Contra Costa Water District
Concord, California · PWSID: CA0710003
Concord Water Quality Summary
Contra Costa Water District supplies drinking water to about 198,000 people in Concord, California, and draws from surface water (rivers, lakes, or reservoirs), which requires fuller treatment for runoff, sediment, and microbial risk. On the IsWaterSafe scale it earns an excellent Water Safety Score of 100 out of 100 (Grade A), a composite of its EPA SDWIS violation and contaminant record.
EPA SDWIS shows no health-based or monitoring violations on record for Contra Costa Water District. Its compliance record is clean across the reported period.
No individual contaminant detections are reported for Contra Costa Water District in the current EPA SDWIS extract; the score reflects its violation and enforcement record alone.
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Detected Contaminants
No contaminant data available.
Violation History
No violations on record.
Frequently Asked Questions
Contra Costa Water District has a Water Safety Score of A (100/100). The system serves 198,000 people and has 0 health violations on record. Check the contaminant table above for specific detected substances.
Contra Costa Water District has 0 contaminant exceedances above EPA health guidelines. See the full contaminant detection table above for all tested substances and their levels relative to legal limits and health guidelines.
The Water Safety Score (0-100, grades A through F) is based on contaminant levels relative to legal limits, health guideline exceedances, violation history, and enforcement actions. Higher scores indicate fewer concerns.
If your water system has violations, request the Consumer Confidence Report from your utility, consider getting an independent water test from a certified lab, and look into certified water filters for specific contaminants of concern. For lead, run cold water for 30 seconds before drinking.
Water quality data sourced from EPA's Safe Drinking Water Information System (SDWIS). Safety scores are calculated based on contaminant levels, violations, and enforcement history. This is not a substitute for your utility's official Consumer Confidence Report.
Source: EPA Ground Water and Drinking Water, 2026.