Also detected, no federal limit: PFBA, PFPeA, PFHxA.
Is there PFAS in Ctwc - Unionville System water?
Some. At least one sample reached an EPA limit, but the average at every sampling point stayed below it.
Ctwc - Unionville System is a public water system drawing on surface water, based in Clinton, Connecticut, serving about 14,693 people, including Avon, Bristol, Farmington, New Britain, Plainville, Unionville. Under EPA's Fifth Unregulated Contaminant Monitoring Rule it was tested for 29 PFAS and lithium 10 times across 2 sampling points between Mar 2023 and Dec 2023.
Every PFAS detected
| PFAS | Detected | Highest | Worst point avg | EPA limit |
|---|---|---|---|---|
| PFBA Perfluorobutanoic acid |
2 of 10 | 7.0 ppt | 2.0 ppt | none |
| PFOS Perfluorooctanesulfonic acid |
2 of 10 | 6.0 ppt | 1.8 ppt | 4 ppt |
| PFOA Perfluorooctanoic acid |
2 of 10 | 6.0 ppt | 1.7 ppt | 4 ppt |
| PFPeA Perfluoropentanoic acid |
2 of 10 | 4.0 ppt | 1.2 ppt | none |
| PFHxA Perfluorohexanoic acid |
2 of 10 | 4.0 ppt | 1.2 ppt | none |
| PFHxS Perfluorohexanesulfonic acid |
2 of 10 | 3.0 ppt | 1.0 ppt | 10 ppt |
Not detected: PFPeS, 4:2 FTS, 8:2 FTS, PFMPA, 6:2 FTS, PFMBA, NFDHA, PFHpS, PFEESA, PFTrDA, 11Cl-PF3OUdS, PFTA, NEtFOSAA, NMeFOSAA, PFBS, PFHpA, PFDA, PFDoA, PFUnA, 9Cl-PF3ONS, PFNA, HFPO-DA, ADONA.
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 Connecticut
- Aquarion Water CO of Ct-simsbury System 4 PFAS detected
- Cromwell Fire District Water Department 2 PFAS detected
- East Lyme Water & Sewer Commission above an EPA limit
- Aquarion Water CO of Ct-new Milford 5 PFAS detected
- Aquarion Water CO of Ct-valley System above an EPA limit
- Waterford Wpca none detected
All 63 tested systems in Connecticut
ZIP codes served
06001 06010 06032 06053 06062 06085
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 Ctwc - Unionville System water: EPA UCMR 5 results." Data: U.S. EPA Fifth Unregulated Contaminant Monitoring Rule, final release August 2026, PWSID CT0520011. https://wellandtap.com/pfas/connecticut/ctwc-unionville-system/
About this data
Source: U.S. EPA, UCMR 5 occurrence data, final release August 2026 (PWSID CT0520011). Population: EPA SDWIS. Averages count results below the reporting level as zero, the same convention EPA uses for running annual averages. Full method.