City Water Quality Rankings in California
601 cities ranked by drinking water quality.
Popular city water quality comparisons
Trending Cities
#433
Olivehurst
County, CA
90 A
#434 Ontario
County, CA
90 A
#435 San Juan Bautista
County, CA
90 A
#436 Santa Rosa
County, CA
90 A
#437 Santa Ysabel
County, CA
90 A
#438 Selma
County, CA
90 A
#439 Shingle Springs
County, CA
90 A
#440 Tustin
County, CA
90 A
#441 Villa Park
County, CA
90 A
#442 Weed
County, CA
90 A
#443 Brooks
County, CA
89 B
#444 Carnelian Bay
County, CA
89 B
#445 Green Valley Lake
County, CA
89 B
#446 Hilmar
County, CA
89 B
#447 La Grange
County, CA
89 B
#448 Oakdale
County, CA
89 B
#449 Placerville
County, CA
89 B
#450 Plymouth
County, CA
89 B
#451 Tehachapi
County, CA
89 B
#452 Angelus Oaks
County, CA
88 B
#453 Big Pine
County, CA
88 B
#454 Clearlake Oak
County, CA
88 B
#455 Cobb
County, CA
88 B
#456 Earlimart
County, CA
88 B
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.