WaterQ

City Water Quality Rankings in Illinois

635 cities ranked by drinking water quality.

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Popular city water quality comparisons

Alto Pass, IL vs Aurora, IL Compare → Beach Park, IL vs Cahokia Heights, IL Compare → Chatham, IL vs Davis Junction, IL Compare → Evanston, IL vs Forrest, IL Compare →

Trending Cities

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#49
Vernon Hills
County, IL
96 A
#50
Salem
County, IL
95 A
#51
Wayne City
County, IL
95 A
#52
Chebanse
County, IL
94 A
#53
Clayton
County, IL
94 A
#54
Columbia
County, IL
94 A
#55
Freeport
County, IL
94 A
#56
Girard
County, IL
94 A
#57
Havana
County, IL
94 A
#58
Marquette Heights
County, IL
94 A
#59
Mason City
County, IL
94 A
#60
Minonk
County, IL
94 A
#61
New Athens
County, IL
94 A
#62
Odin
County, IL
94 A
#63
Olive Branch
County, IL
94 A
#64
Oquawka
County, IL
94 A
#65
Park Forest
County, IL
94 A
#66
Winchester
County, IL
94 A
#67
Winfield
County, IL
94 A
#68
Decatur
County, IL
93 A
#69
Glen Carbon
County, IL
93 A
#70
Park Ridge
County, IL
93 A
#71
Posen
County, IL
93 A
#72
Bethalto
County, IL
92 A

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.

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