Connecticut drinking water quality
Connecticut has 2,334 active public water systems serving 2.9 million people. 1,316 of them, 56%, had at least one EPA violation in the past three years, 704 have an unresolved violation today, and 37 are designated serious violators by the EPA.
Active systems
2,334
in 8 counties
People served
2.9M
476 community systems serve 2.8M
Violations, past 3 years
1,316
56% of active systems
Serious violators
37
372 systems carry a health flag
Largest counties
All 8 counties| County | People served | Systems | With violations |
|---|---|---|---|
| Hartford | 835,730 | 217 | 135 |
| Fairfield | 778,705 | 336 | 245 |
| New Haven | 723,643 | 212 | 108 |
| New London | 209,369 | 392 | 199 |
| Litchfield | 130,993 | 348 | 196 |
| Middlesex | 97,827 | 278 | 149 |
| Windham | 63,893 | 255 | 139 |
| Tolland | 59,500 | 295 | 145 |
Largest community water systems
All 2,334 systems| System | Serves | Status |
|---|---|---|
| Regional Water Authority New Haven County |
418,900 | |
| Metropolitan District Commission Hartford County |
390,887 | |
| Aquarion-Eastern Fairfield County Fairfield County |
351,756 | |
| Aquarion-Stamford Fairfield County |
119,214 | |
| Waterbury Water Department New Haven County |
107,271 | |
| Ctwc Northern Reg-Western System Hartford County |
101,313 | |
| New Britain Water Department Hartford County |
73,534 | |
| Danbury Water Department Fairfield County |
62,055 | |
| Meriden Water Division New Haven County |
58,441 | |
| Aquarion-Greenwich Fairfield County |
53,297 |
About the Connecticut data
Retrieved from EPA ECHO on Oct 11, 2026.