Nonpoint Source Pollution

Nonpoint source pollution (NPS) occurs when rainfall, snowmelt, or irrigation flows over land or through the ground, picks up pollutants, and delivers them into rivers, lakes, coastal waters, or groundwater. Imagine the path taken by a drop of rain from the time it hits the ground to when it reaches a river, groundwater, or the ocean. Any pollutant it picks up on its journey can ultimately affect natural habitats and the living organisms they sustain. Nonpoint source pollution, particularly sediment, also alters the shape and flow of streams and other aquatic systems and may promote conditions for nonnative species invasion. NPS pollution is widespread and it can occur any time activities disturb the land.

Tremendous advances have been made to clean up the aquatic environment by controlling pollution from point sources such as industries and sewage treatment plants. Unfortunately, we have not done enough to control runoff from diffuse, or nonpoint, sources. Today, nonpoint source pollution, or runoff, remains our largest cause of water quality problems. It's the main reason that approximately 40% of our rivers, lakes, and estuaries are not clean enough to allow basic uses such as fishing or swimming.

Runoff from urban areas is the largest cause of water quality impairments to estuaries such as the Long Island Sound and the New York-New Jersey Harbor estuary. Concern over polluted runoff has resulted in an ever-increasing number of state and federal laws. The federal government recently enacted the Total Maximum Daily Load (TMDL) and Phase II stormwater regulations. In addition to implementing these federal programs, many states have passed laws altering local land use (planning and zoning) processes and building codes to address the problem of nonpoint source pollution. Polluted runoff is one of the most important matters being addressed by local governments in New York today.