protecting public health
State and Federal PFAS Regulations
In 2026, state regulators approved updated water quality standards that limit per- and polyfluoroalkyl substances (PFAS) in municipal drinking water, a move that aligns Wisconsin with federal limits set by the Biden administration. Having strong state standards helps insulate Wisconsin from the Trump Administration’s plans to weaken federal PFAS standards.
FEDERAL STANDARDS FOR MUNICIPAL DRINKING WATER
In April 2024, the Environmental Protection Agency under President Biden announced a limit of 4 parts per trillion for PFOA and PFOS, two of the most widely studied PFAS compounds. The EPA regulates four other PFAS compounds as a mixture, using a hazard index* to determine if the combined levels of these substances pose a public health risk.
*A hazard index is a tool designed to evaluate the health risk from exposure to multiple chemicals of concern that have similar adverse health effects. The hazard index approach is used or recommended across the country by expert agencies and organizations, including the EPA and the Wisconsin Department of Health Services. The hazard index is particularly important when test results show levels of concentration for multiple PFAS that are below the individual or combined safety guidelines.
STATE STANDARDS FOR MUNICIPAL DRINKING WATER
Prior to 2026, the State of Wisconsin had a drinking water enforcement standard of 70 parts per trillion for PFOA and PFOS. When the EPA established a federal limit of 4 parts per trillion, Wisconsin updated its enforcement standards to align with federal standards, as required by the Safe Drinking Water Act.
FAQs
Are PFAS a threat to human health?
Yes. Even at extremely low levels, exposure to PFAS has been linked to an increased risk of cancer and other serious health problems, such as reproductive and developmental problems, thyroid hormone disruption, high cholesterol, ulcerative colitis, negative impacts to the immune system and more. Young children and pregnant women are particularly vulnerable to PFAS exposure.
Do state and federal PFAS standards protect people whose drinking water comes from private wells?
No. State and federal PFAS standards give customers of municipal water systems some measure of protection from PFAS pollution, but the standards do not protect rural residents who rely on groundwater from private wells. The lack of enforceable standards for PFAS in groundwater is an urgent public health issue that MEA is working to address.
When will Wisconsin establish water quality standards for PFAS in groundwater?
Wisconsin began developing PFAS groundwater standards in 2022, but the rulemaking process stalled out due to a provision in a controversial Walker-era law known as the REINS Act. The REINS Act interferes with agency rulemaking by requiring that separate legislation be enacted for any proposed rule that is expected to exceed $10 million in compliance costs over any two-year period—even if the estimated benefits far exceed the costs. The law prohibits DNR from resuming work on PFAS groundwater standards without explicit legislative approval. Governor Tony Evers has repeatedly called on the legislature to remove this procedural roadblock, but the legislature’s Republican majority has so far refused to do so. MEA continues to advocate for PFAS groundwater standards in order to minimize PFAS exposure for the two-thirds of Wisconsinites who rely on private wells for their drinking water. Learn more here.
How do state regulators establish and update water quality standards?
In Wisconsin, water quality standards are developed through the administrative rulemaking process. Administrative rules are written and enforced by state agencies such as the Department of Natural Resources. Rules have the force of law. They are used to implement, interpret or clarify statutes passed by the legislature. Before the DNR can make a new rule, public input must be considered.
How do PFAS end up in groundwater?
PFAS contamination can come from a number of different sources, including discharges from manufacturing facilities that use PFAS, discharges from wastewater treatment plants, percolation of water through the soil around landfills and run-off of firefighting foam.
What difference will groundwater standards make?
Once statewide groundwater standards are established, the DNR will be able to test for PFAS as part of its groundwater monitoring system. The DNR will also be able to work with dischargers to comply with preventive action limits, prohibit activities causing an exceedance, and require cleanup where necessary.