Chelmsford Water District
PWSID MA3056000 · Chelmsford, Massachusetts · serves 28,750 people · groundwater source
F
Failing
PFAS test results (EPA UCMR 5)
| Contaminant | Result | Federal limit (MCL) | Sampled |
|---|---|---|---|
| PFOA | 8.9 ppt | 4 ppt | 10/12/2023 |
| PFOA | 7.7 ppt | 4 ppt | 12/27/2023 |
| PFOA | 7.7 ppt | 4 ppt | 5/14/2024 |
| PFOA | 7.3 ppt | 4 ppt | 10/8/2024 |
| PFOA | 7.2 ppt | 4 ppt | 4/9/2024 |
| PFOS | 7.2 ppt | 4 ppt | 10/12/2023 |
| PFOA | 7.1 ppt | 4 ppt | 10/12/2023 |
| PFOA | 6.7 ppt | 4 ppt | 4/9/2024 |
| PFOS | 5.8 ppt | 4 ppt | 10/8/2024 |
| PFOS | 5.5 ppt | 4 ppt | 5/14/2024 |
| PFOS | 5.3 ppt | 4 ppt | 12/27/2023 |
| PFOS | 4.5 ppt | 4 ppt | 4/9/2024 |
| PFBS | 4.2 ppt | — | 10/12/2023 |
| PFPeA | 3.7 ppt | — | 12/27/2023 |
| PFPeA | 3.6 ppt | — | 10/12/2023 |
| PFHxA | 3.5 ppt | — | 12/27/2023 |
| PFPeA | 3.4 ppt | — | 10/12/2023 |
| PFHxA | 3.3 ppt | — | 10/12/2023 |
| PFHxA | 3.2 ppt | — | 4/9/2024 |
| PFPeA | 3.2 ppt | — | 4/9/2024 |
| PFHxA | 3.2 ppt | — | 10/12/2023 |
| PFPeA | 3.1 ppt | — | 4/9/2024 |
| PFHxA | 3.1 ppt | — | 4/9/2024 |
| PFHxA | 3.1 ppt | — | 5/14/2024 |
| PFHxA | 3.1 ppt | — | 10/8/2024 |
ppt = parts per trillion (ng/L). Rows highlighted red meet or exceed the 2024 federal limit.
Violation history
| Date | Violation | Type | Health-based | Status |
|---|---|---|---|---|
| 2026-01-01 | TTHM | MCL | Yes | Archived |