Cohasset Water Dept
Published drinking-water records and contacts for Cohasset Water Dept. System MA4065000. Review sources and dates; not a real-time water assessment.
- System ID
- MA4065000
- State or territory
- MA
- Published population served
- 7555
- System type (source code)
- CWS
Published records and dates
- PFAS / lithium (EPA UCMR 5): 120 — 2025-03-04 – 2025-12-02
- Lead and copper monitoring summaries: 22 — 1992-07-01 – 2025-12-31
- Massachusetts EEA PFAS monitoring results: 1025 — 2020-06-30 – 2026-08-21
Missing records here do not mean the provider did not test. Published records are not a real-time assessment of your tap water.
Published testing results
Selected recent records are shown below. Different sampling locations and dates are not interchangeable. These excerpts are not a complete testing history.
“<” means below the stated reporting limit, not zero. A reported measurement alone is not a safety verdict. Read an example
| Substance | Published result | Reporting limit | Sample date | Sampling location |
|---|---|---|---|---|
| 11Cl-PF3OUdS | < 0.005 µg/L | 0.005 µg/L | 2025-12-02 | COHASSET WTP - FIN / 10198 |
| 4:2 FTS | < 0.003 µg/L | 0.003 µg/L | 2025-12-02 | COHASSET WTP - FIN / 10198 |
| 6:2 FTS | < 0.005 µg/L | 0.005 µg/L | 2025-12-02 | COHASSET WTP - FIN / 10198 |
| 8:2 FTS | < 0.005 µg/L | 0.005 µg/L | 2025-12-02 | COHASSET WTP - FIN / 10198 |
| 9Cl-PF3ONS | < 0.002 µg/L | 0.002 µg/L | 2025-12-02 | COHASSET WTP - FIN / 10198 |
| ADONA | < 0.003 µg/L | 0.003 µg/L | 2025-12-02 | COHASSET WTP - FIN / 10198 |
| HFPO-DA | < 0.005 µg/L | 0.005 µg/L | 2025-12-02 | COHASSET WTP - FIN / 10198 |
| NEtFOSAA | < 0.005 µg/L | 0.005 µg/L | 2025-12-02 | COHASSET WTP - FIN / 10198 |
| NFDHA | < 0.02 µg/L | 0.02 µg/L | 2025-12-02 | COHASSET WTP - FIN / 10198 |
| NMeFOSAA | < 0.006 µg/L | 0.006 µg/L | 2025-12-02 | COHASSET WTP - FIN / 10198 |
| PFBA | < 0.005 µg/L | 0.005 µg/L | 2025-12-02 | COHASSET WTP - FIN / 10198 |
| PFBS | < 0.003 µg/L | 0.003 µg/L | 2025-12-02 | COHASSET WTP - FIN / 10198 |
| PFDA | < 0.003 µg/L | 0.003 µg/L | 2025-12-02 | COHASSET WTP - FIN / 10198 |
| PFDoA | < 0.003 µg/L | 0.003 µg/L | 2025-12-02 | COHASSET WTP - FIN / 10198 |
| PFEESA | < 0.003 µg/L | 0.003 µg/L | 2025-12-02 | COHASSET WTP - FIN / 10198 |
| PFHpA | < 0.003 µg/L | 0.003 µg/L | 2025-12-02 | COHASSET WTP - FIN / 10198 |
| PFHpS | < 0.003 µg/L | 0.003 µg/L | 2025-12-02 | COHASSET WTP - FIN / 10198 |
| PFHxA | < 0.003 µg/L | 0.003 µg/L | 2025-12-02 | COHASSET WTP - FIN / 10198 |
| PFHxS | < 0.003 µg/L | 0.003 µg/L | 2025-12-02 | COHASSET WTP - FIN / 10198 |
| PFMBA | < 0.003 µg/L | 0.003 µg/L | 2025-12-02 | COHASSET WTP - FIN / 10198 |
| PFMPA | < 0.004 µg/L | 0.004 µg/L | 2025-12-02 | COHASSET WTP - FIN / 10198 |
| PFNA | < 0.004 µg/L | 0.004 µg/L | 2025-12-02 | COHASSET WTP - FIN / 10198 |
| PFOA | 0.0046 µg/L | 0.004 µg/L | 2025-12-02 | COHASSET WTP - FIN / 10198 |
| PFOS | < 0.004 µg/L | 0.004 µg/L | 2025-12-02 | COHASSET WTP - FIN / 10198 |
| PFPeA | < 0.003 µg/L | 0.003 µg/L | 2025-12-02 | COHASSET WTP - FIN / 10198 |
| PFPeS | < 0.004 µg/L | 0.004 µg/L | 2025-12-02 | COHASSET WTP - FIN / 10198 |
| PFTA | < 0.008 µg/L | 0.008 µg/L | 2025-12-02 | COHASSET WTP - FIN / 10198 |
| PFTrDA | < 0.007 µg/L | 0.007 µg/L | 2025-12-02 | COHASSET WTP - FIN / 10198 |
| PFUnA | < 0.002 µg/L | 0.002 µg/L | 2025-12-02 | COHASSET WTP - FIN / 10198 |
| lithium | < 9 µg/L | 9 µg/L | 2025-12-02 | COHASSET WTP - FIN / 10198 |
Download all EPA UCMR 5 records (CSV)
Lead and copper: 90th-percentile summaries
These describe a monitoring period across sampled locations, not the result at your home. How to read the 90th percentile
| Substance | Published 90th percentile | Monitoring period | Source quarter |
|---|---|---|---|
| Lead (PB90) | 0.002 mg/L | 2023-01-01 – 2025-12-31 | 2026Q3 |
| Lead (PB90) | 0.002 mg/L | 2020-01-01 – 2022-12-31 | 2026Q3 |
| Lead (PB90) | 0.011 mg/L | 2017-01-01 – 2019-12-31 | 2026Q3 |
| Lead (PB90) | 0.005 mg/L | 2014-01-01 – 2016-12-31 | 2026Q3 |
| Lead (PB90) | 0.013 mg/L | 2013-01-01 – 2013-12-31 | 2026Q3 |
| Lead (PB90) | 0.002 mg/L | 2012-01-01 – 2012-12-31 | 2026Q3 |
| Lead (PB90) | 0.004 mg/L | 2011-01-01 – 2011-12-31 | 2026Q3 |
| Lead (PB90) | 0.012 mg/L | 2010-07-01 – 2010-12-31 | 2026Q3 |
| Substance | Published result | Sample date | Location / source |
|---|---|---|---|
| PERFLUOROTETRADECANOIC ACID - PFTA | Below a limit; numeric threshold unavailable ng/L | 2026-08-21 | COHASSET WTP - FIN / Massachusetts EEA PFAS monitoring results |
| PERFLUOROHEXANESULFONIC ACID-PFHXS | 0.809 J ng/L | 2026-08-21 | COHASSET WTP - FIN / Massachusetts EEA PFAS monitoring results |
| N-METHYL PERFLUOROOCTANESULFONAMIDOACETIC ACID - NMEFOSAA | Below a limit; numeric threshold unavailable ng/L | 2026-08-21 | COHASSET WTP - FIN / Massachusetts EEA PFAS monitoring results |
| PERFLUOROOCTANESULFONIC ACID-PFOS | 2.66 ng/L | 2026-08-21 | COHASSET WTP - FIN / Massachusetts EEA PFAS monitoring results |
| 4,8-DIOXA-3H-PERFLUORONONANOIC ACID - ADONA | Below a limit; numeric threshold unavailable ng/L | 2026-08-21 | COHASSET WTP - FIN / Massachusetts EEA PFAS monitoring results |
| N-ETHYL PERFLUOROOCTANESULFONAMIDOACETIC ACID - NETFOSAA | Below a limit; numeric threshold unavailable ng/L | 2026-08-21 | COHASSET WTP - FIN / Massachusetts EEA PFAS monitoring results |
| PERFLUORONONANOIC ACID-PFNA | 0.634 J ng/L | 2026-08-21 | COHASSET WTP - FIN / Massachusetts EEA PFAS monitoring results |
| PERFLUOROHEPTANOIC ACID-PFHPA | 1.09 ng/L | 2026-08-21 | COHASSET WTP - FIN / Massachusetts EEA PFAS monitoring results |
| PERFLUOROOCTANOIC ACID-PFOA | 2.95 ng/L | 2026-08-21 | COHASSET WTP - FIN / Massachusetts EEA PFAS monitoring results |
| PERFLUOROUNDECANOIC ACID - PFUNA | Below a limit; numeric threshold unavailable ng/L | 2026-08-21 | COHASSET WTP - FIN / Massachusetts EEA PFAS monitoring results |
| PERFLUOROBUTANESULFONIC ACID-PFBS | 1.3 ng/L | 2026-08-21 | COHASSET WTP - FIN / Massachusetts EEA PFAS monitoring results |
| 9-CHLOROHEXADECAFLUORO-3-OXANONE-1-SULFONIC ACID-9CL-PF3ONS | Below a limit; numeric threshold unavailable ng/L | 2026-08-21 | COHASSET WTP - FIN / Massachusetts EEA PFAS monitoring results |
State sampling points can include untreated water. Publisher qualifiers and units are retained; consult the full source notes before interpreting a record.
Download state records with source notes (CSV)
Published compliance history
71 imported records. Status is as recorded in the source; historical records are not current advisories. Missing records do not establish that no violations occurred.
| Rule / record | Period | Recorded status | Health-based (EPA classification) | Source quarter |
|---|---|---|---|---|
| Stage 2 Disinfectants and Disinfection Byproducts Rule / Maximum Contaminant Level Violation, Average | 2026-07-01 – 2026-09-30 | Addressed | Yes | 2026Q3 |
| Stage 2 Disinfectants and Disinfection Byproducts Rule / Maximum Contaminant Level Violation, Average | 2026-04-01 – 2026-06-30 | Archived | Yes | 2026Q3 |
| Stage 2 Disinfectants and Disinfection Byproducts Rule / Maximum Contaminant Level Violation, Average | 2026-01-01 – 2026-03-31 | Archived | Yes | 2026Q3 |
| Stage 2 Disinfectants and Disinfection Byproducts Rule / Maximum Contaminant Level Violation, Average | 2025-10-01 – 2025-12-31 | Archived | Yes | 2026Q3 |
| Stage 2 Disinfectants and Disinfection Byproducts Rule / Maximum Contaminant Level Violation, Average | 2025-07-01 – 2025-09-30 | Archived | Yes | 2026Q3 |
| Consumer Confidence Rule / Consumer Confidence Report Complete Failure to Report | 2022-07-01 – — | Resolved | No | 2026Q3 |
| Interim and Long Term 1 Enhanced Surface Water Treatment Rule / Monitoring, Turbidity (Enhanced SWTR) | 2021-06-01 – 2021-06-30 | Archived | No | 2026Q3 |
| Synthetic Organic Chemicals / Monitoring, Regular | 2021-04-01 – 2021-06-30 | Archived | No | 2026Q3 |
| Synthetic Organic Chemicals / Monitoring, Regular | 2021-04-01 – 2021-06-30 | Archived | No | 2026Q3 |
| Synthetic Organic Chemicals / Monitoring, Regular | 2021-04-01 – 2021-06-30 | Archived | No | 2026Q3 |
| Synthetic Organic Chemicals / Monitoring, Regular | 2021-04-01 – 2021-06-30 | Archived | No | 2026Q3 |
| Synthetic Organic Chemicals / Monitoring, Regular | 2021-04-01 – 2021-06-30 | Archived | No | 2026Q3 |
| Synthetic Organic Chemicals / Monitoring, Regular | 2021-04-01 – 2021-06-30 | Archived | No | 2026Q3 |
| Synthetic Organic Chemicals / Monitoring, Regular | 2021-04-01 – 2021-06-30 | Archived | No | 2026Q3 |
| Synthetic Organic Chemicals / Monitoring, Regular | 2021-04-01 – 2021-06-30 | Archived | No | 2026Q3 |
| Synthetic Organic Chemicals / Monitoring, Regular | 2021-04-01 – 2021-06-30 | Archived | No | 2026Q3 |
| Synthetic Organic Chemicals / Monitoring, Regular | 2021-04-01 – 2021-06-30 | Archived | No | 2026Q3 |
| Synthetic Organic Chemicals / Monitoring, Regular | 2021-04-01 – 2021-06-30 | Archived | No | 2026Q3 |
| Synthetic Organic Chemicals / Monitoring, Regular | 2021-04-01 – 2021-06-30 | Archived | No | 2026Q3 |
| Synthetic Organic Chemicals / Monitoring, Regular | 2021-04-01 – 2021-06-30 | Archived | No | 2026Q3 |
Source dates and refresh checks
A refresh check is not a sample date. Publication periods, sample dates and checks are shown separately.
- EPA SDWIS lead/copper summaries and service areas — source period: — – —; last checked: 2026-10-17
- EPA SDWIS contacts and compliance records — source period: — – —; last checked: 2026-10-17
- EPA UCMR 5 sample results — source period: 2023-01-03 – 2026-06-17; last checked: 2026-10-17
- Massachusetts EEA PFAS monitoring results — last successful check: 2026-10-12
Administrative contact (EPA filing)
Cohasset Water Dept: 7813830057
An administrative filing contact may not be a customer-service line. Confirm current contact details with the provider.