Timeline: PFAS in Wisconsin

Per- and polyfluoroalkyl substances are a large family of chemicals used in products from fire extinguishing foam to non-stick pans, food packaging containers, and dry-cleaning services. The chemicals cause harm to human health, are persistent in our environment, and are difficult to destroy. PFAS substances are associated with certain types of cancer, harm to the immune system, interference with hormones, increased cholesterol, low birth weight, increased blood pressure in those who are pregnant and others.

Our Summer 2022 print newsletter featured a timeline of significant PFAS-related events across a two-page spread. The timeline below offers additional information and hyperlinks to learn more. This list can evolve over time. We welcome additional suggestions of noteworthy activity at [email protected]




The Ansul Company, which is now known as Tyco Fire Products and now a subsidiary of Johnson Controls, tests firefighting foam in Marinette, WI. Water testing shows elevated levels of PFAS contamination where the foam was used on land and washed into the Marinette sewer system. For an in-depth timeline of what how the state of Wisconsin has responded to pollution problems in the Marinette and Peshtigo area, visit the Department of Natural Resources page, “Activites, Actions and Updates” section.

Contamination impacts groundwater in nearby Peshtigo.

La Crosse finds PFAS in drinking water.





Governor Evers declares 2019 the Year of Clean Drinking Water. 


Water Quality Task Force hearings begin and are held around the state through September.

Water testing on the southern boundary of the Badger Army Ammunition Plant near the Town of Merrimac shows elevated levels of PFAS.

Madison municipal drinking well is closed due to PFAS contamination. Contamination is also found in Starkweather Creek, the Yahara River, and Lakes Monona, Waubesa, and Kegonsa.

Governor Evers asks for state staff to address PFAS in the budget proposal, which is rejected by the legislature. 


The Chemical Level Enforcement and Remediation Act (SB 302), or Clear Act, is introduced in the 2019 legislative session but does not get a hearing.

The Wisconsin Department of Health Services issues PFOA/PFOS recommendations for groundwater at 20 ng/L.

Wausau Water Utility conducts first voluntary tests and finds PFAS/PFOS in wells. 


Wisconsin Department of Natural Resources sends a request to 125 wastewater treatment plants to voluntarily test drinking water for PFAS.


DNR begins work on Drinking, Surface, and Groundwater standards for certain PFAS chemicals.

Governor Evers issues a scope statement for groundwater standards. 


Rhinelander shuts down two municipal drinking water wells near the Rhinelander-Oneida County Airport.

Milwaukee water wells near Mitchell International Airport are contaminated with PFAS, including private wells. 





Bill to regulate existing stocks of PFAS-containing firefighting foam is passed, but the legislature will kill the emergency rules to implement regulations in December.


A compromise testing bill passes committees in both houses but is not brought to the floor for a vote. 


Town of Campbell on French Island tests of private drinking water wells show extensive contamination, likely due to firefighting foam use at the La Crosse Regional Airport.





Wisconsin Manufacturers and Commerce files a lawsuit challenging the DNR’s ability to take action on PFAS contamination under the Spills Law.


The Clear Act (SB 361) is reintroduced in the 2021 legislative session but does not get a hearing.


Wisconsin Manufacturers and Commerce files a lawsuit to prevent testing and the release of testing results but is not successful.


Wisconsin Department of Natural Resources issues a notice of noncompliance to Tyco Fire Products and orders more environmental testing of farm properties where PFAS-contaminated sewage sludge was spread.


Nearly half of Eau Claire drinking water wells are taken offline due to PFAS contamination. 


President Biden signs an infrastructure bill which includes money for addressing PFAS.


Rib Mountain closes four municipal wells





Wisconsin Department of Natural Resources begins work on a plan to spend federal infrastructure funds.


State Natural Resources Board votes on PFOA and PFOS rules, rejects a proposed groundwater standard (which would have helped people on private wells), increases the drinking water limit from 20 to 70 parts per trillion, and adopts a surface water standard.

Wausau shuts down all six municipal wells.

Rothschild shuts down a municipal well. 


Cycle 11 rules contain standards for several more PFAS substances, but they now face an uncertain future given the NRB actions.

Peshtigo residents petition the U.S. Environmental Protection Agency for an assessment under the federal Superfund Law.

Village of Weston shuts down two of its six municipal wells.


Waukesha County Circuit Court Judge rules in favor of WMC on the lawsuit challenging the DNR’s authority to regulate PFAS under Wisconsin’s Spills Law but in June stays the decision pending appeal.


Marshfield closes four municipal wells. Adams closes a drinking water well.

Mosinee reduces pumping from a municipal well that contains PFAS.


West Bend closes a municipal well

U.S. Environmental Protection Agency issues updated health advisories for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) that replace those the EPA issued in 2016.


Governor Evers’ administration files a lawsuit against chemical companies alleging companies were aware the intended use of PFAS substances would negative impact human and environmental health. Companies include 3M, Du Pont, Chemours, Buckeye Fire Equipment, Tyco, Kidde-Fenwal, National Foam, Chemguard, Amerex Corp., Chemdesign Products, BASF Corp., Dynax, Archoroma, Carrier Global, UTC Fire & Security, Clariant and others. The complaint can be found on the Wisconsin Department of Justice website.

National Academies of Sciences, Engineering, and Medicine issues a report for doctors on how to test, diagnose and treat people who may have been exposed to PFAS. 


Statewide PFAS standards go into effect. State PFOA and PFOS rules are thousands of times lower than updated EPA health advisory limits. Learn more about how the new rules impact urban and rural drinking water systems via Wisconsin Public Radio.


Governor Evers signs a scope statement to add PFOS, PFOA, PFBS and GenX chemicals to the list of contaminants under the state’s groundwater law. The DNR restarts the process to set improved groundwater standards. The rulemaking process may take up to 30 months and will require approval of the governor, the Natural Resources Board and the Legislature.


The DNR begins collecting PFAS foam waste at a site in Appleton. The DNR also launches an interactive map with the locations of municipal drinking water systems’ sampling information, clean up sites, and fish and wildlife advisories.


Other links

DNR PFAS investigation and cleanup webpage

DNR map of known PFAS sites

PFAS fish advisories

More information about PFAS and the rules for drinking water, surface water and firefighting foam are available on the DNR’s website.