City Water Quality Rankings in Illinois
631 cities ranked by drinking water quality.
Popular city water quality comparisons
Trending Cities
#553
Lemont
County, IL
35 F
#554 Manteno
County, IL
35 F
#555 Monee
County, IL
35 F
#556 Vandalia
County, IL
35 F
#557 Brighton
County, IL
33 F
#558 West Frankfort
County, IL
32 F
#559 Carlinville
County, IL
30 F
#560 La Salle
County, IL
30 F
#561 Port Byron
County, IL
29 F
#562 Benton
County, IL
28 F
#563 Buffalo
County, IL
28 F
#564 Christopher
County, IL
28 F
#565 Ford Heights
County, IL
28 F
#566 Manhattan
County, IL
28 F
#567 Vienna
County, IL
28 F
#568 Peoria Heights
County, IL
27 F
#569 Carthage
County, IL
26 F
#570 O'Fallon
County, IL
26 F
#571 Wilmington
County, IL
25 F
#572 Carbon Cliff
County, IL
24 F
#573 Elgin
County, IL
24 F
#574 Granville
County, IL
24 F
#575 Coal City
County, IL
23 F
#576 Benld
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.