Fairfield County tap water
7 of 12 water systems serving Fairfield County with full PFAS testing averaged above a 2024 federal PFAS level at one or more sampling points.
- 61 community water systems list this county as served; 12 serve 3,300+ people with full PFAS testing.
- 11 had a health-based violation since 2021-10-26.
Largest systems serving this county
| System | Source | People served (whole system) | PFAS above a 2024 level? | Violations since 2021-10-26 |
|---|---|---|---|---|
| Aquarion-Eastern Fairfield County | Surface water | 351,756 | No | 0 |
| Aquarion-Stamford | Surface water | 119,214 | No | 0 |
| Danbury Water department | Surface water | 62,055 | Yes | 0 |
| Aquarion-Greenwich | Surface water | 53,297 | Yes | 0 |
| South Norwalk Electric & Water | Surface water | 42,000 | No | 0 |
| Norwalk First Taxing District | Surface water | 40,256 | Yes | 0 |
| Aquarion-Darien | Purchased surface water | 18,737 | No | 0 |
| Aquarion-New Milford Regional | Groundwater | 13,331 | Yes | 0 |
| Aquarion-New Canaan | Purchased surface water | 10,097 | No | 0 |
| Bethel Water dept | Surface water | 9,507 | Yes | 0 |
| Aquarion-Ridgefield | Purchased surface water | 7,476 | Yes | 0 |
| Aquarion-Newtown Regional | Groundwater | 6,054 | Yes | 0 |
Which one is yours? A county usually has several utilities. Your bill or your utility's annual water-quality report names yours. Population is for the whole system, which can cross county lines.
Not medical or legal advice. UCMR 5 results are screening data, not compliance determinations.
Sources and freshness
Public-water-system facts, violations and lead/copper results: EPA ECHO SDWA download (SDWIS snapshot 2026-10-13). PFAS and lithium results: EPA UCMR 5 final data (sampling 2023–2025). Both are U.S. government works, downloaded 2026-10-26. Numbers are computed by the published method; the same fields are in the open data files.