Connecticut
Water quality data from the EPA Safe Drinking Water Information System
Water Systems
11,255
Active public water systems
Population Served
2.99M
Residents with piped water
Lead Violations
74
Systems exceeding 15 ppb
Copper Violations
378
Lead & Copper Rule
Average Lead Level
EPA Action Level: 15 ppb
MCLG (health goal): 0 ppb
Average across 1589 systems with reported lead data.
Violations Detected
452 water systems in Connecticut have reported violations under the Lead and Copper Rule. These utilities are required to notify customers and take corrective action.
Schools & Daycares
1 school or daycare water system identified in this state.
Children are especially vulnerable to lead exposure. Schools are required to test for lead and remediate violations.
Water Systems: Highest Lead Levels
| System Name | City | Population | Lead Level | Status | Sample Date |
|---|---|---|---|---|---|
| MANSFIELD CENTER | 21,214 | 4.30 ppb | OK | 2025-12-31 | |
| WATERBURY | 107,271 | 4.00 ppb | OK | 2025-12-31 | |
| NORWALK | 40,256 | 3.00 ppb | OK | 2025-12-31 | |
| SHELTON | 10,788 | 3.00 ppb | OK | 2025-12-31 | |
| Uncasville | 31,961 | 2.60 ppb | OK | 2025-12-31 | |
| CLINTON | 14,693 | 2.40 ppb | OK | 2025-12-31 | |
| WILTON | 42,000 | 2.00 ppb | OK | 2025-12-31 | |
| SHELTON | 18,737 | 2.00 ppb | OK | 2023-12-31 | |
| WATERFORD | 16,578 | 1.50 ppb | OK | 2023-12-31 | |
| GROTON | 30,200 | 1.20 ppb | OK | 2025-06-30 | |
| SHELTON | 13,080 | 1.10 ppb | OK | 2025-12-31 | |
| MASHANTUCKET | 26,445 | 1.00 ppb | OK | 2025-12-31 | |
UNIVERSITY OF CONNECTICUT - MAIN CAMPUSSchool/Daycare | STORRS | 27,199 | 0.70 ppb | OK | 2023-12-31 |
| ENFIELD | 18,544 | 0.70 ppb | OK | 2024-12-31 | |
| NEW HAVEN | 418,900 | 0.00 ppb | OK | 2026-12-31 |
Showing top 15 of 1511 systems with lead data. Action level: 15 ppb.
Systems With Active Violations
These water systems have exceeded EPA limits and must take corrective action.
SOUTHINGTON · Pop. 43,069
Lead: 0.00 ppb (2024-12-31)
CLINTON · Pop. 11,590
Lead: 0.00 ppb (2026-12-31)
Water Source Types
Air Quality
GoodAvg AQI
40.8
PM2.5
5.5 µg/m³
Unhealthy Days
3
Primary Pollutant
Ozone
Source: EPA AirNow & American Lung Association 2024 State of the Air. AQI scale: 0–50 Good · 51–100 Moderate · 101–150 Sensitive Groups · 151+ Unhealthy.
PFAS Contamination
Moderate DetectionPFAS (per- and polyfluoroalkyl substances), known as “forever chemicals,” are a group of synthetic chemicals that persist indefinitely in the environment and human body. The EPA set a maximum contaminant level (MCL) of 4 parts per trillion (ppt) for PFOA and PFOS in April 2024. View national PFAS tracker →
Systems Tested
148
PFAS Detected
58
Detection Rate
39.2%
Exceeding MCL (4 ppt)
14(9.5%)
Highest recorded level: 42 ppt (EPA MCL: 4 ppt). Dense industrial history; above-average detection rates