City Water Quality Rankings in California
599 cities ranked by drinking water quality.
Popular city water quality comparisons
Trending Cities
#169
Laguna Beach
County, CA
98 A
#170 Larkspur
County, CA
98 A
#171 Littlerock
County, CA
98 A
#172 Los Molinos
County, CA
98 A
#173 Mariposa
County, CA
98 A
#174 Menlo Park
County, CA
98 A
#175 Midway City
County, CA
98 A
#176 Modesto
County, CA
98 A
#177 Monrovia
County, CA
98 A
#178 Moreno Valley
County, CA
98 A
#179 Pacifica
County, CA
98 A
#180 Palm Desert
County, CA
98 A
#181 Petaluma
County, CA
98 A
#182 Pinedale
County, CA
98 A
#183 Pittsburg
County, CA
98 A
#184 Rancho Cordova
County, CA
98 A
#185 Rancho Santa Margarita
County, CA
98 A
#186 Reedley
County, CA
98 A
#187 Santee
County, CA
98 A
#188 Scotts Valley
County, CA
98 A
#189 Solvang
County, CA
98 A
#190 South San Francisco
County, CA
98 A
#191 Susanville
County, CA
98 A
#192 Sutter
County, CA
98 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.