Chapter 6 Construction And Post- Construction

6.1.1 SWPPP Construction Erosion andSediment Control ComponentAll SWPPPs must include an erosion and sediment controlcomponent. The erosion and sediment control componentmust meet the requirements in the NYS Standards andSpecifications for Erosion and Sediment Control.1 TheSWPPP must include practices to avoid erosion andcontrol sedimentation for each step in the constructionprocess. The SWPPP should also include site plans thatshow the location of each process; the practices associatedwith that process; and the details specifying size, materials,and endurance of each practice.6.1.2 SWPPP Post-Construction StormwaterManagement ComponentDepending on the covered development project, aSWPPP must also include post-construction SMPs thatthe property owner must implement and maintain tomanage stormwater runoff from the developed site afterconstruction is completed. The NYSDEC CGP establisheswhich covered development projects require only anerosion and sediment control component and which alsorequire post-construction SMPs.The stormwater management component must describepost-construction SMPs that prevent or reduce pollutionfrom stormwater runoff to waterbodies. SMPs mustmeet the performance standards in the NYS StormwaterManagement Design Manual2, including an Operation andMaintenance manual that addresses each SMP. DEP is alsodeveloping a NYC Stormwater Design Manual to addressCity-specific requirements and preferred practices forcovered development projects. This NYC manual will beavailable on the DEP website.SWPPPs with stormwater management componentsshould include site plans showing both the preconstruction and the proposed post-constructioncondition of the site. The developer must show thelocations, materials, sizes, and inlet and outlet conditionsof all SMPs. In supporting documentation, the developermust include calculations demonstrating that the sizeand operation of the SMP are adequate, and results ofany field-testing performed to locate and size the SMP.An operation and maintenance manual must also beincluded to address the requirements for the long termmaintenance of the SMPs.1http://www.dec.ny.gov/docs/water al/29072.html6.1.3 No Net Increase RequirementCovered development projects involving a non-negligiblechange in land use (i.e., land disturbances greater than orequal to one acre where there is an increase in imperviouscover) draining to impaired waters are required to includea pollutant load analysis in the SWPPP. This analysisshould demonstrate that there will be no net increase ofthe POC(s) for which a waterbody is impaired. NYSDECprovided the list of impaired waters in Appendix 2 ofthe MS4 Permit and specified the particular pollutant(s)causing the impairment for each listed waterbodysegment. The City’s Draft Procedures for No Net Increase(NNI) Pollutant Load Analysis is available on the DEPwebsite.3 The City will provide status updates on the NNIrequirement in Annual Reports.The POCs listed in Appendix 2 of the MS4 Permit arefloatables, nitrogen, phosphorus, and pathogens. Refer toChapter 11: Special Conditions for Impaired Waters formore information on NYC impaired waters and POCs.The SWPPP pollutant load analysis must consist of anarrative that identifies each POC causing impairment inthe waterbody and the potential sources of those pollutants;and the management practices that will be used to ensureno net increase of those pollutants to impaired waters.Projects in areas draining to an impaired waterbody mustdemonstrate compliance for the individual pollutant(s) forwhich the waterbody is impaired as follows: Floatables: Design and implement SMPs in accordancewith the NYS Stormwater Management Design Manual. Nitrogen: Design and implement practices to show nonet increase in total nitrogen load. Provide pollutantcalculations using the loading and removal dataprovided in the NYC Stormwater Design Manual. Phosphorus: Design and implement SMPs inaccordance with Chapter 10 of the NYS StormwaterManagement Design Manual. Pathogens: Design and implement SMPs inaccordance with the NYS Stormwater ManagementDesign Manual, with added enhancements and sitemanagement practices to reduce the potential forpathogens to enter the MS4, as detailed in the NYCStormwater Design Manual.The NYC Stormwater Design Manual will detail how todetermine whether a site drains to an impaired waterbodyand how to demonstrate no net increase for the POC(s)causing the impairment.3http://www.nyc.gov/html/dep/pdf/water sewer/deliverable ms4-permit-IIb-1-d.pdf106

6.1.4 SWPPP Requirements for FloodManagement ProjectsCovered development projects that meet the MS4 Permitdefinition of a flood management project are required toassess in the SWPPP the impacts on the water quality ofthe receiving water.Flood management projects refer exclusively to projectsdesigned and functioning to capture, detain, or conveyoverland flow from a large drainage area to preventdownstream flooding associated with a 100-year or greaterstorm event. The MS4 Permit excludes projects such asinstallation and maintenance of storm sewers, high-levelstorm sewers, Bluebelt storm sewers, drainage inlets, andother projects to improve drainage, alleviate localizedflooding, or reduce coastal flooding.Additionally, SWPPPs prepared for major maintenanceor rehabilitation of City-owned structural flood controldevices in flood management projects shall, if feasible andcost effective, incorporate the recommended controlsresulting from the facility assessments conducted underthe Pollution Prevention/Good Housekeeping provisionsof the MS4 Permit. Refer to Chapter 7: PollutionPrevention/Good Housekeeping for more details onfacility assessments. The City has not identified anyexisting flood management devices within the MS4 areathat meet the MS4 Permit definition.The City engaged targeted stakeholders todiscuss the development of the Construction/Post-Construction Program. These stakeholdersincluded: General Public Stormwater Advisory Group Design, construction, and developmentcommunity Environmental organizationsIn addition, the City entered into a partnership withthe Urban Green Council (UGC) and the Real EstateBoard of New York (REBNY) to bring togethera broader audience of professionals who will beimpacted by the Construction/Post-Constructionprovisions.In response to comments received on this program,the City has: Included Owner as the defined person tosubmit annual certifications for StormwaterMaintenance Permits instead of a QualifiedProfessional. Altered the threshold analysis by: »changing the life cycle analysis from a20-year to 30-year life cycle.»adding 7,500 and 12,500 square foot lotsize thresholds into the analysis (the initialanalysis included lot sizes in 5,000 squarefoot increments up to and including 1 acre).Revised cost estimates per input from developerworkshops held in conjunction with REBNY andUGC.Green Roof at Zerega EMS Station107

6.2 DEP Issued Stormwater PermitsAfter the rulemaking process is complete and DEP’s rulesgo into effect, DEP will begin accepting applications fortwo types of stormwater permits for covered developmentprojects: Stormwater Construction Permit and StormwaterMaintenance Permit. Covered development projects thathave a NYSDEC SPDES acknowledgement letter indicatingthat the project has coverage under the constructiongeneral permit before the effective date of the rules willnot be required to apply for either of DEP’s permits.DEP may periodically inspect permitted sites. Appendix1.1: Enforcement Response Plan includes DEP’s protocolfor investigating, documenting and, where appropriate,enforcing against unauthorized discharges from constructionand post-construction pollution sources into the MS4.6.2.1 Stormwater Construction PermitStormwater Construction Permits are required for allcovered development projects in addition to obtainingcoverage under the NYSDEC CGP. A developer mustobtain a Stormwater Construction Permit prior toconstruction. Before issuing the permit, DEP must receivetwo forms through the SWPTS:1. The Permit Initiation Form that requires thedeveloper to submit the names of the QualifiedInspector, the Contractor, and where required, a fullyexecuted and recorded maintenance easement, asdescribed below; and2. The Permit Request Form that requires the Contractorto complete a Contractor’s Certification, andprovide the Trained Contractor information and theNYSDEC SPDES number received with the NYSDECAcknowledgement after filing an NOI.Except as noted below, covered development projectsthat require a post-construction SMP(s) are required toexecute and record a maintenance easement and submit acopy to DEP to receive a Stormwater Construction Permitfrom DEP. The purpose of the maintenance easement isto ensure that future owners of the property are aware ofthe post-construction SMPs and their ongoing obligationto operate and maintain them in accordance with theoperation and maintenance manual in the approvedSWPPP. The easement also puts the property owner onnotice that DEP may inspect post-construction SMPsto confirm that the operation and maintenance meetsapplicable standards. Public properties with SMPs, publicprojects, and projects that only require erosion andsediment controls during construction do not require amaintenance easement. However, if a public entity latertransfers a public property with an SMP to a private entity,the NYC Corporation Counsel may require a maintenanceeasement at that time. The maintenance easement mustbe recorded with the Office of the City Register or, ifapplicable, the County Clerk, after approval by the NYCCorporation Counsel.In addition, DEP requires a Contractor’s Certification thatensures that the Contractor has reviewed and agrees toimplement the approved SWPPP. Subcontractors that areresponsible for specific parts of a development activity willneed to sign certifications and provide Trained Contractorinformation as well. Subcontractor certifications andTrained Contractor credentials must be kept withthe SWPPP on the site. In order to receive a permit, adeveloper must also have a DEP-approved SWPPP, andan NYSDEC-acknowledged notice of intent (NOI) forcoverage under the NYSDEC CGP.The purpose of these forms is to identify the individualsresponsible for SWPPP implementation. These roles andresponsibilities include: The Qualified Inspector, who is responsible for weeklyinspections of the construction site. The Contractor, who is the construction manageror the primary contractor responsible for thedevelopment activity. The Contractor must alsoprovide the information for at least one TrainedContractor. The Trained Contractor, who is responsible for thedaily erosion and sediment control inspection. Thisindividual must have taken the NYSDEC erosion andsediment control 4-hour class within the last threeyears and be employed by the contractor responsiblefor the job.108

Permit IssuanceDEP will issue a Stormwater Construction Permit once all ofthe required submittals have been entered in the SWPTS, andDEP’s review is completed. Stormwater Construction Permitswill be valid for 2 years from the date of issuance. A renewalof the Stormwater Construction Permit may be submittedthrough SWPTS. Once DEP issues the permit and receivesa 7-day notification of the construction start date from thecontractor or developer, DEP will add the project to DEP’sinventory of active construction sites in the MS4 area.The City currently responds to a variety of publiccomplaints related to construction activities suchas excessive debris, noise or dust; work withouta permit or outside approved plans; and illegaldumping of construction materials in catchbasins. Refer to Chapter 2: Public Educationand Outreach, Section 2.5, for details on howto report illicit discharges and other potentiallyharmful water quality impacts through 311.Permit ConditionsThe applicant and all contractors and subcontractors areresponsible for implementing the approved SWPPP, complyingwith DEP rules, and complying with the terms and conditionsof the Stormwater Construction Permit. A StormwaterConstruction Permit must be renewed every two years fromdate of issuance.During construction, unforeseen issues may make itnecessary for the develop

Overview of C/PC Permitting Process Figure 6.1 The C/PC Program requires two types of stormwater permits for covered development projects: Stormwater Construction Permits for all covered development projects, and Stormwater Maintenance Permits for pr