Onset Fire Districtwater Dept.
PWSID MA4310003 · Onset, Massachusetts · serves 5,392 people · groundwater source
D
Poor
PFAS test results (EPA UCMR 5)
| Contaminant | Result | Federal limit (MCL) | Sampled |
|---|---|---|---|
| PFOS | 7.1 ppt | 4 ppt | 6/24/2025 |
| PFOS | 5.2 ppt | 4 ppt | 12/2/2025 |
ppt = parts per trillion (ng/L). Rows highlighted red meet or exceed the 2024 federal limit.
Violation history
| Date | Violation | Type | Health-based | Status |
|---|---|---|---|---|
| 2022-07-01 | Consumer Confidence Rule | Other | No | Resolved |