Guerneville, CA 95446
4 water systems • 9,835 residents
Excellent water quality with minimal contaminants
Score: 97/100
Graded on EPA violations, contaminants, severity, compliance, and enforcement history. See methodology.
Data updated June 2026 • Sources: EPA ECHO and EPA Envirofacts
5
Contaminants Detected
21
Violations on Record
6
Health-Based Violations
0
Recent Violations
Grade Breakdown
97 / 100 points
Recommended Water Filters
- ✓Point-of-Use Carbon Filter (NSF-certified for lead)
- ✓Ultraviolet (UV) Purification
- ✓Activated Carbon Filter (disinfection byproducts)
Consult a water quality specialist for personalized recommendations.
Guerneville vs CA & National Average
Detected Contaminants
5 contaminants detected across water systems serving this ZIP code
| Contaminant | Category |
|---|---|
| Total Haloacetic Acids (HAA5) | Disinfection Byproduct |
| TTHM | Disinfection Byproduct |
| Lead and Copper Rule | Heavy Metal |
| Coliform (TCR) | Microorganism |
| Revised Total Coliform Rule | Microorganism |
Water System Information
- Systems Serving This ZIP:
- RAMBLING HILLS ESTATES, SWEETWATER SPRINGS CWD - MONTE RIO, SWEETWATER SPRINGS CWD - GUERNEVILLE, ODD FELLOWS RECREATION CLUB
- Population Served:
- 9,835
- Systems With Violations:
- 3 of 4
- Major Violations:
- 2
- Enforcement Actions:
- 21
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.