Nonpoint Source Pollution

To understand Nonpoint Source Pollution, it helps to first understand Point Source Pollution. Point source pollution comes from a defined, specific source such as a discharge pipe from a factory, a municipal sewage treatment or water reclamation facility, or a power generating station. The state’s clean water laws as well as the federal Clean Water Act have made great strides towards identifying, controlling and cleaning up point source pollution.

Nonpoint Source Pollution

Nonpoint Source (NPS) Pollution, on the other hand, is a more difficult type of pollution to identify and clean up. As the name suggests, cannot be pinpointed to one distinct location or source. NPS pollution refers to both water and air pollution from diffuse sources. NPS water pollution affects a water body from sources such as polluted runoff from agricultural areas draining into a river, or wind-borne debris blowing out to sea. NPS air pollution affects air quality from sources such as smokestacks or car tailpipes. Although these pollutants have originated from a point source, the long-range transportability and multiple sources of the pollutant make it a nonpoint source of pollution.

We recommend the Environmental Protection Agency (EPA) webpage to expand your knowledge of Non-point Source Pollution.

This web page includes links to the following NPS categories:
  • Abandoned Mine Drainage
  • Agriculture
  • Forestry
  • Hydromodification and Habitat Alteration
  • Marinas and Boating
  • Roads, Highways and Bridges
  • Urban Areas - Low Impact Development
  • Wetland and Riparian Management

Department of Ecology (Doe)

The Department of Ecology (DOE) page provides information specific to what is being done about NPS pollution in Washington State.

What You Can Do

Simple, but important, actions that all of us can take to reduce NPS pollution, here are some tips: