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FAQ: Nonpoint Source Pollution

Rain and rainbow on the St. Mary's River
Environment, Great Lakes, and Energy

FAQ: Nonpoint Source Pollution

Nonpoint Source (NPS) pollution is caused when rain, snowmelt, or wind carry pollutants off the land and into lakes, streams or wetlands. Also, large quantities of runoff can impact water quality and aquatic life when “flashy flows” cause excessive stream bank erosion.  Michigan’s NPS program helps local stakeholders reduce NPS pollution and excessive runoff by supporting efforts to develop and implement watershed management plans.

  • Unlike point source pollution, which is caused by distinct sources like industrial and sewage treatment plants, nonpoint source pollution comes from many diffuse sources and results when rain, snowmelt, or wind carries pollutants off the land and into lakes, streams or wetlands.

  • A watershed management plan is a plan developed by an organization or group with the primary goal of restoring and protecting designated uses from the impacts of NPS pollutants. You can find more information on developing a watershed management plan by visiting Developing an Approvable Watershed Management Plan.

  • Funding is typically available on an annual basis in the form of Nonpoint Source Grants. Specific information and timelines can be found on EGLE’s Nonpoint Source Program webpage (  

  • BMP stands for Best Management Practice and is a measure taken that will help improve water quality by diverting, treating, or capturing pollutants from runoff.  EGLE has developed a BMP manual with information on BMP options and implementation that can be found at NPS BMP Manual, Other BMP Design References, and Pollutants Controlled.

  • EGLE maintains a webpage that summarizes all of the Nonpoint Source Projects funded by EGLE at Nonpoint Source Project Summaries. You can find information on projects that have been funded as well as the dates and locations they were completed.

  • Start by contacting your local District field staff. The Nonpoint Source district staff map and additional contact information may be found at the Nonpoint Source Staff page.