Connecticut Drinking Water Compliance Records
707 water systems serving 3,095,698 people. 44,282 historical EPA violation records in the Q2 2026 snapshot.
TapScore Compliance-History Grades
A
278
39%
B
95
13%
C
192
27%
D
117
17%
F
25
4%
707
Water Systems
3,095,698
Population Served
44,282
Historical Records
3,417
Health-Based (All Years)
Systems With the Most Recent EPA Records
Pit River Montgomery Creek Rancheria
90 served256 historical records244 recent
C
WINDSORVILLE WATER ASSOCIATION
29 served240 historical records233 recent
C
Yomba Indian Reservation
30 served326 historical records163 recent
D
Aguirre MHP
60 served163 historical records163 recent
D
Arizona Village
3,211 served484 historical records145 recent
D
Grindstone Rancheria
150 served899 historical records129 recent
F
Havasu Water Company
361 served130 historical records129 recent
F
SCUA Upper Seven Mile
8,478 served516 historical records119 recent
F
Lower Moencopi - Spring Source
465 served366 historical records89 recent
D
ROUND HILL LLC - WELL# 1&2
72 served120 historical records89 recent
D
Large Systems With No Recent Records
REGIONAL WATER AUTHORITY
418,900 served19 historical records
A
METROPOLITAN DISTRICT COMMISSION
390,887 served0 historical records
A
AQUARION-EASTERN FAIRFIELD COUNTY
351,756 served7 historical records
A
CTWC - NORTHERN REG-WESTERN SYSTEM
101,313 served106 historical records
A
NEW BRITAIN WATER DEPARTMENT
73,534 served1 historical record
A
NORWALK FIRST TAXING DISTRICT
40,256 served0 historical records
A
TORRINGTON WATER COMPANY
37,915 served40 historical records
A
NORWICH PUBLIC UTILITIES
36,163 served2 historical records
A
CTWC - SHORELINE REGION-GUILFORD SYSTEM
33,975 served118 historical records
A
GROTON UTILITIES
30,200 served0 historical records
A
Largest Water Systems in Connecticut
| Water System | Grade | Population | Historical Records |
|---|---|---|---|
| REGIONAL WATER AUTHORITY | A | 418,900 | 19 |
| METROPOLITAN DISTRICT COMMISSION | A | 390,887 | 0 |
| AQUARION-EASTERN FAIRFIELD COUNTY | A | 351,756 | 7 |
| AQUARION-STAMFORD | B | 119,214 | 35 |
| WATERBURY WATER DEPARTMENT | C | 107,271 | 11 |
| CTWC - NORTHERN REG-WESTERN SYSTEM | A | 101,313 | 106 |
| NEW BRITAIN WATER DEPARTMENT | A | 73,534 | 1 |
| DANBURY WATER DEPARTMENT | B | 62,055 | 48 |
| MERIDEN WATER DIVISION | C | 58,441 | 50 |
| AQUARION-GREENWICH | B | 53,297 | 26 |
| BRISTOL WATER DEPARTMENT | B | 52,079 | 56 |
| MANCHESTER WATER DEPARTMENT | B | 51,198 | 8 |
| SOUTHINGTON WATER DEPARTMENT | C | 43,069 | 300 |
| SOUTH NORWALK ELECTRIC & WATER | B | 42,000 | 61 |
| MIDDLETOWN WATER DEPARTMENT | C | 41,019 | 11 |
| NORWALK FIRST TAXING DISTRICT | A | 40,256 | 0 |
| TORRINGTON WATER COMPANY | A | 37,915 | 40 |
| WALLINGFORD WATER DEPARTMENT | C | 37,267 | 83 |
| NORWICH PUBLIC UTILITIES | A | 36,163 | 2 |
| CTWC - SHORELINE REGION-GUILFORD SYSTEM | A | 33,975 | 118 |
Contaminants in Connecticut
Lead in ConnecticutArsenic in ConnecticutNitrate in ConnecticutFluoride in ConnecticutPFOS in ConnecticutPFOA in ConnecticutTHMs in ConnecticutHAA5 in Connecticut
Cities in Connecticut
SEYMOUR(5)SHELTON(68)SOUTHINGTON(6)WOLCOTT(9)STAMFORD(10)BERLIN(8)PROSPECT(5)SOUTH WINDSOR(5)MANCHESTER(4)DARIEN(4)GREENWICH(4)CHESHIRE(4)WALLINGFORD(4)FARMINGTON(7)EAST GRANBY(8)WINDSOR LOCKS(2)MERIDEN(2)NEWINGTON(5)WEST HARTFORD(2)NEW CANAAN(5)NORTH HAVEN(3)NORWALK(5)CROMWELL(3)GLASTONBURY(4)WILTON(4)BETHANY(3)ANSONIA(2)WOODBRIDGE(2)RIDGEFIELD(8)ORANGE(3)DERBY(2)BRANFORD(3)NORTH BRANFORD(3)WEST HAVEN(2)NEW HAVEN(1)EAST HAVEN(1)HAMDEN(1)MILFORD(1)PORTLAND(4)WETHERSFIELD(2)EAST HARTFORD(11)WESTPORT(2)BLOOMFIELD(5)ROCKY HILL(2)HARTFORD(2)WINDSOR(1)BEACON FALLS(3)NEWTOWN(5)WESTON(2)FAIRFIELD(2)MONROE(2)TRUMBULL(2)BRIDGEPORT(1)EASTON(1)REDDING(1)STRATFORD(1)CLINTON(67)PLAINVILLE(6)VERNON(8)MANSFIELD(21)WATERBURY(5)ENFIELD(9)WATERTOWN(6)MIDDLEBURY(5)EAST WINDSOR(5)TOLLAND(13)STAFFORD(3)SUFFIELD(3)ELLINGTON(1)BRISTOL(4)NEW BRITAIN(2)BROOKFIELD(16)DANBURY(20)BETHEL(6)MONTVILLE(25)PLYMOUTH(3)BURLINGTON(4)MIDDLETOWN(4)LEDYARD(9)GROTON(7)NEW HARTFORD(4)WATERFORD(4)NEW LONDON(2)LISBON(6)LITCHFIELD(6)MIDDLEFIELD(6)TORRINGTON(4)HARWINTON(2)LEBANON(7)NORWICH(6)PRESTON(3)FRANKLIN(1)BOZRAH(1)MADISON(3)GUILFORD(3)WESTBROOK(2)OLD SAYBROOK(1)Sacaton(5)AVON(4)Temecula(1)