COHASSET WATER DEPT
PWS ID: MA4065000 · COHASSET, Massachusetts 02025
PFAS Detected
5 PFAS "forever chemicals" detected in testing under EPA's UCMR5 monitoring program.
Population Served
7,555
Total Violations
64
Health-Based Violations
3
Water Source
Surface Water
System Details
- System Type
- Community
- Owner Type
- Local
- Connections
- 2,692
- County
- Norfolk
- School/Daycare
- No
- MCL Violations
- 1
- Monitoring Violations
- 52
- Treatment Tech Violations
- 2
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Coliform (TCR) | MR | 7 | 2012 |
| Endrin | MR | 3 | 2021 |
| Toxaphene | MR | 3 | 2021 |
| 2,4,5-TP | MR | 3 | 2021 |
| BHC-GAMMA | MR | 3 | 2021 |
| Methoxychlor | MR | 3 | 2021 |
| 2,4-D | MR | 3 | 2021 |
| Lead and Copper Rule | TT | 2 | 2008 |
| Consumer Confidence Rule | Other | 2 | 2022 |
| Lead and Copper Rule | MR | 2 | 2010 |
| Coliform (TCR) | Other | 2 | 2012 |
| Carbofuran | MR | 1 | 2021 |
| Chlordane | MR | 1 | 2021 |
| ETHYLENE DIBROMIDE | MR | 1 | 2021 |
| Heptachlor | MR | 1 | 2021 |
| Pentachlorophenol | MR | 1 | 2021 |
| Total Polychlorinated Biphenyls (PCB) | MR | 1 | 2021 |
| 1,2-DIBROMO-3-CHLOROPROPANE | MR | 1 | 2021 |
| Dalapon | MR | 1 | 2021 |
| Di(2-ethylhexyl) phthalate | MR | 1 | 2021 |
| Dinoseb | MR | 1 | 2021 |
| Diquat | MR | 1 | 2021 |
| HEXACHLOROBENZENE | MR | 1 | 2021 |
| Hexachlorocyclopentadiene | MR | 1 | 2021 |
| Simazine | MR | 1 | 2021 |
| Interim Enhanced Surface Water Treatment Rule | MR | 1 | 2021 |
| LASSO | MR | 1 | 2021 |
| Heptachlor epoxide | MR | 1 | 2021 |
| Atrazine | MR | 1 | 2021 |
| Picloram | MR | 1 | 2021 |
PFAS Testing Results (UCMR5)
Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 6 of 90 samples detected PFAS.
| Contaminant | Date | Result | MRL | Status |
|---|---|---|---|---|
| PFNA | 9/16/2025 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFPeA | 9/16/2025 | 0.0046 µg/L | 0.003 µg/L | Detected |
| PFMBA | 9/16/2025 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFEESA | 9/16/2025 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFMPA | 9/16/2025 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFDoA | 9/16/2025 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFDA | 9/16/2025 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| NFDHA | 9/16/2025 | <0.02 µg/L | 0.02 µg/L | Not Detected |
| PFOS | 9/16/2025 | 0.0045 µg/L | 0.004 µg/L | Detected |
| PFHxS | 9/16/2025 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFHpA | 9/16/2025 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFBS | 9/16/2025 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFHpS | 9/16/2025 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFPeS | 9/16/2025 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFOA | 9/16/2025 | 0.0067 µg/L | 0.004 µg/L | Detected |
| HFPO-DA | 9/16/2025 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| NMeFOSAA | 9/16/2025 | <0.006 µg/L | 0.006 µg/L | Not Detected |
| NEtFOSAA | 9/16/2025 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFTrDA | 9/16/2025 | <0.007 µg/L | 0.007 µg/L | Not Detected |
| PFTA | 9/16/2025 | <0.008 µg/L | 0.008 µg/L | Not Detected |
| 8:2 FTS | 9/16/2025 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| 4:2 FTS | 9/16/2025 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFBA | 9/16/2025 | 0.0073 µg/L | 0.005 µg/L | Detected |
| lithium | 9/16/2025 | <9 µg/L | 9 µg/L | Not Detected |
| ADONA | 9/16/2025 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| 9Cl-PF3ONS | 9/16/2025 | <0.002 µg/L | 0.002 µg/L | Not Detected |
| 11Cl-PF3OUdS | 9/16/2025 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFUnA | 9/16/2025 | <0.002 µg/L | 0.002 µg/L | Not Detected |
| PFHxA | 9/16/2025 | 0.0040 µg/L | 0.003 µg/L | Detected |
| 6:2 FTS | 9/16/2025 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| NMeFOSAA | 6/9/2025 | <0.006 µg/L | 0.006 µg/L | Not Detected |
| 11Cl-PF3OUdS | 6/9/2025 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFUnA | 6/9/2025 | <0.002 µg/L | 0.002 µg/L | Not Detected |
| PFHxA | 6/9/2025 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFDoA | 6/9/2025 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFDA | 6/9/2025 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFOA | 6/9/2025 | 0.0049 µg/L | 0.004 µg/L | Detected |
| PFOS | 6/9/2025 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFNA | 6/9/2025 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFBS | 6/9/2025 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| NEtFOSAA | 6/9/2025 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| 8:2 FTS | 6/9/2025 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFHxS | 6/9/2025 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFHpA | 6/9/2025 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| 9Cl-PF3ONS | 6/9/2025 | <0.002 µg/L | 0.002 µg/L | Not Detected |
| ADONA | 6/9/2025 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| HFPO-DA | 6/9/2025 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFBA | 6/9/2025 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| 4:2 FTS | 6/9/2025 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFMPA | 6/9/2025 | <0.004 µg/L | 0.004 µg/L | Not Detected |
Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025.
PFAS data from EPA UCMR5 monitoring program (2023-2025).
This data is provided for informational purposes only.