Is there PFAS in Clark Public Utilities water?

Yes. EPA's final UCMR 5 results show Clark Public Utilities averaged 4.2 ppt of PFOS at its worst sampling point, 1.1 times the EPA limit of 4 ppt.

Clark Public Utilities is a public water system drawing on groundwater, based in Vancouver, Washington, serving about 153,526 people, including Amboy, Battle Ground, Brush Prairie, La Center, Ridgefield, Vancouver. Under EPA's Fifth Unregulated Contaminant Monitoring Rule it was tested for 29 PFAS and lithium 20 times across 10 sampling points between Mar 2023 and Sep 2023.

Every PFAS detected

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

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 Washington

• Lakehaven Water and Sewer District 6 PFAS detected
• City of Redmond Water System 2 PFAS detected
• City of Bellingham-water Division none detected
• Kent Water Department 1 PFAS detected
• City of Olympia 5 PFAS detected
• City of Kennewick above an EPA limit

All 248 tested systems in Washington

ZIP codes served

98601 98604 98606 98629 98642 98662 98663 98664 98665 98675 98682 98683 98684 98685 98686

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 Clark Public Utilities water: EPA UCMR 5 results." Data: U.S. EPA Fifth Unregulated Contaminant Monitoring Rule, final release August 2026, PWSID WA5313333. https://wellandtap.com/pfas/washington/clark-public-utilities/

About this data

Source: U.S. EPA, UCMR 5 occurrence data, final release August 2026 (PWSID WA5313333). Population: EPA SDWIS. Averages count results below the reporting level as zero, the same convention EPA uses for running annual averages. Full method.