City Water Quality Rankings in California
601 cities ranked by drinking water quality.
Popular city water quality comparisons
Trending Cities
#49
Fair Oaks
County, CA
100 A
#50 Felton
County, CA
100 A
#51 Folsom
County, CA
100 A
#52 Foster City
County, CA
100 A
#53 Fountain Valley
County, CA
100 A
#54 Garberville
County, CA
100 A
#55 Garden Grove
County, CA
100 A
#56 Gerber
County, CA
100 A
#57 Glendale
County, CA
100 A
#58 Granite Bay
County, CA
100 A
#59 Grizzly Flats
County, CA
100 A
#60 Gualala
County, CA
100 A
#61 Hesperia
County, CA
100 A
#62 Hidden Valley Lake
County, CA
100 A
#63 Kelseyville
County, CA
100 A
#64 Keyes
County, CA
100 A
#65 Kirkwood
County, CA
100 A
#66 La Canada Flintridge
County, CA
100 A
#67 La Habra Heights
County, CA
100 A
#68 La Mesa
County, CA
100 A
#69 Laguna Hills
County, CA
100 A
#70 Lake Arrowhead
County, CA
100 A
#71 Lake Elsinore
County, CA
100 A
#72 Lake Forest
County, CA
100 A
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.