City Water Quality Rankings in Illinois
631 cities ranked by drinking water quality.
Popular city water quality comparisons
Trending Cities
#505
Elmwood Park
County, IL
46 D
#506 Gorham
County, IL
46 D
#507 Midlothian
County, IL
46 D
#508 New Burnside
County, IL
46 D
#509 Norridge
County, IL
46 D
#510 Prophetstown
County, IL
46 D
#511 Clinton
County, IL
45 D
#512 Downs
County, IL
45 D
#513 Elkville
County, IL
45 D
#514 Grayville
County, IL
45 D
#515 Milford
County, IL
45 D
#516 Mt. Morris
County, IL
45 D
#517 Collinsville
County, IL
44 F
#518 Dixmoor
County, IL
44 F
#519 Enfield
County, IL
44 F
#520 Murrayville
County, IL
44 F
#521 Plano
County, IL
44 F
#522 Polo
County, IL
44 F
#523 Chrisman
County, IL
43 F
#524 Mount Prospect
County, IL
43 F
#525 North Chicago
County, IL
43 F
#526 Prospect Heights
County, IL
43 F
#527 Aviston
County, IL
42 F
#528 Johnsburg
County, IL
42 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.