Stormwater Phase II Overview

In response to the 1987 Amendments to the Clean Water Act (CWA), the US Environmental Protection Agency (EPA) developed Phase I of the National Pollutant Discharge Elimination System (NPDES) Storm Water Program in 1990. The Phase I program addressed sources of storm water runoff that had the greatest potential to negatively impact water quality. The Department of Environmental Conservation (DEC) is responsible for administering the program in NYS as part of the State Pollutant Discharge Elimination System (SPDES). Under Phase I, SPDES permit coverage was required for storm water discharges from medium and large municipal separate storm sewer systems (MS4s) located in incorporated places or counties, eleven categories of industrial activity and construction activity that disturbed five or more acres of land.

The Phase II Final Rule, published in the Federal Register on December 8, 1999, expanded the stormwater permit program to include stormwater discharges from certain regulated small MS4s and construction activity that disturbs between 1 and 5 acres of land. On January 8, 2003, the DEC finalized two-new permits for stormwater discharges in NYS as required by the Federal EPA; the small MS4 and small construction permits.

The Construction Stormwater General Permit requires owners and operators of projects disturbing one or more acres of soil to develop and comply with a Stormwater Pollution Prevention Plan (SWPPP).  The NYS DEC issued an update to the Stormwater Construction General Permit in January 2020, effective on January 29, 2020.  GP-0-20-001 contains substantial changes.  The permit and fact sheet are available on the its website at dec.ny.gov/chemical/43133.html.

The Municipal Separate Storm Sewer System  (MS4) General Permit requires regulated municipal MS4s (those with a minimum population density of 1000 people per square mile and are located in urban areas as defined by the U.S. Census Bureau) to develop and fully implement a stormwater management program by 2008. There are 32 automatically designated MS4s in the Syracuse Urbanized Area.

As a first step toward obtaining SPDES permit coverage regulated MS4s are required to submit a Notice of Intent (NOI) form to the NYS DEC. The NOI requires MS4s to provide an initial outline of planned management practices and to identify measurable goals to annually assess progress toward the full implementation of an appropriate stormwater management plan. Although the NYS DEC has specified a few required actions and provided a list of approved management practices for each minimum control category, regulated MS4s are encouraged to tailor the development of their stormwater management programs to best address local stormwater pollutants of concern. Applicants seeking new authorizations to discharge will be required to file a Notice of Intent to obtain such authorization.

View more information on the NYS Stormwater MS4 Permit Program on NYS DEC's Stormwater page.

These general permits authorize new and existing discharges of stormwater from construction activities and MS4s required to have permits in accordance with Environmental Conservation Law.