City Water Quality Rankings in California
599 cities ranked by drinking water quality.
Popular city water quality comparisons
Trending Cities
#241
Hume
County, CA
96 A
#242 Huntington Park
County, CA
96 A
#243 Jamestown
County, CA
96 A
#244 La Puente
County, CA
96 A
#245 Lake Arrowhead
County, CA
96 A
#246 Lakewood
County, CA
96 A
#247 Lompoc
County, CA
96 A
#248 Manhattan Beach
County, CA
96 A
#249 Morgann Hill
County, CA
96 A
#250 Nevada City
County, CA
96 A
#251 Oakland
County, CA
96 A
#252 Orangevale
County, CA
96 A
#253 Palo Alto
County, CA
96 A
#254 Patterson
County, CA
96 A
#255 Phelan
County, CA
96 A
#256 Pine Mountain Club
County, CA
96 A
#257 Point Mugu
County, CA
96 A
#258 Point Reyes Station
County, CA
96 A
#259 Redwood City
County, CA
96 A
#260 Rio Linda
County, CA
96 A
#261 Rohnert Park
County, CA
96 A
#262 San Francisco
County, CA
96 A
#263 San Jose
County, CA
96 A
#264 Santa Ynez
County, CA
96 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.