City Water Quality Rankings in California
599 cities ranked by drinking water quality.
Popular city water quality comparisons
Trending Cities
#361
Pleasanton
County, CA
93 A
#362 San Andreas
County, CA
93 A
#363 San Bernardino
County, CA
93 A
#364 San Dimas
County, CA
93 A
#365 Terra Bella
County, CA
93 A
#366 Anderson
County, CA
92 A
#367 Burlingame
County, CA
92 A
#368 Calabasas
County, CA
92 A
#369 Citrus Heights
County, CA
92 A
#370 Clovis
County, CA
92 A
#371 Cottonwood
County, CA
92 A
#372 Cudahy
County, CA
92 A
#373 Grand Terrace
County, CA
92 A
#374 Healdsburg
County, CA
92 A
#375 Holtville
County, CA
92 A
#376 La Palma
County, CA
92 A
#377 Lodi
County, CA
92 A
#378 Long Beach
County, CA
92 A
#379 Montara
County, CA
92 A
#380 Oxnard
County, CA
92 A
#381 Placentia
County, CA
92 A
#382 Rancho Cucuamonga
County, CA
92 A
#383 Rancho Murieta
County, CA
92 A
#384 Riverbank
County, CA
92 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.