Wisconsin Supreme Court Says Landowners Can Be Held Accountable for PFAS Cleanup 

On June 24, 2025, the Wisconsin Supreme Court ruled in Wisconsin Manufacturers and Commerce, Inc. v. Wisconsin Department of Natural Resources that state regulators have the power to enforce regulations on emerging pollutants before they are officially designated as hazardous substances. The 5-2 decision struck down a challenge to the Wisconsin Department of Natural Resources (DNR), in which an organization representing businesses and manufacturers in the state argued that the DNR needed chemicals to be officially classified as hazardous before they could be regulated, and it went around public oversight in order to do so.

The chemicals at the center of this decision are per- and polyfluoroalkyl substances (PFAS), also known as “forever chemicals” due to their inability to be broken down by natural means. When PFAS contaminates land and water sources, it can be ingested by humans and wildlife, leading to negative health outcomes such as reproductive issues, stunted development, and cancer. These effects have put PFAS in the crosshairs of regulators, despite recent moves by the federal government to roll back restrictions on PFAS contamination in water.

“The Wisconsin Supreme Court's decision is a victory for the health and wellbeing of the people of Wisconsin. We are pleased that the court rejected WMC's reckless attempt to undermine a bedrock environmental and public health protection that has kept Wisconsinites safe from toxic contamination for almost fifty years,” said Midwest Environmental Advocates (MEA) Staff Attorney Rob Lee.

Plaintiffs: DNR Overstepped Its Legal Authority

The lawsuit that led to the decision by the Wisconsin Supreme Court was filed in 2021 by Wisconsin Manufacturers and Commerce (WMC), the state's largest business group, on behalf of Leather Rich, a dry-cleaning business in Oconomowoc. The lawsuit challenged the authority of the DNR to regulate chemicals under the state's 1978 Hazardous Substance Spills Law, which requires immediate reporting and cleanup of hazardous substance releases, regardless of when they occurred, and gives the DNR authority to oversee and enforce cleanup actions to protect public health and natural resources.

The plaintiffs argued that the DNR had overstepped its legal authority by unilaterally redefining hazardous substances, imposing cleanup standards, and altering the rules of the Remediation and Redevelopment (RR) and Voluntary Party Liability Exemption (VPLE) programs, all without going through the required public rulemaking process. They claimed the DNR's evolving standards and lack of transparency hindered property owners' ability to complete remediation and blocked economic development.

In a conversation with Wisconsin State Senator Eric Wimberger earlier this year, Wimberger shared similar concerns with the DNR's decisions that put innocent landowners at risk.

“The way that Wisconsin law functions is that if PFAS passes through their property into the water table and then into a neighboring property, they become what we would describe here as emitters. The law does not care how PFAS gets on the property, just that you possess it, and then it goes to the neighbor, so people unknowingly become emitters. Because of this, we have people who are terrified of having their property tested for PFAS and being [held] liable for the contamination,” Wimberger told 3E.

In 2022, a Waukesha County judge sided with the WMC, but paused the ruling while appeals progressed, allowing the DNR to continue PFAS-related cleanups in the interim. The Wisconsin Court of Appeals upheld that ruling in 2024, prompting the MEA to urge the State Supreme Court to review the case. The MEA, which had submitted multiple amicus briefs throughout the litigation, stressed that invalidating the Spills Law would eliminate one of Wisconsin's only meaningful tools for managing PFAS pollution and safeguarding public health.

In the end, the Wisconsin Supreme Court sided with the MEA, ruling that the DNR did have the authority to require cleanup of hazardous substances discharges without going through the formal rulemaking process.

“Wisconsin's Spills Law safeguards human health and the environment in real time by directly regulating parties responsible for a hazardous substance discharge,” said Justice Janet Protasiewicz, writing for the majority. “The DNR has explicit authority to enforce a threshold for reporting the discharge of hazardous substances.”

The WMC has yet to share any plans for continued litigation but released the following statement on the decision: “The DNR refuses to tell the regulated community which substances must be reported under the spills law, yet threatens severe penalties for getting it wrong. Businesses and homeowners are left to guess what's hazardous, and if they're wrong, they face crushing fines and endless, costly litigation. This ruling blesses a regulatory approach that is fundamentally unfair, unworkable, and impossible to comply with.”

Wisconsin Supreme Court in the Spotlight

The ruling comes as the Wisconsin Supreme Court has found itself increasingly at the center of politically charged legal battles that test the balance of power between branches of government. Just days before upholding the Spills Law, the court unanimously struck down a law that required the state attorney general to seek legislative approval before settling lawsuits. The justices ruled that the provision violated the separation of powers, affirming that the state legislature cannot give itself the power to execute a law that it wrote.

These recent rulings underscore the court's pivotal role in shaping Wisconsin's legal and political landscape, especially as high-stakes cases on voting rights, executive power, and environmental regulation continue to surface. The importance of the court gained national attention earlier this year, when massive outside spending - most notably from Elon Musk's America PAC - attempted to control the outcome of the election of the most recent member of the court. This attention underscores the importance of the Wisconsin Supreme Court and the possible impact its decisions will have not only on the state, but nationwide, as the country continues to navigate the regulatory landscape and the relationship between state regulators and federal oversight.