The deadline to complete the New York State Department of Environmental Conservation (NYS DEC) Municipal Separate Storm Sewer System (MS4) annual report for March 10, 2021 to March 9, 2022 reporting year is June 1st, 2022! Failure to submit the report to the NYS DEC office by the designated date will result in a permit violation.

What is an MS4?

An MS4 is a conveyance or system of conveyances that are:

  • owned by a state, city, town, village, or other public entity that discharges to waters of the U.S.;
  • designed or used to collect or convey stormwater;
  • not a combined sewer, and
  • not part of a sewage treatment plant, or publicly owned treatment works (POTW).

MS4s Stormwater Management Program (SWMP) and Minimum Control Measures (MCM)

MS4s covered by the NYS DEC General Permit for Stormwater Discharges (GP-0-15-003) are required to develop and implement a comprehensive Storm Water Management Program (SWMP). MS4s covered under the NYS DEC General Permit are within the boundaries of a Census Bureau defined “urbanized area”. The goal of the SWMP is to reduce the number of pollutants carried by stormwater during storm events to waterbodies to improve water quality and recreational use of waterways. MS4 stormwater programs have six elements called minimum control measures (MCM), that when implemented together, are expected to result in a reduction of pollutants discharged into waterbodies. The main goals of these MCMs are to promote awareness and good practices in order to reduce discharges of anything other than rainwater or snowmelt to stormwater collection systems.


The six MCMs are:

  1. Public Education and Outreach
  2. Public Involvement/Participation
  3. Illicit Discharge Detection and Elimination
  4. Construction Site Stormwater Runoff Control
  5. Post-Construction Stormwater Runoff Control
  6. Pollution Prevention/Good Housekeeping for Municipal Operations


What are the MS4 reporting requirements?

Under the NYS DEC General Permit, MS4s are required to submit a report annually. The annual report summarizes the activities performed throughout the reporting period and includes the status of compliance with the General Permit conditions, an assessment of the progress made towards achieving the goal of reducing pollutant discharge to the maximum extent practicable, and the identified measurable goals for each of the MCMs.


How to Obtain Permit Coverage if You Don’t Already Have One?

In order for a MS4 operator to obtain coverage under the NYS DEC General Permit, they must submit an accurate Notice of Intent (NOI) application form to the NYS DEC. The NOI includes an initial outline of planned management practices and identifies the goals to annually assess progress toward implementing an appropriate SWMP.


Keep on the Lookout for an Update from the NYSDEC

The NYS DEC recently issued an updated draft General Permit with proposed changes to certain MS4 requirements. Look for an upcoming blog from Walden regarding the proposed changes to the General Permit to keep you up to date and informed.


Walden is Here to Help

Walden works with municipalities to develop and implement MS4 programs to comply with the six (6) MCMs. Walden’s stormwater experts can help you conduct MS4 refresher training, prepare the annual MS4 report and address any stormwater issues to help you maintain compliance with the MS4 General Permit requirements.  Call us today at 516-758-1273 to discuss your stormwater compliance needs.