Is there PFAS in Collinsville water?
Yes. EPA's final UCMR 5 results show Collinsville averaged 9.0 ppt of PFOA at its worst sampling point, 2.3 times the EPA limit of 4 ppt.
Collinsville
Serves 29,500 people · 2 PFOA samples from 1 sampling point · Feb 2024 to Aug 2024
Average above an EPA limit
PFOA Perfluorooctanoic acid
9.0 ppt avg · max 18.0
PFOS Perfluorooctanesulfonic acid
4.5 ppt avg · max 8.9
PFHxS Perfluorohexanesulfonic acid
6.0 ppt avg · max 12.0
Hazard index GenX, PFBS, PFNA, PFHxS combined
0.6 avg · max 1.2
Also detected, no federal limit: PFHxA, PFPeA, PFBS, PFBA, PFHpA.
Collinsville is a public water system drawing on groundwater, based in Collinsville, Illinois, serving about 29,500 people. Under EPA's Fifth Unregulated Contaminant Monitoring Rule it was tested for 29 PFAS and lithium 2 times across 1 sampling point between Feb 2024 and Aug 2024.
Every PFAS detected
Not detected: 6:2 FTS, 4:2 FTS, 8:2 FTS, PFMPA, PFMBA, PFEESA, PFHpS, PFPeS, PFNA, NFDHA, ADONA, 9Cl-PF3ONS, 11Cl-PF3OUdS, PFUnA, PFDoA, PFDA, NMeFOSAA, PFTrDA, PFTA, NEtFOSAA, HFPO-DA.
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
Two routes work for PFAS. For drinking and cooking water only, a reverse osmosis system certified to NSF/ANSI 58 with a PFOA/PFOS reduction claim is the cheapest proven option. To treat every tap and shower, a whole-house carbon system with enough contact time works, but check that the maker has PFAS test data, not just a marketing claim. See the best filters for PFAS and how PFAS removal works.
Other systems in Illinois
All 487 tested systems in Illinois
ZIP codes served
62234
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 Collinsville water: EPA UCMR 5 results." Data: U.S. EPA Fifth Unregulated Contaminant Monitoring Rule, final release August 2026, PWSID IL1194280. https://wellandtap.com/pfas/illinois/collinsville/
About this data
Source: U.S. EPA, UCMR 5 occurrence data, final release August 2026 (PWSID IL1194280). Population: EPA SDWIS. Averages count results below the reporting level as zero, the same convention EPA uses for running annual averages. Full method.
