Is there PFAS in Liberty Water Rio Rico water?

Yes. EPA's final UCMR 5 results show Liberty Water Rio Rico averaged 40.5 ppt of PFOS at its worst sampling point, 10.1 times the EPA limit of 4 ppt.

Liberty Water Rio Rico is a public water system drawing on groundwater, based in Sierra Vista, Arizona, serving about 17,960 people. Under EPA's Fifth Unregulated Contaminant Monitoring Rule it was tested for 29 PFAS and lithium 12 times across 6 sampling points between Apr 2023 and Apr 2024.

Every PFAS detected

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

Lithium, tested in the same program: highest 20.2 ppb, detected in 12 of 12 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 Arizona

• Lago Del Oro Water Company 2 PFAS detected
• Sahuarita Water Company none detected
• Town of Payson above an EPA limit
• Vail Water Company none detected
• Usaf Davis Monthan Afb none detected
• City of Show Low none detected

All 152 tested systems in Arizona

ZIP codes served

85648

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 Liberty Water Rio Rico water: EPA UCMR 5 results." Data: U.S. EPA Fifth Unregulated Contaminant Monitoring Rule, final release August 2026, PWSID AZ0412011. https://wellandtap.com/pfas/arizona/liberty-water-rio-rico/

About this data

Source: U.S. EPA, UCMR 5 occurrence data, final release August 2026 (PWSID AZ0412011). Population: EPA SDWIS. Averages count results below the reporting level as zero, the same convention EPA uses for running annual averages. Full method.