PFAS in Connecticut drinking water
EPA's final UCMR 5 data covers 63 public water systems in Connecticut, serving about 2.6 million people. PFAS turned up in 40 of them (63%). 16 averaged above at least one EPA limit at a sampling point, affecting about 696,986 people.
Highest PFOA and PFOS averages among systems serving 1,000 or more: Manchester Water Department (12.5 / 16.0 ppt), Aquarion Water CO of Ct-newtown System (9.0 / 8.7 ppt), Aquarion Water CO of Ct-main System (10.9 / 6.6 ppt), East Lyme Water & Sewer Commission (8.6 / 7.0 ppt) and Southington Water Department (7.5 / 5.5 ppt).
Every tested system in Connecticut
Largest first. PFOA and PFOS columns show the average at each system's worst sampling point; EPA's limit for each is 4 ppt. Filter by name:
| Water system | People | PFOA | PFOS | PFAS found | Result |
|---|---|---|---|---|---|
| Regional Water Authority · New Haven | 418,900 | 0.8 | 1.3 | 4 | Sample at limit |
| Metropolitan District Commission · Hartford | 390,887 | - | - | 0 | None found |
| Aquarion Water CO of Ct-main System · Shelton | 351,756 | 10.9 | 6.6 | 7 | Above limit |
| Aquarion Water CO of Ct-stamford · Shelton | 119,214 | 2.1 | - | 3 | Sample at limit |
| Waterbury Water Department · Waterbury | 107,271 | - | - | 0 | None found |
| Ctwc - Northern Reg-western System · Clinton | 101,313 | 2.6 | 1.2 | 7 | Sample at limit |
| New Britain Water Department · New Britain | 73,534 | - | - | 0 | None found |
| Danbury Water Department · Danbury | 62,055 | 4.1 | - | 4 | Above limit |
| Meriden Water Division · Meriden | 58,441 | 0.6 | 1.5 | 7 | Sample at limit |
| Aquarion Water CO of Ct-greenwich System · Shelton | 53,297 | 4.9 | 1.0 | 4 | Above limit |
| Bristol Water Department · Bristol | 52,079 | 0.8 | - | 2 | Sample at limit |
| Manchester Water Department · Manchester | 51,198 | 12.5 | 16.0 | 7 | Above limit |
| Southington Water Department · Southington | 43,069 | 7.5 | 5.5 | 7 | Above limit |
| South Norwalk Electric & Water · Wilton | 42,000 | - | - | 0 | None found |
| Middletown Water Department · Middletown | 41,019 | - | - | 0 | None found |
| Norwalk First Taxing District · Norwalk | 40,256 | 5.0 | 3.4 | 6 | Above limit |
| Torrington Water Company · Shelton | 37,915 | - | - | 0 | None found |
| Wallingford Water Department · Wallingford | 37,267 | - | 3.1 | 3 | Sample at limit |
| Norwich Public Utilities · Norwich | 36,163 | 1.6 | 3.6 | 5 | Sample at limit |
| Ctwc - Shoreline Region-guilford System · Clinton | 33,975 | 2.2 | 2.7 | 7 | Sample at limit |
| Groton Utilities · Groton | 30,200 | - | - | 0 | None found |
| New London Dept. of Public Utilities · Waterford | 27,620 | - | - | 0 | None found |
| University of Connecticut - Main Campus · Storrs | 27,199 | - | 4.5 | 2 | Above limit |
| Ctwc - Naugatuck Region-central System · Clinton | 22,735 | - | - | 0 | None found |
| Windham Water Works · Mansfield Center | 21,214 | - | - | 1 | Below limits |
| Aquarion Water CO of Ct-noroton System · Shelton | 18,737 | 2.5 | - | 4 | Sample at limit |
| Hazardville Water Company · Enfield | 18,544 | 2.1 | 0.9 | 6 | Sample at limit |
| Valley Water Systems, INC. · Shelton | 18,231 | 2.5 | 3.2 | 3 | Sample at limit |
| Waterford Wpca · Waterford | 16,578 | - | - | 0 | None found |
| East Lyme Water & Sewer Commission · Niantic | 15,245 | 8.6 | 7.0 | 6 | Above limit |
| Ctwc - Unionville System · Clinton | 14,693 | 1.7 | 1.8 | 6 | Sample at limit |
| Aquarion Water CO of Ct-simsbury System · Shelton | 14,691 | 1.4 | 0.7 | 4 | Sample at limit |
| Cromwell Fire District Water Department · Cromwell | 14,316 | - | 2.3 | 2 | Sample at limit |
| Aquarion Water CO of Ct-new Milford · Shelton | 13,331 | 2.4 | 1.1 | 5 | Sample at limit |
| Aquarion Water CO of Ct-valley System · Shelton | 13,080 | 5.3 | 2.2 | 6 | Above limit |
| Avon Water Co. · Clinton | 11,590 | 2.3 | 2.1 | 4 | Sample at limit |
| Aquarion Water CO of Ct-mystic · Shelton | 10,788 | - | - | 1 | Below limits |
| Aquarion Water CO of Ct-new Canaan Sys · Shelton | 10,097 | 2.5 | - | 3 | Sample at limit |
| Watertown Water & Sewer Authority · Oakville | 9,972 | - | - | 0 | None found |
| Bethel Water Dept · Bethel | 9,507 | 5.7 | - | 3 | Above limit |
| Winsted Water Works · Winsted | 7,784 | - | - | 0 | None found |
| Kensington Fire District · Kensington | 7,553 | - | - | 0 | None found |
| Aquarion Water CO of Ct-ridgefield Sys · Shelton | 7,476 | 5.4 | 1.1 | 7 | Above limit |
| Putnam Water Pollution Control Authority · Putnam | 7,300 | 3.2 | 1.2 | 5 | Sample at limit |
| Heritage Water Company · Clinton | 7,300 | 2.1 | - | 2 | Sample at limit |
| Jewett City Water Company · Enfield | 6,840 | - | - | 1 | Below limits |
| Watertown Fire District · Watertown | 6,718 | - | - | 0 | None found |
| Ctwc - Crystal System · Clinton | 6,378 | 7.4 | 4.5 | 4 | Above limit |
| Ctwc - Naugatuck Reg-collinsville Sys · Clinton | 6,324 | 4.7 | 5.4 | 2 | Above limit |
| Aquarion Water CO of Ct-newtown System · Shelton | 6,054 | 9.0 | 8.7 | 8 | Above limit |
| Ctwc - Naugatuck Reg-terryville System · Clinton | 5,607 | - | - | 0 | None found |
| Berlin Water Control Commission · Berlin | 5,128 | - | - | 1 | Below limits |
| Ctwc - Shoreline Region-chester System · Clinton | 5,030 | - | - | 0 | None found |
| Portland Water Department · Portland | 5,010 | - | - | 2 | Below limits |
| Colchester Sewer & Water Commission · Colchester | 4,020 | - | 4.0 | 2 | Above limit |
| Ctwc - Naugatuck Reg-thomaston System · Clinton | 3,789 | - | - | 0 | None found |
| Aquarion Water CO of Ct-litchfield Sys · Shelton | 3,097 | - | - | 0 | None found |
| New Hartford Water Department · Shelton | 1,872 | - | - | 0 | None found |
| Greenwich American Center · Greenwich | 800 | - | - | 0 | None found |
| Ctwc - Coventry Hills Div · Clinton | 700 | - | - | 0 | None found |
| Sterling Engineering Corp. · Barkhamsted | 110 | - | - | 0 | None found |
| Middlebury Hamlet · Prospect | 75 | - | - | 0 | None found |
| Aquarion Water CO of Ct-tlwc Woodrich · Shelton | 72 | 5.6 | 5.5 | 5 | Above limit |
On a private well in Connecticut?
EPA's program only covers public systems. Private wells are never part of UCMR 5, so the only way to know is to test. Our well testing guide covers which lab tests to order, and the best well water systems covers what to install once you have results.
Cite this page
Well & Tap. "PFAS in Connecticut drinking water: results for 63 systems." Data: U.S. EPA UCMR 5, final release August 2026. https://wellandtap.com/pfas/connecticut/
Source: EPA UCMR 5 final occurrence data (August 2026); population from EPA SDWIS. Method.