City Water Quality Rankings in Illinois
631 cities ranked by drinking water quality.
Popular city water quality comparisons
Trending Cities
#481
Colchester
County, IL
52 D
#482 Lindenhurst
County, IL
52 D
#483 Dieterich
County, IL
51 D
#484 Murphysboro
County, IL
51 D
#485 Round Lake Beach
County, IL
51 D
#486 Western Springs
County, IL
51 D
#487 Illiopolis
County, IL
50 D
#488 Marion
County, IL
50 D
#489 Mt Carroll
County, IL
50 D
#490 Pinckneyville
County, IL
50 D
#491 Rochelle
County, IL
50 D
#492 Savanna
County, IL
50 D
#493 Monmouth
County, IL
49 D
#494 Rockdale
County, IL
49 D
#495 Washburn
County, IL
49 D
#496 Burnham
County, IL
48 D
#497 Carmi
County, IL
48 D
#498 Crete
County, IL
48 D
#499 Virginia
County, IL
48 D
#500 Lansing
County, IL
47 D
#501 Sparta
County, IL
47 D
#502 Sugar Grove
County, IL
47 D
#503 Valmeyer
County, IL
47 D
#504 Capron
County, IL
46 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.