezing while curing, if necessary) Forms stripped & inspected for "honeycomb" prior to backfilling; parge if necessary Appendix F:Construction Inspection Checklists F-4 CONSTRUCTION SEQUENCE SATISFACTORY/ COMMENTS UNSATISFACTORY 5. Embankment Construction Fill material Compaction Embankment 1. Fill placed in specified lifts and compacted with appropriate equipment 2. Constructed to design cross-section, side slopes and top width 3. Constructed to design elevation plus allowance for settlement 6. Impounded Area Construction Excavated /graded to design contours and side slopes Inlet pipes have adequate outfall protection Forebay(s) Pond benches 7. Auxiliary (if applicable) and Emergency Spillway Construction Spillway located in cut or structurally stabilized with riprap, gabions, concrete, etc. Excavated to proper cross-section, side slopes and bottom width Entrance channel, crest, and exit channel constructed to design grades and elevations Appendix F:Construction Inspection Checklists F-5 CONSTRUCTION SEQUENCE SATISFACTORY/ COMMENTS UNSATISFACTORY 8. Outlet Protection A. End section Securely in place and properly backfilled B. Endwall Footing excavated or formed on stable subgrade, to design dimensions and reinforcing steel set, if specified Endwall formed to design dimensions with reinforcing steel set as per plan Concrete of an approved mix and vibrated into place (protected from freezing, if necessary) Forms stripped and structure inspected for "honeycomb" prior to backfilling; parge if necessary C. Riprap apron /channel Apron /channel excavated to design cross-section with proper transition to existing ground Filter fabric in place Stone sized as per plan and uniformly place at the thickness specified 9. Vegetative Stabilization Approved seed mixture or sod Proper surface preparation and required soil amendments Excelsior mat or other stabilization, as per plan Appendix F:Construction Inspection Checklists F-6 CONSTRUCTION SEQUENCE SATISFACTORY/ COMMENTS UNSATISFACTORY 10. Miscellaneous Drain for ponds having a permanent pool Trash rack/anti-vortex device secured to outlet structure Trash protection for low flow pipes, orifices, etc. Fencing (when required) Access road Set aside for clean-out maintenance 11. Stormwater Wetlands Adequate water balance Variety of depth zones present Approved pondscaping plan in place Reinforcement budget for additional plantings Plants and materials ordered 6 months prior to construction Construction planned to allow for adequate planting and establishment of plant community (April-June planting window) Wetland buffer area preserved to maximum extent possible Comments: Appendix F:Construction Inspection Checklists F-7 Actions to be Taken: Appendix F:Construction Inspection Checklists F-8 Infiltration Trench Construction Inspection Checklist Project: Location: Site Status: Date: Time: Inspector: CONSTRUCTION SEQUENCE SATISFACTORY/ COMMENTS UNSATISFACTORY 1. Pre-Construction Pre-construction meeting Runoff diverted Soil permeability tested Groundwater/ bedrock sufficient at depth 2. Excavation Size and location Side slopes stable Excavation does not compact subsoils 3. Filter Fabric Placement Fabric specifications Placed on bottom, sides, and top Appendix F:Construction Inspection Checklists F-9 CONSTRUCTION SEQUENCE SATISFACTORY/ COMMENTS UNSATISFACTORY 4. Aggregate Material Size as specified Clean /washed material Placed properly 5. Observation Well Pipe size Removable cap/footplate Initial depth = ft 6. Final Inspection Pretreatment device in place Contributing watershed stabilized prior to flow diversion Outlet Comments: Appendix F:Construction Inspection Checklists F-10 Actions to be Taken: Appendix F:Construction Inspection Checklists F-11 Infiltration Basin Construction Inspection Checklist Project: Location: Site Status: Date: Time: Inspector: CONSTRUCTION SEQUENCE SATISFACTORY/ COMMENTS UNSATISFACTORY 1. Pre-Construction Runoff diverted Soil permeability tested Groundwater/ bedrock depth 2. Excavation Size and location Side slopes stable Excavation does not compact subsoils 3. Embankment Barrel Anti-seep collar or Filter diaphragm Fill material Appendix F:Construction Inspection Checklists F-112 CONSTRUCTION SEQUENCE SATISFACTORY/ COMMENTS UNSATISFACTORY 4. Final Excavation Drainage area stabilized Sediment removed from facility Basin floor tilled Facility stabilized 5. Final Inspection Pretreatment device in place Inlets/ outlets Contributing watershed stabilized before flow is routed to the facility Comments: Actions to be Taken: Appendix F:Construction Inspection Checklists F-13 Sand Filter System Construction Inspection Checklist Project: Location: Site Status: Date: Time: Inspector: CONSTRUCTION SEQUENCE SATISFACTORY/ COMMENTS UNSATISFACTORY 1. Pre-construction Pre-construction meeting Runoff diverted Facility area cleared Facility location staked out 2. Excavation Size and location Side slopes stable Foundation cleared of debris If designed as exfilter, excavation does not compact subsoils Foundation area compacted 3. Structural Components Dimensions and materials Forms adequately sized Concrete meets standards Prefabricated joints sealed Underdrains (size, materials) Appendix F:Construction Inspection Checklists F-14 CONSTRUCTION SEQUENCE SATISFACTORY/ COMMENTS UNSATISFACTORY 4. Completed Facility Components 24-hr water filled test Contributing area stabilized Filter material per specification Underdrains installed to grade Flow diversion structure properly installed Pretreatment devices properly installed Level overflow weirs, multiple orifices, distribution slots 5. Final Inspection Dimensions Surface completely level Structural components Proper outlet Ensure that site is properly stabilized before flow is directed to the structure. Appendix F:Construction Inspection Checklists F-15 Comments: Actions to be Taken: Appendix F:Construction Inspection Checklists F-16 Bioretention Construction Inspection Checklist Project: Location: Site Status: Date: Time: Inspector: CONSTRUCTION SEQUENCE SATISFACTORY/ COMMENTS UNSATISFACTORY 1. Pre-Construction Pre-construction meeting Runoff diverted Facility area cleared If designed as exfilter, soil testing for permeability Facility location staked out 2. Excavation Size and location Lateral slopes completely level If designed as exfilter, ensure that excavation does not compact subsoils. Longitudinal slopes within design range Appendix F:Construction Inspection Checklists F-17 CONSTRUCTION SEQUENCE SATISFACTORY/ COMMENTS UNSATISFACTORY 3. Structural Components Stone diaphragm installed correctly Outlets installed correctly Underdrain Pretreatment devices installed Soil bed composition and texture 4. Vegetation Complies with planting specs Topsoil adequate in composition and placement Adequate erosion control measures in place 5. Final Inspection Dimensions Proper stone diaphragm Proper outlet Soil/filter bed permeability testing Effective stand of vegetation and stabilization Construction generated sediments removed Contributing watershed stabilized before flow is diverted to the practice Appendix F:Construction Inspection Checklists F-18 Comments: Actions to be Taken: Appendix F:Construction Inspection Checklists F-19 Open Channel System Construction Inspection Checklist Project: Location: Site Status: Date: Time: Inspector: CONSTRUCTION SEQUENCE SATISFACTORY/ COMMENTS UNSATISFACTORY 1. Pre-Construction Pre-construction meeting Runoff diverted Facility location staked out 2. Excavation Size and location Side slope stable Soil permeability Groundwater/ bedrock Lateral slopes completely level Longitudinal slopes within design range Excavation does not compact subsoils 3. Check dams Dimensions Spacing Materials Appendix F:Construction Inspection Checklists F-20 CONSTRUCTION SEQUENCE SATISFACTORY/ COMMENTS UNSATISFACTORY 4. Structural Components Underdrain installed correctly Inflow installed correctly Pretreatment devices installed 5. Vegetation Complies with planting specifications Topsoil adequate in composition and placement Adequate erosion control measures in place 6. Final inspection Dimensions Check dams Proper outlet Effective stand of vegetation and stabilization Contributing watershed stabilized before flow is routed to the facility Comments: Appendix F:Construction Inspection Checklists F-21 Actions to be Taken: Appendix F:Construction Inspection Checklists F-22 ��K Department of STATE Environmental Conservation This Page is Left Intentionally Blank NEW Department of PORK STATE Environmental Conservation Appendix G: Non-Erosive Velocities of Vegetated Channels Velocity Maximum velocities of flow in vegetated channels absent of permanent turf reinforcement matting shall not exceed the values shown in the following table: Table GA Permissible Non Erosive Velocities for Channels with Vegetative Lining Channel Slope Vegetative Lining Maximum Velocity(ft/sec) Reed canarygrass 5 Tall fescue Kentucky bluegrass Grass-legume mixture 4 0-5% Red fescue 2.5 Redtop Serices lespedeza Annual lespedeza Small grains Reed canarygrass 4 Tall fescue 5-10% Kentucky bluegrass Grass-legume mixture 3 Reed canarygrass 3 Greater than 10% Tall fescue Kentucky bluegrass Source: Soil and Water Conservation Engineering, Schwab, et al. For highly erodible soils, maximum velocities should be decreased 25%. An erodibility factor(K)greater than 0.35 would indicate a highly erodible soil. Erodibility factors(K-factors)can be obtained from local NRCS offices. For vegetated earth channels having permanent turf reinforcement matting, the maximum flow velocity shall not exceed 8 ft/sec. Turf reinforcement matting shall be a machine produced mat of nondegradable fibers or elements having a uniform thickness and distribution of weave throughout. Matting shall be installed per manufacturer's recommendations with appropriate fasteners as required. Appendix G: Non-Erosive Velocities of Vegetated Channels G-1 Manning's n value The roughness coefficient, n, varies with the type of vegetative cover and flow depth. At very shallow depths, where the vegetation height is equal to or greater than the flow depth, the n value should be approximately 0.15. This value is appropriate for flow depths up to 4"typically. For higher flow rates and flow depths, the n value decreases to a minimum of 0.03 for grass channels at a depth of approximately 12". The n value must be adjusted for varying flow depths between 4" and 12" (see Figure G.1). 0.16 0.14 0.12 c 0.1 a 0.08 c 0.06 0.04 0.02 0 0 2 4 6 8 10 12 Flow Depth [Inches] Figure GA Manning's n Value with Varying Flow Depth (Source: Claytor and Schueler, 1986) Appendix G: Non-Erosive Velocities of Vegetated Channels G-2 ��K Department of STATE Environmental Conservation APPENDIX H . . Climate Sizing Criteria This Page is Left Intentionally Blank NEW Department of PORK STATE Environmental Conservation Appendix H: Cold Climate Sizing Criteria Traditional SMP sizing criteria are based on the hydrology and climatic conditions of moderate climates. These criteria are not always applicable to cold climate regions due to snowmelt, rain-on-snow and frozen soils. This Appendix identifies methods to adjust water quality (Section H.1) sizing criteria for cold climates. Annual precipitation data for local regions can be supped from climate information websites such as NOAA (https://www.weather.gov/wrh/Climate?wfo=aly). Section H.1 Water Quality Sizing Criteria The water quality volume is the portion of the SMP reserved to treat stormwater either through detention, filtration, infiltration or biological activity. Base criteria developed for SMP sizing nationwide are based on rainfall events in moderate climates (e.g., Schueler, 1992). Designers may wish to increase the water quality volume of SMPs to account for the unique conditions in colder climates, particularly when the spring snowfall represents a significant portion of the total rainfall. Spring snowmelt, rain-on-snow and rain-on-frozen ground may warrant higher treatment volumes. It is important to note that the base criteria required by a region must always be met, regardless of calculations made for cold climate conditions. RISER INCREASED COLD CLIMATE 5MRAGE" 14000 WQr FOR, fNLEr AfOOERA7LC PIPE CLIMA7ES AOV© CR41A1 l3�4►�RCL Figure H.1 Increased Water Quality Volume in Cold Climates The goal of treating 90% of the annual pollutant load (Schueler, 1992), can be applied to snowmelt runoff and rain-on snow events. In the following conditions, cold climate sizing may be greater than base criteria sizing: Snowfall represents more than 10% of total annual precipitation. This value is chosen because, at least some portion of the spring snowmelt needs to be treated in order to treat 90% of annual runoff in these conditions. Using the rule of thumb that the moisture content of snowfall has about 10% moisture content, this rule can be simplified as: Oversize when average annual snowfall depth is greater than or equal to annual precipitation depth. The area is in a coastal or Great Lakes region with more than 3' of snow annually. In these regions, rain-on-snow events occur frequently enough to justify oversizing stormwater SMPs for water quality. The following caveats apply to the sizing criteria presented in this section: These criteria are not appropriate for very deep snowpacks (i.e., greater than 4') because the volume to be treated would be infeasible, and often unnecessary. Snowmelt is a complicated process, with large annual variations. While the criteria presented here address the effects of snowmelt and rain-on-snow, several simplifying assumptions are made. Where local data or experience are available, more sophisticated methods should be substituted. Appendix H:Cold Climate Sizing Criteria H-1 Section H.1.1 Water Quality Volume for Snowmelt In order to treat 90% of annual runoff volume, sizing for snowmelt events needs to be completed in the context of the precipitation for the entire year. In relatively dry regions that receive much of their precipitation as snowfall, the sizing is heavily influenced by the snowmelt event. On the other hand, in regions with high annual rainfall, storm events are more likely to carry the majority of pollutants annually. The sizing criteria for this section are based on three assumptions: 1) SMPs should be sized to treat the spring snowmelt event 2)Snowmelt runoff is influenced by the moisture content of the spring snowpack and soil moisture 3) No more than five percent of the annual runoff volume should bypass treatment during the spring snowmelt event and 4) SMPs can treat a snowmelt volume greater than their size. SMPs should be sized to treat the spring snowmelt runoff event Snowmelt occurs throughout the winter in small, low-flow events. These events have high concentrations of soluble pollutants such as chlorides and metals, because of"preferential elution"from the snowpack(Jeffries, 1988). Although these events have significant pollutant loads, the flows are very low intensity, and generally will not affect SMP sizing decisions. The spring snowmelt, on the other hand, is higher in suspended solids and hydrophobic elements, such as hydrocarbons, which can remain in the snowpack until the last five to ten percent of water leaves the snowpack (Marsalek, 1991). In addition, a large volume of runoff occurs over a comparatively short period of time (i.e., approximately two weeks). Most SMPs rely on settling to treat pollutants, and the pollutants carried in the spring snowmelt are more easily treated by these mechanisms. In addition, the large flow volume during this event may be the critical water quality design event in many cold regions. Snowmelt runoff is influenced by the moisture content of the spring snowpack and soil moisture Because of small snowmelt events that occur throughout the winter, losses through sublimation, and management practices such as hauling snow to other locations, the snowpack only contains a fraction of the moisture from the winter snowfall. Thus, the remaining moisture in the snowpack can be estimated by: M = 0ASn —L1 —L2 —L3 (Equation H.1) Where M = Moisture in the Spring Snowpack(inches) Sn =Annual Snowfall (inches) L1, L2 and L3 = Losses to Hauling, Sublimation and Winter Melt, respectively. The volume of snow hauled off site can be determined based on available information on current plowing practices. In New York, sublimation to the atmosphere is not very important The design examples in this section use a simple "rule of thumb" approach, to estimate winter snowmelt for simplicity (Table H.1). The method assumes that winter snowmelt is influenced primarily by temperature, as represented by the average daily temperature for January. One half of the snow (adjusted for plowing and sublimation) is assumed to melt during the winter in very cold regions (Average Tmax <25°F) and two thirds is assumed to melt during the winter in moderately cold regions (Average Tmax <350F). Winter snowmelt can be estimated using several methods, such as the simple degree-day method, or through more complex continuous modeling efforts. Appendix H:Cold Climate Sizing Criteria H-2 Table H.1 Winter Snowmelt*,--: Adjusted Snowfall Moisture Winter Snowmelt Winter Snowmelt Equivalent (January Tmax<25°F) (January Tmax<35°F) 2" 1.0" 1.3" 4" 2.0" 2.7" 6" 3.0" 4.0" 8" 4.0" 5.3" 10" 5.0" 6.7" 12" 6.0" 8.0" Snowmelt occurring before the spring snowmelt event,based on the moisture content in the annual snowfall.The value in the first column is adjusted for losses due to sublimation and plowing off site. Snowmelt is converted to runoff when the snowmelt rate exceeds the infiltration capacity of the soil. Although the rate of snowmelt is slow compared with rainfall events, snowmelt can cause significant runoff because of frozen soil conditions. The most important factors governing the volume of snowmelt runoff are the water content of the snowpack and the soil moisture content at the time the soil freezes (Granger et al., 1984). If the soil is relatively dry when it freezes, its permeability is retained. If, on the other hand, the soil is moist or saturated, the ice formed within the soil matrix acts as an impermeable layer, reducing infiltration. Section H.1.3 outlines a methodology for computing snowmelt runoff based on this principle. No more than 5% of the annual runoff volume should bypass treatment during spring snowmelt In order to treat 90% of the annual runoff volume, at least some of the spring snowmelt, on average, will go un-treated. In addition, large storm events will bypass treatment during warmer months. Limiting the volume that bypasses treatment during the spring snowmelt to 5% of the annual runoff volume allows for these large storm events to pass through the facility untreated, while retaining the 90%treatment goal. The resulting equation is: Vol = (RS — 0.05Q)(A/12) (Equation H.2) where Vol = Volume Treated (acre-ft) Rs= Snowmelt Runoff[See Section H.1.3] Q =Annual Runoff Volume (inches) [See Section H.1.2] A=Area (acres) SMPs can treat a volume greater than their normal size. Snowmelt occurs over a long period of time, compared to storm events. Thus, the SMP does not have to treat the entire water quality treatment volume computed over 24-hrs, but over a week or more. As a result, the necessary water quality volume in the structure will be lower than the treatment volume. For this manual, we have assumed a volume of% of the value of the computed treatment volume (Vol) calculated in Equation H.2. Thus, WQ„ = z Vol (Equation H.3) Section H.1.2 Base Criteria/Annual Runoff The base criterion is the widely used, traditional water quality sizing rule. This criterion, originally developed for moderate climates, represents the minimum recommended water quality treatment volume. In this manual, the runoff from a 1 inch rainfall event is used as the base criteria. The basis behind this sizing criteria is that approximately 90% of the storms are Appendix H:Cold Climate Sizing Criteria H- treated using this event. This value may vary nationwide, depending on local historical rainfall frequency distribution data. However, the 1 inch storm is used as a simplifying assumption. The base criteria included in this manual is chosen because it incorporates impervious area in the sizing of urban SMPs, and modifications are used nationwide. The cold climate sizing modifications used in this manual may be applied to any base criteria, however. Runoff for rain events can be determined based on the Simple Method (Schueler, 1987). r = (p)(0.05 + 0.91) (Equation H.4) where r= Event Rainfall Runoff(inches) p = Event Precipitation (inches) I = Impervious Area Fraction Thus, the water quality volume for the base criteria can be determined by: WQ„ _ (0.05 + 0.91)(AI12) (Equation H.5) where WQv=Water Quality Volume (acre-ft) 1= Impervious Fraction A=Area (acres) The Simple Method can also be used to determine the annual runoff volume. An additional factor, Pj, is added because some storms do not cause runoff. Assume Pj = 0.9 (Schueler, 1987). Therefore, annual runoff volume from rain can be determined by: R = (0.9P)(0.05 + 0.91) (Equation H.6) where R =Annual Runoff(inches) P =Annual Rainfall (inches) Section H.1.3 Calculating the Snowmelt Runoff To complete water quality sizing, it is necessary to calculate the snowmelt runoff. Several methods are available, including complex modeling measures. For the water quality volume, however, simpler sizing methods can be used since the total water quality volume, not peak flow, is critical. One method, modified from Granger et al. (1984) is proposed here. Other methods can be used, particularly those adjusted to local conditions. According to Granger et al. (1984) the infiltration into pervious soils is primarily based on the saturation of the soils prior to freezing. While saturated soils allow relatively little snowmelt to infiltrate, dry soils have a high capacity for infiltration. Thus, infiltration volumes vary between wet, moderate and dry soil conditions (Figure H.2). Appendix H:Cold Climate Sizing Criteria H-4 x2 V CI e t Solt MOIstMe Dry —a——rMedetala —�Wel 0 0 2 4 n H Snoupaek Water Equivalent{Inches Figure H.2 Snowmelt Infiltration Based on Soil Moisture Assume also that impervious area produces 100% runoff. The actual percent of snowmelt converted to runoff from impervious areas such as roads and sidewalks may be less than 100% due to snow removal, deposition storage and sublimation. However, stockpiled areas adjacent to paved surfaces often exhibit increased runoff rates because of the high moisture content in the stockpiled snow (Buttle and Xu, 1988). This increased contribution from pervious areas off- sets the reduced runoff rates from cleared roads and sidewalks. The resulting equation to calculate snowmelt runoff volume based on these assumptions is: Rs= [runoff generated from the pervious areas] + [runoff from the impervious areas] RS = [(1 —I)(M—Inf)] + [(I)(1)(M)] (Equation H.7) where Rs= Snowmelt Runoff I = Impervious Fraction M = Snowmelt (inches) Inf= Infiltration (inches) Appendix H:Cold Climate Sizing Criteria H- Sizing Example 1: Snowpack Treatment Scenario: 50 Acre Watershed 40% Impervious Area Average Annual Snowfall=5'=60" Average Daily Maximum January Temperature=20' Average Annual Precipitation =30" 20%of snowfall is hauled off site Sublimation is not significant Prewinter soil conditions: moderate moisture. Step 1: Determine if oversizing is necessary Since the average annual precipitation is only'/2 of average annual snowfall depth, oversizing is needed. Step 2: Determine the annual losses from sublimation and snow plowing. Since snow hauled off site is about 20%of annual snowfall, the loss from snow hauling, Li, can be estimated by: Ll = (0.2)(0.1)(S.n) where Li =Water equivalent lost to hauling snow off site(inches) Sn=Annual snowfall (inches) 0.1 = Factor to convert snowfall to water equivalent Therefore, the loss to snow hauling is equal to: Ll = (0.2)(0.1)(60 inches) L1 = 1.2 inches Since sublimation is negligible, L2=0 Step 3: Determine the annual water equivalent loss from winter snowmelt events Using the information in Step 2, the moisture equivalent in the snowpack remaining after hauling is equal to: (60inches)(0.1)— 1.2 inches =4.8inches Substituting this value into Table H.1, and interpolating, find the volume lost to winter melt, L3. L3 = 2.4 inches Step 4: Calculate the final snowpack water equivalent, M M = (0.1)(S.n)—Ll—L2 —L3 (Equation H.1) Sn=60" Li = 1.2" Li = 0" L3=2.4" Therefore, M =2.4" Appendix H:Cold Climate Sizing Criteria H- Step 5: Calculate the snowmelt runoff volume, Rs RS = (1—1)(M—Inf) +(1•M) (Equation H.7) M =2.4" 1 =0.4 Inf=0.8" (From Figure H.2; assume average moisture) Therefore, Rs= 1.9" Step 6: Determine the annual runoff volume, R Use the Simple Method to calculate rainfall runoff: R = (0.9)(0.05+0.91)(P) (Equation H.6) 1=0.4 P=30" Therefore, R=11" Step 7: Determine the runoff to be treated Treatment, T should equal: T= (RS—0.05R)(A/12) (Equation H.2) Rs=1.9" R=11" A=50 Acres Therefore, T=5.6 acre-ft Step 8: Size the SMP The volume treated by the base criteria would be: WQ = [0.05+(0.9)(0.4)](1 ft/12 inches)(50 acres) (Equation H.5) For cold climates: WQ = a T= 2.8 acre•ft (Equation H.3) The cold climate sizing criteria is larger and should be used to size the SMP. HA A Rain-on-Snow Events For water quality volume, an analysis of rain-on-snow events is important in coastal regions. In non-coastal regions, rain- on-snow events may occur annually but are not statistically of sufficient volume to affect water quality sizing, especially after snowpack size is considered. In coastal regions, on the other hand, flooding and annual snowmelt are often driven by rain-on-snow events (Zuzel et al., 1983). Nearly 100% of the rain from rain-on-snow events and rain immediately following the spring melt is converted to runoff(Bengtsson, 1990). Although the small rainfall events typically used for SMP water quality do not produce a significant amount of snowmelt (ACOE, 1956), runoff produced by these events is high because of frozen and saturated ground under snow cover. Appendix H:Cold Climate Sizing Criteria HJ Many water quality volume sizing rules are based on treating a certain frequency rainfall event, such as treating the 1- year, 24- rainfall event. The rationale for treating 90% of the pollutant load (Schueler, 1992) can also be applied to rain- on-snow events, as shown in the following example. Step 1: Develop a rain-on-snow data set. Find all the rainfall events that occur during snowy months. Rainfall from December through April were included. Please note that precipitation data includes both rainfall and snowfall, and only data from days without snowfall should be included. Exclude non- runoff-producing events (less than 0.1"). Some of these events may not actually occur while snow is on the ground, but they represent a fairly accurate estimate of these events. Step 2: Calculate a runoff distribution for rain-on-snow events Since rain-on-snow events contribute directly to runoff, the runoff distribution is the same as the precipitation distribution in Figure H.3. 4,% f t i 2.5D —_.. •-- - - - c 140 A 0,50 • r!� i • # •# iil�ri � ain 9!6 10% M% 30% 40% 50% 00% To% W% 10M Figure H.3 Rainfall Distribution for Snowy Months Step 3: Calculate a rainfall distribution for non-snow months. Develop a distribution of rainfall for months where snow is not normally on the ground. The rainfall distribution for May through November is included in Figure HA. Appendix Ha Cold CHroate Bring Criteria H-8 a_oo 7.00 d a 0,4Q aao 4M 3.00 7.{i6 �.W -.. J'i4�M o!i 14% "% 4% +I D+Ii sm "% ns W% Dp96 10044 Figure HA Rainfall Distribution for Non-Snowy Months Step 4: Calculate the runoff distribution for non-snow months. Use a standard method to convert rainfall to runoff, particularly methods that are calibrated to local conditions. For this example, use the Simple Method. Runoff is calculated as: r = (0.05+0.91)(p) (Equation HA) For this example, 1=0.3(30%impervious area), so: r = (0.32)(p) The runoff distribution for non-snow months is calculated by multiplying the rainfall in Figure HA by 0.32. Step 5: Combine the runoff distributions calculated in Steps 2 and 4 to produce an annual runoff distribution. The resulting runoff distribution (Figure H.5)will be used to calculate the water quality volume. Appendix H:Cold Climate Sizing Criteria H- #.S 3 I a 1 a 1.5 i 1 0,5 - 0% 29% 40% 9 0% am 1 iP494 Figure H.5 Annual Runoff Distribution Step 6: Size the SMP. In this case, use the 90%frequency runoff event(Figure H.4), or 0.65 watershed inches. This value is greater than the base criteria of 0.32 watershed inches (1"storm runoff). Therefore, the greater value is used. WQ = (0.65 inches)(1 ft/12 inches)(50 acres) = 2.7 acre ft Appendix H:Cold Climate Sizing Criteria H-10 ��K Department of STATE Environmental Conservation GeomorphicAPPENDIX I - - This Page is Left Intentionally Blank NEW Department of PORK STATE Environmental Conservation Appendix I: Geomorphic Assessment Distributed Runoff Control Methodology Pond Outlet Structure Design Example The following design example illustrates a step-by-step methodology for the design of a weir for the control of instream erosion potential using a Stormwater Management (SWM)wet pond design based on the Distributed Runoff Control (DRC) approach. The DRC approach incorporates boundary material composition and its sensitivity to erosion (entrainment and transport) into the design protocol. The boundary materials are characterized at the point of maximum boundary shear stress on the bed and the point of secondary maximum boundary shear stress on the bank. By examining the channel at selected sites downstream of the SWM facility the DRC protocol provides a pseudo 3- dimensional assessment of the impact of development and the SWM facility on the receiving channel. This design example involves 5 Steps as listed in Table 1.1. Table 1.1 Overview of Key Steps in the DRC Design Approach 1) Determine the"stability" and"mode-of-adjustment" of the receiving channel 2) Complete a Diagnostic Geomorphic Survey of the receiving channel 3) Determine channel sensitivity to an alteration in the sediment-flow regime 4) Approximate the elevation-discharge curve for the pond. 5) Size the DRC weir Step 1. Determine Channel "Stability" and "Mode-of-Adjustment" Channel stability is determined using a Rapid Geomorphic Assessment (RGA) of the channel downstream of the outlet of the proposed Stormwater Management (SWM) pond. The RGA protocol involves the identification of the presence of in- stream features resulting from a variety of geomorphic processes to provide a semi-quantitative assessment of a stream's stability and mode-of-adjustment. The processes are represented by four Factors: aggradation (AF), widening (WF), downcutting (DF), and planimetric form adjustment (PF)). Each Factor is composed of 7 to 10 indices for which a "present" or"absent" response is required. The total number of"present" or"yes" responses is summed and divided by the total number of responses (both "yes" and "no")to derive a value for each Factor. An index that is not relevant is not assigned a response. An example of an RGA Form is provided in Table 1.2. A Stability Index(SI) value is determined from the Factor values using the following equation: ,SI _ {AF+DF+WF +PF} [Equation 1.1] m Where: m =the number of Factors (typically 4 for alluvial streams). Appendix I:Geomorphic Assessment aA FORM/ GEOMORPHIC INDICATOR PRESENT FACTOR PROCESS No. Description No Yes VALUE 1 Lobate bar 1 2 Coarse material in riffles embedded 1 Evidence of 3 Siltation in pools 1 Aggradation 4 Medial bars 1 1/7=0.143 (AI) 5 Accretion on point bars 1 6 Poor longitudinal sorting of bed materials 1 7 Deposition in the overbank zone 1 1 Exposed bridge footing(s) - - 2 Exposed sanitary/storm sewer/pipeline/etc. - - 3 Elevated stormsewer outfall(s) - - 4 Undermined gabion baskets/concrete aprons/etc. - - Evidence of 5 Scour pools d/s of culverts/stormsewer outlets 1 Degradation 2/6=0.333 (DI) 6 Cut face on bar forms 1 7 Head cutting due to knick point migration 1 8 Terrace cut through older bar material 1 9 Suspended armor layer visible in bank 1 10 Channel worn into undisturbed overburden/bedrock 1 1 Fallen/leaning trees/fence posts/etc. 1 2 Occurrence of Large Organic Debris 1 3 Exposed tree roots 1 4 Basal scour on inside meander bends 1 Evidence of 5 Basal scour on both sides of channel through riffle 1 Widening g 6 Gabion baskets/concrete walls/armor stone/etc. out flanked 1 3/10=0.30 (WI7 Length of basal scour>50%through subject reach 1 8 Exposed length of previously buried pipe/cable/etc. 1 9 Fracture lines along top of bank 1 10 Exposed building foundation 1 1 Formation of cute(s) 1 Evidence of 2 Evolution of single thread channel to multiple channel 1 Planimetric 3 Evolution of pool-riffle form to low bed relief form 1 Form 4 Cutoff channel(s) 1 0/7=0 Adjustment 5 Formation of island(s) 1 (PI) 6 Thalweg alignment out of phase with meander geometry 1 7 1 Bar forms poorly formed/reworked/removed 1 STABILITY INDEX(SI)_(AI+DI+WI+PI)/m Sl= 0.19 The Stability Index(SI) provides an indication of the stability of the creek channel at a given time based on the guidelines provided in Table 1.3. The SI Value, however, does not differentiate between current and past disturbances. Appendix I:Geomorphic Assessment 11-2 Table 1.3 Interpretation of the RGA Stability Index Value Stability Index Stability Class Description Value Metrics describing channel form are within the expected range of 0.0<SI<0.25 Stable variance(typically accepted as one standard deviation from the mean) for stable channels of similar type 0.25<SI<0.4 Transitional Metrics are within the expected range of variance as defined above but with evidence of stress 0.4<SI<1.0 In Adjustment Metrics are outside of the expected range of variance for channels of similar type. The guidelines presented in Table 1.3 for the interpretation of the SI Value will vary with the field experience and the bias of the observer. The SI Values however, have been shown to be consistent between observers indicating that the protocol, once calibrated to the observer provides a reliable means of screening the channel for stability and mode-of- adjustment. The RGA protocol is applied to channel segments of two meanders in length or the equivalent of 20 bankfull channel widths (the width of the channel at the geomorphically dominant discharge, recurrence interval of between 1 and 2 years or 1.5 years on average). The segment chosen for application of the RGA assessment is selected to be representative of the morphology of the channel for some distance up and downstream of the surveyed segment. That is, the parameters defining channel cross- section and plan form (e.g. width, depth, meander wavelength, etc.) are within a consensual level of variance for this reach of channel. An acceptable level of variance is typically defined as within one standard deviation of the mean. These reaches are referred to as being of"like" morphology. Since the morphology of the channel will vary in the longitudinal direction with changes in flow, slope, physiography, etc., it will be necessary to re-apply the RGA protocol where the parameters characterizing the morphology of the channel have changed beyond the consensual level of variance from the previous survey reach. In this manner the channel is divided into a series of reaches of"like" morphology. Having determined the length of the survey reach, the longitudinal profile can be plotted from topographic mapping as illustrated in Figure 1.1 (Topo). Examination of Figure 1.1 (topographic map data) suggests that the channel can be differentiated into three distinct reaches. In the first reach (length L=146 ft, the channel has an average slope of S=0.00385 ft/ft and a meander-pool-riffle morphology. In the middle reach (L;z-,356 ft; S;z-,0.0142 ft/ft) the channel has cascade morphology. The third reach (L;z-,258 ft; S;z-,0.00794 ft/ft) returns to the meander-pool-riffle form. Land use through the study reach is homogeneous (forest) and there are no other features (e.g. bridges, dams, weirs, instream works, etc.)that would affect the hydraulic characteristics of the active channel. Consequently, a preliminary definition of"like" reaches includes the three morphologies described above. A synoptic geomorphic survey was conducted through the subject reach with an RGA assessment completed for each of the three reaches of"like" morphology. The results of the RGA assessment for the first reach (Reach 1) are reported in Table 1.2 and Table 1.4. Referring to Table 1.2, the Stability Index(SI) value was found to be SI=0.19, which is less than 0.25, therefore the channel is considered to be "stable" (Table 1.3). Appendix I:Geomorphic Assessment a•3 100 99 t Survey Topo 98 97 96 Q 95 0 94 93 - j R a� > 92 91 90 89 0 200 400 600 800 Horizontal Distance, L (ft) Figure 1.1 Longitudinal Profile from Topographic Mapping and Field Survey of Channel Thalweg Table 1.4 Summary of Average Longitudinal Slope and Pool Riffle Dimensions r Parameter Reach 1 Reach 2 Reach 3 Longitudinal Gradient, SL 0.00385 0.0142 0.00794 (ft/ft) Riffle Length, LRIF (ft) 16 34 27 Pool Length, LPOL(ft) 37 10 18 Total Pool-Riffle Length, 53 44 45 LTOT(ft) Appendix I:Geomorphic Assessment a 4 Step 2. Diagnostic Geomorphic Survey Following completion of the identification of reaches of"like" morphology and the synoptic survey to finalize the delineation of the "like" reaches, a diagnostic geomorphic survey is undertaken to characterize the morphological attributes of the channel. This information has two primary functions. The optimization of the erosion control benefit of the pond; and, The provision for establishing a baseline condition from which it is possible to assess the performance of the SWM measures. A detailed diagnostic survey includes a collection of a comprehensive set of parameters to assess and evaluate stream geomorphic conditions. A complete survey is typically required when: A post-construction monitoring program is mandated; and, Data are required for the design and construction of instream works. Only a partial diagnostic survey is needed where the above issues are not relevant to the project. The following lists those parameters required for the partial diagnostic survey: In the absence of flow measurements, a field estimate of Manning's `n'value is obtained for comparison with sediment computed estimates. Detailed survey of the channel cross-section, including the floodplain, to determine hydraulic geometry metrics at a so called "Master cross-section" and the relative location of bank material strata. The longitudinal profile of the bed along the channel thalweg and the water surface at the time of survey over a distance of one meander wavelength or 10 bankfull widths. These data are used to determine the longitudinal gradient of the channel from riffle crest to riffle crest and to determine the dimensions of the pool-riffle complex. At least one estimate of bankfull depth (the depth of flow at the dominate discharge) at the Master cross-section and all ancillary cross-sections (3 alternative methods are described in this example for illustrative purposes). Bed material characteristics based on pebble counts of the bed material at a riffle crossover. These data are collected to help assess roughness coefficients, bed material resistance, and provide an alternate method for the estimation of bankfull depth. Soil pits in the banks to map bank stratigraphy and to determine bank material composition using soil consistency tests (stickiness, plasticity and firmness) or particle size analysis (percent silt clay) with Atterberg Limits (Plasticity Index) for each stratigraphic unit. These data are required to help assess historic degradation or aggradation patterns and determine bank material resistance. Map riparian vegetation and root zone characteristics in the soil pits for assessment of the affect of root binding on bank material resistance. The cross-section data and bank material characterization is completed at a Master cross-section within the representative segment of each "like" reach. The Master cross-section is typically located at a riffle crossover on a straight reach between meander bends. Ancillary cross-sections are located in the lower one third of the meander bends and riffle crossover points up and downstream of the Master cross-section. Data collected at the ancillary cross-sections includes a cross-section profile (typically 7 to 9 ordinates) and estimates of bankfull stage. The longitudinal profile is collected throughout the survey segment along with characterization of plan form geometry. Design Case: Diagnostic Geomorphic Survey The longitudinal survey of the channel along the thalweg is presented in Figure 1.1 ("Survey"data points). This profile more clearly demonstrates the differences between the three reaches as represented by slope and pool-riffle dimensions (Table 1.4). Other parameter values derived from the geomorphic survey are summarized in Table 1.5. These data are combined with the cross-section, soils and sediment data to generate values for key parameters as described in the following series of calculations. The following calculations are required to determine the 3 different estimates of the dominant discharge. Appendix I:Geomorphic Assessment a Estimate of Geomorphic Referenced Dominant Discharge 1. The longitudinal data are plotted to generate estimates of the channel gradient in order of priority as follows: Water surface profile based on estimates of bankfull stage from the Master and ancillary cross-sections. Bed slope (riffle crest to riffle crest), and Water surface profile (dry weather flow at the time of the survey). 2. The pebble count data (length, width and breadth) are transformed into an equivalent diameter and used to generate a mass curve wherein cumulative percent finer by mass is plotted as a function of particle diameter; 3. The D5o and D84 particle size values (the particle diameter below which 50 and 84% of the particles are finer by mass, respectively) are determined from the mass curve; 4. Manning's roughness coefficient is estimated at bankfull stage using: Standard field guides, and Empirical relations such as: the Strickler(1923) and Limerinos (1970) equations. 5 The cross-section ordinates collected at the Master cross-section are plotted to produce a cross-section profile and a stage-area curve; The stage-area curve is combined with the longitudinal gradient (S) and the estimate of Manning's roughness coefficient (n) to generate the stage-discharge curve for the cross-section using Manning's equation, Q = -r! AR:%'S [Equation 1.2] in which Q represents the flow rate (cfs) at depth `y' above the thalweg, `A' is the cross-section area of the channel at depth `y', `R' represents the hydraulic radius at depth `y' and `S' is the longitudinal gradient of the channel (ft/ft). An example of a stage-discharge curve is provided in Figure 1.2; Appendix I:Geomorphic Assessment a Table 1.5 Summary of Hydraulic and Sediment Parameters Parameter Reach Rosgen 2 Year Wetted Stream Width Depth Flow Base No. Flow W/d Ratio WBFL dBFL QBFL B Perimeter Type ifs; (ft) (ft) (cfs) (ft) (ft) 1 C3 8.9 3.00 3.00 1.00 4.76 2.00 4.24 2 133 9.54 3.23 2.75 0.85 5.10 1.90 3.80 3 C3 10.1 2.87 2.83 0.99 5.40 1.85 4.06 Parameter Reach Bed Material Mean Hydraulic Particle Area Slope Velocity No. Size ABFL Radius S v Riparian Vegetation Type (ft2) (R (ft/ft) (fps) D50(in) D84(in) 1 2.8 3.3 2.50 0.590 .00385 1.90 Woody 2 5.1 7.5 1.99 0.521 .0142 2.57 Woody 3 3.7 5.2 2.32 0.570 .00794 2.35 Woody Parameter Bank Material Composition Critical Shear Excess Boundary Shear Reach Stress Depth of Stress Stratigraphic T CRT No. Soil Class Soil Consistence Test Bank(") Bed Unit I (Ibs/ft2) T CRT T CRT (ft) Class Not X1 X2 X3 SCORE (Ibs/ft2) (Ibs/ft2) Bank Bed SiLm 1 1 2 1 4 0.36<h<_1.00 1 SiSa 2 0 0 1 1 0.120 0.548 0.10<h<_0.36 0.057 -0.334 CoGr 3 N/a N/a N/a N/a 0.0<h<_0.10 CoBo 1 N/a N/a N/a N/a 0.573 0.39<h<_0.85 2 1.206 -0.016 -0.526 GrCo 2 N/a N/a N/a N/a 0.0<h<_0.39 SiLm 1 2 1 3 6 0.32<h<_0.99 3 SiCI 2 2 2 2 6 0.329 0.12<h<_0.32 0.03 -0.446 0.878 SiCI 1 3 1 2 1 3 1 2 7 0.0<h<_0.12 (')Least resistant lower bank stratigraphic unit corresponding to the zone of secondary maximum boundary shear stress. Appendix I:Geomorphic Assessment (J The dominant discharge (QGEo) is determined from the stage-discharge curve and field estimate of bankfull stage (dBFL). For Reach 1 in this example, dBFL=1.0 ft, consequently QGEo=4.76 cfs (Figure 1.2). This procedure is repeated for each cross-section within the reach and the flow rate most common to all cross-sections is adopted as the geomorphic referenced estimate of the dominant discharge. If a wide disparity exists between estimates of (QGEo)than the determination of slope, Manning's `n' value and the geomorphic indicators of bankfull stage are revisited to determine if a miss-interpretation of the data or an error in calculations has occurred. 5 dBFL 4.5 4 �Q 3.5 v CY 3 0.75 dBFL 2.5 L 0.66 dBFL 2 ea C� 0.55dBFL 6 1.5 b 1 0.5 0 0 0.2 0.4 0.6 0.8 1 1.2 Flow Depth Above the Thalweg, y (ft) Figure 1.2 Stage-Discharge Curve for Reach 1 Downstream of the Proposed Development Estimate of Bed Material Critical Shear Stress 8. Critical shear stress is estimated for the 0 84 particle size value of the bed material using procedures such as: The modified Shield's equation (Vanoni, 1977), or Various empirical relations (from the literature) that express critical shear stress as a function of particle size, one such is Equation 1.3 proposed by Lane (1955) (ZcRT)BED = 0.164084 [Equation 1.3] in which 084 is the particle size for which 84% of the materials are finer(inches) and TORT represents the critical shear stress (Ibs/ftz). Applying, [Equation 1.3] : (T cRT)BED= 0.164084 = 0.164 (3.34 in) = 0.548 Ibs/ftz at the Master cross-section (Reach 1); Appendix I:Geomorphic Assessment a•8 Estimate of Instantaneous Bed Shear Stress 9. A stage-shear stress curve is generated for the Master cross-section using DuBoy's relation for average shear stress and a channel shape adjustment factor proposed by Lane (1955) as follows: zo =kb pg(d—d,)S [Equation 1.4] and, kb =0.00054 3 —0.012(B z +0.09�B)+0.75 [Equation 1.5] in which to represents the instantaneous boundary shear stress at point `P' on the bed (Ibs/ft sz), kb is a channel shape adjustment factor(dimensionless; Figure 1.3), A is the density of the sediment-water mixture being conveyed by the channel (62.4 Ibs/ft3), `g' is acceleration due to gravity (32.2 ft/sz), `d' is the depth of the flow above the thalweg (ft), dP is the depth of flow above the thalweg at point `P' (ft), `S' represents the longitudinal gradient of the flow at depth `d' and `B' is the bottom width of the channel (assuming a trapezoidal configuration). In this design case, a mapping of the isovels through the Master cross-section indicates that the point of maximum boundary shear stress occurs at the thalweg. Since the thalweg is the deepest part of the channel, the term dP=O in Equation 1.4. A stage-shear stress curve for Reach 1 is illustrated in Figure 1.4. Note that the units for 90 are reported in Ibs/ftz to be consistent with the estimate of critical shear stress reported in Task 8. To obtain units of Ibs/ftz remove `g' from Equation 1.4. Lane(1955)Average Boundary Shear Stress Adjustment Factor For the Determination of Maximum Bed Shear Stress 1 0.98 0.96 0.94 0.92 0.9 y=0.000547x3-0.0121x2+0.092x+0.75 0.88 0 2 4 6 8 10 B/d Figure 1.3 Determination of kB for the Adjustment of Average Boundary Shear Stress for Variations in Channel Shape Assuming A Trapezoidal Channel Cross-Section Configuration Appendix I:Geomorphic Assessment 1-9 0.25 L Q Cn 0.2 0.15 O m CD to o Q 0.1 a� c � c� c 0.05 c� to c 0 0 0.2 0.4 0.6 0.8 1 1.2 Flow Depth, (d-dp) in ft Figure 1.4 Stage-Shear Stress Curve for Reach 1 (Master Cross-section): Bed Station. Estimate the Sediment Referenced Dominant Discharge 10. The stage-shear stress curve is used to determine the depth of flow at which the boundary shear stress on the bed is equal to the critical shear stress of the N84 particle size fraction. This depth is transformed into an estimate of flow rate from the stage-discharge curve (Task 5 above), providing a second, independent estimate of the dominant discharge (QSED). This calculation also provides a basis for determination of the sensitivity of the bed material to an alteration in the sediment-flow regime. This assessment is described in Task 21 below; Estimate the Flow Recurrence Interval of the Referenced Dominant Discharge 11. A flow time series is generated using: Flow gauge data if available, or A continuous hydrologic model to generate a synthetic flow time series of 6 to 13 years in length. Ili. The flow time series is used to derive a flood frequency curve from which a third independent estimate of the dominant discharge (QRI) is determined as the flow having a recurrence interval between 1 and 2 years (average RI=1.5 years); Finalize the Estimate of Dominant Discharge 13. The three estimates of dominant discharge are compared for consistency. If consistent (e.g. the range is equal to or less than 20% of the mean), then the mean value of the dominant discharge can be accepted with a higher degree of confidence Appendix I:Geomorphic Assessment B•13 Step 3. Determine the Sensitivity of the Boundary Materials Sensitivity of the Bed Material 14. Using the stage-shear stress relationship developed in Task 9 and the estimate of flow depth (dBFL, Task 10) from the dominant discharge (Task 13), determine the boundary shear stress (TO)BED being applied to the bed at point `P' at the dominant discharge. Point `P' is located on the bed within the zone of maximum boundary shear stress. In this example the value of maximum instantaneous boundary shear stress at a depth of dBFL= 1.0 ft was found to be (To)BED = 0.214 Ibs/ftz at the Master cross-section in Reach 1 (Figure 1.4). Similarly, for Reaches 2 and 3 the maximum value of instantaneous boundary shear stress was found to be (To)BED = 0.680 and 0.432 Ibs/ftz respectively. Compute the value of(ie)BED for the Master cross-section knowing (TO)BED and (icRT)BED as, (Ze)BED = (zo —ZCRT)BED [Equation 1.6] in which (-Ce)BED represents the effective boundary shears stress, -co is the instantaneous boundary shear stress at the dominant discharge and TCRT is the critical shear stress of the bed material at point `P'. 16. Repeat the bed shear stress analysis for all Master cross-sections in all reaches of"like" morphology. 17. Compare the value of(ie)BED for all Master cross-sections through the study reach and select the Master cross- section for which the value of(ie)BED is greatest. The reach represented by the Master cross-section having the highest value of(ie)BED is referred to as the "Control Reach". In this example, effective boundary shear stress on the bed was found to range from between -0.526 and -0.334 (Table 1.5). The negative values infer that the channel bed is armored and the bed material is mobile under flood flow events in excess of the dominant discharge. However, of the three Master cross-sections the value of(Te)BED was greatest for Reach 1, consequently, Reach 1 was identified as the "Control Reach". Sensitivity of the Bank Material 18. The bank material for the "Control Reach" is classified according to soil type for each stratigraphic unit using: Soil consistency tests; or Particle size analysis and Atterberg Limits. In this example the bank materials were mapped and differentiated into stratigraphic units as summarized for the three reaches in Table 1.5. The soil consistency test results determined using standard soil classification guidelines (as quantified by MacRae, 1991)), are summarized below and reported in Table 1.5. Assign a value for the stickiness of the material, e.g. not sticky, (X1=0)to extremely sticky (X1=4), Assign a value for the plasticity of the material, e.g. not plastic (X2=0)to extremely plastic(X2=4), Assign a value for the firmness of the material, e.g. loose, no structure (X3=0) to stiff (X4=4). Sum the consistency test values, 3 SCORE x, [Equation 1.7] in which SCORE represents the sum of the values assigned for stickiness, plasticity and firmness. 19. Construct stage-shear stress curves for selected bank stations approximated by 0.25dBFL, 0.33dBFL, 0.4dBFL. More than one bank station may be required in a stratigraphic unit depending upon the thickness of the unit. The curves may be approximated as follows: Appendix I:Geomorphic Assessment I.1 TO =ks(pg(d—dR)S) [Equation 1.8] in which ks is a correction factor for points on the channel bank determined as a function of channel shape (see Equation 1.9, Figure 1.5), `d' is the depth of flow (ft), A is the density of water(62.4 Ibs/ft3), `g' is acceleration due to gravity (32.2 ft/sz) and dP is the depth of flow at the elevation of the boundary station (ft). ks =0.723�B0.0241 ) [Equation 1.9] in which B is the channel bottom (ft)width and `d' is the depth of flow (ft). Note, to obtain units of Ibs/ftz remove the constant `g'from Equation 1.8. Lane(1955)Average Boundary Shear Stress Adjustment Factor For the Determination of Instantaneous Bank Shear Stress 0.765 0.76 0.755 0.75 0.745 0 0241 0.74 y = 0.7236x ' 0.735 R2 = 0.9858 0.73 0 2 4 6 8 10 B/d Figure 1.5 Adjustment Factor kS for Bank Shear Stress for Channels Approximating a Trapezoidal Shape 20. Estimate the critical shear stress (9cRT) within each stratigraphic unit using available empirical relationships. These relations are typically based on percent silt and clay content, degree of compaction, particle size (Vanoni, 1977) or the SCORE value (MacRae, 1991); 21 Compute the excess boundary shear stress for each bank station at a flow depth of between 0.6 and 0.75 ft by reading the boundary shear stress off the stage-shear stress curve for each boundary station and subtracting the critical shear stress as described in DuBoy's relation, (ze)aNx = (zo —ZcRT)BNK [Equation 1.10] in which (-Ce)BNK represents the excess boundary shear stress (Ibs/ftz) at the selected boundary station (P), -co is the instantaneous boundary shear stress (Ibs/ftz) at any specified depth of flow at point P and TCRT represent the critical shear stress (Ibs/ftz) of the boundary material at point P. 2.1 Compare the estimates of excess boundary shear stress (ie)BNK at each bank station and select that station having the highest value of(ie)BNK as the bank station controlling bank response (controlling stratigraphic unit) to a change in the flow regime. Using the guidelines presented in Table 1.6 determine channel sensitivity to an alteration in the sediment-flow regime and the corresponding Over Control (OC) curve and Inflection Point Appendix I:Geomorphic Assessment 1.1 2 UsingTable 1.6 General Guidelines for the Application of the DRC Approach Based on Bank Material Sensitivity SCORE BANK SENSITIVITY BED SENSITIVITY DRC PARAMETERS Excess Excess Bank Resistance Over Shear Sensitivity Shear Sensitivity Control Inflection Stress Class Stress Class Multiplier Point �TOBED �Te)BNK SOII Class SCORE ROC <0 Very Stiff N/a L 1.0—0.9 a Stiff 10-12 ML 0.9-0.7 a <0 L z�0 Firm 7-9 M 0.7-0.5 b Soft <6 H 0.5-0.2 C >0 N/a 0.5-0.2 C <0 N/a 0.9-0.7 a Stiff 10-12 ML 0.9-0.7 a ML z�0 Firm 7-9 M 0.7-0.5 b Soft <6 H 0.5-0.2 C >0 N/a 0.5-0.2 C �0 <0 N/a 0.7-0.5 b Stiff N/a 0.7-0.5 b M z�0 Firm 7-9 M 0.7-0.5 b Soft <6 H 0.5-0.2 C >0 N/a 0.5-0.2 C H N/a 0.5-0.2 C >0 H N/a 0.5-0.2 C Appendix I:Geomorphic Assessment q•1 The multiplier(Roc) in Table 1.6 is used in the following manner: The 2 year peak flow attenuation technique is used to derive the stage-discharge curve for the erosion control component of the SWM pond. A multiplier of unity is equivalent to the traditional 2-year peak flow attenuation approach. The multiplier is used to adjust the 2-year stage-discharge curve to account for differences in the erodability of the boundary materials. The adjustment is performed by multiplying each ordinate of the stage-discharge curve by Roc. For stiff materials, the multiplier approaches unity (Roc-1.0). For very sensitive materials, the multiplier is between 0.2 and 0.3, which is equivalent to 80%OC to 70%OC respectively. Bank materials may be grouped according to the SCORE value if the soil consistency tests apply (i.e. fine-grained material with few stones). For coarse-grained materials, resistance can be determined from observation of bank erosion following a high flow event. As an alternative the resistance of the coarse-grained stratigraphic unit can be inferred from bank form and shear stress distribution through comparison with adjoining strata of fine-grained material. Finally, relations expressing critical shear stress as a function of particle size are available in the literature. Many of these relations were derived from flume experiments using disturbed material that has been re-compacted. These relations tend to underestimate the resistance of the material as it is observed in the field. Consequently, these relations should be employed with caution or corrected to account for root binding, imbrication, compaction and structurization. Step 4. Approximate the Elevation-Discharge Curve for the DRC Pond. The DRC outflow control structure can be constructed as set of pipes or nested weirs. This design example is for a nested, sharp crested weir. Determine the stage-discharge curve for the flow rate having a recurrence interval of 2 years for the baseline land use condition. For this example, the baseline condition is the reforested land use scenario. The flow having a recurrence interval 2 years was determined previously as between 8.9 and 10.1 cfs for Reaches 1 through 3 respectively (Table 1.5). Construct the 2 year stage-discharge curve using an equation for sharp crested weirs with end contractions: 3 Q=CeLehe3 [Equation 1.11] in which, `Q' represents the rate of flow (cfs), `Ce' is the effective weir coefficient (C=3.19, Brater and King, 1982), Le is the effective length of the weir(ft) and `he' is the effective depth of flow above the weir crest (ft). Set the invert of the weir at 628.0 ft. The terms Le, Ce and he are adjusted to account for losses due to end contractions (Brater and King, 1982). In this illustration it is assumed that the stage-volume curve has already been derived and that the approximate head at QBFL=8.9 cfs is h=2.25 ft. Re-arranging Equation 1.11 and solving for`Le' at Q=(Q2YR)PRE=8.9 cfs yields, Le = Q = 8.9 3 =0.83ft [Equation 1.12] Cehe3�2) 3.19(2.25)�2 Compute the stage-discharge curve for the 2-year weir using Equation 1.11 as illustrated in Figure 1.6 (Q2YR, curve AB. This stage-discharge curve represents the rating curve for the 2-year post-to pre-development peak flow attenuation approach. Appendix I:Geomorphic Assessment 1.14 10 —0—Q2YR --#--30%OC f INF(a) --A—50%OC B 9 INF(b) —0—70%OC —0—INF(c) 8 C 7 v CO 6 ai � 5 Q 2) L 4 c� t v to 3 a � b 2 c El A 0 0 0.2 0.4 0.6 0.8 1 1.2 1.4 Stage in Pond Above Weir Crest, h (ft) Figure 1.6 The 2 Year Peak Flow Attenuation and DRC Rating Curves for 30%OC, 50%OC and 70%OC Construct the DRC stage-discharge curve as follows: Determine the level of OC control and the inflection point from Table 1.6. Since (re)BED<0 (Table 1.5) then the bed is classified as "Low"sensitivity (shaded boxes in the first two columns of Table 1.6); The value of(re)BNK>0 consequently, Row 3 of Column 3 (shaded box in Table 1.6) was selected; The bank material was classified as soft (SCORE=1), consequently, the 4th Row of Column 4 was chosen providing a range of Roc between 0.5 and 0.2 with an inflection point at"c". In this case Roc=0.3 was selected in accordance with the guidelines in Table 1.6. Note: 70%OC means that the multiplier for the 2 year curve is Roc=0.3 The 70%OC curve (designated as curve AE in Figure 1.6) is created by multiplying the ordinance of the 2 year stage-discharge curve (Q2YR in Figure 1.6) by the multiplier Roc=0.3. The inflection point (c) is determined using the guidelines provided in Table 1.7. Appendix I:Geomorphic Assessment I• PointTable 1.7 Guidelines For Determination of the Flow Rate for the DRC Curve Inflection Ratio of Inflection Point Bankfull Depth Inflection Point Dominant Flow Rate at Inflection Point Depth to dBFL Depth Discharge Inflection Point Bankfull Depth (ft) d; QBFL Qi d;/dBFL (ft) (cfs) (cfs) (dim) a .75 .75 2.88 b .67 1.0 .67 4.76 2.30 c .55 .55 1.74 The point do=0.55 ft, dBFL=1.0 ft, characterize the Control Reach, consequently the ratio, d, 0.55 ft —0.55 [Equation 1.13] dBFL 1.O ft The flow rate at dc/dBFL=0.55 was estimated from Figure 1.6 to be Qc=1.74 cfs. Point (c) can be located on curve AE at a flow corresponding to Qc=1.74 cfs. The DRC stage-discharge curve follows the curve A(c)B in Figure 1.6. For the purpose of illustration, the stage- discharge curves for 30%OC (inflection point (a)) and 50%OC (inflection point (b)) are also provided in Figure 1.6. Step 5. Sizing the DRC Weir After establishing the DRC stage-discharge curve the next step is to size the DRC weir. This is done using a nested weir configuration as illustrated in Figure 1.7. The equation for the nested weir can be approximated from Equation 1.1 for sharp crested weirs as, 3 3 Q = C,Lehe 2) + Ce(Le —Le)(he —he) 2 [Equation 1.14] INSET in which Q represents the discharge from the nested weir, `Ce' is a coefficient (3.19) adjusted to account for end contractions, Le is the length of the inset weir, he represents the height of the inset weir where 0<_he<_h2 (h2 represents the total height of the nested weir) and he* is the depth of flow through the nested weir above the inset weir(he<_he*<_h2). Appendix I:Geomorphic Assessment 1-16 3.5 - - - - - - - - - - a - - - - - - - - - 3 2.5 v � +� 2 v 1.5 v t DRC-70%OC[c] 'C 1 - ❑ -2YR 0.5 0 0 5 10 15 Horizontal Distance (ft) Figure 1.7 Comparison of the 70%OC DRC Weir with Inflection Point at[c]and the Traditional 2-year Peak Flow Attenuation Weir Solving Equation 1.1 for results in the dimensions and flow values reported in Table 1.8. Table 1.8 Summary of Dimensions and Flow Characteristics for a Nested DRC Weir: Reach 1 DRC Weir Parameter Inflection Point Inflection Point Inflection Point 2 Year Weir (a) (b) (c) U(ft) 1.77 1.00 0.62 he(ft) 0.67 0.78 0.93 N/A Qi at he(cfs) 2.89 2.21 1.74 6e (ft) 0.80 4.32 11.0 0.83 h2(ft) 2.25 Q at h2(cfs) 8.94 Parameters in Table 1.8 are defined in the preceding text. Note:the weir dimensions for DRC stage discharge curves 30%OC(inflection point'a')and 50%OC(inflection point V)are provided for comparison with the selected option(inflection point'c'). 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Rain on Snow: Shallow, Transient Snowpacks with Frozen Soils. Proceedings of the Western Snow Conference. pp. 67-75. References This Page is Left Intentionally Blank NEW Department of PORK STATE Environmental Conservation Glossary ALTERNATIVE SIZING CRITERIA-The sizing criteria that can be achieved on construction projects that include redevelopment activities. ALTERNATIVE STORMWATER MANAGEMENT PRACTICE - Stormwater management practices that are outlined in Chapter 9 for potential application to redevelopment activities and are designed and implemented in accordance with the recommendations in Chapter 9. ANTI-SEEP COLLAR - An impermeable diaphragm usually of sheet metal or concrete constructed at intervals within the zone of saturation along the conduit of a service spillway to increase the seepage length along the conduit and thereby prevent piping or seepage along the conduit. ANTI-VORTEX DEVICE - A device designed and placed on the top of a riser or at the entrance of a pipe to prevent the formation of a vortex in the water at the entrance. "AS-BUILT" - Drawing or certification of conditions as they were actually constructed. AQUATIC BENCH -A ten to fifteen foot wide bench which is located around the inside perimeter of a permanent pool and is normally vegetated with aquatic plants; the goal is to provide pollutant removal and enhance safety in areas using stormwater pond SMPs. AQUIFER -A geological formation which contains and transports groundwater. AUXILIARY SPILLWAY - A spillway designed and constructed to only operate during large floods, less than the Extreme Flood Event. BAFFLES - Guides, grids, grating or similar devices placed in a pond to deflect or regulate flow and create a longer flow path. BANKFULL FLOW - The condition where streamflow just fills a stream channel up to the top of the bank and at a point where the water begins to overflow onto a floodplain. BARREL- The closed conduit used to convey water under or through an embankment: part of the service spillway. BASE FLOW- The stream discharge from ground water. BERM -A shelf that breaks the continuity of a slope; a linear embankment or dike. BETTER SITE DESIGN - Incorporates non-structural and natural approaches to new and redevelopment projects to reduce effects on watersheds by conserving natural areas, reducing impervious cover and better integrating stormwater treatment. BIORETENTION - A water quality practice that utilizes landscaping and a designed filter media to treat urban stormwater runoff by collecting it in shallow depressions, filtering it through the media then infiltrating it into the native soil or collecting it through an outlet drainage system. CHANNEL-A natural stream that conveys water; a ditch or channel excavated for the flow of water. CHANNEL STABILIZATION - Erosion prevention and stabilization of velocity distribution in a channel using jetties, drops, revetments, structural linings, vegetation and other measures. CHECK DAM - A small dam constructed in a gully or other small watercourse to decrease the stream flow velocity (by reducing the channel gradient), minimize channel scour, and promote deposition of sediment. CHUTE -A high velocity, open channel for conveying water to a lower level without erosion. CLAY(SOILS) - 1. A mineral soil separate consisting of particles less than 0.002 millimeter in equivalent diameter. 2. A soil texture class. 3. (Engineering)A fine grained soil (more than 50 percent passing the No.200 sieve)that has a high plasticity index in relation to the liquid limit. COCONUT ROLLS - Also known as coir rolls, these are rolls of natural coconut fiber designed to be used for streambank stabilization and as a possible organic constituent of bioretention media. Glossary COMPACTION (SOILS) - Any process by which the soil grains are rearranged to decrease void space and bring them in closer contact with one another,thereby increasing the weight of solid material per unit of volume, increasing the shear and bearing strength and reducing permeability. CONDUIT-Any channel intended for the conveyance of water, whether open or closed. CONSERVATION DESIGN - Includes laying out the elements of a development project in such a way that the site design takes advantage of a site's natural features, preserves the more sensitive areas and identifies any site constraints and opportunities to prevent effects. CONSERVATION EASEMENT - a voluntary, legal agreement that protects the natural resources of a parcel of land by restricting future land use and/or development on the property"in perpetuity"(permanently).This agreement is held between a landowner and a government agency or land trust,with the landowner maintaining ownership.The conservation easement can either be sold or donated, resulting in a variety of tax benefits for the landowner. The easement is recorded with the property's deed and transfers to all future landowners. CONTOUR- 1. An imaginary line on the surface of the earth connecting points of the same elevation. 2. A line drawn on a map connecting points of the same elevation. CONTRIBUTING AREA-the total on-site and off-site area, including pervious and impervious surfaces, that is tributary to an SMP. CONVENTIONAL SITE DESIGN - For the purposes of this document, conventional design can be viewed as the style of suburban development that has evolved during the past 50 years and generally involves larger lot development, clearing and grading of significant portions of a site, wider streets and larger cul-de-sacs, enclosed drainage systems for stormwater conveyance and large "hole-in-the-ground" detention basins. CORE TRENCH - A trench, filled with relatively impervious material intended to reduce seepage of water through porous strata. CRADLE - A structure usually of concrete shaped to fit around the bottom and sides of a conduit to support the conduit, increase its strength and in dams, to fill all voids between the underside of the conduit and the soil. CREST - 1. The top of a dam, dike, spillway or weir, frequently restricted to the overflow portion. 2. The summit of a wave or peak of a flood. CRUSHED STONE -Aggregate consisting of angular particles produced by mechanically crushing rock. CURVE NUMBER (CN) -A numerical representation of a given area's hydrologic soil group, plant cover, impervious cover, interception and surface storage derived in accordance with Natural Resources Conservation Service methods.This number is used to convert rainfall volume into runoff volume. CUT - Portion of land surface or area from which earth has been removed or will be removed by excavation; the depth below original ground surface to excavated surface. CUT-AND-FILL - Process of earth moving by excavating part of an area and using the excavated material for adjacent embankments or fill areas. CUTOFF -A wall or other structure, such as a trench, filled with relatively impervious material intended to reduce seepage of water through porous strata. CZARA - Acronym used for the Coastal Zone Act Reauthorization Amendments of 1990. These amendments sought to address the issue of nonpoint source pollution issue by requiring states to develop Coastal Nonpoint Pollution Control Programs in order to receive federal funds. DAM -A barrier to confine or raise water for storage or diversion,to create a hydraulic head, to prevent gully erosion, or for retention of soil, sediment or other debris. DESIGN GUIDANCE - Features that enhance the performance but may not be necessary for all applications and may be modified if it does not improve the performance of the practices in a specific site. Glossary DESIGN POINT—A location, on-site or off-site including but not limited to a concentrated point (end section, catch basin, etc.), the entire perimeter of a waterbody or permanent pool (wetland, stream, etc.), the full length of an existing on-site channel that is not being disturbed, or the full length of a natural flow spreader, where stormwater runoff from a given subcatchment or subcatchments converges and discharges. DETENTION - The temporary storage of storm runoff in a SMP with the goals of controlling peak discharge rates and providing gravity settling of pollutants. DETENTION STRUCTURE -A structure constructed for the purpose of temporary storage of stream flow or surface runoff and gradual release of stored water at controlled rates. DEVIATION FROM STANDARDS - Non-compliance with the technical standards set by this technical standard. To be in compliance with this technical standard (Design Manual), projects must meet both performance and sizing criteria. The Department will only accept deviations from the technical standards that involve the use of an alternative post-construction stormwater management practice or a modification to one of the practices from this technical standard that has been demonstrated to be equivalent to this technical standard. DIKE -An embankment to confine or control water, for example, one built along the banks of a river to prevent overflow or lowlands; a levee. DISCONNECTED IMPERVIOUS AREA- Impervious area that is not directly connected to a stream or drainage system, but which directs runoff towards pervious areas where it can infiltrate, be filtered, and slowed down. DISTRIBUTED RUNOFF CONTROL (DRC) -A stream channel protection criteria which utilizes a non-uniform distribution of the storage stage-discharge relationship within a SMP to minimize the change in channel erosion potential from predeveloped to developed conditions. DISTURBED AREA - An area in which the natural vegetative soil cover has been removed or altered and, therefore, is susceptible to erosion. DIVERSION - A channel with a supporting ridge on the lower side constructed across the slope to divert water from areas where it is in excess to sites where it can be used or disposed of safely. Diversions differ from terraces in that they are individually designed. DRAINAGE - 1. The removal of excess surface water or ground water from land by means of surface or subsurface drains. 2. Soils characteristics that affect natural drainage. DRAINAGE AREA (WATERSHED) -All land and water area from which runoff may run to a common (design) point. DROP STRUCTURE - A structure for dropping water to a lower level and dissipating surplus energy; a fall. The drop may be vertical or inclined. DRY SWALE-An open drainage channel explicitly designed to detain and promote the filtration of stormwater runoff through an underlying fabricated soil media. EFFECTIVE BYPASS -The runoff that leaves the site untreated. Example: flow that pass over the weir in a filter system not treated (i.e., not effected by the primary removal mechanism). EMERGENCY SPILLWAY-A spillway designed and constructed to only operate during large floods, exceeding the Extreme Flood Event. ENERGY DISSIPATOR-A designed device such as an apron of riprap or a concrete structure placed at the end of a water transmitting apparatus such as pipe, paved ditch or paved chute for the purpose of reducing the velocity, energy and turbulence of the discharged water. EROSION - 1. The wearing away of the land surface by running water,wind, ice, or other geological agents, including such processes as gravitational creep. 2. Detachment and movement of soil or rock fragments by water,wind, ice or gravity. The following terms are used to describe different types of water erosion: Accelerated erosion - Erosion much more rapid than normal, natural or geologic erosion, primarily as a result of the influence of the activities of man or, in some cases, of other animals or natural catastrophes that expose base surfaces, for example, fires. Glossary Gully erosion - The erosion process whereby water accumulates in narrow channels and, over short periods, removes the soil from this narrow area to considerable depths, ranging from 1 or 2 feet to as much as 75 to 100 feet. Rill erosion -An erosion process in which numerous small channels only several inches deep are formed. See rill. Sheet erosion -The spattering of small soil particles caused by the impact of raindrops on wet soils. The loosened and spattered particles may or may not subsequently be removed by surface runoff. EROSIVE VELOCITIES-Velocities of water that are high enough to wear away the land surface. Exposed soil will generally erode faster than stabilized soils. Erosive velocities will vary according to the soil type, slope, structural, or vegetative stabilization used to protect the soil. EXFILTRATION - The downward movement of water through the soil; the downward flow of runoff from the bottom of an infiltration SMP into the soil. EXTENDED DETENTION (ED) - A stormwater design feature that provides for the gradual release of a volume of water over a 12 to 48 hour interval in order to increase settling of urban pollutants and protect downstream channels from frequent storm events. EXTREME FLOOD (QF)-The storage volume required to control those infrequent but large storm events in which overbank flows approach the floodplain boundaries of the 100-year flood. FILTER BED - The section of a constructed filtration device that houses the filter media and the outflow piping. FILTER FENCE -A geotextile fabric designed to trap sediment and filter runoff. FILTER MEDIA - The sand, soil, or other organic material in a filtration device used to provide a permeable surface for pollutant and sediment removal. FILTER STRIP-A strip of permanent vegetation above ponds,diversions and other structures to retard flow of runoff water, causing deposition of transported material, thereby reducing sediment flow. FINES (SOIL) - Could include particles small enough to pass through a U.S. standard #200 sieve. FLOODPLAIN - The land area that is subject to inundation from a flood that has a one percent chance of being equaled or exceeded in any given year. This is typically thought of as the 100-year flood. FLOW SPLITTER-An engineered, hydraulic structure designed to divert a percentage of storm flow to a SMP located out of the primary channel, or to direct stormwater to a parallel pipe system, or to bypass a portion of baseflow around a SMP. FOREBAY- Storage space located near a stormwater SMP inlet that serves to trap incoming coarse sediments before they accumulate in the main treatment area. FREEBOARD (HYDRAULICS) -The distance between the maximum water surface elevation anticipated in design and the top of retaining banks or structures. Freeboard is provided to prevent overtopping due to unforeseen conditions. FOURTH ORDER STREAM - Designation of stream size where many water quantity requirements may not be needed. A first order stream is identified by "blue lines" on USGS quad sheets. A second order stream is the confluence of two first order streams, and so on. FRENCH DRAIN - A type of drain consisting of an excavated trench refilled with pervious material, such as coarse sand, gravel or crushed stone, through whose voids water percolates and flows to an outlet. GABION -A flexible woven-wire basket composed of two to six rectangular cells filled with small stones. Gabions may be assembled into many types of structures such as revetments, retaining walls, channel liners, drop structures and groins. GABION MATTRESS -A thin gabion, usually six or nine inches thick, used to line channels for erosion control. GRADE - 1. The slope of a road, channel or natural ground. 2. The finished surface of a canal bed, roadbed, top of embankment, or bottom of excavation; any surface prepared for the support of construction, like paving or laying a conduit. 3. To finish the surface of a canal bed, roadbed, top of embankment or bottom of excavation. Glossary GRASS CHANNEL - A open vegetated channel used to convey runoff and to provide treatment by filtering out pollutants and sediments. GRAVEL - 1. Aggregate consisting of mixed sizes of 1/4 inch to 3 inch particles which normally occur in or near old streambeds and have been worn smooth by the action of water. 2. A soil having particle sizes, according to the Unified Soil Classification System, ranging from the No. 4 sieve size angular in shape as produced by mechanical crushing. GRAVEL DIAPHRAGM -A linear trench filled with gravel used as pretreatment and inflow regulation in stormwater filtering systems. GRAVEL FILTER - Washed and graded sand and gravel aggregate placed around a drain or well screen to prevent the movement of fine materials from the aquifer into the drain or well. GREEN INFRASTRUCTURE— In the context of stormwater management, the term green infrastructure includes a wide array of practices at multiple scales to manage and treat stormwater, maintain and restore natural hydrology and ecological function by infiltration, evapotranspiration, capture and reuse of stormwater, and establishment of natural vegetative features. On a regional scale, green infrastructure is the preservation and restoration of natural landscape features, such as forests, floodplains and wetlands, coupled with policies such as infill and redevelopment that reduce overall imperviousness in a watershed or ecoregion. On the local scale green infrastructure consists of site- and neighborhood-specific practices and runoff reduction techniques. Such practices essentially result in runoff reduction and or establishment of habitat areas with significant utilization of soils, vegetation, and engineered media rather than traditional hardscape collection, conveyance and storage structures. Some examples include green roofs, trees and tree boxes, pervious pavement, rain gardens, vegetated swales, planters, reforestation, and protection and enhancement of riparian buffers and floodplains. GROUND COVER - Plants which are low-growing and provide a thick growth which protects the soil as well as providing some beautification of the area occupied. GULLY - A channel or miniature valley cut by concentrated runoff through which water commonly flows only during and immediately after heavy rains or during the melting of snow. The distinction between gully and rill is one of depth. A gully is sufficiently deep that it would not be obliterated by normal tillage operations, whereas a rill is of lessor depth and would be smoothed by ordinary farm tillage. HEAD (HYDRAULICS) - 1. The height of water above any plane of reference. 2. The energy, either kinetic or potential, possessed by each unit weight of a liquid expressed as the vertical height through which a unit weight would have to fall to release the average energy possessed. Used in various terms such as pressure head, velocity head, and head loss. HERBACEOUS PERENNIAL (PLANTS) -A plant whose stems die back to the ground each year. HI MARSH -A pondscaping zone within a stormwater wetland which exists from the surface of the normal pool to a six inch depth and typically contains the greatest density and diversity of emergent wetland plants. HI MARSH WEDGES - Slices of shallow wetland (less than or equal to 6 inches) dividing a stormwater wetland. HOT SPOT - Area where land use or activities generate highly contaminated runoff, with concentrations of pollutants in excess of those typically found in stormwater. HYDRAULIC GRADIENT- The slope of the hydraulic grade line. The slope of the free surface of water flowing in an open channel that has uniform flow. HYDROGRAPH -A graph showing variation in stage (depth) or discharge of a stream of water over a period of time. HYDROLOGIC SOIL GROUP (HSG) - A Natural Resource Conservation Service classification system in which soils are categorized into four runoff potential groups. The groups range from A soils, with high permeability and little runoff production, to D soils, which have low permeability rates and produce much more runoff. HYDROSEED - Seed or other material applied to areas in order to re-vegetate after a disturbance. HYPDXIA- Lack of oxygen in a waterbody resulting from eutrophication. Glossary IMPERVIOUS AREA (COVER) (1) —All impermeable surfaces that cannot effectively infiltrate rainfall. This includes paved, concrete and compacted gravel surfaces (i.e. parking lots, driveways, roads, runways, and sidewalks); building rooftops and miscellaneous impermeable structures such as patios, pools, and sheds. INDUSTRIAL STORMWATER PERMIT - An NPDES permit issued to a commercial industry or group of industries which regulates the pollutant levels associated with industrial storm water discharges or specifies on-site pollution control strategies. INFEASIBLE— Not technologically possible, or not economically practicable and achievable in light of best industry practices. INFILTRATION RATE (Fc) -The rate at which stormwater percolates into the subsoil measured in inches per hour. INFILTRATION TRENCH -A shallow excavated channel backfilled with gravel and designed to provide temporary storage and permit percolation of runoff into the soil substrate. INFLOW PROTECTION -A water handling device used to protect the transition area between any water conveyance (dike, swale, or swale dike) and a sediment trapping device. LEVEL SPREADER - A device for distributing stormwater uniformly over the ground surface as sheet flow to prevent concentrated, erosive flows and promote infiltration. LIVING MULCH—A living mulch is a cover crop interplanted or under sown a main crop that suppresses undesirable weeds, holds moisture and regulates soil temperature. LONG TERM RUNOFF VOLUME -Total runoff over a long period of time (>25 years). MANNING'S FORMULA(HYDRAULICS)-A formula used to predict the velocity of water flow in an open channel or pipeline: V — 1.486 Rz/3S1/z n Where V is the mean velocity of flow in feet per second; R is the hydraulic radius; S is the slope of the energy gradient or for assumed uniform flow the slope of the channel, in feet per foot; and n is the roughness coefficient or retardance factor of the channel lining. MICROPOOL - A smaller permanent pool which is incorporated into the design of larger stormwater ponds to avoid resuspension or settling of particles and minimize impacts to adjacent natural features. MICROTOPOGRAPHY - The complex contours along the bottom of a shallow marsh system, providing greater depth variation which increases the wetland plant diversity and increases the surface area to volume ratio of a stormwaterwetland. MULCH - Covering on surface of soil to protect and enhance certain characteristics, such as water retention qualities. MUNICIPAL STORMWATER PERMIT - A SPDES permit issued to municipalities to regulate discharges from municipal separate storm sewers for compliance with EPA established water quality standards and/or to specify stormwater control strategies. NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES) — The national system for the issuance of wastewater and stormwater permits under the Federal Water Pollution Control Act (Clean Water Act). NATURAL AREAS -This is undisturbed land or previously disturbed land that has been restored and that retains pre- development hydrologic and water quality characteristics. NATURAL BUFFER—An undisturbed area with natural cover running along a surface water(e.g. wetland, stream, river, lake etc.). NEW DEVELOPMENT—Any land disturbance that does not meet the definition of Redevelopment Activity included in this glossary. NITROGEN-FIXING (BACTERIA) - Bacteria having the ability to fix atmospheric nitrogen, making it available for use by plants. Inoculation of legume seeds is one way to insure a source of these bacteria for specified legumes. NON-EROSIVE VELOCITY—The velocity within a channel that does not cause exposed soil to move or vegetative lining to unravel. Glossary NON-STRUCTURAL STORMWATER CONTROL— Natural measures that reduce pollution level, do not require extensive construction or engineering efforts and/or promote pollutant reduction by eliminating the pollutant source. NORMAL DEPTH - Depth of flow in an open conduit during uniform flow for the given conditions. OFF-SITE-Areas outside of the "project area"that may contribute to the same design point as the "project area." OFF-LINE-A stormwater management system designed to manage a storm event by diverting a percentage of stormwater events from a stream or storm drainage system. ON-LINE-A stormwater management system designed to manage stormwater in its original stream or drainage channel. ONE YEAR STORM (QP - A stormwater event which statistically has a 100% chance of being equaled or exceeded on average in a given year. ONE HUNDRED YEAR STORM (QPP loo)A extreme rainfall which statistically has a one percent chance of being equaled or exceeded in any given year. OPEN CHANNELS - Also known as vegetated swales, dry swales and wet swales. These systems are used for the conveyance, retention, infiltration and filtration of stormwater runoff. OUTFALL-The point where water flows from a conduit, stream, or drain. OUTLET - The point at which water discharges from such things as a stream, river, lake, tidal basin, pipe, channel or drainage area. OUTLET CHANNEL - A waterway constructed or altered primarily to carry water from man-made structures such as terraces, subsurface drains, diversions and impoundments. PEAK DISCHARGE RATE - The maximum instantaneous rate of flow during a storm, usually in reference to a specific design storm event. PERFORMANCE CRITERIA—The six performance criteria for each group of SMPs in Chapters 5 and 6 of this Manual. These include feasibility, conveyance, pretreatment, treatment, landscaping, and maintenance. It does not include the Sizing Criteria outlined in Chapter 4 and/or 9 (i.e. WQv, RRv, Cpv, Qp, and Qf) of this Manual. PERMANENT SEEDING - Results in establishing perennial vegetation which may remain on the area for many years. PERMEABILITY-The rate of water movement through the soil column under saturated conditions PERMISSIBLE VELOCITY (HYDRAULICS) - The highest average velocity at which water may be carried safely in a channel or other conduit. The highest velocity that can exist through a substantial length of a conduit and not cause scour of the channel. A safe, non-eroding or allowable velocity PH - A number from 0 to 14 denoting the common logarithm of the reciprocal of the hydrogen ion concentration. A pH of 7.0 denotes neutrality, higher values indicate alkalinity and lower values indicate acidity. PHOSPHORUS INDEX- In this context, the Phosphorus Index or P Index is a risk assessment tool to quantify the potential for phosphorus runoff from soil. It is determined by laboratory testing using the Mehlick-3 phosphorus soil test and dividing the analytical result (in mg/I or ppm) by 1.2. Values greater than 100 are considered very high. Values ranging between 50 and 100 are considered high. Values between 25 and 50 are medium; values less than 25 are low. In general, a soil with a very high or high P-Index is less able to retain phosphorus because its sorption sites are already occupied. Conversely, a soil with a low or medium P Index is better able to retain phosphorus and reduce phosphorus runoff from soil. PIPING - Removal of soil material through subsurface flow channels or"pipes"developed by seepage water. PLUGS - Pieces of turf or sod, usually cut with a round tube, which can be used to propagate the turf or sod by vegetative means. POCKET WETLAND - A stormwater wetland design adapted for the treatment of runoff from small drainage areas (< 5 acres) and which has little or no baseflow available to maintain water elevations and relies on ground water to maintain a permanent pool. Glossary POND BUFFER-The area immediately surrounding a pond which acts as filter to remove pollutants and provide infiltration of stormwater prior to reaching the pond. Provides a separation barrier to adjacent development. POND DRAIN -A pipe or other structure used to drain a permanent pool within a specified time period. PONDSCAPING - Landscaping around stormwater ponds which emphasizes native vegetative species to meet specific design intentions. Species are selected for up to six zones in the pond and its surrounding buffer, based on their ability to tolerate inundation and/or soil saturation. POROSITY- Ratio of pore volume to total solids volume. PRETREATMENT- Techniques employed in stormwater SMPs to provide storage or filtering to help trap coarse materials before they enter the system. REDEVELOPMENT ACTIVITY - Disturbance and reconstruction of existing impervious area, including impervious areas that were removed from a project site within five (5) years of preliminary project plan submission to the local government (i.e. site plan, subdivision, etc.). REQUIRED ELEMENT-Features of the design that are integral to the performance of the practice and must be used in all applications. RETENTION - The amount of precipitation on a drainage area that does not escape as runoff. It is the difference between total precipitation and total runoff. REVERSE-SLOPE PIPE - A pipe which draws from below a permanent pool extending in a reverse angle up to the riser and which determines the water elevation of the permanent pool. RIGHT-OF-WAY - Right of passage, as over another's property. A route that is lawful to use. A strip of land acquired for transport or utility construction. RIP-RAP- Broken rock, cobbles, or boulders placed on earth surfaces, such as the face of a dam or the bank of a stream, for protection against the action of water (waves); also applies to brush or pole mattresses, or brush and stone, or similar materials used for soil erosion control. RISER-A vertical pipe or structure extending from the bottom of a pond SMP and houses the control devices(weirs/orifices) to achieve the discharge rates for specified designs. ROUGHNESS COEFFICIENT (HYDRAULICS) - A factor in velocity and discharge formulas representing the effect of channel roughness on energy losses in flowing water. Manning's "n" is a commonly used roughness coefficient. RR TECHNIQUE (AREA REDUCTION) — A green infrastructure technique that provides runoff reduction credit by subtracting a reduced Water Quality Volume, deducting a portion or the entirety of the contributing drainage area or contributing impervious area, from the required Water Quality Volume. RR TECHNIQUE (VOLUME REDUCTION) — A green infrastructure technique that provides runoff reduction credit as a percentage of the provided Water Quality Volume. RUNOFF (HYDRAULICS) - That portion of the precipitation on a drainage area that is discharged from the area in the stream channels. Types include surface runoff, ground water runoff or seepage. RUNOFF COEFFICIENT(RV) -A value derived from a site impervious cover value that is applied to a given rainfall volume to yield a corresponding runoff volume. SAFE CONVEYANCE—Discharging runoff through the practice outlet/overflow at a non-erosive velocity and only discharge through controlled outlets. SAFE PASSAGE—Safely passing the Spillway Design Flood (SDF) and Service Spillway Design flood (SSDF) as defined in the NYSDEC "Guidelines for Design of Dams." SAFETY BENCH - A flat area above the permanent pool and surrounding a stormwater pond designed to provide a separation from the pond pool and adjacent slopes. Glossary SAND - 1. (Agronomy)A soil particle between 0.05 and 2.0 millimeters in diameter. 2.A soil textural class. 3. (Engineering) According to the Unified Soil Classification System, a soil particle larger than the No. 200 sieve (0.074mm) and passing the No. 4 sieve (approximately 1/4 inch). SEDIMENT- Solid material, both mineral and organic,that is in suspension, being transported, or has been moved from its site of origin by air, water, gravity, or ice and has come to rest on the earth's surface either above or below sea level. SEEPAGE - 1. Water escaping through or emerging from the ground. 2. The process by which water percolates through the soil. SEEPAGE LENGTH - In sediment basins or ponds,the length along the pipe and around the anti-seep collars that is within the seepage zone through an embankment. SERVICE SPILLWAY- The primary pipe or weir which carries baseflow and storm flow through the embankment. SETBACKS - The minimum distance requirements for location of a structural SMP in relation to roads, wells, septic fields, other structures. SHEET FLOW- Water, usually storm runoff, flowing in a thin layer over the ground surface. SIDE SLOPES (ENGINEERING) - The slope of the sides of a channel, dam or embankment. It is customary to name the horizontal distance first, as 1.5 to 1, or frequently, 1 'h: 1, meaning a horizontal distance of 1.5 feet to 1 foot vertical. SILT- 1. (Agronomy) A soil separate consisting of particles between 0.05 and 0.002 millimeter in equivalent diameter. 2. A soil textural class. 3. (Engineering) According to the Unified Soil Classification System a fine grained soil (more than 50 percent passing the No. 200 sieve)that has a low plasticity index in relation to the liquid limit. SITE -At minimum applies to areas of disturbance. This technical standard refers to contributing areas to one design point as "site" or"project area". SITE LIMITATIONS—Site conditions that prevent the use of an infiltration technique and or infiltration of the total WQv. Typical site limitations include: seasonal high groundwater, shallow depth to bedrock, and soils with an infiltration rate less than 0.5 inches/hour. The existence of site limitations shall be confirmed and documented using actual field testing (i.e. test pits, soil borings, and infiltration test) or using information from the most current United States Department of Agriculture (USDA) Soil Survey for the County where the project is located. SIZING CRITERIA—Criteria used to size post-construction stormwater management control practices. The criteria include: Water Quality Volume (WQv), Runoff Reduction Volume (RRv), Channel Protection Volume (CPv), Overbank Flood (Qp) and Extreme Flood (Qf). SOIL TEST- Chemical analysis of soil to determine needs for fertilizers or amendments for species of plant being grown. SPILLWAY-An open or closed channel, or both, used to convey excess water from a reservoir. It may contain gates, either manually or automatically controlled to regulate the discharge of excess water. STABILIZATION - Providing adequate measures, vegetative and/or structural that will prevent erosion from occurring. STAGE (HYDRAULICS) -The variable water surface or the water surface elevation above any chosen datum. STEEP SLOPES - Land area designated on the current United States Department of Agriculture ("USDA") Soil Survey as Soil Slope Phase "D", (provided the map unit name is inclusive of slopes greater than 25%) , or Soil Slope Phase E or F, (regardless of the map unit name), or a combination of the three designations. STILLING BASIN -An open structure or excavation at the foot of an outfall, conduit, chute, drop, or spillway to reduce the energy of the descending stream of water. STORMWATER FILTERING - Stormwater treatment methods which utilize an artificial media to filter out pollutants entrained in urban runoff. STORMWATER MANAGEMENT PRACTICE (SMP) —A standard stormwater management practice that appears in Chapter 3 of this Manual, is sized in accordance with Chapter 4 or 10, and is designed in accordance with Chapter 6 or 10 of this Manual. STORMWATER PONDS -A land depression or impoundment created for the detention or retention of stormwater runoff. Glossary STORMWATER WETLANDS-Shallow, constructed pools that capture stormwater and allow for the growth of characteristic wetland vegetation. STREAM BUFFERS - Zones of variable width which are located along both sides of a stream and are designed to provide a protective natural area along a stream corridor. STREAM CHANNEL PROTECTION (CPv) - A design criteria which requires 24-hour detention of the one year post- developed, 24-hour storm event for the control of stream channel erosion. STRUCTURAL SMPS - Devices which are engineered and constructed to provide temporary storage and treatment of stormwater runoff. SUBGRADE- The soil prepared and compacted to support a structure or a pavement system. TAILWATER- Water, in a river or channel, immediately downstream from a structure. TECHNICAL RELEASE NO. 20 (TR-20) -A Soil Conservation Service (now NRCS)watershed hydrology computer model that is used to compute runoff volumes and route storm events through a stream valley and/or ponds. TECHNICAL RELEASE No. 55 (TR-55) - A watershed hydrology model developed by the Soil Conservation Service (now NRCS) used to calculate runoff volumes and provide a simplified routing for storm events through ponds. TEMPORARY SEEDING - A seeding which is made to provide temporary cover for the soil while waiting for further construction or other activity to take place. TEN YEAR STORM (QP lo) - The peak discharge rate associated with a 24-hour storm event that has a 100% chance of being equaled or exceeded in a given ten year. TIME OF CONCENTRATION - Is quantified from the hydraulically most distant point by time NOT the remotest point. TOE (OF SLOPE) - Where the slope stops or levels out. Bottom of the slope. TOE WALL- Downstream wall of a structure, usually to prevent flowing water from eroding under the structure. TOPSOIL- Fertile or desirable soil material used to top dress road banks, subsoils, parent material, etc. TOTAL IMPERVIOUS AREA- This is the total area of impervious cover, within the contributing area to an SMP, that prevents water from infiltrating into the underlying soils. TOTAL SUSPENDED SOLIDS - The total amount of soil particulate matter, including both organic and inorganic material, suspended in the water column. TRASH RACK- Grill, grate or other device at the intake of a channel, pipe, drain or spillway for the purpose of preventing oversized debris from entering the structure. TROUT WATERS -Waters classified as (T) or(TS) by the New York State DEC. TWO YEAR STORM (QP 2) - The peak discharge rate associated with a 24 hour storm event that has a 100% chance of being equaled or exceeded in a given two year. ULTIMATE CONDITION - Full watershed build-out based on existing zoning. ULTRA-URBAN - Densely developed urban areas in which little pervious surface exists. VELOCITY HEAD- Head due to the velocity of a moving fluid, equal to the square of the mean velocity divided by twice the acceleration due to gravity (32.16 feet per second per second). VOLUMETRIC RUNOFF COEFFICIENT (Ry) - The value that is applied to a given rainfall volume to yield a corresponding runoff volume based on the percent impervious cover in a drainage basin. WALKING ZONE—The clear width of the sidewalk where pedestrian can walk unobstructed. WATER QUALITY EFFICIENCY-A term that is intended to indicate the performance of the SMP by itself(not the full system including bypass). Glossary WATER QUALITY VOLUME (WQv) - The volume of stormwater runoff, generated from the 90th percentile rain event, that shall be captured and treated by stormwater management practice(s) or, in Enhanced Phosphorus Watersheds, the runoff from the 1-year, 24-hour storm event. WATER SURFACE PROFILE-The longitudinal profile assumed by the surface of a stream flowing in an open channel;the hydraulic grade line. WEDGES - Design feature in stormwater wetlands which increases flow path length to provide for extended detention and treatment of runoff. WET SWALE - An open drainage channel or depression, explicitly designed to retain water or intercept groundwater for water quality treatment. WETTED PERIMETER - The length of the line of intersection of the plane or the hydraulic cross-section with the wetted surface of the channel. WING WALL- Side wall extensions of a structure used to prevent sloughing of banks or channels and to direct and confine overflow. Glossary This Page is Left Intentionally Blank NEW Department of PORK STATE Environmental Conservation APPENDIX I DOW - 5.1.11 DivisionNew York, State Departinent of Envirmiliental Conservation, Division of Water of Water Technical and Operational Guidance Issuing Authors ark Klotz Title: Snow Disposal Director i ~ ate Signatur 7 Date Issued: Latest Date Revised: New Originator: Angus Eaton and Ken Kosinski *** NOTICE ** This document has been developed to provide Department staff with guidance on how to ensure compliance with the statutory and regulatory requirements,including case law interpretations, and to provide consistent treatment of similar situations. This document may also be used by the public to gain technical guidance and insight regarding how Departnxent staff•may analyze an issue and factors in their consideration of particular facts and circumstances. This guidance document is not a fixed rule under the State Administrative Procedures Act subsection 102(2)(a)(I). Furthermore,nothing set forth herein prevents staff from varying from this guidance as the specific facts and circumstances may dictate,provided staffs actions comply with applicable statutory and regulatory requirements. This document does not create any enforceable rights for the benefit of any party. 1. Purpose: Given the periodic need to clear,remove and dispose of accumulated amounts of snow From roads, parking lots and walkways. the practice of direct disposal of sno,%v into New York's surface waters is an activity that. under certain circumstances, takes place in New York. This practice should he carefully monitored given environmental. aesthetic and legal concerns. The i«llow•ing includes Best Management Practices (BNIPs) for upland disposal of snow.which is preferred, and guidance for handling direct disposal of snow to surface:waters where upland disposal is not practicable. 11. 13,ackgrotind: Direct snow disposal is disposal of snow collected from land areas and disposed of in surface waters ofthe state (e.g. lakes. rivers, estuaries). Typically this includes loading trucks with snow from roads. parking lots, and walkways that do not harc adjacent storage capacity and then transporting. the snow to a location where the snow from the trucks,can be transferred to 1 surface waters. Accumulated snow, which is collected and then directly disposed of, may contain a variety of pollutants such as salt and sand; other settleable, suspended and dissolved solids; oil and grease; lead and other trace elements from vehicular traffic and emissions; incidental trash; pathogens from pet waste; and other debris. Discharge of these materials can be prevented through proper management techniques such as upland disposal or at least minimized through BMPs that address how and where snow is collected and loaded if upland disposal is not an option. LEGAL New York's Environmental Conservation Law (ECL)has two Articles which address this issue -Articles 11 and 17. ECL §17-0501 states that, "[i]t shall be unlawful for any person, directly or indirectly, to throw, drain, run or otherwise discharge into such waters organic or inorganic matter that shall cause or contribute to a condition in contravention of the standards adopted by the department pursuant to section 17-0301. " ECL §11-0503(4) states that, "No earth, soil, refuse or other solid substances, except snow or ice, shall be disposed of in any stream or tributary thereto which is inhabited by trout; nor shall any earth, soil, refuse or other solid substance, except snow or ice,be disposed of on the banks of trout streams or tributaries thereto in such a manner that such solid substance can enter the stream at any stage of water level. Dumps and disposal areas for refuse along the banks of trout streams, or tributaries thereto, shall be operated by the owner or lessee of such an area in such manner that the solid substances deposited thereon shall not enter the stream at any stage of water level." III. Guidance: To provide the best protection of the aquatic environment and protect against violation of water quality standards, it is recommended that individuals, municipalities and other persons responsible for conducting snow removal re-evaluate their past and present operations, and develop upland snow disposal alternatives where practicable. If upland disposal areas have been exhausted, and snow must be removed to alleviate safety issues, disposal of snow should be in accordance with the BMPs below under"Direct Snow Disposal". Upland Disposal Best Management Practices Planning for the upland disposal of collected snow will require the identification and advance preparation of a site(s). In determining the size and location(s) of an upland disposal site,the following information should be considered: A. Estimate, based on long-term weather forecasts, the snow disposal capacity that may be necessary for the season so that an adequate number of upland disposal sites can be selected and prepared. 2 B. Identify sites in upland locations that could potentially be used for snow disposal, such as municipal open space (e.g., parking lots, parks, golf courses). Sites located in upland locations that are not likely to impact sensitive environmental resources should be selected first. C. If more storage space is still required,prioritize the sites in upland locations with the least potential for adverse environmental impact using the site selection criteria and GIS mapping for guidance. Additionally, municipalities should identify areas that are likely to contain"heavily contaminated snow,"which cannot be directly disposed of into nearby waterbodies. Heavily contaminated snow is considered to be snow that is collected and removed from locations, such as: A. downtown areas or other dense commercial/industrial areas where snow has not been removed for more than 7 days; B. areas heavily or frequently sanded or salted C. areas of heavy litter and debris; or D. areas that have experienced pavement separation and breakage. Also, when collecting snow for disposal, municipalities should avoid dumping snow that has a distinct visual appearance of being dirty such as a coat of black or brown, or a distinct visual contrast with fresh snow into waterbodies and target that snow for upland disposal. This snow is more likely to be heavily contaminated BMPs associated with upland disposal of snow and treatment include: A. installation and on-going maintenance of a down gradient sediment/trash barrier(such as a silt fence or a series of staked hay bales); B. installation of a coarse gravel berm down gradient of the upland disposal site to disperse flow and trap solids as the pile melts; C. establishment and maintenance of vegetation at the disposal site during the growing season; D. removal of accumulated trash, debris and sediment incidental to snow removal and disposal from the site before the start of the growing season; E. establishment and maintenance of a buffer(minimum recommended distances range from 50 to 100 feet)between disposal site and surface water; 3 F. avoidance of wellhead protection areas of a public water supply or within 300 feet of a private well'; G. avoidance of sanitary landfills - snow meltwater will create more leachate in landfills, which will require collection and treatment; H. avoidance of areas serving as onsite sewage system leachfields; and I. while vegetated upland disposal sites are preferred, flat areas such as vacant parking lots may be utilized, if vegetated areas are exhausted and proper controls are employed(e.g. inlet protection for catch basins). Direct Snow Disposal If despite planning, upland disposal sites have been exhausted and snow must be removed to alleviate safety issues, disposal of snow in nearby waterbodies may be appropriate provided the snow is not heavily contaminated as described above and provided the disposal is: A. compliant with local ordinances and bylaws (this determination can be made after consultation with appropriate municipal officials); B. in surface waters with adequate flow and mixing to prevent ice jams from forming; and C. in coastal communities,preference should be given to disposal in salt water if available. Snow disposal should not occur in the following areas A. coastal or freshwater wetlands, eelgrass beds, vegetated shallows, vernal pools, shellfish beds, mudflats, outstanding water resources, or drinking water reservoirs and their tributaries; B. where trucks may cause shoreline damage or stream bank damage or erosion; C. any waterbody, including rivers, reservoirs, ponds, lakes,wetlands, bays or the ocean where disposal has the reasonable potential to cause water quality impairments (e.g. waterbodies designated as trout and/or trout spawning and waterbodies with downstream drinking water intakes); D. any area or waterbody where snow disposal can cause flooding or navigational hazards when it freezes; and E. in or near a storm drain catch basins or in stormwater drainage swales or ditches. Snow combined with sand and debris may block a storm drainage system, causing localized flooding. In addition, a high volume of sand, sediment and litter released from melting 'This is consistent with NYSDOH's Required Minimum Separation Distances to Protect Water Wells From Contamination from chemical storage sites not protected from the elements(e.g.,salt and sand/salt storage). 4 snow also may be quickly transported through the drainage system into surface water. Further, disposing of snow in stormwater collection systems can dramatically increase the maintenance costs for those systems. Industrial Snow Melters Although not widespread, it is also recognized that the availability of land suitable for dumping is limited, especially in highly urbanized areas, thus some municipalities may utilize an industrial snow melter,which is a piece of snow removal equipment designed to melt snow using flame burners, hot water or both. Industrial snow melters may also be used in areas such as the top floor of a parking garage where physical removal of snow is difficult. The melted water is typically discharged into a storm drain or onto the ground. Many of the concerns noted above including those regarding the removal of accumulated trash, debris and sediment incidental to snow removal, avoiding discharge of the melted water to sensitive areas and potential issues related to discharges to storm drainage systems, are applicable to the use of an industrial snow melter. IV. Responsibility: Administration of this guidance document is handled by Central Office, Division of Water, Bureau of Water Resource Management. Implementation of the guidance is handled by regional staff. V. Procedure: In responding to inquiries, regional staff should send a copy of the guidance or refer to the website where the guidance is posted. The direct disposal of snow into New York's surface waters is strongly discouraged, except under the circumstances set forth herein. 5 SWEEPER REPORT Please circle one or more areas below: ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC CUTCHOGUEwTT'ITUCK LAUREL FISHERS ISLAND DATE: Q o OPERATOR: "_ i TT PLEASE LIST THE STREETS COMPLETED 1. & .. J, 1N0A 9. 3. C 10. 4. �>7e& 11. 12. . 13. 7,. 14. SWEEPER REPORT Please circle one or more areas below: ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC CUTCHOGUE T� K LAUREL FISHERS ISLAND DATE: —O` ` OPERATOR: PLEASE LIST THE STREETS COMPLETED 1. 8. 3. ®lYI�L[P 10. 4. M 11. 5, 12. 6. 13. 7. 14. SWEEPER REPORT Please circle one or more areas below: ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC CUTCHOGUE MATTITUCK LAUREL FISHERS ISLAND DATE: S -z/ l OPERATOR: �GK k. GL� PLEASE LIST THE STREETS COMPLETED 1. LOu-t 8. 2. S-00 Old Sou4j 9. 3. t 5 lo. 4. 5. 12. 6, 13. 7. 14. SWEEPER REPORT Please circle one or more areas below: ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC CUTCHOGUE MATTIT JfK LAUREL FISHERS ISLAND OPERATOR: w PLEASE LIST THE STREETS COMPLETED 1. 0 8. 2. f1 Ir " 9, 3. �- 10. 4. 11. 55. 12.. 13. 7. 14. SWEEPER REPORT Please circle one or more areas below: ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC CUTCHOGUE MATTITUC LAUREL FISHERS ISLAND DATE: OPERATOR: " PLEASE LIST THE STREETS COMPLETED & 2. 9. 3. AS �-� JC1� 1& 4. 11.. 5. 12. 6. 13. 7. 14. SWEEPER REPORT Please circle one or more areas below: ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC CUTCHOGUE MATTITUCK LAUREL FISHERS ISLAND DATE: I 0 l 1 ( 12 OPERATOR- �E n' ', J ;tlmvA- PLEASE LIST THE STREETS COMPLETED Z2gt-e 8. 2. Cox Let f-e 9. 3. V 4. 11. 5. 12, 6. 13, 7. 14, SWEEPER REPORT Please circle one or more areas below: ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC CUTCHOGUE MATTITUCK LAUREL FISHERS ISLAND 71 Z DATE: / If OPERATOR: 'F O✓� ff PLEASE LIST THE STREETS COMPLETED 1. J�') �G��f � v✓ � ' 2. 9. 3. ��c ,� ! 10.. 4. 5. 12. 6, 13, 7. 14. SWEEPER REPORT Please circle one or more areas below; ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC CUTCHOGUE MATTITUCK LAUREL FISHERS ISLAND DATE Z OPERATOR: f PLEASE LIST THE STREETS COMPLETED 8 �r Cc ✓!v?, 9. ir��T 2, 3. G2o✓ � 10. S Q C(7^d 4. " 11. � � d 12. o,,.�� J� 6, a 13. 7. ©'r , S _ 14. SWEEPER REPORT Please circle one or more areas below: ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC P CUTCHOGUE MATTITUCK LAUREL FISHERS ISLAND DATE: l3► a ba`i OPERATOR:, PLEASE LIST THE STREETS COMPLETED J,%&T,b0(- A s. , " (LA-Tv%wA LA`V E 9. 3, S'v N S S.T M'\vg- 10 Y N -S 4, p �, a 11. ____......... __ .. .........._ __ ...... 12. 6. ... 13. 7. 14. SWEEPER REPORT Please circle one or more areas below: ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC CUTCHOGUE MATTITUCK LAUREL FISHERS ISLAND DATE: I S 1 vjay OPERATOR: r�� I1- 62ocN� #3 c O� a. PLEASE LIST THE STREETS COMPLETED pW,J) 4 r 0 8. S 4rr10 bit2.N .� _ AqQ f U s 9. 3. _.... . ........ ................................................. 10. 4. 11. 5. 12, 6. 13. 7. 14. SWEEPER REPORT Please circle one or more areas below: ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC CUTCHOGUE MATTITUCN LAUREL FISHERS ISLAND DATE: OPERATOR: 'R� r 201� fi'�ab PLEASE LI TTHE STREETS COMPLETED 1.. �Avk( & 2. �Lr}fir 9. 3. P-kQ14- AV f _ 10. 4. V % L "� ...._....... ................. ........ 11. ....... ._ .......... 5. 12. 6._._..._...._.._. ._. ._ _. _ 13.__ .................................. 7............... 14. _.�............ �a DANIEL J. GOODWIN 4 Tel.(631) 765-3140 Superintendent (631) 734-5211 Fax(631) 765-1750 Highway Department Town of Southold 275 Peconic Lane - P.O. Box 178 • Peconic, N.Y. 11958-0178 SWEEPER REPORT Please circle one or more areas below: ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC MATTITUCK LAUREL FISHERS ISLAND 2�ILH 0 G Uf DATE: OPERATOR: PLEASE LIST THE STREETS COMPLETED 1. I ` APL� AVNVE 8. �1 `^4 i tl(h 9 a 4. 5. � 1 . 6, MA �� � 13. DANIEL J. GOODWIN �i Tel.(631) 765-3140 Superintendent q°� (631) 734-5211 Fax(631) 765-1750 Highway Department Town of Southold 275 Peconic Lane • P.O. Box 178 • Peconic, N.Y. 11958-0178 SWEEPER REPORT Please circle one or more areas below: ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC C EHOg MATTITUCK LAUREL FISHERS ISLAND DATE: Co12 a O�l 1 OPERATOR: PLEASE LIST THE STREETS COMPLETED 1f'\10W �49 Va L 8. 2. N �(\ T1 C1 S� DA� 9 (40 1.0. a«y� 4VZ( K5 ?t RDAD lQ�,►tS'. 1.1. 5. OLD PAVT41E KAID 12. 6. WC. ST ( g C fl< AV ZtiWE 13. 7. 14, DAMEL J. GOODWIN (631) 765-3140 � m� Tel. Superintendent (631) 734-5211 ' G Fax(631) 765-1750 Highway Department Town of Southold 275 Peconic Lane • P.O. Box 178 • Peconic, N.Y. 11958-0178 SWEEPER REPORT Please circle one or more areas below: ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC CUTCHOGUE MATTITUCK LAUREL FISHERS ISLAND DATE: g1;z u�`OPERATOR.,- PLEASE LIST THE STREETS COMPLETED S W � r 2. ���Z AJ4 2 0�. 9ry 3. 1.0. 4. 11. 5. 12. 5, 13. 7. 14. sr DANIEL J. GOODWIN Tel.(631) 765-3140 Superintendent t: (631) 734-5211 Fax(631) 765-1750 Highway Department Town of Southold 275 Peconic Lane • P.O. Box 178 • Peconic, N.Y. 11958-0178 SWEEPER REPORT Please circle one or more areas below: ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC CUTCHOGdF„ " MATTITUCK LAUREL FISHERS ISLAND DATE: -4 / g 0 a q OPERATOR ^%% K- CRIWVI`4 3a° ' PLEASE LIST THE STREETS COMPLETED 8. LW AT 3, C'AK 10. 4. B% s. � �C� 'l� 12. 6. 13.. 7. 14. SWEEPER REPORT Please circle one or more areas below: ORIENT EAST MARION GREENPORT %EEL� PECONIC CEED MATTITUCK LAUREL FISHERS ISLAND DATE:.` OPERATOR: �b`' ,`' tAN PLEASE LIST THE STREETS COMPLETED 1(vA%^ �A.%f 8. ................................................ n 3 ` �J'!N 10, �"5 :........_.... S�ArtT�.O use 5. 12, 6, 13, 7. 14. SWEEPER REPORT Please circle one or more areas below: ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC CUTCHOGUE MATTITUCK LAUREL FISHERS ISLAND DATE'. l/ OPERATOR: PLEASE LIST THE STREETS COMPLETED 2. 10 EVV P 0 Ilk 9.. 3. c.A5 r' J U. 10. 4.C " Q 5 11, 5. 12. 6. 13, 7. 14. SWEEPER REPORT Please circle one or more areas below: ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC CUTCHOGUE MATTITUCK LAUREL FISHERS ISLAND DATE: OPERATOR: PLEASE LIST THE STREETS COMPLETED To MAC L VE 9. 3. Flk T t T 10. 4. 6gUhItt 11. 5. SrcCoo j 12, 67 ( - 13, 7. 14. SWEEPER REPORT Please circle one or more areas below: ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC C=L UE MATTITUCK LAUREL FISHERS ISLAND DATE: (C� " OPERATOR:�I PLEASE LIST THE STREETS COMPLETED 1.r0 0 9 S 8. I(? 2. 9. V . . 10.04 K 4: 0 fvA-)-1 I--n 11. 03 5. O OA O 12._ LV tj JX 8 C 6. rA !"►" IN" G 13. 7. J l 14, SWEEPER REPORT Please circle one or more areas below; ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC UCH MATTITUCK LAUREL FISHERS ISLAND DATE: OPERATOR; Og K PLEASE LIST THE STREETS COMPLETED i�w A..(�. 1. A D r 1Ve 2, l�cmq DC 1VQ 9, 3. Q.�('V-1 � �' c Q.2 1 10. NvA T'A.11L AYe s;&k 4. S�t �c. e S�• � {2^l 11. 9 `'� �� 12. 6, Ctksjt, ►`o G� 1 . 7, MQtX0A Lam 14, SWEEPER REPORT Please circle one or more areas below: ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC C'UTCHOGUE MATTITUCK LAUREL FISHERS ISLAND DATE: a �� s OPERATOR: - 41� D PLEASE LIST THE STREETS COMPLETED 1. C O a t\�f 1 I v�j �v 8. 2. {`� ft S 9.. L,� * A 107 4. 5. 12. 6. 13, 7. 14, SWEEPER REPORT Please circle one or more areas below: ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC CUTCHOGUE MATTITUCK LAUREL FISHERS ISLAND DATE:: c� Q S OPERATOR: e� K- i3(tour� 35� PLEASE LIST THE STREETS COMPLETED j,jzp,v�- 8, V Q rNy k ".r'A`t �• g L0.rR- 10. 4. �� cNj 5. 12. 6. 13, 7. 14. SWEEPER REPORT Please circle one or more areas below: ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC CUTCHOGUE MA ITU LAUREL FISHERS ISLAND DATE: 6'—30 —, 4— OPERATOR: F—MkA kllzz--� PLEASE LIST THE STREETS COMPLETED 2. 0 3 u C L. 9. 3. U cS 10�. 4. pf �� I' eev 11. 5. 12. 6. 13. 7. 14. SWEEPER REPORT Please circle one or more areas below: ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC CU'TCI MATTITUCK LAUREL FISHERS ISLAND DATE: J °� OPERATOR: I�1U PLEASE LIST THE STREETS COMPLETED 8. 3. 10. 4, 11. S. 12. 6. 13. 7.. 14. SWEEPER REPORT Please circle one or more areas below: ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC CUTCHOE MATTITUCK LAUREL FISHERS ISLAND DATE: OPERATOR: ,' PLEASE LIST THE STREETS COMPLETED 1. W OOD 8, 2. H N 9. 3, $eTIS T 10, 4. Al -T 11. 5. L 12. 13. 7. T",N (0av 14. SWEEPER REPORT Please circle one or more areas below: ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC CUTCHOGUE MATTITUCK LAUREL FISHERS ISLAND DATE: ® , - OPERATOR: s, PLEASE LIST THE STREETS COMPLETED 2. T4 IC j_Q, U E 9. 3,, r L Ir 10. 4, jeV11. 5. 12. & 13, 7. 14. SWEEPER REPORT Please circle one or more areas below: ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC CUTCHOGUE MATTITUCK LAUREL FISHERS ISLAND DATE: OPERATOR: PLEASE LIST THE STREETS COMPLETED 1. 8. A)v-r 3. 10. 4. 11. 5. 12. 6. 13. 7. 14. I SWEEPER REPORT Please circle one or more areas below: ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC CUTCHOGUE MATTITUCK LAUREL FISHERS ISLAND DATE: U ' 2-5— OPERATOR: "" 4 PLEASE LIST THE STREETS COMPLETED 1, ��a o U) 8, it m u 4. VIEW 11. 5. KNOU W O 1) (-,A— 12. 6, L L U W � 13. 7. A ) 14. SWEEPER REPORT Please circle one or more areas below: ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC CUTCHOGUE MATTITUCK LAUREL FISHERS ISLAND DATE. PLR t of 5 OPERATOR: M�°� 1�- � gg,'Olb10 �350 PLEASE LIST THE STREETS COMPLETED 1. U V �1 a�DQb�; , plc�K A Vb41;N 9. �����Arl tiAfl 10, 4. 5. 12, 6. 13, 7. 14. SWEEPER REPORT Please circle one or more areas below: ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC CUTCHOGUE MATTITUC LAUREL FISHERS ISLAND DATE: Va 5 � oa OPERATOR: P,,4e PLEASE LIST THE STREETS COMPLETED Qw' ^j 8. \N is{ Ai�;1, R.� o4.� s'. 2. 9. 3„ 10, 4, 11, 5. 12„ 6. 13. 7. 14. SWEEPER REPORT Please circle one or more areas below: ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC CUTCHOGUE ATTITUCK LAUREL FISHERS ISLAND DATE: I a 4 a 0, 5 OPERATOR:lZri`p PLEASE LIST THE STREETS COMPLETED 1. uC¢o.J�.wQ� �oU� ptbr\S 8. �1 2Srir 9 3. 10, 4. 11. 5. 12. 6. 13 7. 14. SWEEPER REPORT Please circle one or more areas below: ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC CU:TC=GU MATTITUCK LAUREL FISHERS ISLAND , DATE: / rLC-� OPERATOR ���� 35� PLEASE LIST THE STREETS COMPLETED 2. �v S 9. 1 )10. 4. koAor Lck%-Nk ��' 11, 5. Q6014" � �Q+lt 12, 6. 13, 7. 14. SWEEPER REPORT Please circle one or more areas below ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC CUTCHOGU MATTITUCK LAUREL FISHERS ISLAND DATE: O� OPERATOR.: 0 B(Zo,�n� 35 b PLEASE LIST THE STREETS COMPLETED A �I a 1 , �� yQ, 1�Qck , 2. S L G�i�Q. 9. IA 3. 10, M nn 5. • � L Ck T' Q 12. 6. �OOS� C o,l� 13. SWEEPER REPORT Please circle one or more areas below: ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC CUTCHOGUE MATTITUCK LAUREL FISHERS ISLAND DATE: OPERATOR:, PLEASE LIST THE STREETS COMPLETED 1. �� � v 8. 2. 9, 3. 10. 4. 11. 5. 12. 6.. 13. 7. 14. SWEEPER REPORT Please circle one or more areas below: ORIENT EAST MARION GREENPORT SOUTHOLD PECONIC C" c n MATTITUCK LAUREL FISHERS ISLAND DATE: OPERATOR; PLEASE LIST THE STREETS COMPLETED 1. 8. 2. ! 9. 4. JUL � 6 � 11, 5. 12. 6. 13. 7. 14.