California
Water Quality Report
90 Excellent
Average Score
90/100
Water Systems
1,081
Population
40.8M
Violations
0 all resolved
Score Distribution
8 A
4 B
1 C
0 D
0 F
Top Contaminant Violations
| Contaminant | Violations |
|---|---|
| Nitrate | 2 |
| Total Trihalomethanes | 1 |
| Atrazine | 1 |
| Nitrite | 1 |
| Chloramine | 1 |
Lowest Scoring Water Systems
69
Riverside Public Utilities C
CA3310001 Riverside, CA 314,998 served
73
City of Anaheim Public Utilities B
CA3010037 Anaheim, CA 353,085 served
77
San Diego County Water Authority B
CA3710020 San Diego, CA 3,300,000 served
81
Metropolitan Water District of Southern California B
CA1910099 Los Angeles, CA 19,000,000 served
89
City of Fresno Water Division B
CA1010001 Fresno, CA 544,510 served
Counties in California
Los Angeles County
3 systems
83 B
San Diego County
2 systems
84 B
Orange County
1 systems
73 B
Riverside County
1 systems
69 C
San Bernardino County
111 systems
66 C
Santa Clara County
1 systems
100 A
Alameda County
1 systems
100 A
Sacramento County
1 systems
93 A
Fresno County
1 systems
89 B
Kern County
1 systems
100 A
Cities in California
View all 601 cities →Popular City Comparisons in California
Quickly compare major cities in California by water quality score and grade.
Frequently Asked Questions
Is tap water in California safe to drink?
California has an average WaterQ score of 90/100 across 1,081 public water systems. Safety can vary by city and system, so check your local report for recent violations and contaminants.
How many water systems are in California?
WaterQ currently tracks 1,081 public water systems in California.
Where can I compare cities in California?
Use the city list below to open detailed reports, or visit the compare tool to benchmark two cities side-by-side on score, grade, and system coverage.