All water systems in Connecticut
2,334 systems
| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Regional Water Authority Ansonia, Bethany, Branford and 17 more · New Haven County |
418,900 | 0 | 0 | |
|
Metropolitan District Commission Berlin, Bloomfield, Cromwell and 14 more · Hartford County |
390,887 | 1 | 0 | |
|
Aquarion-Eastern Fairfield County Beacon Falls, Bridgeport, Darien and 17 more · Fairfield County |
351,756 | 2 | 0 | |
|
Aquarion-Stamford Darien, Greenwich, Stamford · Fairfield County |
119,214 | 0 | 0 | |
|
Waterbury Water Department Middlebury, Prospect, Waterbury and 2 more · New Haven County |
107,271 | 2 | 0 | |
|
Ctwc Northern Reg-Western System East Granby, East Windsor, Ellington and 9 more · Hartford County |
101,313 | 1 | 1 | |
|
New Britain Water Department Berlin, Farmington, New Britain and 3 more · Hartford County |
73,534 | 1 | 0 | |
|
Danbury Water Department Bethel, Brookfield, Danbury and 1 more · Fairfield County |
62,055 | 0 | 0 | |
|
Meriden Water Division Berlin, Cheshire, Meriden and 2 more · New Haven County |
58,441 | 4 | 0 | |
|
Aquarion-Greenwich Greenwich, Stamford · Fairfield County |
53,297 | 1 | 0 | |
|
Bristol Water Department Bristol, Burlington, Plainville and 2 more · Hartford County |
52,079 | 1 | 0 | |
|
Manchester Water Department Glastonbury, Manchester, South Windsor and 1 more · Hartford County |
51,198 | 2 | 0 | |
|
Southington Water Department Cheshire, Southington, Wolcott · Hartford County |
43,069 | 4 | 0 | |
|
South Norwalk Electric & Water Darien, New Canaan, Norwalk and 1 more · Fairfield County |
42,000 | 1 | 0 | |
|
Middletown Water Department Cromwell, Middlefield, Middletown · Middlesex County |
41,019 | 1 | 0 | |
|
Norwalk First Taxing District New Canaan, Norwalk, Westport and 1 more · Fairfield County |
40,256 | 0 | 0 | |
|
Torrington Water Company Harwinton, Litchfield, New Hartford and 1 more · Litchfield County |
37,915 | 0 | 0 | |
|
Wallingford Water Department North Haven, Wallingford · New Haven County |
37,267 | 2 | 0 | |
|
Norwich Public Utilities Bozrah, Franklin, Lebanon and 4 more · New London County |
36,163 | 0 | 0 | |
|
Ctwc Shoreline Region-Guilford System Clinton, Guilford, Madison and 2 more · New Haven County |
33,975 | 0 | 0 | |
|
Mohegan Tribal Utility Authority County |
31,961 | 0 | 0 | |
|
Groton Utilities Groton, Ledyard · New London County |
30,200 | 1 | 0 | |
|
New London Dept. of Public Utilities New London, Waterford · New London County |
27,620 | 1 | 0 | |
|
University of Connecticut Main Campus Mansfield · Tolland County |
27,199 | 0 | 0 | |
|
Ctwc Naugatuck Region-Central System Beacon Falls, Naugatuck, Prospect and 1 more · New Haven County |
22,735 | 0 | 0 | |
|
Mashantucket Pequot Water System County |
22,171 | 1 | 0 | |
|
Windham Water Works Mansfield, Windham · Windham County |
21,214 | 1 | 0 | |
|
Aquarion-Darien Darien, New Canaan, Norwalk and 1 more · Fairfield County |
18,737 | 0 | 0 | |
|
Hazardville Water Company East Windsor, Enfield, Somers · Hartford County |
18,544 | 0 | 0 | |
|
Aquarion-Plainville Regional Bristol, Farmington, Plainville and 1 more · Hartford County |
18,231 | 1 | 0 | |
|
Waterford Wpca Montville, New London, Waterford · New London County |
16,578 | 2 | 1 | |
|
East Lyme Water & Sewer Commission East Lyme · New London County |
15,245 | 1 | 0 | |
|
Ctwc Unionville System Avon, Bristol, Farmington and 1 more · Hartford County |
14,693 | 1 | 0 | |
|
Aquarion-Simsbury Regional East Granby, Granby, Simsbury · Hartford County |
14,691 | 0 | 0 | |
|
Cromwell Fire District Water Department Berlin, Cromwell · Middlesex County |
14,316 | 1 | 0 | |
|
Aquarion-New Milford Regional Brookfield, New Milford · Fairfield County |
13,331 | 4 | 0 | |
|
Aquarion-Valley Ansonia, Beacon Falls, Bethany and 3 more · New Haven County |
13,080 | 0 | 0 | |
|
Avon Water CO Avon, Farmington, Simsbury · Hartford County |
11,590 | 1 | 1 | |
|
Aquarion-Mystic Groton, Ledyard, Stonington · New London County |
10,788 | 0 | 0 | |
|
Aquarion-New Canaan New Canaan, Stamford · Fairfield County |
10,097 | 0 | 0 | |
|
Watertown Water & Sewer Authority Middlebury, Waterbury, Watertown · Litchfield County |
9,972 | 2 | 0 | |
|
Bethel Water Dept Bethel, Danbury · Fairfield County |
9,507 | 6 | 0 | |
|
Winsted Water Works Barkhamsted, Winchester · Litchfield County |
7,784 | 0 | 0 | |
|
Kensington Fire District Berlin, New Britain, Newington · Hartford County |
7,553 | 4 | 0 | |
|
Aquarion-Ridgefield Ridgefield · Fairfield County |
7,476 | 1 | 0 | |
|
Heritage Water Company Middlebury, Oxford, Southbury · New Haven County |
7,300 | 0 | 0 | |
|
Putnam Water Pollution Control Authority Putnam, Thompson, Woodstock · Windham County |
7,300 | 1 | 0 | |
|
Jewett City Water Company Griswold, Lisbon · New London County |
6,840 | 3 | 0 | |
|
Watertown Fire District Watertown · Litchfield County |
6,718 | 1 | 1 | |
|
Ctwc Crystal System Brooklyn, Killingly · Windham County |
6,378 | 0 | 0 |
About this data
Rules violated counts the rules a system was in violation of in the past three years, including monitoring and reporting lapses; one rule can carry several violations. Unresolved is the number of those rules still in violation at EPA's latest data refresh.
Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The Connecticut records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet. Retrieved from ECHO on Oct 11, 2026.