EPA UCMR 5 results for 63 public water systems. 40 had at least one PFAS detected; 35 had a highest single PFOA or PFOS result above 4.0 ppt.
UCMR 5 is a one-time EPA monitoring program, not a compliance determination. The values shown are the highest single sample result at any of the system's sampling points; one result above 4.0 ppt does not mean the system violates the PFAS rule, which is judged on running annual averages under separate compliance monitoring. Results describe the public water system, not an individual home.
| Water system | Serves | PFOA max (ppt) | PFOS max (ppt) | PFAS detected |
|---|---|---|---|---|
| Aquarion Water Co of CT-Greenwich System CT0570011 | Greenwich, Stamford | 5.6 | 4.1 | 4 |
| Aquarion Water Co of CT-Litchfield Sys CT0740011 | Goshen, Litchfield, Torrington | ND | ND | 0 |
| Aquarion Water Co of CT-Main System CT0150011 | Beacon Falls, Bridgeport, Darien and others | 10.9 | 6.6 | 7 |
| Aquarion Water Co of CT-Mystic CT1370011 | Groton, Ledyard, Stonington | ND | ND | 1 |
| Aquarion Water Co of CT-New Canaan Sys CT0900011 | New Canaan, Stamford | 5.6 | ND | 3 |
| Aquarion Water Co of CT-New Milford CT0960011 | Brookfield, New Milford | 5.3 | 5.3 | 5 |
| Aquarion Water Co of CT-Newtown System CT0970011 | Newtown | 15.9 | 12.7 | 8 |
| Aquarion Water Co of CT-Noroton System CT0350011 | Darien, New Canaan, Norwalk and others | 5.8 | ND | 4 |
| Aquarion Water Co of CT-Ridgefield Sys CT1180011 | Ridgefield | 10.6 | 6.1 | 7 |
| Aquarion Water Co of CT-Simsbury System CT1280021 | East Granby, Granby, Simsbury | 4.4 | 4.3 | 4 |
| Aquarion Water Co of CT-Stamford CT1350011 | Darien, Greenwich, Stamford | 4.3 | ND | 3 |
| Aquarion Water Co of CT-TLWC Woodrich CT1666011 | Wolcott | 6.3 | 6.2 | 5 |
| Aquarion Water Co of CT-Valley System CT1240011 | Ansonia, Beacon Falls, Bethany and others | 8.1 | 6.9 | 6 |
| Avon Water Co. CT0040011 | Avon, Farmington, Simsbury | 7 | 8 | 4 |
| Berlin Water Control Commission CT0070021 | Berlin, Middletown, Newington | ND | ND | 1 |
| Bethel Water Dept CT0090011 | Bethel, Danbury | 5.9 | ND | 3 |
| Bristol Water Department CT0170011 | Bristol, Burlington, Plainville and others | 4.1 | ND | 2 |
| CTWC - Coventry Hills Div CT0320091 | Coventry | ND | ND | 0 |
| CTWC - Crystal System CT0690011 | Brooklyn, Killingly | 9.9 | 6.8 | 4 |
| CTWC - Naugatuck Reg-Collinsville Sys CT0230011 | Avon, Burlington, Canton and others | 4.9 | 5.6 | 2 |
| CTWC - Naugatuck Reg-Terryville System CT1110011 | Plymouth | ND | ND | 0 |
| CTWC - Naugatuck Reg-Thomaston System CT1400011 | Plymouth, Thomaston | ND | ND | 0 |
| CTWC - Naugatuck Region-Central System CT0880011 | Beacon Falls, Naugatuck, Prospect and others | ND | ND | 0 |
| CTWC - Northern Reg-Western System CT0473011 | East Granby, East Windsor, Ellington and others | 8 | 6 | 7 |
| CTWC - Shoreline Region-Chester System CT0261031 | Chester, Deep River, Essex | ND | ND | 0 |
| CTWC - Shoreline Region-Guilford System CT0608011 | Clinton, Guilford, Madison and others | 6 | 12 | 7 |
| CTWC - Unionville System CT0520011 | Avon, Bristol, Farmington and others | 6 | 6 | 6 |
| Colchester Sewer & Water Commission CT0280011 | Colchester | ND | 9 | 2 |
| Cromwell Fire District Water Department CT0330011 | Berlin, Cromwell | ND | 4.6 | 2 |
| Danbury Water Department CT0340011 | Bethel, Brookfield, Danbury and others | 5.4 | ND | 4 |
| East Lyme Water & Sewer Commission CT0450011 | East Lyme | 9.2 | 7.2 | 6 |
| Greenwich American Center CT0570062 | Greenwich | ND | ND | 0 |
| Groton Utilities CT0590011 | Groton, Ledyard | ND | ND | 0 |
| Hazardville Water Company CT0490021 | East Windsor, Enfield, Somers | 8.6 | 5.4 | 6 |
| Heritage Water Company CT1300021 | Middlebury, Oxford, Southbury | 4.1 | ND | 2 |
| Jewett City Water Company CT0580011 | Griswold, Lisbon | ND | ND | 1 |
| Kensington Fire District CT0070011 | Berlin, New Britain, Newington | ND | ND | 0 |
| Manchester Water Department CT0770021 | Glastonbury, Manchester, South Windsor and others | 13 | 16 | 7 |
| Meriden Water Division CT0800011 | Berlin, Cheshire, Meriden and others | 6.1 | 9.5 | 7 |
| Metropolitan District Commission CT0640011 | Berlin, Bloomfield, Cromwell and others | ND | ND | 0 |
| Middlebury Hamlet CT0810054 | Middlebury | ND | ND | 0 |
| Middletown Water Department CT0830011 | Cromwell, Middlefield, Middletown | ND | ND | 0 |
| New Britain Water Department CT0890011 | Berlin, Farmington, New Britain and others | ND | ND | 0 |
| New Hartford Water Department CT0920011 | New Hartford | ND | ND | 0 |
| New London Dept. of Public Utilities CT0950011 | New London, Waterford | ND | ND | 0 |
| Norwalk First Taxing District CT1030011 | New Canaan, Norwalk, Westport and others | 9.5 | 11.2 | 6 |
| Norwich Public Utilities CT1040011 | Bozrah, Franklin, Lebanon and others | 6.7 | 16.2 | 5 |
| Portland Water Department CT1130011 | Middletown, Portland | ND | ND | 2 |
| Putnam Water Pollution Control Authority CT1160011 | Putnam, Thompson, Woodstock | 8.5 | 7.5 | 5 |
| Regional Water Authority CT0930011 | Ansonia, Bethany, Branford and others | 7.1 | 10.7 | 4 |
| South Norwalk Electric & Water CT1030021 | Darien, New Canaan, Norwalk and others | ND | ND | 0 |
| Southington Water Department CT1310011 | Cheshire, Southington, Wolcott | 8 | 6 | 7 |
| Sterling Engineering Corp. CT0050062 | Barkhamsted | ND | ND | 0 |
| Torrington Water Company CT1430011 | Harwinton, Litchfield, New Hartford and others | ND | ND | 0 |
| University of Connecticut - Main Campus CT0780021 | Mansfield | ND | 5 | 2 |
| Valley Water Systems, Inc. CT1100011 | Bristol, Farmington, Plainville and others | 5.2 | 6.8 | 3 |
| Wallingford Water Department CT1480011 | North Haven, Wallingford | ND | 13.9 | 3 |
| Waterbury Water Department CT1510011 | Middlebury, Prospect, Waterbury and others | ND | ND | 0 |
| Waterford WPCA CT1520071 | Montville, New London, Waterford | ND | ND | 0 |
| Watertown Fire District CT1530011 | Watertown | ND | ND | 0 |
| Watertown Water & Sewer Authority CT1530021 | Middlebury, Waterbury, Watertown | ND | ND | 0 |
| Windham Water Works CT1630011 | Mansfield, Windham | ND | ND | 1 |
| Winsted Water Works CT1620011 | Barkhamsted, Winchester | ND | ND | 0 |
ND = not detected (below the 4 ppt UCMR 5 reporting level). Values are the highest single sample result, not an annual average.