City Water Quality Rankings in Illinois
635 cities ranked by drinking water quality.
Popular city water quality comparisons
Trending Cities
#577
Burbank
County, IL
33 F
#578 Port Byron
County, IL
33 F
#579 O'Fallon
County, IL
32 F
#580 West Frankfort
County, IL
32 F
#581 Dolton
County, IL
31 F
#582 Brighton
County, IL
30 F
#583 Goreville
County, IL
30 F
#584 Ford Heights
County, IL
29 F
#585 Highland
County, IL
29 F
#586 La Salle
County, IL
29 F
#587 Altamont
County, IL
28 F
#588 Calumet Park
County, IL
28 F
#589 Christopher
County, IL
28 F
#590 Kewanee
County, IL
28 F
#591 La Harpe
County, IL
28 F
#592 Carthage
County, IL
27 F
#593 Arlington Heights
County, IL
26 F
#594 Winthrop Harbor
County, IL
26 F
#595 Carbon Cliff
County, IL
24 F
#596 Granville
County, IL
24 F
#597 Greenfield
County, IL
24 F
#598 Carbondale
County, IL
23 F
#599 Maywood
County, IL
23 F
#600 Melrose Park
County, IL
22 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.