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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#73
Lamont
County, CA
100 A
#74
Larkspur
County, CA
100 A
#75
Lathrop
County, CA
100 A
#76
Laytonville
County, CA
100 A
#77
Lincoln
County, CA
100 A
#78
Linden
County, CA
100 A
#79
Littlerock
County, CA
100 A
#80
Live Oak
County, CA
100 A
#81
Livermore
County, CA
100 A
#82
Lockeford
County, CA
100 A
#83
Lod
County, CA
100 A
#84
Loma Linda
County, CA
100 A
#85
Lomita
County, CA
100 A
#86
Los Alamos
County, CA
100 A
#87
Los Osos
County, CA
100 A
#88
Marina
County, CA
100 A
#89
Martinez
County, CA
100 A
#90
Marysville
County, CA
100 A
#91
Maywood
County, CA
100 A
#92
Mckittrick
County, CA
100 A
#93
Millbrae
County, CA
100 A
#94
Moffett Field
County, CA
100 A
#95
Mojave
County, CA
100 A
#96
Moorpark
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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