WaterQ

City Water Quality Rankings in California

601 cities ranked by drinking water quality.

Popular city water quality comparisons

Trending Cities

#169
Bellflower
County, CA
98 A
#170
Boron
County, CA
98 A
#171
Borrego Springs
County, CA
98 A
#172
Carmichael
County, CA
98 A
#173
Chester
County, CA
98 A
#174
Colton
County, CA
98 A
#175
Corte Madera
County, CA
98 A
#176
Del Mar
County, CA
98 A
#177
Desert Hot Springs
County, CA
98 A
#178
East Palo Alto
County, CA
98 A
#179
El Centro
County, CA
98 A
#180
Elmira
County, CA
98 A
#181
Esparto
County, CA
98 A
#182
Fortuna
County, CA
98 A
#183
Galt
County, CA
98 A
#184
Grover Beach
County, CA
98 A
#185
Half Moon Bay
County, CA
98 A
#186
Hawthorne
County, CA
98 A
#187
Hillsborough
County, CA
98 A
#188
La Verne
County, CA
98 A
#189
Laguna Beach
County, CA
98 A
#190
Lompoc
County, CA
98 A
#191
Los Molinos
County, CA
98 A
#192
Mariposa
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.

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