Stormwater Permitting

The U.S. Environmental Protection Agency (EPA) regulates stormwater through the National Pollutant Discharge Elimination System (NPDES) permit program.

To implement the federal law, New York State Department of Environmental Conservation (DEC) regulates stormwater as part of the State Pollutant Discharge Elimination System (SPDES) permit program.

• NPDES PermitsFederal Stormwater Regulations

  The U.S. Environmental Protection Agency (EPA) regulates stormwater through the National Pollutant Discharge Elimination System (NPDES) permit program.

  In 1990, EPA issued Phase I regulations that apply to:

  1) medium and large municipal separate storm sewer systems (MS4s) located in incorporated places or counties with populations of 100,000 or more, and
  2) eleven categories of industrial activity which includes construction activity that disturbs five or more acres of land.

  In 1999, EPA issued Phase II regulations that apply to:

  1) certain regulated small MS4s, and
  2) construction activity disturbing between 1 and 5 acres of land.

• SPDES & MS4 PERMITSNew York State Stormwater Regulations

  To implement the federal law, New York regulates stormwater as part of the State Pollutant Discharge Elimination System (SPDES) permit program.

  Stormwater Discharges from Construction Activity

  New York’s SPDES program is broader than the federal NPDES program because it regulates discharges to groundwater as well as surface water. Under the SPDES program, stormwater from construction sites is regulated either by a general or individual permit in accordance with the requirements of the General Permit for Stormwater Discharges from Construction Activities (GP-02-01).

  Stormwater Discharges from MS4s

  New York’s SPDES program implements the requirements of the federal NPDES program. Operators of municipal separate storm sewer systems must reduce the discharge of pollutants to the “maximum extent practicable.” To do this, GP-02-02 requires operators to develop a program comprising of six elements:

  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, and
  6) pollution prevention/good housekeeping.

  The Phase II permit for small MS4s came into effect in 2003. Because it is critical to protect water quality in the heavily developed East-of-Hudson (EOH) New York City Watershed, Riverkeeper urged DEC to adopt heightened requirements for the region. A draft permit was issued in 2004 and adopted in 2006.