Waltham, MA: 8 Violations — 62/100 (2026)
4 ZIP codes · 2 water systems · Updated 2026-06-03
Waltham, MA: middle-tier water safety by the latest federal monitoring.
How Waltham Compares
Data: EPA SDWIS Last verified: 2026-06-03
What You Should Know About Waltham Water
- Your city's water systems recorded 8 violations in the past 5 years.
- Average lead level: 0.0019 mg/L.
- Homes built before 1986: 75% — older plumbing may contain lead solder.
- Estimated remediation: $2,250 per household.
- CDC health risk index: 9.88.
Who Supplies Your Water in Waltham
2 water systems are tracked federally in Waltham, MA. The top 2 providers collectively serve most residential addresses, but because they operate independently, infrastructure maintenance standards and compliance histories differ from one service zone to another.
Overview
We track water quality and home safety data for 4 ZIP codes in Waltham, Massachusetts, covering 2 community water systems serving approximately 64,640 people.
4 of 4 ZIP codes (100%) have recorded EPA violations. All violations are monitoring/reporting type.
Home Safety Score
Average Home Safety Score for Waltham: C (62/100)
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
Waltham water systems draw from: Groundwater, Surface water.
Lead & Copper
- Average lead level (90th percentile): 0.0019 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)
- Zone 1 (High): 4 ZIP codes
- Zone 2 (Moderate): 0 ZIP codes
- Zone 3 (Low): 0 ZIP codes
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Top Contaminants
| Contaminant | Category | Violations | ZIPs Affected |
|---|---|---|---|
| Contaminant 4002 | Other | 5 | 4 |
| Consumer Confidence Report Rule | Reporting | 5 | 4 |
Areas with Most Violations
| ZIP Code | Safety Score | Violations | Health-Based | System |
|---|---|---|---|---|
| 02451 | C | 2 | 0 | Waltham Water Department |
| 02452 | C | 2 | 0 | Waltham Water Department |
| 02453 | C | 2 | 0 | Waltham Water Department |
| 02454 | C | 2 | 0 | Waltham Water Department |
All ZIP Codes in Waltham
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 Waltham
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 Waltham Water
Based on EPA violation records. Check your ZIP code report for system-specific contaminant data.
Housing & Infrastructure in Waltham
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
Reading the housing age data for Waltham — median build year 1960 — the overriding implication is that the plumbing materials inside a typical home here reflect pre-1986 construction standards. In practical terms, that means lead-soldered copper joints are common across much of the housing stock. Where those materials are present, water can leach lead as it moves through joints — a pathway that corrosion control treatment under federal rules is designed to reduce, though it cannot eliminate lead risk where the plumbing materials themselves contain lead.
Over half of homes in Waltham 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 Waltham Homeowners
When remediation costs are measured against Waltham home values, the resulting ratio is in the low tier — addressing documented water and safety issues here claims only a minor fraction of typical equity, and most homeowners are in a position where the financial commitment is straightforward rather than a material burden on their household budget.
Remediation costs in Waltham are relatively low compared to home values. The $1,500–$3,025 estimated range is a small fraction of median property value. Home values are 26% above the Massachusetts average.
Lead Exposure Risk for Children in Waltham
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.
75% of Waltham housing dates to the pre-rule era, alongside aggregate readings hovering at the federal action mark — household-level confirmation through a draw-test kit fits the local picture.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Flood & Climate Risk in Waltham
FEMA data shows 75% of Waltham's ZIP codes mapped into designated flood zones, paired with an NFIP record of 155 claims. That footprint places local flood exposure in the range where it warrants attention without rising to high-severity planning territory.
Waltham has a moderate flood history with 155 FEMA claims averaging $16,910 per payout. 75% 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>$2,250</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 Waltham
- 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 4002 can reduce the most common contaminant found in Waltham'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 Waltham, MA