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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#313
Blairsden
County, CA
94 A
#314
Buellton
County, CA
94 A
#315
China Lake
County, CA
94 A
#316
Corona
County, CA
94 A
#317
Cotati
County, CA
94 A
#318
Cottonwood
County, CA
94 A
#319
Covina
County, CA
94 A
#320
Crestline
County, CA
94 A
#321
Davis
County, CA
94 A
#322
Durham
County, CA
94 A
#323
El Verano
County, CA
94 A
#324
Escalon
County, CA
94 A
#325
Fillmore
County, CA
94 A
#326
Firebaugh
County, CA
94 A
#327
Fontana
County, CA
94 A
#328
Frazier Park
County, CA
94 A
#329
Guadalupe
County, CA
94 A
#330
Helendale
County, CA
94 A
#331
Hemet
County, CA
94 A
#332
Hollister
County, CA
94 A
#333
Holtville
County, CA
94 A
#334
Huntington Beach
County, CA
94 A
#335
Imperial Beach
County, CA
94 A
#336
Irvine
County, CA
94 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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