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DEP Skimmer Boat Collecting Trash and Debris

Municipal Separate Storm Sewer System

A municipal separate storm sewer system (MS4) is a publicly-owned conveyance or system of conveyances (including but not limited to streets, ditches, catch basins, curbs, gutters, and storm drains) that is designed or used for collecting or conveying stormwater and that discharges to surface waters of the State.

As stormwater flows over streets and other impervious surfaces, it sweeps up pollutants such as oils, chemicals, pathogens and sediments. In separate sewer areas, this pollution is carried by stormwater runoff and discharged directly into the City’s waterways. This can have a negative impact on water quality and recreational uses.


Stormwater Management Program (SWMP) Plan

The MS4 Permit requires the City to develop a Stormwater Management Program (SWMP), which includes numerous programs designed to reduce pollution in stormwater.

The SWMP Plan describes the ways in which the City will satisfy the requirements of the MS4 Permit by managing stormwater discharges into and from the City’s separate storm sewers. Most chapters of the Plan include a description of any relevant existing City programs; new initiatives and/or program enhancements; and measureable goals for future assessment of the program.

The SWMP Plan was released to the Public on April 4, 2018. The public is invited to submit comments on the SWMP Plan online from April 4, 2018 through May 15, 2018 by e-mailing MS4@dep.nyc.gov. DEP will also hold two stakeholder meetings to provide background on the Plan and to accept verbal comments from meeting attendees.


Stakeholder Meetings on Draft Plan

Topics When Where
April 24, 2018 6:30–8:30pm
The Arsenal at Central Park
830 Fifth Avenue,
New York, NY 10065
May 2, 2018 5:30–7:30pm
Staten Island Borough Hall
10 Richmond Terrace
Staten Island, NY 10301

To receive notifications about upcoming MS4 meetings, request a meeting on a specific MS4 topic, or provide feedback, please use the below contact form.

Past Stakeholder Meetings

To provide all stakeholders with multiple opportunities to comment on the Stormwater Management Program (SWMP) during development, DEP held frequent meetings with other agencies, NYSDEC, key stakeholders, and the public.

The meetings listed below were open to the public and sought to brief all stakeholders on each provision of the MS4 Permit before the first draft of the SWMP was completed.

Topics When Where
  • Control of Floatable and Settleable Trash and Debris (Part 3 - Draft Work Plan)
October 4, 2017 6–8pm Newtown Creek Visitor Center
329 Greenpoint Avenue Greenpoint,
Brooklyn NY, 11222
  • Industrial and Commercial Stormwater Sources
June 15, 2017 6-8pm JCC of Staten Island
466 Manor Rd
Staten Island, NY 10314
June 8, 2017 DEP presented the PPGH and Industrial Commercial provisions of the SWMP to the SWIM Coalition
  • Annual Stormwater Management Program Progress Report
May 16, 2017
6pm–8pm
CUNY School of Law
2 Court Square W
Long Island City, NY 11101
  • Control of Floatable and Settleable Trash and Debris (Part 2)
  • Public Education & Outreach
Apr 19, 2017
6:30pm–8:30pm
Hudson River Foundation
17 Battery Place
Suite 915
New York, NY 10015
  • Mapping
  • Illicit Discharge Detection and Elimination (IDDE)
  • Monitoring and Assessment of Controls
Feb 22, 2017
6:30pm–8:30pm
St. Francis College
182 Remsen Street
Room 4202
Brooklyn, NY 11201
  • Public Involvement/Participation,
  • Legal Authority
  • Construction Site Stormwater Runoff Control
  • Post-Construction Stormwater Management
Dec 13, 2016
6:30pm–8:30pm
Hostos Community College - C Building
450 Grand Concourse
JFK Room
Bronx, NY 10451
  • Control of Floatable and Settleable Trash and Debris (Part 1)
Sep 27, 2016
4pm–6pm
Newtown Creek Visitor Center
329 Greenpoint Avenue Greenpoint,
Brooklyn NY, 11222
  • Pollution Prevention/Good Housekeeping for Municipal Operations and Facilities (Part 1)
Sep 27, 2016
2pm–3:30pm
Newtown Creek Visitor Center
329 Greenpoint Avenue Greenpoint,
Brooklyn NY, 11222
Jun 22, 2016
6:30pm–8:30pm
NYS Department of Public Service
90 Church St.
4th FL Board Room
New York, NY

MS4 Permit Deliverables

The Municipal Separate Storm Sewer System (MS4) Permit requires the City to submit several written deliverables to the New York State Department of Environmental Conservation (NYSDEC). Key submitted deliverables are available below. For a complete list of deliverables, please review the full MS4 permit (PDF).

Deliverable Description Permit Provision Permit Deadline
  IV.D.5 August 1, 2018, and annual thereafter
Proposal for programs to meet the MS4 permit requirement to reduce pollutants in impaired waters. Part II.B.1 February 1, 2018
Draft SWMP Plan for Public Review during the following time period, April 4–May 15, 2018.    
Proposal for programs to meet the MS4 permit requirement to reduce pollutants in impaired waters. Part II.B.1 February 1, 2018
Draft Work Plan to determine the loading rate of floatable and settleable trash and debris discharged from the MS4. Part IV.1.3 August 1, 2017
Updated description of the City’s legal authority to control discharges to the MS4. This description includes details on Local Law 97 of 2017 which consolidates, clarifies, and supplements existing legal authority, to enable the City to act in a regulatory capacity to control pollutant discharges to and from its MS4. Part III.B.1 August 1, 2017
Progress reports on the development of the SWMP Plan, including public involvement/ participation components Part IV. Introduction August 1, 2017
Progress reports on the development of the SWMP Plan, including public involvement/ participation components. Part IV. Introduction August 1, 2016
Description of existing legal authority to control discharges to the MS4. Part III.B.1.a February 1, 2016
Submit certification that an interim floatable and settleable trash and debris reduction media campaign has been developed with implementation schedule. Part IV.I November 1, 2015

MS4 Permit

The City of New York received its first MS4 Permit on August 1, 2015. This permit is required under the Clean Water Act and is issued by NYSDEC. The intent of the MS4 permit is for the City to implement measures to reduce pollution in stormwater runoff. The MS4 Permit significantly expands the City’s previous obligations to reduce pollutants discharging to the MS4. Numerous City agencies have significant responsibilities under the MS4 Permit. The New York City Department of Environmental Protection (DEP) is responsible for coordinating the interagency efforts to meet the City’s MS4 Permit requirements.


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