Is there PFAS in City of Riverton water?
Yes. EPA's final UCMR 5 results show City of Riverton averaged 18.5 ppt of PFHxS at its worst sampling point, 1.9 times the EPA limit of 10 ppt.
City of Riverton
Serves 10,330 people · 29 PFOA samples from 15 sampling points · May 2023 to Nov 2023
Average above an EPA limit
PFOA Perfluorooctanoic acid
not detected
PFOS Perfluorooctanesulfonic acid
3.5 ppt avg · max 7.0
PFHxS Perfluorohexanesulfonic acid
18.5 ppt avg · max 37.0
Hazard index GenX, PFBS, PFNA, PFHxS combined
1.9 avg · max 3.7
Also detected, no federal limit: PFHxA, PFPeA, PFPeS, PFBS, PFBA, PFHpA.
City of Riverton is a public water system drawing on surface water, based in Riverton, Wyoming, serving about 10,330 people. Under EPA's Fifth Unregulated Contaminant Monitoring Rule it was tested for 29 PFAS and lithium 29 times across 15 sampling points between May 2023 and Nov 2023.
Every PFAS detected
Not detected: NFDHA, NEtFOSAA, NMeFOSAA, PFUnA, PFDA, PFNA, PFDoA, 9Cl-PF3ONS, ADONA, PFTA, PFOA, PFHpS, HFPO-DA, PFMBA, PFTrDA, 11Cl-PF3OUdS, 6:2 FTS, 4:2 FTS, 8:2 FTS, PFMPA, PFEESA.
Lithium, tested in the same program: highest 11 ppb, detected in 3 of 29 samples. EPA's health-based screening level is 10 ppb.
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 Wyoming
All 33 tested systems in Wyoming
ZIP codes served
82501
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 City of Riverton water: EPA UCMR 5 results." Data: U.S. EPA Fifth Unregulated Contaminant Monitoring Rule, final release August 2026, PWSID WY5600047. https://wellandtap.com/pfas/wyoming/city-of-riverton/
About this data
Source: U.S. EPA, UCMR 5 occurrence data, final release August 2026 (PWSID WY5600047). Population: EPA SDWIS. Averages count results below the reporting level as zero, the same convention EPA uses for running annual averages. Full method.
