City Water Quality Rankings in California
599 cities ranked by drinking water quality.
Popular city water quality comparisons
Trending Cities
#145
Baldwin Park
County, CA
98 A
#146 Bloomington
County, CA
98 A
#147 Blue Lake
County, CA
98 A
#148 Boron
County, CA
98 A
#149 Borrego Springs
County, CA
98 A
#150 Chester
County, CA
98 A
#151 Cold Springs
County, CA
98 A
#152 Colton
County, CA
98 A
#153 Corte Madera
County, CA
98 A
#154 Del Mar
County, CA
98 A
#155 Desert Hot Springs
County, CA
98 A
#156 East Palo Alto
County, CA
98 A
#157 El Centro
County, CA
98 A
#158 Elmira
County, CA
98 A
#159 Esparto
County, CA
98 A
#160 Fortuna
County, CA
98 A
#161 Galt
County, CA
98 A
#162 Gilroy
County, CA
98 A
#163 Grass Valley
County, CA
98 A
#164 Grover Beach
County, CA
98 A
#165 Half Moon Bay
County, CA
98 A
#166 Hawthorne
County, CA
98 A
#167 Hillsborough
County, CA
98 A
#168 La Verne
County, CA
98 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.