Stormwater Regulations

Principal sources of contaminated stormwater runoff are construction and industrial activities. In addition, municipal storm sewer systems convey stormwater to receiving waters and often discharge it with inadequate treatment. Reducing and/or capturing and treating stormwater runoff before it reaches streams and other receiving waters enhances their protection and allows streams to perform their function as natural processors of waterborne contaminants.

The U.S. Environmental Protection Agency (EPA) regulates stormwater through the National Pollutant Discharge Elminiation 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.

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 groundwaters as well as surface waters. 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).

• Individual Permit - At its discretion, at any time, DEC may deny coverage under a General Permit and require the submission of an application for an individual stormwater permit.
  
  
• General Permit - Coverage under a General Permit requires preparation of a Storm Water Pollution Prevention Plan (SWPPP), and submission of a Notice of Intent (NOI) in which an applicant certifies that it’s SWPPP has been prepared and will be implemented in accordance with the terms of GP-02-01.

To learn more about the impacts associated with construction site activity and to learn what you can do to help spot and enforce clean water violations, see Riverkeeper's Construction Watch program.

Stormwater Discharges from MS4s

New York's SPDES program implements the requirements of the federal NPDES program. Operators of municipal seperate 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.