Belmont, CA Water Safety: 78/100 (2026)
1 ZIP code · 2 water systems · Updated 2026-06-03
Drinking water tracked for Belmont by CA authorities posts above-average scores — the majority of systems are free from health-based exceedances and the city's grade sits above the state median.
How Belmont Compares
Data: EPA SDWIS Last verified: 2026-06-03
What You Should Know About Belmont Water
- Average lead level: 0.0027 mg/L.
- Homes built before 1986: 85% — older plumbing may contain lead solder.
- Estimated remediation: $1,600 per household.
- CDC health risk index: 9.58.
Who Supplies Your Water in Belmont
Water delivery in Belmont, CA is handled by 2 utilities rather than a single system — drawn from 2 providers in federal records, each filing its own compliance reports and setting its own rates.
Overview
We track water quality and home safety data for 1 ZIP code in Belmont, California (population ~27,730), covering 2 community water systems serving approximately 123,428 people region-wide.
No EPA violations recorded across any ZIP codes in Belmont — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Belmont: B (78/100)
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): 0.0027 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.
Areas with No Violations
| ZIP Code | Safety Score | System | Population |
|---|---|---|---|
| 94002 | B | Mid-peninsula Water District | 30,609 |
All ZIP Codes in Belmont
- 94002 [B]
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
Housing & Infrastructure in Belmont
With 85% 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
Heavily weighted toward older construction, Belmont's housing stock carries a median build year of 1963. That profile puts a majority of homes in the era when lead-soldered copper plumbing was standard practice.
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 $800–$2,600 estimated range is a small fraction of median property value. Home values are 171% above the California 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.
Routinely in Belmont, where 85% of housing predates the solder ban and aggregate utility readings hover near the federal threshold, a faucet-level draw functions as a standard household step for families with small kids.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Flood & Climate Risk in Belmont
Flood risk in Belmont occupies the middle ground: 29 NFIP claims and 100% of local ZIP codes within FEMA flood zones. At that level, the risk pathways connecting flooding to water quality — treatment system stress, well infiltration, distribution backflow — become relevant considerations during significant flood events, even if day-to-day water quality is unaffected by flood history.
Belmont has a moderate flood history with 29 FEMA claims averaging $6,011 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>$1,600</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.
Deep Dive Reports
Detailed analysis for Belmont, CA