D26/100
COHASSET WATER DEPT — Water Quality Report 2026
Serving 7,555 people · Massachusetts
Water Source
Surface Water
County
—
System ID
MA4065000
Violations
47
Contaminant Test Results
3 contaminants above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
PFOA | 0.007 µg/L | 0.004 µg/L | Over Limit |
PFOS | 0.004 µg/L | 0.004 µg/L | Over Limit |
Lead (90th percentile) | 0.002 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
2
Violations (last 5yr)
1
Unresolved
0
Health-Related
TIER 3Resolved
Surface water treatment technique failure
When: July 1, 2022 – August 15, 2022Enforcement: Formal — state order issued
TIER 3Unresolved
Missed required monitoring deadline
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: June 1, 2021 – June 30, 2021Rule: Surface Water Treatment RuleEnforcement: Formal — state order issuedVerify on EPA.gov
Understanding violation severity
Tier 1Urgent health risk. Utility must notify all customers within 24 hours.Tier 2Important health or treatment issue. Customers notified within 30 days.Tier 3Administrative or monitoring issue. Reported in the annual water quality report.
Source: EPA Safe Drinking Water Information System (SDWIS) · Updated quarterly
Frequently Asked Questions About COHASSET WATER DEPT
Is COHASSET WATER DEPT water safe to drink?
COHASSET WATER DEPT water receives a grade of D (26/100), which is considered poor. 2 contaminant(s) exceed EPA legal limits and 47 violation(s) are on record. Customers may want to consider using a water filter.
What contaminants has COHASSET WATER DEPT detected?
34 contaminants were tested in COHASSET WATER DEPT's water. Notable contaminants include PFOA, PFOS, Lead (90th percentile). 2 exceed EPA legal limits (MCLs). 3 exceed EPA health goals (MCLGs).
Does COHASSET WATER DEPT have any EPA violations?
Yes, COHASSET WATER DEPT has 47 EPA violation(s) on record, with the most recent in 2022. Violation types include Other, MR, TT. 2 are health-based violations.
How many people does COHASSET WATER DEPT serve?
COHASSET WATER DEPT serves approximately 7,555 people, Massachusetts. The system provides water to 1 community: Cohasset.
What type of water does COHASSET WATER DEPT provide?
COHASSET WATER DEPT sources its water from surface water. Surface water comes from rivers, lakes, or reservoirs and typically requires more extensive treatment. The utility's system ID is MA4065000.
How does COHASSET WATER DEPT compare to other utilities in Massachusetts?
COHASSET WATER DEPT scores 26/100 with a grade of D (poor). This score suggests significant water quality concerns relative to other utilities. Visit our Massachusetts state page for a full comparison of water systems.