PFAs Monitoring

Milwaukee Riverkeeper joined Waterkeeper Alliance in a national effort to understand levels of PFAS or “forever chemicals” in surface waters. In 2023, Waterkeeper groups across the nation took samples to better understand levels of the most common PFAS chemicals in rivers and streams from coast to coast. Riverkeeper also tested several upstream areas of the Milwaukee River, which were downstream of common PFAS sources, using the same sampling methodology.

Our work with Waterkeeper Alliance continued in 2024, using passive water samplers to collect information on PFAS entering our waterways from a variety of sources over time. These samplers were installed in rivers downstream from wastewater treatment plants and fields where municipal wastewater was spread. This analysis is ongoing.

What are PFAS?

PFAS (per- and polyfluoroalkyl substances) are a group of chemicals that have been incorporated in products for both home and manufacturing use since the mid 1900s. The most common of these chemicals are Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonate (PFOS). Often referred to as “forever chemicals,” they break down very slowly and build up over time if left untreated. Although much of the media attention on PFAS is recent, these chemicals have been studied for decades. Scientists have determined that exposure to and consumption of PFAS is extremely harmful to both the health of humans and the environment.

Why Do We Monitor PFAS?

Often finding their way into our waters from a variety of sources, PFAS can be ingested by drinking contaminated water or consuming fish and other animals that are in contact with contaminated water. There are dozens of communities in Wisconsin that have PFAS contaminated drinking water, and have been drinking this water for decades.

Locally, PFAS have been found in the Milwaukee River Basin, especially in groundwater and rivers draining Mitchell Airport where firefighting foam is still used frequently. Historically, the Department of Defense and National Guard also used a significant amount of fire fighting foams as part of their operations. PFAS have heavily contaminated groundwater in the area, and made its way into Wilson Creek, the Kinnickinnic River, and Lake Michigan.

Milwaukee Riverkeeper monitors PFAS to better understand affected waterways and the communities most at risk, and to help advocate for better state and federal regulations to protect our communities and environment from these harmful pollutants.

How are PFAS Regulated?

Wisconsin formally set regulations for PFOA and PFOS in public drinking water supplies, but the set limit (70 parts per trillion or ppt) on the combined amount of PFOA and PFOS in drinking water is not strict enough. The EPA recently passed federal drinking water standards mandating that water no more than 0.004 ppt of PFOA and 0.02 ppt of PFOS, and they set a hazard index for 4 other chemicals.

Wisconsin did pass PFAS standards for surface waters, including 8 ppt for PFOS for all waters except those that cannot naturally support fish and do not have downstream waters that support fish. For PFOA, the preventive action limit is 20 ppt for waters classified as public water supplies and 95 ppt for other surface waters.

There are currently no federal or state regulations for PFAS in groundwater, which is the source of drinking water for about 70% of Wisconsin residents that rely on wells, especially in rural areas where municipal surface water systems are unavailable. Efforts to pass groundwater standards have failed twice in Wisconsin, and there are state regulations now that freeze any rulemaking efforts where implementation would cost more than $10 million. We are working with many state partner organizations to continue to advocate for these important protections.

To learn more, please visit the Wisconsin DNR website.