Non-Point Pollution

Nonpoint source pollution (NPS) is created when rain falls to the earth or snow melts and water moves over and through the ground, taking with it topsoil, bacteria, fertilizers, pesticides, pet waste, oil, and many other toxic or harmful materials (DNR). This land run-off pollution is called "nonpoint." It's the opposite of "point" pollution discharge which is pollution from direct pipe discharge, such as pollution caused by a factory smokestack (EPA).

One way this type of pollution enters our environment is through every day, normal occurrences: running a car, fertilizing lawns, construction of roads and buildings, and maintaining roads during the wintertime.

NPS is "the greatest threat to Wisconsin water quality," as of Wisconsin's plan for managing NPS pollution from 2021 through 2025. In March 2023, a factory farm in Kewaunee County agreed to pay $215,000 to settle allegations of improperly spreading manure, according to the Milwaukee Journal Sentinel.

The Impact on Wisconsin's Water

Nonpoint source pollution has wide-ranging impacts on Wisconsin's water quality. Over seventy percent of the lakes and streams within assessed watersheds are estimated to be degraded by NPS pollution, according to the Wisconsin NPS plan. Lakes, streams, or rivers can be polluted by manure, fertilizers, or sediment, as well as the incorrect disposal of pesticides, herbicides or medicines (DNR).

Agricultural pollution is a major player in the contamination of Wisconsin's waters, including drinking water. For example, agriculture is responsible for 90% of the nitrate contamination in our groundwater, according to the Groundwater Coordinating Council's 2022 Report to the Legislature. About ten percent of Wisconsin private well samples didn't meet the standard for nitrate, according to 2013 and 2015 studies cited by the GCC. A federal study predicted that each year, 230 cases of acute gastrointestinal illness in Kewaunee County were being caused by cow manure (Wisconsin Watch).

Nonpoint source pollution also harms aquatic life, and it reduces the recreational and economic uses of our lakes and streams. Manure and other agricultural runoff cause algae blooms and lower oxygen levels in the water and leads to overgrowth of water plants. This harms aquatic life and can prevent people from using bodies of water for recreation. Wetlands, which can help control flooding and improve water quality, are harmed by agriculture and construction pollutants (DNR).

The Clean Water Action Council is working to build awareness and respond to nonpoint source pollution. Here's how you can help:

Take Action!

- If you see evidence of an agricultural operation that has caused water pollution through manure, you can report your concern to the DNR. If you would like to remain anonymous, you can use the DNR Tip Hotline at 1-800-TIP-WDNR (1-800-847-9367) or cell #367 (DNR).

• If you think your concern might have an adverse impact to human health, welfare or the environment, call the 24/7 DNR Spills Hotline at 1-800-943-0003 (DNR)

- Subscribe to CWAC's Weekly Update to receive opportunities to help protect the environment every week. Email contact@cleanwateractioncouncil.org and ask us to place you on the Weekly Update mailing list.

- Raise your voice during public comment periods for regulations that affect nonpoint source pollution.

- If you have a private well, regularly test the water. See more information on private wells from the DNR.

- Search for an "Adopt Your Drain" program in your area.

- Advocate for your local government to enact ordinances that reduce nonpoint source pollution.

- There are many steps citizens can take to mitigate stormwater runoff, such as cleaning up pet waste, avoiding overuse of pesticides, and using porous pavement or paver blocks for a patio area (DNR). Learn more here.

- To reduce your personal contribution to NPS pollution, visit this list of recommended actions from the Wisconsin DNR.

- Raise your voice on stormwater with the help of this outreach toolkit from the University of Wisconsin-Madison.

More Resources

- Read about how restoration efforts have countered nonpoint source pollution in Wisconsin, among other EPA resources

- Read about the Wisconsin nonpoint source program and program management plan here

- Learn about storm water permits for construction sites, industrial facilities, and municipalities here

- Storm water publications/guidance from the DNR

- Learn more about the impact of factory farms here

- A 2023 study: "Effectiveness of local regulations on nonpoint source pollution; Evidence from Wisconsin dairy farms"

This article was last updated in October, 2023.