WaterQ

City Water Quality Rankings in Illinois

631 cities ranked by drinking water quality.

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Popular city water quality comparisons

Alto Pass, IL vs Beach Park, IL Compare → Cahokia Heights, IL vs Chatham, IL Compare → Davis Junction, IL vs Evanston, IL Compare → Freeport, IL vs Groveland, IL Compare →

Trending Cities

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#25
Marseilles
County, IL
99 A
#26
Dupo
County, IL
98 A
#27
East Moline
County, IL
98 A
#28
Minier
County, IL
98 A
#29
Mossville
County, IL
98 A
#30
Virden
County, IL
98 A
#31
Girard
County, IL
97 A
#32
Havana
County, IL
97 A
#33
Lagrange
County, IL
97 A
#34
Okawville
County, IL
97 A
#35
Salem
County, IL
97 A
#36
Sublette
County, IL
97 A
#37
Bunker Hill
County, IL
96 A
#38
Mackinaw
County, IL
96 A
#39
Odell
County, IL
96 A
#40
Olney
County, IL
96 A
#41
Oquawka
County, IL
96 A
#42
Rochester
County, IL
96 A
#43
Roxana
County, IL
96 A
#44
Wayne City
County, IL
96 A
#45
Cerro Gordo
County, IL
95 A
#46
Columbia
County, IL
95 A
#47
Olive Branch
County, IL
95 A
#48
Dowell
County, IL
94 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.

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