Claremont, CA Water Safety: 83/100 (2026)
1 ZIP code · 8 water systems · Updated 2026-06-03
Looking at federal monitoring data for Claremont, CA: the city clears benchmarks set under the Safe Drinking Water Act with room to spare — recorded exceedances are rare, and the systems serving local households have not triggered any pattern of repeat deficiencies in recent cycles.
How Claremont Compares
Data: EPA SDWIS Last verified: 2026-06-03
Claremont Water: The Quick Version
- Average lead level: 0.0017 mg/L.
- Homes built before 1986: 82% — older plumbing may contain lead solder.
- Estimated remediation: $1,600 per household.
- CDC health risk index: 10.71.
Water Systems Serving Claremont
Structurally, Claremont, CA's water supply is divided. Federal data identifies 8 water systems in the area, with 3 providers serving the bulk of residential connections. These utilities operate independently, meaning rate-setting authority and EPA compliance accountability are distributed rather than centralized.
Overview
We track water quality and home safety data for 1 ZIP code in Claremont, California (population ~37,538), covering 8 community water systems serving approximately 224,566 people region-wide.
No EPA violations recorded across any ZIP codes in Claremont — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Claremont: B (83/100)
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
Claremont water systems draw from: Groundwater, Surface water.
Lead & Copper
- Average lead level (90th percentile): 0.0017 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 |
|---|---|---|---|
| 91711 | B | Three Valleys Mwd | 0 |
All ZIP Codes in Claremont
- 91711 [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.
CDC Health Data for Claremont
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
How Old Is Claremont's Housing Stock?
With 82% 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
When a city's housing median build year is 1963, as in Claremont, the implication for water quality research is straightforward: municipal-level data captures what leaves the treatment plant, but household plumbing from before 1986 determines what actually arrives at the tap. In cities where older housing predominates, that gap between system-level and household-level data is widest.
Over half of homes in Claremont 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.
Claremont: Remediation Cost in Perspective
Across Claremont, the equity share taken up by estimated remediation is small — a favorable ratio for most property owners.
Remediation costs in Claremont are relatively low compared to home values. The $800–$2,600 estimated range is a small fraction of median property value. Home values are 18% above the California average.
Protecting Children from Lead in Claremont
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.
Even where utility-side monitoring meets Lead and Copper Rule requirements, the 82% pre-rule share in Claremont keeps interior-plumbing variation as a household-level question that aggregate data cannot resolve.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Climate-Related Water Risk for Claremont
Flood risk in Claremont occupies the middle ground: 5 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.
Claremont has a moderate flood history with 5 FEMA claims averaging $1,646 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 Claremont, CA