City Water Quality Rankings in California
601 cities ranked by drinking water quality.
Popular city water quality comparisons
Trending Cities
#577
Montclair
County, CA
50 D
#578 Thermal
County, CA
50 D
#579 Corning
County, CA
49 D
#580 Jamul
County, CA
47 D
#581 San Jacinto
County, CA
47 D
#582 Havasu Lake
County, CA
44 F
#583 Chino Hills
County, CA
40 F
#584 Le Grand
County, CA
36 F
#585 Valley Center
County, CA
32 F
#586 Richgrove
County, CA
30 F
#587 Alpine
County, CA
24 F
#588 Lemoore
County, CA
24 F
#589 Needles
County, CA
23 F
#590 North Edwards
County, CA
20 F
#591 Dos Palos
County, CA
9 F
#592 Campo
County, CA
2 F
#593 Cutler
County, CA
0 F
#594 El Cajon
County, CA
0 F
#595 Friant
County, CA
0 F
#596 Geyserville
County, CA
0 F
#597 Hoopa
County, CA
0 F
#598 Hughson
County, CA
0 F
#599 Linsday
County, CA
0 F
#600 Loleta
County, CA
0 F
Frequently Asked Questions
How are city water quality rankings calculated in California?
WaterQ city rankings are based on EPA SDWIS data across local public water systems, including contaminant detections, compliance violations, and recency-weighted score signals.
Can I compare two cities in California?
Yes. Use the city comparison links on this page or open the Compare tool to evaluate two cities side by side on score, grade, and water system coverage.
How often does WaterQ refresh city data?
City-level metrics refresh when new EPA data is processed. Check city pages for latest score and violation context.