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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#409
Earlimart
County, CA
90 A
#410
Fall River Mills
County, CA
90 A
#411
Farmersville
County, CA
90 A
#412
Fowler
County, CA
90 A
#413
Green Valley
County, CA
90 A
#414
Happy Camp
County, CA
90 A
#415
La Habra
County, CA
90 A
#416
Laton
County, CA
90 A
#417
Los Banos
County, CA
90 A
#418
Merced
County, CA
90 A
#419
Middletown
County, CA
90 A
#420
Mira Loma
County, CA
90 A
#421
Montague
County, CA
90 A
#422
Mount Hermon
County, CA
90 A
#423
Oakdale
County, CA
90 A
#424
Oceanside
County, CA
90 A
#425
Olivehurst
County, CA
90 A
#426
Ontario
County, CA
90 A
#427
Planada
County, CA
90 A
#428
Red Bluff
County, CA
90 A
#429
Represa
County, CA
90 A
#430
Santa Rosa
County, CA
90 A
#431
Santa Ysabel
County, CA
90 A
#432
Seeley
County, CA
90 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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