City Water Quality Rankings in Illinois
631 cities ranked by drinking water quality.
Popular city water quality comparisons
Trending Cities
#577
Dolton
County, IL
22 F
#578 Kewanee
County, IL
22 F
#579 Melrose Park
County, IL
22 F
#580 Arlington Heights
County, IL
20 F
#581 Ingleside
County, IL
20 F
#582 Highland
County, IL
19 F
#583 Greenfield
County, IL
18 F
#584 Markham
County, IL
18 F
#585 Fairfield
County, IL
16 F
#586 Winthrop Harbor
County, IL
15 F
#587 Makanda
County, IL
14 F
#588 Toulon
County, IL
14 F
#589 St Anne
County, IL
13 F
#590 Calumet Park
County, IL
10 F
#591 New Berlin
County, IL
10 F
#592 Carbondale
County, IL
9 F
#593 Eldorado
County, IL
8 F
#594 Joliet
County, IL
8 F
#595 Durand
County, IL
6 F
#596 Huntley
County, IL
5 F
#597 Anna
County, IL
4 F
#598 Buncombe
County, IL
4 F
#599 Galva
County, IL
4 F
#600 Gardner
County, IL
4 F
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.