San Marino, CA Water Safety: 75/100 (2026)
2 ZIP codes · 4 water systems · Updated 2026-06-03
The water systems supplying San Marino show a track record of above-average compliance with federal standards — consistently among the better performers in CA.
How San Marino Compares
Data: EPA SDWIS Last verified: 2026-06-03
San Marino Water: The Quick Version
- Average lead level: 0.008 mg/L.
- Estimated remediation: $2,300 per household.
- CDC health risk index: 10.71.
Water Systems Serving San Marino
4 water systems are tracked federally in San Marino, CA. The top 3 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 2 ZIP codes in San Marino, California (population ~12,464), covering 4 community water systems serving approximately 237,695 people region-wide.
No EPA violations recorded across any ZIP codes in San Marino — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for San Marino: B (75/100)
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
San Marino water systems draw from: Groundwater.
Lead & Copper
- Average lead level (90th percentile): 0.0080 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)
- Zone 1 (High): 0 ZIP codes
- Zone 2 (Moderate): 2 ZIP codes
- Zone 3 (Low): 0 ZIP codes
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Areas with No Violations
| ZIP Code | Safety Score | System | Population |
|---|---|---|---|
| 91108 | B | Pasadena Water and Power | 164,344 |
| 91118 | B | Lodi Lake Mobile Home Park | 104 |
All ZIP Codes in San Marino
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 San Marino
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
San Marino: Remediation Cost in Perspective
How much of a San Marino home's value does documented remediation represent? A small fraction — the equity share here is in the low tier, and from a household financial perspective, most property owners are considering a commitment that fits comfortably within standard planning rather than a decision that rises to the level of a material budget event or significant equity consideration.
Remediation costs in San Marino are relatively low compared to home values. The $1,500–$3,300 estimated range is a small fraction of median property value. Home values are 171% above the California average.
Protecting Children from Lead in San Marino
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.
Lead risk in San Marino appears low overall, but individual homes may differ. Testing is the only way to confirm your water's lead content.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Climate-Related Water Risk for San Marino
Flood exposure in San Marino is meaningful by NFIP measures — 3 claims on record and 50% 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.
San Marino has a moderate flood history with 3 FEMA claims. 50% 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>$2,300</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 San Marino, CA