Connecticut Water Report Card: Worst Water Systems
The most contaminated public water systems in Connecticut, ranked by PFAS levels, lead, and EPA violations from official EPA data.
Quick Answer
Norwich Public Utilities has the highest PFAS in Connecticut at 16.2 ppt (4x the EPA limit). Waterbury Water Department has the highest lead at 34 ppb. The tables below rank the worst systems in each category so you can see how your water compares.
Highest PFAS Levels in Connecticut
Public water systems in Connecticut with the highest peak PFAS ("forever chemical") reading in EPA UCMR5 testing (2023-2025). The EPA enforceable limit for PFOA and PFOS is 4 ppt.
| # | Water System | Location | Peak PFAS (ppt) | Compounds | vs 4 ppt limit |
|---|---|---|---|---|---|
| 1 | Norwich Public Utilities | Norwich · 36,163 served | 16.2 | 4 | 4x |
| 2 | Manchester Water Department | Manchester · 51,198 served | 16 | 5 | 4x |
| 3 | Aquarion Water Co Of Ct-Newtown System | Shelton · 6,054 served | 15.9 | 8 | 4x |
| 4 | Wallingford Water Department | Wallingford · 37,267 served | 13.9 | 2 | 3x |
| 5 | Jewett City Water Company | Enfield · 6,840 served | 12.1 | 1 | 3x |
| 6 | Ctwc - Shoreline Region-Guilford System | Clinton · 33,975 served | 12 | 4 | 3x |
| 7 | Norwalk First Taxing District | Norwalk · 40,256 served | 11.2 | 6 | 3x |
| 8 | Aquarion Water Co Of Ct-Main System | Shelton · 351,756 served | 10.9 | 6 | 3x |
| 9 | Regional Water Authority | New Haven · 418,900 served | 10.7 | 2 | 3x |
| 10 | Aquarion Water Co Of Ct-Ridgefield Sys | Shelton · 7,476 served | 10.6 | 6 | 3x |
| 11 | Ctwc - Crystal System | Clinton · 6,378 served | 9.9 | 2 | 2x |
| 12 | Meriden Water Division | Meriden · 58,441 served | 9.5 | 5 | 2x |
Highest Lead Levels in Connecticut
Community water systems in Connecticut with the highest 90th-percentile lead result under the EPA Lead and Copper Rule. The EPA action level is 15 ppb; there is no safe level of lead for children.
| # | Water System | Location | Lead 90th-pctile (ppb) | vs 15 ppb |
|---|---|---|---|---|
| 1 | Waterbury Water Department | Waterbury · 107,271 served | 34 | 2.3x over |
| 2 | South Norwalk Electric & Water | Wilton · 42,000 served | 32 | 2.1x over |
| 3 | Ctwc - Legend Hill System | Clinton · 1,368 served | 16 | 1.1x over |
| 4 | Ctwc - Northern Reg-Western System | Clinton · 101,313 served | 14 | within |
| 5 | Watertown Fire District | Watertown · 6,718 served | 14 | within |
| 6 | Montville Water Supply | Uncasville · 1,300 served | 11.2 | within |
| 7 | Ledyard Wpca, Gales Ferry System | Ledyard · 2,369 served | 10 | within |
| 8 | Ledyard Wpca - Ledyard Center | Ledyard · 3,294 served | 10 | within |
| 9 | Groton Utilities | Groton · 30,200 served | 9 | within |
| 10 | Wolcott Water Department | Wolcott · 2,550 served | 9 | within |
| 11 | Bristol Water Department | Bristol · 52,079 served | 9 | within |
| 12 | Aquarion-Marlborough | Shelton · 1,348 served | 9 | within |
Most EPA Violations in Connecticut
Community water systems in Connecticut with the most health-based EPA Safe Drinking Water Act violations on record. A health-based violation means a contaminant exceeded its federal limit or required treatment was not applied.
| # | Water System | Location | Health-based violations |
|---|---|---|---|
| 1 | Norwich Public Utilities | Norwich · 36,163 served | 9 |
| 2 | Bethel Water Dept | Bethel · 9,507 served | 3 |
| 3 | Ledyard Wpca - Ledyard Center | Ledyard · 3,294 served | 3 |
| 4 | Jewett City Water Company | Enfield · 6,840 served | 2 |
| 5 | Fairfield Hills | Newtown · 2,610 served | 2 |
| 6 | Meriden Water Division | Meriden · 58,441 served | 2 |
| 7 | Torrington Water Company | Shelton · 37,915 served | 2 |
| 8 | Aquarion-Ridgefield | Shelton · 7,476 served | 1 |
| 9 | Berlin Water Control Commission | Berlin · 5,128 served | 1 |
| 10 | Aquarion-Eastern Fairfield County | Shelton · 351,756 served | 1 |
| 11 | Danbury Water Department | Danbury · 62,055 served | 1 |
| 12 | Durham Center Division | Durham · 1,601 served | 1 |
How This Report Card Is Built
PFAS rankings use EPA UCMR5 monitoring (2023-2025), showing each system's peak detection above the 4 ppt EPA limit. Lead rankings use the EPA Lead and Copper Rule 90th-percentile tap results. Violation counts come from the EPA Safe Drinking Water Information System (SDWIS) and count health-based violations. Lead and violation lists are limited to community water systems serving 1,000 or more people. Figures are the most severe on record and do not necessarily reflect current treated water.
Frequently Asked Questions
What is the most PFAS-contaminated water system in Connecticut?
In EPA UCMR5 testing (2023-2025), Norwich Public Utilities in Norwich had the highest recorded PFAS level in Connecticut at 16.2 ppt - about 4x the EPA's 4 ppt limit for PFOA and PFOS.
Which Connecticut water system has the highest lead levels?
Waterbury Water Department in Waterbury had the highest 90th-percentile lead result in Connecticut under the EPA Lead and Copper Rule at 34 ppb - 2.3x the 15 ppb action level.
Which Connecticut water system has the most EPA violations?
Norwich Public Utilities in Norwich has the most health-based EPA Safe Drinking Water Act violations on record in Connecticut, with 9 violations.
Where does the Connecticut water report card data come from?
PFAS figures come from EPA UCMR5 monitoring (2023-2025), lead from the EPA Lead and Copper Rule 90th-percentile tap results, and violations from EPA SDWIS health-based violation records. Figures are the most severe on record and do not necessarily reflect current treated water. Check your exact address at knowyourexposure.com.
What Connecticut Residents Should Do
- Look up your exact address at knowyourexposure.com for your system's data
- See the full Connecticut water quality overview
- If your system is listed, a certified filter (reverse osmosis for PFAS, NSF-53 for lead) reduces exposure at the tap. See the best water filters.