Stormwater Information

What is Stormwater?

Stormwater is rainwater and melted snow that runs off streets, lawns, and other sites. When stormwater is absorbed into the ground, it is filtered and ultimately replenishes aquifers or flows into streams and rivers. In developed areas, however, impervious surfaces such as pavement and roofs prevent precipitation from naturally soaking into the ground. Instead, the water runs rapidly into storm drains, sewer systems, and drainage ditches and can cause: Downstream flooding Stream bank erosion Increased turbidity (muddiness created by stirred up sediment) from erosion Habitat destruction Changes in the stream flow hydrograph (a graph that displays the flow rate of a stream over a period of time) Combined sewer overflows Infrastructure damage Contaminated streams, rivers, and coastal water.

What is Illicit Discharge?

Federal regulations define an illicit discharge as “....any discharge to an MS4 that is not composed entirely of stormwater....” with some exceptions. These exceptions include discharges from NPDES-permitted industrial sources and discharges from fire-fighting activities. Illicit discharges are considered “illicit” because MS4s are not designed to accept, process, or discharge such non-stormwater wastes. Sources of illicit discharges include: sanitary wastewater, effluent from septic tanks, car wash wastewaters, improper oil disposal, radiator flushing disposal, laundry wastewaters, spills from roadway accidents, and improper disposal of auto and household toxics. To report illicit discharges into the storm sewer system, please e-mail:

Stormwater Discharge - MS4 Report & MCC Form

In accordance with the NYSDEC requirements, the Town of Greenburgh prepared and filed the Notice of Intent (NOI) with the NYSDEC on March 5, 2003, to be covered under the Phase II SPDES General Permit GP-02-02 available through the NYSDEC. The Town prepared an initial Storm Water Management Program (SWMP), with an aim to set measurable goals that the Town has to implement and enforce in order to comply with the permit requirements. It describes various actions that the Town proposes to undertake over a period of five years starting from 2003, to protect the Town's storm water quality and reduce pollutants, until the full implementation of the SWMP (not later than January 8, 2008). In order to document progress towards achieving the measurable goals identified in the SWMP, the Town evaluates its program and submits an annual report with the results to the NYSDEC. Recently the Town of Greenburgh prepared the Storm Water Management Program Annual Report for the period March 10, 2018 to March 9, 2019, that was posted on the Town website for public review and input. The report illustrates the progress made by the Town towards the Notice of Intent and the Storm Water Management Program (SWMP) submitted by the Town to the NYSDEC in 2003. 

Storm Water Contact Person: Aaron Schmidt Deputy Commissioner Community Development and Conservation Town of Greenburgh 

To report illicit discharges into the storm sewer system, please call the Bureau of Engineering at (914) 989-1583.

Relevant Websites for further information on these and other topics to prevent Pollution of Rivers, Streams and Water Bodies: United States Environmental Protection Agency and New York State Department of Environmental Conservation.

MS4 Reports & MCC Forms

Educational Information