City Water Quality Rankings in California
599 cities ranked by drinking water quality.
Popular city water quality comparisons
Trending Cities
#553
Portola
County, CA
69 C
#554 Pine Grove
County, CA
68 C
#555 Vista
County, CA
68 C
#556 Chico
County, CA
67 C
#557 Hayfork
County, CA
67 C
#558 Lebec
County, CA
66 C
#559 Signal Hill
County, CA
66 C
#560 Tulare
County, CA
65 C
#561 Lancaster
County, CA
64 C
#562 Tuolumne
County, CA
64 C
#563 Porterville
County, CA
63 C
#564 Banning
County, CA
62 C
#565 Salinas
County, CA
62 C
#566 Temecula
County, CA
61 C
#567 Chino
County, CA
56 D
#568 Pine Valley
County, CA
55 D
#569 Huron
County, CA
53 D
#570 Mcfarland
County, CA
52 D
#571 Colusa
County, CA
50 D
#572 Hilmar
County, CA
50 D
#573 Montclair
County, CA
50 D
#574 Corning
County, CA
49 D
#575 Norco
County, CA
49 D
#576 San Jacinto
County, CA
47 D
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.