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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#481
St. Charles
County, IL
58 D
#482
Woodstock
County, IL
58 D
#483
Zeigler
County, IL
58 D
#484
Bement
County, IL
57 D
#485
Waukegan
County, IL
57 D
#486
Wyoming
County, IL
57 D
#487
Bushnell
County, IL
56 D
#488
Elburn
County, IL
56 D
#489
Harvard
County, IL
56 D
#490
Pontiac
County, IL
56 D
#491
Warsaw
County, IL
56 D
#492
Dawson
County, IL
55 D
#493
Duquoin
County, IL
55 D
#494
Mokena
County, IL
55 D
#495
Annapolis
County, IL
54 D
#496
Batavia
County, IL
54 D
#497
Divernon
County, IL
54 D
#498
Forest Park
County, IL
54 D
#499
Galena
County, IL
54 D
#500
Herscher
County, IL
54 D
#501
Riverside
County, IL
54 D
#502
Rock Falls
County, IL
54 D
#503
St Elmo
County, IL
54 D
#504
Warrensburg
County, IL
54 D

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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