City Water Quality Rankings in Illinois
635 cities ranked by drinking water quality.
Popular city water quality comparisons
Trending Cities
#505
Washburn
County, IL
54 D
#506 Morris
County, IL
53 D
#507 Moweaqua
County, IL
53 D
#508 Tinley Park
County, IL
53 D
#509 Chrisman
County, IL
52 D
#510 Colchester
County, IL
52 D
#511 Lansing
County, IL
52 D
#512 Lindenhurst
County, IL
52 D
#513 Midlothian
County, IL
52 D
#514 Marseilles
County, IL
51 D
#515 Milford
County, IL
51 D
#516 Sparta
County, IL
51 D
#517 Mt Carroll
County, IL
50 D
#518 Murrayville
County, IL
50 D
#519 Pinckneyville
County, IL
50 D
#520 Savanna
County, IL
50 D
#521 South Roxana
County, IL
50 D
#522 Capron
County, IL
49 D
#523 Eldorado
County, IL
49 D
#524 Murphysboro
County, IL
49 D
#525 Nauvoo
County, IL
49 D
#526 Carmi
County, IL
48 D
#527 Johnsburg
County, IL
48 D
#528 Monmouth
County, IL
48 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.