City Water Quality Rankings in Illinois
635 cities ranked by drinking water quality.
Popular city water quality comparisons
Trending Cities
#241
Desoto
County, IL
80 B
#242 Dixon
County, IL
80 B
#243 East Dundee
County, IL
80 B
#244 Geneseo
County, IL
80 B
#245 Geneva
County, IL
80 B
#246 Glencoe
County, IL
80 B
#247 Hillside
County, IL
80 B
#248 Lacon
County, IL
80 B
#249 Lake Villa
County, IL
80 B
#250 Louisville
County, IL
80 B
#251 Mahomet
County, IL
80 B
#252 Monticello
County, IL
80 B
#253 North Lake
County, IL
80 B
#254 South Chicago Heights
County, IL
80 B
#255 Toledo
County, IL
80 B
#256 Westville
County, IL
80 B
#257 Antioch
County, IL
79 B
#258 Frankfort
County, IL
79 B
#259 Genoa
County, IL
79 B
#260 Gilman
County, IL
79 B
#261 Glenview
County, IL
79 B
#262 Granite City
County, IL
79 B
#263 Lincoln
County, IL
79 B
#264 Rossville
County, IL
79 B
Frequently Asked Questions
How are city water quality rankings calculated in Illinois?
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 Illinois?
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.