Is there PFAS in Madison Water Utility water?
Yes, at low levels. 2 PFAS were detected, all below EPA's 2024 limits.
Madison Water Utility
Serves 272,000 people · 40 PFOA samples from 20 sampling points · Oct 2023 to Oct 2024
PFAS found, below EPA limits
PFOA Perfluorooctanoic acid
not detected
PFOS Perfluorooctanesulfonic acid
not detected
PFHxS Perfluorohexanesulfonic acid
6.9 ppt avg · max 7.3
Hazard index GenX, PFBS, PFNA, PFHxS combined
0.7 avg · max 0.7
Also detected, no federal limit: PFBA.
Madison Water Utility is a public water system drawing on groundwater, Wisconsin, serving about 272,000 people, including Mc Farland, Middleton, Verona, Madison. Under EPA's Fifth Unregulated Contaminant Monitoring Rule it was tested for 29 PFAS and lithium 40 times across 20 sampling points between Oct 2023 and Oct 2024.
Every PFAS detected
Not detected: PFMBA, NMeFOSAA, NEtFOSAA, PFTrDA, PFTA, PFHpS, PFPeS, PFEESA, PFPeA, PFMPA, 8:2 FTS, 4:2 FTS, 6:2 FTS, PFOA, PFBS, NFDHA, HFPO-DA, PFOS, PFHpA, PFDA, PFDoA, PFHxA, PFUnA, 11Cl-PF3OUdS, 9Cl-PF3ONS, ADONA, PFNA.
Lithium, tested in the same program: not detected.
What the EPA limits mean here
In April 2024 EPA set enforceable limits of 4 ppt for PFOA and PFOS, 10 ppt each for PFHxS, PFNA and GenX, and a hazard index of 1 for mixtures. Utilities were given until 2029 to comply. In May 2026 EPA proposed keeping only the PFOA and PFOS limits and moving that deadline to 2031. Until that proposal is final, the 2024 limits stand.
Compliance is judged on a running annual average at each entry point, so we show the average at this system's worst sampling point next to its single highest result. UCMR 5 results do not by themselves put a utility in or out of compliance.
What you can do at home
Levels here are under EPA's limits, so no treatment is required. If you want them lower anyway, a certified reverse osmosis system under the sink handles drinking water, and a whole-house carbon filter also takes out the chlorine or chloramine your utility adds.
Other systems in Wisconsin
All 202 tested systems in Wisconsin
ZIP codes served
53558 53562 53593 53703 53704 53705 53706 53711 53713 53714 53715 53716 53717 53718 53719 53726
As reported by the utility to EPA. Neighbouring ZIPs are often split between systems; your water bill names yours.
Cite this page
Well & Tap. "PFAS in Madison Water Utility water: EPA UCMR 5 results." Data: U.S. EPA Fifth Unregulated Contaminant Monitoring Rule, final release August 2026, PWSID WI1130224. https://wellandtap.com/pfas/wisconsin/madison-water-utility/
About this data
Source: U.S. EPA, UCMR 5 occurrence data, final release August 2026 (PWSID WI1130224). Population: EPA SDWIS. Averages count results below the reporting level as zero, the same convention EPA uses for running annual averages. Full method.
