WaterQ

City Water Quality Rankings in Illinois

635 cities ranked by drinking water quality.

All States AL AK AZ AR CA CO CT DE FL GA HI ID IL IN IA KS KY LA ME MD MA MI MN MS MO MT NE NV NH NJ NM NY NC ND OH OK OR PA RI SC SD TN TX UT VT VA WA WV WI WY

Popular city water quality comparisons

Alto Pass, IL vs Aurora, IL Compare → Beach Park, IL vs Cahokia Heights, IL Compare → Chatham, IL vs Davis Junction, IL Compare → Evanston, IL vs Forrest, IL Compare →

Trending Cities

Fairbanks, AK Fresno, CA San Jose, CA Sacramento, CA San Francisco, CA Houston, TX Fargo, ND
#1
Alto Pass
County, IL
100 A
#2
Aurora
County, IL
100 A
#3
Beach Park
County, IL
100 A
#4
Cahokia Heights
County, IL
100 A
#5
Chatham
County, IL
100 A
#6
Davis Junction
County, IL
100 A
#7
Evanston
County, IL
100 A
#8
Forrest
County, IL
100 A
#9
Groveland
County, IL
100 A
#10
Hardin
County, IL
100 A
#11
Heyworth
County, IL
100 A
#12
Hoffman Estates
County, IL
100 A
#13
Jacksonville
County, IL
100 A
#14
Lancaster
County, IL
100 A
#15
Maroa
County, IL
100 A
#16
Newton
County, IL
100 A
#17
Oakbrook Terrace
County, IL
100 A
#18
Oblong
County, IL
100 A
#19
Okawville
County, IL
100 A
#20
Payson
County, IL
100 A
#21
Round Lake Heights
County, IL
100 A
#22
Somonauk
County, IL
100 A
#23
Sumner
County, IL
100 A
#24
Tamms
County, IL
100 A

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.

Explore More Water Quality Data

State Rankings National Rankings Compare Cities All Water Systems