WaterQ

City Water Quality Rankings in California

599 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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#121
Soquel
County, CA
100 A
#122
Spring Valley
County, CA
100 A
#123
Stanford
County, CA
100 A
#124
Templeton
County, CA
100 A
#125
Thermal
County, CA
100 A
#126
Thousand Oaks
County, CA
100 A
#127
Trona
County, CA
100 A
#128
Vernon
County, CA
100 A
#129
Waterford
County, CA
100 A
#130
Westwood
County, CA
100 A
#131
Wheatland
County, CA
100 A
#132
Whittier
County, CA
100 A
#133
Williams
County, CA
100 A
#134
Windsor
County, CA
100 A
#135
Winters
County, CA
100 A
#136
Yuba City
County, CA
100 A
#137
Auburn
County, CA
99 A
#138
Encinitas
County, CA
99 A
#139
Lost Hills
County, CA
99 A
#140
Oroville
County, CA
99 A
#141
Palomar Mountain
County, CA
99 A
#142
Vallejo
County, CA
99 A
#143
Alhambra
County, CA
98 A
#144
Angwin
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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