Chico, CA 95927
19 water systems • 21,155 residents
Good water quality with few concerns
Score: 63/100
Graded on EPA violations, contaminants, severity, compliance, and enforcement history. See methodology.
Data updated June 2026 • Sources: EPA ECHO and EPA Envirofacts
15
Contaminants Detected
782
Violations on Record
468
Health-Based Violations
0
Recent Violations
Grade Breakdown
63 / 100 points
Recommended Water Filters
- ✓Point-of-Use Carbon Filter (NSF-certified for lead)
- ✓Reverse Osmosis or Ion Exchange Filter
- ✓Ultraviolet (UV) Purification
- ✓Activated Carbon Filter (disinfection byproducts)
Consult a water quality specialist for personalized recommendations.
Chico vs CA & National Average
Detected Contaminants
15 contaminants detected across water systems serving this ZIP code
| Contaminant | Category |
|---|---|
| Nitrate | Agricultural |
| Nitrate-Nitrite | Agricultural |
| Total Haloacetic Acids (HAA5) | Disinfection Byproduct |
| COPPER, FREE | Heavy Metal |
| Lead and Copper Rule | Heavy Metal |
| Coliform (TCR) | Microorganism |
| Revised Total Coliform Rule | Microorganism |
| CARBON, TOTAL | Other |
| Consumer Confidence Rule | Other |
| Interim Enhanced Surface Water Treatment Rule | Other |
| Surface Water Treatment Rule | Other |
| Combined Radium (-226 and -228) | Radiological |
| Combined Uranium | Radiological |
| Gross Alpha, Excl. Radon and U | Radiological |
| Benzene | Volatile Organic |
Water System Information
- Systems Serving This ZIP:
- DEL ORO WATER CO.-JOHNSON PARK, DEL ORO CALIFORNIA PINES DISTRICT, DEL ORO WATER CO.-STIRLING BLUFFS, DEL ORO WATER COMPANY - STRAWBERRY DIV., DEL ORO WATER COMPANY - BUZZTAIL DIST. +5 more
- Population Served:
- 21,155
- Systems With Violations:
- 18 of 19
- Major Violations:
- 62
- Enforcement Actions:
- 688
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.