Cohasset, MA: 3 Violations — 69/100 (2026)
1 ZIP code · 2 water systems · Updated 2026-06-03
Cohasset water quality is uneven — some service areas show clean compliance; others carry documented violations in MA EPA records.
How Cohasset Compares
Data: EPA SDWIS Last verified: 2026-06-03
What You Should Know About Cohasset Water
- Your city's water systems recorded 3 violations in the past 5 years.
- Average lead level: 0.002 mg/L.
- Homes built before 1986: 75% — older plumbing may contain lead solder.
- Estimated remediation: $2,200 per household.
- CDC health risk index: 10.28.
Who Supplies Your Water in Cohasset
Federal drinking water records identify 2 systems in Cohasset, MA. The leading 2 providers serve the largest share of residential connections, each operating as a separate entity with its own rate authority, infrastructure management, and EPA compliance obligations — so service conditions are not uniform city-wide.
Overview
We track water quality and home safety data for 1 ZIP code in Cohasset, Massachusetts (population ~8,358), covering 2 community water systems serving approximately 52,894 people region-wide.
1 of 1 ZIP code (100%) have recorded EPA violations. All violations are monitoring/reporting type.
Home Safety Score
Average Home Safety Score for Cohasset: C (69/100)
The score combines three factors:
| Factor | What It Measures |
|---|---|
| Water Quality | EPA violations and compliance history |
| Lead Levels | 90th percentile lead concentration vs EPA action level |
| Radon Risk | EPA radon zone classification |
Water Sources
Cohasset water systems draw from: Surface water.
Lead & Copper
- Average lead level (90th percentile): 0.0020 mg/L (EPA action level: 0.015 mg/L)
- 0 ZIP codes exceed the EPA lead action level
Radon Risk
Dominant radon zone: Zone 2 (Moderate Risk)
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Top Contaminants
| Contaminant | Category | Violations | ZIPs Affected |
|---|---|---|---|
| Contaminant 2051 | Other | 2 | 1 |
| Surface Water Treatment Rule | Treatment Technique | 2 | 1 |
| Fecal Coliform | Microbiological | 2 | 1 |
Areas with Most Violations
| ZIP Code | Safety Score | Violations | Health-Based | System |
|---|---|---|---|---|
| 02025 | C | 3 | 0 | Cohasset Water Department |
All ZIP Codes in Cohasset
- 02025 [C] — 3 violations
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Lead/copper: EPA Lead and Copper Rule sampling data
- Radon: EPA Map of Radon Zones
Updated daily.
Health Outcomes in Cohasset
Source: CDC PLACES (County-level estimates). Water contamination can correlate with respiratory and chronic health conditions.
Compared to National Average
Vertical line = national average. ■ Above national · ■ Below national
Top Contaminants in Cohasset Water
Based on EPA violation records. Check your ZIP code report for system-specific contaminant data.
Housing & Infrastructure in Cohasset
With 75% of homes built before 1986, lead solder in plumbing is a potential concern. The EPA banned lead solder in 1986, but many older homes retain original plumbing.
Source: U.S. Census Bureau American Community Survey (ACS).
Housing Age Profile
Viewed through the lens of construction era, Cohasset is predominantly an older city — a median build year of 1950 puts most of the residential inventory in the range where pre-1986 plumbing materials were the standard.
Over half of homes in Cohasset were built before 1986, when lead solder was banned. Older plumbing may leach lead into drinking water, especially with corrosive water chemistry.
Source: U.S. Census Bureau ACS B25034.
Cost Context: What Remediation Means for Cohasset Homeowners
In Cohasset, property values comfortably outpace what documented remediation typically costs — the equity share is proportionally low.
Remediation costs in Cohasset are relatively low compared to home values. The $1,200–$3,400 estimated range is a small fraction of median property value. Home values are 94% above the Massachusetts average.
Lead Exposure Risk for Children in Cohasset
Why children are most at risk: The CDC states there is no safe level of lead exposure for children. Children under 6 absorb lead more readily than adults, and even low levels can cause developmental delays, learning difficulties, and behavioral problems.
Practically, the structural drivers in Cohasset — 75% pre-rule stock and citywide monitoring at or beyond the regulatory benchmark — make an in-home draw the practical way to translate aggregate averages into the specific conditions at one address.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Flood & Climate Risk in Cohasset
Flood exposure in Cohasset is meaningful by NFIP measures — 148 claims on record and 100% of ZIP codes carrying FEMA flood zone designations. That level of activity makes flood history a relevant factor when evaluating local water quality over time.
Cohasset has a moderate flood history with 148 FEMA claims averaging $10,165 per payout. 100% of ZIP codes fall within FEMA flood zones. Flood events can contaminate drinking water and overwhelm treatment systems.
How flooding affects water quality: Flood events can introduce sewage, agricultural runoff, and industrial chemicals into water supplies. Even after floodwaters recede, contamination can persist in wells and aging infrastructure. Flood damage can add significantly to the estimated <strong>$2,200</strong> remediation cost per household.
Residents in flood-prone areas should consider flood insurance even outside FEMA zones — over 25% of flood claims come from low-to-moderate risk areas. After any flood event, test your water before drinking.
Source: FEMA National Flood Insurance Program (NFIP) claims data, FEMA flood zone designations.
What You Can Do in Cohasset
- Test your water at home. City-level data shows averages — your tap may differ. NSF-certified test kits cost $20-40 and give results in days.
- Install a certified water filter. Filters rated for Contaminant 2051 can reduce the most common contaminant found in Cohasset's water.
- Check your home's plumbing. With 75% of homes built before 1986, lead solder is a real possibility.
Deep Dive Reports
Detailed analysis for Cohasset, MA