City Water Quality Rankings in Illinois
635 cities ranked by drinking water quality.
Popular city water quality comparisons
Trending Cities
#121
Buffalo Grove
County, IL
89 B
#122 Crystal Lake
County, IL
89 B
#123 Hamilton
County, IL
89 B
#124 Lincolnshire
County, IL
89 B
#125 Lombard
County, IL
89 B
#126 Maryville
County, IL
89 B
#127 Plainfield
County, IL
89 B
#128 Quincy
County, IL
89 B
#129 Sheridan
County, IL
89 B
#130 Aledo
County, IL
88 B
#131 Burr Ridge
County, IL
88 B
#132 Darien
County, IL
88 B
#133 Earlville
County, IL
88 B
#134 Elgin
County, IL
88 B
#135 Evergreen Park
County, IL
88 B
#136 Fox River Grove
County, IL
88 B
#137 Highland Park
County, IL
88 B
#138 Hoopeston
County, IL
88 B
#139 Morrisonville
County, IL
88 B
#140 Morton
County, IL
88 B
#141 Richmond
County, IL
88 B
#142 Walnut
County, IL
88 B
#143 Wheaton
County, IL
88 B
#144 Arthur
County, IL
87 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.