City Water Quality Rankings in Illinois
631 cities ranked by drinking water quality.
Popular city water quality comparisons
Trending Cities
#361
Chester
County, IL
66 C
#362 Cicero
County, IL
66 C
#363 Des Plaines
County, IL
66 C
#364 East Dundee
County, IL
66 C
#365 Eureka
County, IL
66 C
#366 Glenwood
County, IL
66 C
#367 Knoxville
County, IL
66 C
#368 Lake Zurich
County, IL
66 C
#369 Mendota
County, IL
66 C
#370 Warrenville
County, IL
66 C
#371 Yorkville
County, IL
66 C
#372 Albers
County, IL
65 C
#373 Elwood
County, IL
65 C
#374 Griggsville
County, IL
65 C
#375 Lakewood
County, IL
65 C
#376 Mchenry
County, IL
65 C
#377 Mcleansboro
County, IL
65 C
#378 Nashville
County, IL
65 C
#379 Oak Brook
County, IL
65 C
#380 Roanoke
County, IL
65 C
#381 Taylorville
County, IL
65 C
#382 Warren
County, IL
65 C
#383 Waterman
County, IL
65 C
#384 Wonder Lake
County, IL
65 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.