WaterQ

City Water Quality Rankings in Illinois

631 cities ranked by drinking water quality.

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Popular city water quality comparisons

Alto Pass, IL vs Beach Park, IL Compare → Cahokia Heights, IL vs Chatham, IL Compare → Davis Junction, IL vs Evanston, IL Compare → Freeport, IL vs Groveland, IL Compare →

Trending Cities

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#337
Belvidere
County, IL
69 C
#338
Herrin
County, IL
69 C
#339
Moline
County, IL
69 C
#340
Oak Lawn
County, IL
69 C
#341
Rock Island
County, IL
69 C
#342
Wauconda
County, IL
69 C
#343
Bensenville
County, IL
68 C
#344
Caseyville
County, IL
68 C
#345
East Peoria
County, IL
68 C
#346
Elmwood
County, IL
68 C
#347
Harrisburg
County, IL
68 C
#348
Johnston City
County, IL
68 C
#349
Long Grove
County, IL
68 C
#350
Mattoon
County, IL
68 C
#351
Romeoville
County, IL
68 C
#352
Winnetka
County, IL
68 C
#353
Chatsworth
County, IL
67 C
#354
Coal Valley
County, IL
67 C
#355
Danvers
County, IL
67 C
#356
Matteson
County, IL
67 C
#357
Waukegan
County, IL
67 C
#358
Zion
County, IL
67 C
#359
Ashland
County, IL
66 C
#360
Broadview
County, IL
66 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.

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