City Water Quality Rankings in California
599 cities ranked by drinking water quality.
Popular city water quality comparisons
Trending Cities
#313
Helendale
County, CA
94 A
#314 Hollister
County, CA
94 A
#315 Huntington Beach
County, CA
94 A
#316 Idyllwild
County, CA
94 A
#317 Imperial Beach
County, CA
94 A
#318 Irvine
County, CA
94 A
#319 Joshua Tree
County, CA
94 A
#320 Kerman
County, CA
94 A
#321 Kingsburg
County, CA
94 A
#322 La Canada
County, CA
94 A
#323 La Crescenta
County, CA
94 A
#324 Los Altos Hills
County, CA
94 A
#325 Lower Lake
County, CA
94 A
#326 Mammoth Lakes
County, CA
94 A
#327 Manteca
County, CA
94 A
#328 Mendota
County, CA
94 A
#329 Mi Wuk Village
County, CA
94 A
#330 Morro Bay
County, CA
94 A
#331 Newhall
County, CA
94 A
#332 Oceano
County, CA
94 A
#333 Ojai
County, CA
94 A
#334 Orosi
County, CA
94 A
#335 Palmdale
County, CA
94 A
#336 Paramount
County, CA
94 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.