State Supreme Court Upholds DNR's Authority to Address PFAS Contamination

Thursday, June 26th, 2025 -- 8:00 AM

(Danielle Kaeding & Rich Kremer, Wisconsin Public Radio) The Wisconsin Supreme Court has upheld the authority of state environmental regulators to address PFAS contamination under the state’s spills law without first designating them as hazardous substances.

According to Danielle Kaeding and Rich Kremer with the Wisconsin Public Radio, the ruling is a victory for environmental advocates and residents of PFAS-contaminated communities and a setback for the state’s largest business lobby, Wisconsin Manufacturers & Commerce, or WMC.

WMC had sued the Wisconsin Department of Natural Resources on behalf of Oconomowoc-based dry cleaner Leather-Rich in 2021. The business group argued the agency can’t force businesses to clean up PFAS without first listing the chemicals as hazardous substances through state government’s rulemaking process.

A Waukesha County judge and state appeals court sided with WMC. The rulemaking process can take years, and environmental advocates argue a 2017 law passed by Republicans has thwarted efforts to enact groundwater standards for the chemicals.

In a 5-2 decision, the court’s four liberal justices, along with conservative Justice Brian Hagedorn, found the DNR has “explicit authority to enforce a threshold for reporting the discharge of hazardous substances” regardless of whether they’ve been designated as such by the agency through an administrative rule.

“Responsible parties must, on their own initiative, immediately report a discharge to the DNR, restore the environment to extent practicable, and minimize the harmful effects on our air, lands, and waters,” Justice Janet Protasiewicz wrote.

Enacted about 50 years ago, Wisconsin’s spills law requires anyone who causes, possesses or controls a hazardous substance that’s been released into the environment to clean it up.

The Wisconsin Department of Justice argued on behalf of the DNR that a ruling in favor of WMC would hamstring the agency’s ability to protect the environment and rewrite the spills law.

In its lawsuit, WMC claimed the DNR issued guidance that was an unlawfully adopted rule that required participants in a voluntary cleanup program to address PFAS contamination.

The group’s attorney said the DNR should provide a list of hazardous substances and criteria so the public knows when they’re violating the spills law. In a concurring opinion, Hagedorn wrote that WMC’s argument was unconvincing.

“As it stands, WMC’s attempt to shoehorn executive communication about how DNR intends to enforce the law into administrative rulemaking is unsuccessful,” Hagedorn wrote.

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