Is there PFAS in Cws - Visalia water?

Yes. EPA's final UCMR 5 results show Cws - Visalia averaged 5.7 ppt of PFOS at its worst sampling point, 1.4 times the EPA limit of 4 ppt.

Cws - Visalia is a public water system drawing on groundwater, based in San Jose, California, serving about 148,496 people, including Porterville, Tulare, Visalia. Under EPA's Fifth Unregulated Contaminant Monitoring Rule it was tested for 29 PFAS and lithium 86 times across 43 sampling points between Jan 2024 and Aug 2025.

Every PFAS detected

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

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

• Rancho California Water District above an EPA limit
• Pomona - City, Water Dept. above an EPA limit
• California Water Service CO. - Ela above an EPA limit
• California Water Service CO. - Dominguez 1 PFAS detected
• City of Roseville none detected
• City of Fullerton above an EPA limit

All 707 tested systems in California

ZIP codes served

93257 93274 93277 93291 93292

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 Cws - Visalia water: EPA UCMR 5 results." Data: U.S. EPA Fifth Unregulated Contaminant Monitoring Rule, final release August 2026, PWSID CA5410016. https://wellandtap.com/pfas/california/cws-visalia/

About this data

Source: U.S. EPA, UCMR 5 occurrence data, final release August 2026 (PWSID CA5410016). Population: EPA SDWIS. Averages count results below the reporting level as zero, the same convention EPA uses for running annual averages. Full method.