Connecticut water providers

Find published drinking-water records, providers, and official agency resources for Connecticut. Review sources, sample dates, and coverage.

Official drinking-water resources

• Connecticut State Department of Public Health - Drinking Water Section
• Connecticut — Published water quality summaries

The responsible agency may differ for tribal systems. Record availability and sample dates vary by provider.

Community systems appear first. Sort: Population served · A–Z

Public water systems

2,337 systems in the imported directory. Includes community systems, schools, workplaces, and other public systems.

• Regional Water AuthorityCT0930011 · CWS · Population served: 418,900
• Metropolitan District CommissionCT0640011 · CWS · Population served: 390,887
• Aquarion-Eastern Fairfield CountyCT0150011 · CWS · Population served: 351,756
• Aquarion-StamfordCT1350011 · CWS · Population served: 119,214
• Waterbury Water DepartmentCT1510011 · CWS · Population served: 107,271
• Ctwc - Northern Reg-Western SystemCT0473011 · CWS · Population served: 101,313
• New Britain Water DepartmentCT0890011 · CWS · Population served: 73,534
• Danbury Water DepartmentCT0340011 · CWS · Population served: 62,055
• Meriden Water DivisionCT0800011 · CWS · Population served: 58,441
• Aquarion-GreenwichCT0570011 · CWS · Population served: 53,297
• Bristol Water DepartmentCT0170011 · CWS · Population served: 52,079
• Manchester Water DepartmentCT0770021 · CWS · Population served: 51,198
• Southington Water DepartmentCT1310011 · CWS · Population served: 43,069
• South Norwalk Electric & WaterCT1030021 · CWS · Population served: 42,000
• Middletown Water DepartmentCT0830011 · CWS · Population served: 41,019
• Norwalk First Taxing DistrictCT1030011 · CWS · Population served: 40,256
• Torrington Water CompanyCT1430011 · CWS · Population served: 37,915
• Wallingford Water DepartmentCT1480011 · CWS · Population served: 37,267
• Norwich Public UtilitiesCT1040011 · CWS · Population served: 36,163
• Ctwc - Shoreline Region-Guilford SystemCT0608011 · CWS · Population served: 33,975
• Mohegan Tribal Utility Authority010109005 · CWS · Population served: 31,961
• Groton UtilitiesCT0590011 · CWS · Population served: 30,200
• New London Dept. of Public UtilitiesCT0950011 · CWS · Population served: 27,620
• University of Connecticut - Main CampusCT0780021 · CWS · Population served: 27,199
• Ctwc - Naugatuck Region-Central SystemCT0880011 · CWS · Population served: 22,735
• Mashantucket Pequot Water System010106001 · CWS · Population served: 22,171
• Windham Water WorksCT1630011 · CWS · Population served: 21,214
• Aquarion-DarienCT0350011 · CWS · Population served: 18,737
• Hazardville Water CompanyCT0490021 · CWS · Population served: 18,544
• Aquarion-Plainville RegionalCT1100011 · CWS · Population served: 18,231
• Waterford WpcaCT1520071 · CWS · Population served: 16,578
• East Lyme Water & Sewer CommissionCT0450011 · CWS · Population served: 15,245
• Ctwc - Unionville SystemCT0520011 · CWS · Population served: 14,693
• Aquarion-Simsbury RegionalCT1280021 · CWS · Population served: 14,691
• Cromwell Fire District Water DepartmentCT0330011 · CWS · Population served: 14,316
• Aquarion-New Milford RegionalCT0960011 · CWS · Population served: 13,331
• Aquarion-ValleyCT1240011 · CWS · Population served: 13,080
• Avon Water CoCT0040011 · CWS · Population served: 11,590
• Aquarion-MysticCT1370011 · CWS · Population served: 10,788
• Aquarion-New CanaanCT0900011 · CWS · Population served: 10,097
• Watertown Water & Sewer AuthorityCT1530021 · CWS · Population served: 9,972
• Bethel Water DeptCT0090011 · CWS · Population served: 9,507
• Winsted Water WorksCT1620011 · CWS · Population served: 7,784
• Kensington Fire DistrictCT0070011 · CWS · Population served: 7,553
• Aquarion-RidgefieldCT1180011 · CWS · Population served: 7,476
• Heritage Water CompanyCT1300021 · CWS · Population served: 7,300
• Putnam Water Pollution Control AuthorityCT1160011 · CWS · Population served: 7,300
• Jewett City Water CompanyCT0580011 · CWS · Population served: 6,840
• Watertown Fire DistrictCT1530011 · CWS · Population served: 6,718
• Ctwc - Crystal SystemCT0690011 · CWS · Population served: 6,378
• Ctwc - Naugatuck Reg-Collinsville SysCT0230011 · CWS · Population served: 6,324
• Aquarion-Newtown RegionalCT0970011 · CWS · Population served: 6,054
• Ctwc - Naugatuck Reg-Terryville SystemCT1110011 · CWS · Population served: 5,607
• Berlin Water Control CommissionCT0070021 · CWS · Population served: 5,128
• Ctwc - Shoreline Region-Chester SystemCT0261031 · CWS · Population served: 5,030
• Portland Water DepartmentCT1130011 · CWS · Population served: 5,010
• Colchester Sewer & Water CommissionCT0280011 · CWS · Population served: 4,020
• Ctwc - Naugatuck Reg-Thomaston SystemCT1400011 · CWS · Population served: 3,789
• Ctwc - Shoreline Region-Sound ViewCT1050732 · CWS · Population served: 3,397
• Ledyard Wpca - Ledyard CenterCT0727091 · CWS · Population served: 3,294
• Aquarion-Litchfield RegionalCT0740011 · CWS · Population served: 3,097
• Connecticut Valley HospitalCT0830021 · CWS · Population served: 2,928
• Worthington Fire DistrictCT0070031 · CWS · Population served: 2,875
• Fairfield HillsCT0970021 · CWS · Population served: 2,610
• Scwa, Montville Division (MTV)CT0860011 · CWS · Population served: 2,570
• Scwa, Tower-Ferry View DivisionCT0720041 · CWS · Population served: 2,567
• Wolcott Water DepartmentCT1661423 · CWS · Population served: 2,550
• Ctwc - Gallup SystemCT1090031 · CWS · Population served: 2,538
• Groton Long Point AssociationCT0590051 · CWS · Population served: 2,400
• Connecticut Correctional InstituteCT0490031 · CWS · Population served: 2,385
• Ledyard Wpca, Gales Ferry SystemCT0727051 · CWS · Population served: 2,369
• Salmon Brook District Water DeptCT0560011 · CWS · Population served: 2,151
• Noank Fire DistrictCT0590031 · CWS · Population served: 1,947
• Aquarion-SalisburyCT1220011 · CWS · Population served: 1,932
• Ctwc - Hebron Center DivisionCT0672031 · CWS · Population served: 1,927
• Aquarion-New HartfordCT0920011 · CWS · Population served: 1,872
• Scwa, North Stonington Division (NST)CT1020021 · CWS · Population served: 1,860
• Ctwc - Plainfield SystemCT1090081 · CWS · Population served: 1,713
• Durham Center DivisionCT0380021 · CWS · Population served: 1,601
• Aquarion-North CanaanCT1000011 · CWS · Population served: 1,481
• Tariffville Fire District Water DeptCT1280011 · CWS · Population served: 1,477
• Scwa, Mohegan DivisionCT0860021 · CWS · Population served: 1,428
• Ctwc - Legend Hill SystemCT0765101 · CWS · Population served: 1,368
• Aquarion-MarlboroughCT0798013 · CWS · Population served: 1,348
• Candlewood Shores Tax DistrictCT0180061 · CWS · Population served: 1,315
• Montville Water SupplyCT0864011 · CWS · Population served: 1,300
• Tolland Water DepartmentCT1423011 · CWS · Population served: 1,251
• Aquarion-WoodburyCT1680011 · CWS · Population served: 1,209
• Aquarion-East DerbyCT0378011 · CWS · Population served: 1,101
• Ctwc - Thompson SystemCT1410011 · CWS · Population served: 1,070
• Ctwc - Shoreline Region-Point O WoodsCT1050752 · CWS · Population served: 1,068
• Sprague Water & Sewer AuthorityCT1330021 · CWS · Population served: 1,058
• Aquarion-Ridgefield KnollsCT1180021 · CWS · Population served: 958
• Aquarion-NorfolkCT0980011 · CWS · Population served: 913
• Woodlake Tax DistrictCT1680031 · CWS · Population served: 912
• Ctwc - Amston Lake DivisionCT0670331 · CWS · Population served: 910
• Scwa, Oakdale Heights DivisionCT0860031 · CWS · Population served: 876
• Aquarion-KentCT0680011 · CWS · Population served: 817
• Southbury Training SchoolCT1300011 · CWS · Population served: 816
• Sharon Water & Sewer CommissionCT1250011 · CWS · Population served: 803