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Is there PFAS in City of Fresno water?

Yes. EPA's final UCMR 5 results show City of Fresno averaged 21.5 ppt of PFOS at its worst sampling point, 5.4 times the EPA limit of 4 ppt.

City of Fresno Serves 545,716 people · 339 PFOA samples from 174 sampling points · Mar 2023 to Dec 2025 Average above an EPA limit
PFOA Perfluorooctanoic acid 13.5 ppt avg · max 16.0
EPA 4
PFOS Perfluorooctanesulfonic acid 21.5 ppt avg · max 30.0
EPA 4
PFHxS Perfluorohexanesulfonic acid 29.0 ppt avg · max 30.0
EPA 10
PFNA Perfluorononanoic acid 8.0 ppt avg
EPA 10
Hazard index GenX, PFBS, PFNA, PFHxS combined 3.7 avg
EPA 1

Also detected, no federal limit: PFPeA, PFHxA, PFHpA, PFBA, PFBS, PFPeS.

Averages are for the worst sampling point, with non-detects counted as zero. Source: EPA UCMR 5.

City of Fresno is a public water system drawing on surface water, based in Fresno, California, serving about 545,716 people. Under EPA's Fifth Unregulated Contaminant Monitoring Rule it was tested for 29 PFAS and lithium 339 times across 174 sampling points between Mar 2023 and Dec 2025.

Every PFAS detected

PFAS Detected Highest Worst point avg EPA limit
PFPeA
Perfluoropentanoic acid
39 of 339 47.0 ppt 35.5 ppt none
PFHxA
Perfluorohexanoic acid
31 of 339 34.0 ppt 24.0 ppt none
PFHpA
Perfluoroheptanoic acid
13 of 339 31.0 ppt 24.5 ppt none
PFHxS
Perfluorohexanesulfonic acid
22 of 339 30.0 ppt 29.0 ppt 10 ppt
PFOS
Perfluorooctanesulfonic acid
43 of 339 30.0 ppt 21.5 ppt 4 ppt
PFBA
Perfluorobutanoic acid
5 of 339 26.0 ppt 25.5 ppt none
PFOA
Perfluorooctanoic acid
36 of 339 16.0 ppt 13.5 ppt 4 ppt
PFBS
Perfluorobutanesulfonic acid
16 of 339 8.6 ppt 6.2 ppt none
PFNA
Perfluorononanoic acid
6 of 339 8.0 ppt 8.0 ppt 10 ppt
PFPeS
Perfluoropentanesulfonic acid
2 of 339 5.3 ppt 5.0 ppt none

Not detected: 11Cl-PF3OUdS, NEtFOSAA, NMeFOSAA, PFDA, PFDoA, PFTrDA, PFUnA, NFDHA, 9Cl-PF3ONS, ADONA, HFPO-DA, 6:2 FTS, 4:2 FTS, 8:2 FTS, PFMPA, PFMBA, PFEESA, PFHpS, PFTA.

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 California

All 707 tested systems in California

ZIP codes served

93701 93702 93703 93704 93705 93706 93710 93711 93720 93721 93722 93723 93725 93726 93727 93728 93730

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 Fresno water: EPA UCMR 5 results." Data: U.S. EPA Fifth Unregulated Contaminant Monitoring Rule, final release August 2026, PWSID CA1010007. https://wellandtap.com/pfas/california/city-of-fresno/

About this data

Source: U.S. EPA, UCMR 5 occurrence data, final release August 2026 (PWSID CA1010007). Population: EPA SDWIS. Averages count results below the reporting level as zero, the same convention EPA uses for running annual averages. Full method.