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Stormwater Management Phase II

Overview | | What is Stormwater? | | Why is Stormwater a Problem? | | What's being done? |



In response to the 1987 Amendments to the Clean Water Act (CWA), the U.S. 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 MS4 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. Stormwater management programs must contain appropriate management practices in each of the following minimum control measure categories: Public Education and Outreach; Public Involvement and Participation; Illicit Discharge Detection and Elimination; Construction Site Stormwater Runoff Control; Post-Construction Site Stormwater Runoff Control; and Pollution Prevention for Municipal Employees.

As a first step toward obtaining SPDES permit coverage regulated MS4s were required to submit a Notice of Intent (NOI) form to DEC by March 10, 2003. The NOI required 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 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 meet local stormwater problems.

DEC is encouraging MS4s to take a watershed approach to local stormwater management by working with neighboring MS4s to develop complementary or cooperative programs for solving shared problems. By combining efforts, sharing costs and working together, regulated municipalities will recognize a higher level of environmental benefits at a decreased program cost.

All publicly funded MS4s operating within the boundaries of regulated municipal MS4s are also subject to the Phase II permit requirements. Examples of other regulated MS4s include school districts, public universities, prisons, state agencies and more. Defining the jurisdictional responsibilities of all regulated entities remains a somewhat difficult process at this time. It's expected that individual responsibilities will become more easily enforceable as municipal programs develop and are fully implemented. Eventually, the MS4 permit program will be expanded statewide.

The small construction permit is somewhat different in that it is already a statewide requirement. Operators of all small construction activities disturbing at least one acre of soil must obtain a construction permit prior to breaking ground regardless of whether or not the construction takes place within a regulated MS4. Small construction operators must file an NOI form and develop an approved stormwater management plan that includes provisions for managing post-construction stormwater runoff over the life of the project. The one-acre soil disturbance is a cumulative threshold. In other words, if a construction activity disturbs less than one acre of soil, but is part of a common development plan that will cumulatively disturb one-acre or more, a construction permit is required for the entire development.

What is Stormwater?

Stormwater is water from rain or melting snow that doesn't soak into the ground but runs off into waterways. As it flows from rooftops, over paved areas, bare soil, and through sloped lawns it picks up a variety of materials including soil, animal waste, salt, pesticides, fertilizers, oil and grease, debris and other potential pollutants. The quality and quantity of runoff is affected by a variety of factors depending on the season, local meteorology, geography and activities taking place along the path of its flow.

Why is Stormwater a Problem?

Stormwater gathers a variety of pollutants that are mobilized during runoff events. Polluted runoff degrades our lakes, rivers, wetland and other waterways . Transported soil clouds receiving waters and interferes with fish habitat and aquatic plant life.

Nutrients such as phosphorus and nitrogen can be harmful to aquatic life by promoting the overgrowth of algae and depleting oxygen in the waterway. Toxic chemicals from automobiles, sediment from construction activities and careless application of pesticides, herbicides and fertilizers threaten the health of the receiving waterway and can kill fish and other aquatic life. Bacteria from animal wastes and illicit connections to sewer systems can make nearby lakes and bays unsafe for wading, swimming and the propagation of edible shellfish. According to an inventory conducted by the United States Environmental Protection Agency (EPA), half of the impaired waterways in the United States are affected by stormwater runoff from urban/suburban and construction sources.

What's Being Done?

Significant improvements have been achieved in controlling pollutants that are discharged from point sources such as sewage and wastewater treatment plants. Across the nation, attention is shifting to non-point sources of pollution such as stormwater runoff. Stormwater management, especially in urban areas, is becoming a necessary step in the process of further reducing water pollution despite the inherent challenges it brings.

Stormwater runoff cannot be treated using the same end-of-pipe controls appropriate for sewage and wastewater treatment plants. Pollutants in Stormwater runoff enter our waterways in numerous ways and the best point of control is usually at the pollutant's source. Significant water quality improvement can be made by employing best management practices, or "BMPs". Proper storage of chemicals, good housekeeping and just plain paying attention to what's happening during runoff events can lay the ground work for developing a relatively inexpensive stormwater pollution prevention program.

The EPA and the NYSDEC are increasing their attention to stormwater pollution prevention in several ways. A federal regulation, commonly known as Stormwater Phase II, requires permits for stormwater discharges from Municipal Separate Storm Sewer Systems (MS4s) in urbanized areas and for construction activities disturbing one or more acres. To implement the law, the New York State Department of Environmental Conservation has issued two general permits, one for MS4s in urbanized areas and one for construction activities. The permits are part of the State Pollutant Discharge Elimination System (SPDES).

Download the permits:


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