Is there PFAS in City of Porterville water?

Yes. EPA's final UCMR 5 results show City of Porterville averaged 21.0 ppt of PFOA at its worst sampling point, 5.3 times the EPA limit of 4 ppt.

City of Porterville is a public water system drawing on groundwater, based in Porterville, California, serving about 63,487 people. Under EPA's Fifth Unregulated Contaminant Monitoring Rule it was tested for 29 PFAS and lithium 58 times across 30 sampling points between May 2023 and Nov 2023.

Every PFAS detected

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

Lithium, tested in the same program: highest 11.6 ppb, detected in 12 of 58 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 California

• Gswc - Florence/graham none detected
• City of La Habra none detected
• California Water Service-s San Francisco none detected
• Liberty Utilities (av Ranchos) Corp. none detected
• City of Pittsburg none detected
• Brentwood none detected

All 707 tested systems in California

ZIP codes served

93257

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 Porterville water: EPA UCMR 5 results." Data: U.S. EPA Fifth Unregulated Contaminant Monitoring Rule, final release August 2026, PWSID CA5410010. https://wellandtap.com/pfas/california/city-of-porterville/

About this data

Source: U.S. EPA, UCMR 5 occurrence data, final release August 2026 (PWSID CA5410010). Population: EPA SDWIS. Averages count results below the reporting level as zero, the same convention EPA uses for running annual averages. Full method.