San Ysidro, CA Water Safety: 66/100 (2026)
2 ZIP codes · 3 water systems · Updated 2026-06-03
Safe water is the norm across most of San Ysidro, CA — but documented violations push the city to the middle safety tier.
How San Ysidro Compares
Data: EPA SDWIS Last verified: 2026-06-03
San Ysidro's Water Providers
Residential addresses in San Ysidro, CA are served by 3 primary water providers out of 3 systems in federal records. Each system maintains separate infrastructure and files its own EPA compliance reports, so service conditions are not uniform across the city.
Overview
We track water quality and home safety data for 2 ZIP codes in San Ysidro, California (population ~26,507), covering 3 community water systems serving approximately 1,491,617 people region-wide.
No EPA violations recorded across any ZIP codes in San Ysidro — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for San Ysidro: C (66/100)
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 Ysidro water systems draw from: Groundwater, Surface water.
Lead & Copper
- Lead data: not yet available for San Ysidro
- 0 ZIP codes exceed the EPA lead action level
Radon Risk
Dominant radon zone: Zone 3 (Low Risk)
- Zone 1 (High): 0 ZIP codes
- Zone 2 (Moderate): 0 ZIP codes
- Zone 3 (Low): 2 ZIP codes
Areas with No Violations
| ZIP Code | Safety Score | System | Population |
|---|---|---|---|
| 92143 | C | LOS TULES MUTUAL WATER COMPANY | 238 |
| 92173 | C | SAN DIEGO, CITY OF | 1,385,379 |
All ZIP Codes in San Ysidro
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.
San Ysidro Community Health Snapshot
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
What You Can Do in San Ysidro
- 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. An NSF-certified pitcher or under-sink filter removes most common contaminants.
- Check your home's plumbing. Homes built before 1986 may have lead solder in pipes. A licensed plumber can assess your risk.
Deep Dive Reports
Detailed analysis for San Ysidro, CA