City Water Quality Rankings in Illinois
631 cities ranked by drinking water quality.
Popular city water quality comparisons
Trending Cities
#97
Greenup
County, IL
90 A
#98 Hartford
County, IL
90 A
#99 Island Lake
County, IL
90 A
#100 Lanark
County, IL
90 A
#101 Momence
County, IL
90 A
#102 Mt Vernon
County, IL
90 A
#103 Neoga
County, IL
90 A
#104 Petersburg
County, IL
90 A
#105 Plainfield
County, IL
90 A
#106 Pleasant Plains
County, IL
90 A
#107 Chebanse
County, IL
89 B
#108 Lakemoor
County, IL
89 B
#109 Lincolnshire
County, IL
89 B
#110 Maryville
County, IL
89 B
#111 Sheridan
County, IL
89 B
#112 Vernon Hills
County, IL
89 B
#113 Aledo
County, IL
88 B
#114 Bethany
County, IL
88 B
#115 Burr Ridge
County, IL
88 B
#116 Clarendon Hills
County, IL
88 B
#117 Earlville
County, IL
88 B
#118 Evergreen Park
County, IL
88 B
#119 Fox River Grove
County, IL
88 B
#120 Highland Park
County, IL
88 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.