Statewide Compliance and Testing

• Overall Compliance: Wisconsin maintains some of the highest water quality standards in the country, with the large majority of public water systems meeting federal Safe Drinking Water Act requirements. The state’s proactive approach to PFAS regulation — adopting state standards in 2022, ahead of federal action — gave Wisconsin a head start in identifying affected systems and accessing federal remediation funding.
• New PFAS Standards — March 2026: Governor Evers signed rules on March 2, 2026 reducing Wisconsin’s enforceable PFAS drinking water standard from 70 ppt to 4 ppt for PFOA and PFOS, and establishing 10 ppt standards for PFNA, PFHxS, and GenX. The Wisconsin Natural Resources Board approved these standards in January 2026. Nearly 100 public water systems will not meet the new requirements and must plan and implement treatment upgrades before the April 2031 federal compliance deadline. Systems must complete initial monitoring by April 2027. Follow our water alerts news for the latest regulatory updates.
• $125M PFAS Package Passed: In March 2026, the Wisconsin Senate unanimously passed two bills creating the framework for spending $125M from the long-frozen PFAS Trust Fund. The bills provide $80M in community grants for PFAS sampling, treatment installation, and connecting private well owners to public systems; support for private well owners; $5.25M for public airports; and expanded testing capabilities. The package now heads to Governor Evers for signature. The $125M was first set aside in Wisconsin’s 2023–25 budget but had been held up by legislative gridlock for nearly three years.

Major Water Sources and Challenges

• Great Lakes Basin: Provides water to major population centres including Milwaukee and Green Bay, with documented PFAS contamination near airports and former industrial sites. A September 2025 DNR/DHS advisory warned of PFAS-based consumption concerns for ducks harvested on Green Bay, while PFAS levels in Great Lakes fish have been slowly declining per February 2026 monitoring data.
• Groundwater Aquifers: Primary source for most rural communities and many municipalities. Facing challenges from nitrate contamination in agricultural areas affecting 10–30% of private wells and PFAS contamination near industrial sites. The towns of Peshtigo, Campbell (French Island near La Crosse), and Stella near Rhinelander have been among the most severely affected private well communities for years — with Campbell residents having relied on bottled water for over three years.
• Infrastructure Scale: EPA estimates $11.8 billion is required over the next two decades to address aging water infrastructure in Wisconsin, with municipal wastewater systems needing an additional $5.5 billion. Wisconsin has received over $535 million in BIL funding to date, with $900M total expected through 2026. In November 2025, $282M was awarded to 74 communities, including $13M for PFAS treatment and $42.6M for lead service line replacement.

PFAS — Affected Communities and Response

• Affected Public Systems: PFAS has been confirmed above federal standards in public water systems in Eau Claire, Wausau, Madison, and La Crosse, along with communities across the state near airports and former firefighting training sites. About 14 systems received federal funding under the 2022–2025 period to install treatment or drill new wells ahead of the new stricter standards.
• Treatment Technology Deployment: Cities such as Wausau have deployed granular activated carbon systems for PFAS removal. Madison Water Utility constructed Wisconsin’s first PFAS treatment system for Well 15. The Town of Campbell is drilling a new well to tap the Mt. Simon aquifer as a long-term clean source for roughly 4,200 French Island residents, using $1M in state Safe Drinking Water Loan Program funding.
• Private Wells — No Groundwater Standard Yet: Wisconsin has PFAS standards for municipal drinking water and surface water but not for groundwater — the source of drinking water for residents with private wells. PFAS has been detected in private wells in Campbell, Peshtigo, and Stella. Advocacy groups are pushing for groundwater PFAS standards as the next critical step. The new $125M package includes grants to help private well owners in PFAS-affected areas. See our water filter solutions guide for home protection options.

Lead Service Lines and Infrastructure

• New Lead Action Level: In December 2025, the Wisconsin Natural Resources Board and Governor approved amendments to the state lead and copper rule, lowering the lead action level from 15 µg/L to 10 µg/L — in line with updated federal standards. Water systems must now take corrective action if they exceed this stricter threshold.
• Lead Line Replacement by 2037: Wisconsin has over 167,000 known lead service lines. The state is targeting full replacement by 2037. Milwaukee received over $30M for lead line replacements in the November 2025 funding round. Governor Evers proposed $300M+ for lead removal statewide in the 2025–27 budget, though Republican lawmakers largely cut this from the final budget.
• Rural and Private Well Challenges: One-third of Wisconsin residents rely on private wells that have no mandatory PFAS testing requirements and no PFAS groundwater standard. Nitrate contamination from agricultural fertiliser and manure remains the most widespread groundwater pollutant statewide, with up to 30% of private wells in intensive farming areas exceeding safety limits.

Looking Forward: 2026 and Beyond

Wisconsin enters the second half of 2026 with a strengthened regulatory framework and significant new funding on the horizon. The March 2026 tightening of PFAS drinking water standards to 4 ppt makes Wisconsin one of the most proactive states in the country, and the bipartisan $125M PFAS package — once signed by Governor Evers — will finally deliver long-awaited relief to communities including Marinette, Peshtigo, French Island, and Stella. The April 2031 compliance deadline gives the nearly 100 affected public water systems time to plan treatment upgrades, with monitoring required by April 2027. The biggest remaining gap is PFAS groundwater standards for private wells — a challenge advocates will continue pressing the Legislature to address. For Wisconsin residents on private wells or in affected communities, NSF-certified reverse osmosis filtration remains the most reliable home protection in the interim.