Polluted Runoff


There are many sources of pollution that impact Wisconsin’s rivers, lakes and watersheds. Some pollutants come from the pipes of factories, sewage treatment plants or cities (known as “point source” pollution). A whole lot comes from farm fields and city streets (known as “non-point” pollution).

One of the most significant sources of pollution is sediment (soil) that runs of the land and into our waters. This sediment carries phosphorus and other contaminants. This pollution can come from multiple sources. Any land-use decision we make that disturbs the soil—from construction to agriculture—can open the door for runoff.

Though phosphorus comes from many places, far and away the most significant source of phosphorus is agriculture. With so much of the state dedicated to farming, addressing this challenge is a major opportunity to improve water quality.


Noxious algae blooms have emerged as one of Wisconsin’s most common water quality problems. Blue-green algae blooms are caused by an excess of nutrients from polluted runoff and wastewater. Not only do these algae blooms keep people from enjoying Wisconsin’s lakes and rivers, they can also impact the businesses that depend on clean water.

Taking Action

Successfully addressing phosphorus pollution depends on the participation of the individuals and entities affected by this problem.

River Alliance of Wisconsin’s role includes:

  • Working with the Wisconsin Dept. of Natural Resources to ensure that water quality standards, such as the Wisconsin River TMDL, are adequately supported and implemented.
  • Empowering Wisconsinites impacted by bad water to take action, including helping them organize to be effective and powerful advocates for water issues in their communities.
  • Providing education on the causes of pollution. Who’s behind it? Who has the power to change it? How can citizen voices change the outcome of what are often contentious and intractable water quality problems?
  • Collaborating with innovative farmers and producer-led watershed groups to increase the use of water-friendly agricultural practices. Learn more about the new Clear Water Farms program.

PFAS contamination in Wisconsin’s water: the big picture

The PFAS rules are a small step in the right direction. But they also show us weaknesses in the system Wisconsin (and almost all other states) has used to regulate toxic substances for almost forty years.

What happened to Wisconsin’s rules on nitrate contamination?

We won't give up on the work to protect Wisconsin's water from nitrate pollution. However, today we heard from the DNR that NR 151 rule revisions intended to curb agricultural pollution won't be completed. Learn why this important, science-driven effort was effectively blocked by the State Legislature's broken rulemaking process.

Nitrate pollution legislation is a step forward

New nitrate pollution bills in the Wisconsin State Senate have strong support from lobby groups representing the agriculture industry and several conservation groups registered in support of the bills. However, River Alliance submitted a letter outlining why farmers and homeowners need better tools to protect human health. Read our letter to the Senate Committee on Agriculture and Tourism.