Is there PFAS in Yarmouth Water Department water?
Yes, at low levels. 5 PFAS were detected, all below EPA's 2024 limits.
Yarmouth Water Department
Serves 38,900 people · 30 PFOA samples from 15 sampling points · Jan 2025 to Jul 2025
PFAS found, below EPA limits
PFOA Perfluorooctanoic acid
not detected
PFOS Perfluorooctanesulfonic acid
not detected
PFHxS Perfluorohexanesulfonic acid
3.1 ppt avg
Hazard index GenX, PFBS, PFNA, PFHxS combined
0.3 avg
Also detected, no federal limit: PFPeA, PFHxA, PFBA, PFHpA.
Yarmouth Water Department is a public water system drawing on groundwater, based in West Yarmouth, Massachusetts, serving about 38,900 people, including South Yarmouth, West Yarmouth, Yarmouth Port. Under EPA's Fifth Unregulated Contaminant Monitoring Rule it was tested for 29 PFAS and lithium 30 times across 15 sampling points between Jan 2025 and Jul 2025.
Every PFAS detected
Not detected: PFEESA, 6:2 FTS, 4:2 FTS, 8:2 FTS, PFMPA, PFMBA, PFNA, NFDHA, PFPeS, ADONA, 11Cl-PF3OUdS, PFUnA, PFDoA, PFDA, PFOS, PFBS, HFPO-DA, PFHpS, PFOA, PFTA, 9Cl-PF3ONS, NMeFOSAA, PFTrDA, NEtFOSAA.
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
Levels here are under EPA's limits, so no treatment is required. If you want them lower anyway, a certified reverse osmosis system under the sink handles drinking water, and a whole-house carbon filter also takes out the chlorine or chloramine your utility adds.
Other systems in Massachusetts
All 263 tested systems in Massachusetts
ZIP codes served
02664 02673 02675
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 Yarmouth Water Department water: EPA UCMR 5 results." Data: U.S. EPA Fifth Unregulated Contaminant Monitoring Rule, final release August 2026, PWSID MA4351000. https://wellandtap.com/pfas/massachusetts/yarmouth-water-department/
About this data
Source: U.S. EPA, UCMR 5 occurrence data, final release August 2026 (PWSID MA4351000). Population: EPA SDWIS. Averages count results below the reporting level as zero, the same convention EPA uses for running annual averages. Full method.
