WaterQ

City Water Quality Rankings in California

601 cities ranked by drinking water quality.

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Popular city water quality comparisons

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Trending Cities

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#25
Cabazon
County, CA
100 A
#26
Calimesa
County, CA
100 A
#27
Camp Meeker
County, CA
100 A
#28
Carlsbad
County, CA
100 A
#29
Carpinteria
County, CA
100 A
#30
Castaic
County, CA
100 A
#31
Cayucos
County, CA
100 A
#32
Cedarpines Park
County, CA
100 A
#33
Cerritos
County, CA
100 A
#34
Claremont
County, CA
100 A
#35
Cold Springs
County, CA
100 A
#36
Concord
County, CA
100 A
#37
Corcoran
County, CA
100 A
#38
Costa Mesa
County, CA
100 A
#39
Cutten
County, CA
100 A
#40
Del Rey
County, CA
100 A
#41
Denair
County, CA
100 A
#42
Discovery Bay
County, CA
100 A
#43
Dixon
County, CA
100 A
#44
Dublin
County, CA
100 A
#45
El Segundo
County, CA
100 A
#46
Elk Grove
County, CA
100 A
#47
Escondido
County, CA
100 A
#48
Eureka
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.

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