City Water Quality Rankings in Illinois
631 cities ranked by drinking water quality.
Popular city water quality comparisons
Trending Cities
#193
Thomasboro
County, IL
83 B
#194 Troy
County, IL
83 B
#195 Byron
County, IL
82 B
#196 Camp Point
County, IL
82 B
#197 Centralia
County, IL
82 B
#198 Depue
County, IL
82 B
#199 Hamel
County, IL
82 B
#200 Hudson
County, IL
82 B
#201 Manito
County, IL
82 B
#202 Oakwood
County, IL
82 B
#203 Rosemont
County, IL
82 B
#204 Whittington
County, IL
82 B
#205 Dixon
County, IL
81 B
#206 Glenview
County, IL
81 B
#207 Henry
County, IL
81 B
#208 Indian Head Park
County, IL
81 B
#209 Lena
County, IL
81 B
#210 Marshall
County, IL
81 B
#211 Palos Heights
County, IL
81 B
#212 Cambria
County, IL
80 B
#213 Carrier Mills
County, IL
80 B
#214 Countryside
County, IL
80 B
#215 Crossville
County, IL
80 B
#216 Davis
County, IL
80 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.