City Water Quality Rankings in California
601 cities ranked by drinking water quality.
Popular city water quality comparisons
Trending Cities
#505
Calistoga
County, CA
84 B
#506 Livingston
County, CA
84 B
#507 Los Alamitos
County, CA
84 B
#508 Olympic Valley
County, CA
84 B
#509 Parlier
County, CA
84 B
#510 Pomona
County, CA
84 B
#511 St. Helena
County, CA
84 B
#512 Tahoe City
County, CA
84 B
#513 West Sacramento
County, CA
84 B
#514 Ione
County, CA
83 B
#515 Lakeside
County, CA
83 B
#516 Paicines
County, CA
83 B
#517 Sea Ranch
County, CA
83 B
#518 South Lake Tahoe
County, CA
83 B
#519 Talmage
County, CA
83 B
#520 Alturas
County, CA
82 B
#521 Biggs
County, CA
82 B
#522 Ceres
County, CA
82 B
#523 Fairfield
County, CA
82 B
#524 Hydesville
County, CA
82 B
#525 Ivanhoe
County, CA
82 B
#526 June Lake
County, CA
82 B
#527 Paso Robles
County, CA
82 B
#528 Sanger
County, CA
82 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.