Belmont, MA: 1 Violation — 63/100 (2026)
1 ZIP code · 1 water system · Updated 2026-06-03
Unlike higher-rated cities in MA, Belmont carries a fair number of documented violations — the pattern of compliance gaps keeps the city in the middle tier of EPA safety rankings.
How Belmont Compares
Data: EPA SDWIS Last verified: 2026-06-03
What You Should Know About Belmont Water
- Your city's water systems recorded 1 violation in the past 5 years.
- Average lead level: 0.0015 mg/L.
- Homes built before 1986: 90% — older plumbing may contain lead solder.
- Estimated remediation: $2,400 per household.
- CDC health risk index: 9.88.
Who Supplies Your Water in Belmont
Supply infrastructure in Belmont, MA runs through a single dominant provider — the main entity among 1 tracked system through which rate decisions, infrastructure work, and federal compliance are managed.
Overview
We track water quality and home safety data for 1 ZIP code in Belmont, Massachusetts, covering 1 community water system serving approximately 26,966 people.
1 of 1 ZIP code (100%) have recorded EPA violations. All violations are monitoring/reporting type.
Home Safety Score
Average Home Safety Score for Belmont: C (63/100)
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
Belmont water systems draw from: Surface water.
Lead & Copper
- Average lead level (90th percentile): 0.0015 mg/L (EPA action level: 0.015 mg/L)
- 0 ZIP codes exceed the EPA lead action level
Radon Risk
Dominant radon zone: Zone 1 (High Risk)
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Top Contaminants
| Contaminant | Category | Violations | ZIPs Affected |
|---|---|---|---|
| Stage 1 DBP Rule | Treatment Technique | 2 | 1 |
Areas with Most Violations
| ZIP Code | Safety Score | Violations | Health-Based | System |
|---|---|---|---|---|
| 02478 | C | 1 | 0 | Belmont Water Department (mwra) |
All ZIP Codes in Belmont
- 02478 [C] — 1 violation
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 Belmont
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 Belmont Water
Based on EPA violation records. Check your ZIP code report for system-specific contaminant data.
Housing & Infrastructure in Belmont
With 90% 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
Plumbing risk in older housing is defined by two eras: the pre-1970 period when lead pipes were commonly used for service lines, and the 1970-to-1986 period when lead solder remained standard in copper plumbing until the federal ban. Belmont's median build year of 1901 lands in a range where both eras are heavily represented in the housing stock. That creates an elevated aggregate environment for plumbing-related lead exposure — one that city-level water quality averages don't capture, because the risk sits inside individual properties rather than in the distribution system.
Over half of homes in Belmont 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 Belmont Homeowners
While no remediation project is entirely without cost, the relationship between estimated remediation and property values in Belmont is notably favorable — the equity share is small enough that the household financial perspective is one of proportionality rather than pressure, and most homeowners can treat it as routine planning rather than a significant financial event.
Remediation costs in Belmont are relatively low compared to home values. The $1,600–$3,300 estimated range is a small fraction of median property value. Home values are 97% above the Massachusetts average.
Lead Exposure Risk for Children in Belmont
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.
Older interior plumbing shapes the local picture: 90% of Belmont homes predate the federal solder ban, and aggregate sampling either approaches or crosses the action benchmark. That mix makes a single-home draw a standard pre-purchase or pre-occupancy step.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Flood & Climate Risk in Belmont
The NFIP claim record for Belmont — 32 filed incidents — reflects genuine, recurring flood exposure rather than an isolated event or two. When a community accumulates flood claims at this volume and carries 100% of its ZIP codes inside FEMA-designated zones, flood history starts to factor into water quality planning in ways it doesn't for lower-exposure areas. Flooding introduces specific contamination pathways — runoff overwhelming treatment facility intake, surface water infiltrating private wells, and pressure disruptions in distribution systems allowing backflow — all of which become more relevant as flood frequency increases.
Belmont has a moderate flood history with 32 FEMA claims averaging $7,797 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>$2,400</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 Belmont
- 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 Stage 1 DBP Rule can reduce the most common contaminant found in Belmont's water.
- Check your home's plumbing. With 90% of homes built before 1986, lead solder is a real possibility.
Deep Dive Reports
Detailed analysis for Belmont, MA