By Lulu Fregoso & Paul Mathewson, Ph.D.
Summary
PFAS, which stands for per- and polyfluoroalkyl substances, are a class of over 3,000 synthetic chemicals that have been produced since the 1940s. The unique physical and chemical characteristics of PFAS give them functional properties valuable in a variety of industrial and commercial applications, including resistance to oil, water, and heat. They are found in many products that we use every day, from non-stick cooking pans to food packaging and waterproof rain jackets. Once PFAS get into the environment or our bodies, they do not break down, and environmental contamination continues to build as more PFAS are introduced to the environment. Any exposure to PFAS can pose health risks. PFAS contamination in drinking water has been identified all over the state, typically found near military bases, airports, and industrial sites. PFAS detections are common, but concentrations above the health-based drinking standards are relatively rare. However, there are hot spots of PFAS contamination in counties such as Marathon and Waukesha. Clean Wisconsin obtained all public water system PFAS testing results from August 2022 through December 2025 from the WDNR’s Drinking Water System Portal and analyzed the data for maximum PFOS concentration, PFOA concentration, and EPA’s hazard index for each system.
Key takeaways:
- Studies suggest that 98% of the United States population has PFAS in their bodies.
- In the Town of Stella, Peshtigo/Marinette, and Town of Campbell/French Island, some wells have PFAS concentrations hundreds to thousands of times over health-based standards.
- PFAS were detected in 32% of tested public water systems in Wisconsin, with detections in 70 of the 71 counties with test results.
- Communities with higher proportions of people of color are more likely to live near PFAS sources, such as airports using firefighting foam, industrial facilities, landfills, military fire training areas, and wastewater treatment plants, reflecting historical segregation, selective migration, and limited influence in siting decisions.
- While public water systems are regulated under state drinking water standards, private wells remain unprotected. Groundwater quality standards for PFAS are essential to protect the health of the 25–30% of Wisconsinites who rely on private wells and to enable the state to provide cost-sharing for remediation of PFAS-contaminated private wells
