Also detected, no federal limit: PFBS, PFHxA, PFPeA.
Is there PFAS in Valley of the Moon Water District water?
Yes. EPA's final UCMR 5 results show Valley of the Moon Water District averaged 4.6 ppt of PFOA at its worst sampling point, 1.1 times the EPA limit of 4 ppt.
Valley of the Moon Water District is a public water system drawing on groundwater, based in El Verano, California, serving about 23,107 people, including El Verano, Glen Ellen, Sonoma. Under EPA's Fifth Unregulated Contaminant Monitoring Rule it was tested for 29 PFAS and lithium 14 times across 7 sampling points between Oct 2024 and Apr 2025.
Every PFAS detected
| PFAS | Detected | Highest | Worst point avg | EPA limit |
|---|---|---|---|---|
| PFOS Perfluorooctanesulfonic acid |
1 of 14 | 5.4 ppt | 2.7 ppt | 4 ppt |
| PFOA Perfluorooctanoic acid |
2 of 14 | 5.2 ppt | 4.6 ppt | 4 ppt |
| PFBS Perfluorobutanesulfonic acid |
3 of 14 | 4.2 ppt | 4.0 ppt | none |
| PFHxS Perfluorohexanesulfonic acid |
2 of 14 | 4.2 ppt | 3.7 ppt | 10 ppt |
| PFHxA Perfluorohexanoic acid |
2 of 14 | 3.6 ppt | 3.5 ppt | none |
| PFPeA Perfluoropentanoic acid |
1 of 14 | 3.0 ppt | 1.5 ppt | none |
Not detected: PFTA, PFDA, PFUnA, 11Cl-PF3OUdS, 9Cl-PF3ONS, PFDoA, PFTrDA, NMeFOSAA, PFHpA, ADONA, PFPeS, PFNA, NEtFOSAA, NFDHA, PFEESA, PFHpS, HFPO-DA, PFMBA, PFMPA, 8:2 FTS, 4:2 FTS, 6:2 FTS, PFBA.
Lithium, tested in the same program: highest 36 ppb, detected in 13 of 13 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
- City of Oakdale none detected
- El Monte-city, Water Dept. 2 PFAS detected
- City of Corcoran none detected
- City of Millbrae none detected
- Cws - North Garden above an EPA limit
- City of Wasco none detected
All 707 tested systems in California
ZIP codes served
95433 95442 95476
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 Valley of the Moon Water District water: EPA UCMR 5 results." Data: U.S. EPA Fifth Unregulated Contaminant Monitoring Rule, final release August 2026, PWSID CA4910013. https://wellandtap.com/pfas/california/valley-of-the-moon-water-district/
About this data
Source: U.S. EPA, UCMR 5 occurrence data, final release August 2026 (PWSID CA4910013). Population: EPA SDWIS. Averages count results below the reporting level as zero, the same convention EPA uses for running annual averages. Full method.