City Water Quality Rankings in Illinois
635 cities ranked by drinking water quality.
Popular city water quality comparisons
Trending Cities
#409
Lake Zurich
County, IL
66 C
#410 Mcleansboro
County, IL
66 C
#411 Merrionette Park
County, IL
66 C
#412 Mount Vernon
County, IL
66 C
#413 South Elgin
County, IL
66 C
#414 Swansea
County, IL
66 C
#415 Warrenville
County, IL
66 C
#416 Wonder Lake
County, IL
66 C
#417 Yorkville
County, IL
66 C
#418 Beardstown
County, IL
65 C
#419 Dixmoor
County, IL
65 C
#420 Green Oaks
County, IL
65 C
#421 Griggsville
County, IL
65 C
#422 Lexington
County, IL
65 C
#423 Nashville
County, IL
65 C
#424 Wilmette
County, IL
65 C
#425 Woodridge
County, IL
65 C
#426 Zion
County, IL
65 C
#427 Atwood
County, IL
64 C
#428 Bridgeview
County, IL
64 C
#429 Coulterville
County, IL
64 C
#430 Downs
County, IL
64 C
#431 Huntley
County, IL
64 C
#432 Justice
County, IL
64 C
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.