City Water Quality Rankings in California
601 cities ranked by drinking water quality.
Popular city water quality comparisons
Trending Cities
#289
Ukiah
County, CA
96 A
#290 Victorville
County, CA
96 A
#291 Weaverville
County, CA
96 A
#292 Westley
County, CA
96 A
#293 Buena Park
County, CA
95 A
#294 El Monte
County, CA
95 A
#295 Fallbrook
County, CA
95 A
#296 Herlong
County, CA
95 A
#297 Huntington Park
County, CA
95 A
#298 Inverness
County, CA
95 A
#299 Jurupa Valley
County, CA
95 A
#300 Mammoth Lakes
County, CA
95 A
#301 Maxwell
County, CA
95 A
#302 Mckinleyville
County, CA
95 A
#303 Novato
County, CA
95 A
#304 Orange
County, CA
95 A
#305 San Marcos
County, CA
95 A
#306 Soledad
County, CA
95 A
#307 Upland
County, CA
95 A
#308 Westminster
County, CA
95 A
#309 Altadena
County, CA
94 A
#310 Atwater
County, CA
94 A
#311 Avalon
County, CA
94 A
#312 Barstow
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.