CALIFORNIA WATER SERVICE - SAN MATEO Water Quality Report
Population
102,348
people served
Water Source
🌊 Surface
rivers, lakes, reservoirs
National Rank
Top 43%
of 49,184 US systems
5-Year Record
✅ Clean
no violations
A
Safe
Safety Grade
0 violations in the past 5 years, including 2 health-based
System Details
- PWSID
- CA4110008
- Population Served
- 102,348
- Water Source
- Surface Water
- Owner
- Private
- State
- California
- EPA Region
- 9
Contaminants of Concern
| Contaminant | Status | Violations |
|---|---|---|
| Contaminant 3100 | ✕ Health-Based | 2 |
Violation History
1992
2
Total violations on record: 2
Service Area
Cities Served
ZIP Codes Served
How does this compare?
This systemNational average
Grade A
Avg: B-C
2violations total
7% of national average
National avg: ~28 per system
🏙️ This is a large system — serving 15× more people than the national average.