Concord, CA 94520
8 water systems • 198,877 residents
Good water quality with few concerns
Score: 78/100
Graded on EPA violations, contaminants, severity, compliance, and enforcement history. See methodology.
Data updated June 2026 • Sources: EPA ECHO and EPA Envirofacts
10
Contaminants Detected
207
Violations on Record
81
Health-Based Violations
0
Recent Violations
Grade Breakdown
78 / 100 points
Recommended Water Filters
- ✓Point-of-Use Carbon Filter (NSF-certified for lead)
- ✓Reverse Osmosis or Ion Exchange Filter
- ✓Ultraviolet (UV) Purification
Consult a water quality specialist for personalized recommendations.
Concord vs CA & National Average
Detected Contaminants
10 contaminants detected across water systems serving this ZIP code
| Contaminant | Category |
|---|---|
| Nitrate-Nitrite | Agricultural |
| Nitrite | Agricultural |
| Arsenic | Heavy Metal |
| Lead and Copper Rule | Heavy Metal |
| LEAD AND COPPER RULE REVISIONS | Heavy Metal |
| Coliform (TCR) | Microorganism |
| Revised Total Coliform Rule | Microorganism |
| Consumer Confidence Rule | Other |
| Surface Water Treatment Rule | Other |
| Gross Alpha, Excl. Radon and U | Radiological |
Water System Information
- Systems Serving This ZIP:
- RIVER RANCH MOBILE HOME PARK, RANDALL-BOLD WATER TREATMENT PLANT, CCWD/BRENTWOOD WTP, DUNROVIN MOBILE HOME VILLAGE, CONTRA COSTA WATER DISTRICT +3 more
- Population Served:
- 198,877
- Systems With Violations:
- 6 of 8
- Major Violations:
- 18
- Enforcement Actions:
- 188
Frequently Asked Questions
What does the grade mean?
Our A–F grade ranks this ZIP code's water quality against every other analyzed ZIP in the country, based on EPA data. A = among the best, F = among the most troubled.
Is my tap water safe to drink?
Water systems regulated by the EPA must comply with Safe Drinking Water Act standards. However, if you're concerned about water quality, consider a water filter appropriate for your contaminants.
How often is the data updated?
We update our data quarterly with the latest EPA ECHO and Envirofacts data. Historical violations are tracked to identify patterns.
What filters do you recommend?
Filter recommendations are based on detected contaminants in your area. See our Filter Guide for detailed information about different filter types.