Not health advice. Contact your local water utility for concerns.
Data from EPA Water Quality Reports. For official information, contact your water utility or health department.
Illinois Water Quality Reports
Water quality scores for 60 cities in Illinois
Romeoville
39,983 residents
Naperville
149,013 residents
Peoria
113,150 residents
Crystal Lake
39,164 residents
Wheeling
38,785 residents
Joliet
150,362 residents
Tinley Park
55,971 residents
St. Charles
34,084 residents
Calumet City
36,033 residents
Carpentersville
37,983 residents
Quincy
39,463 residents
Arlington Heights
77,676 residents
Champaign
88,302 residents
Moline
42,017 residents
Bartlett
41,105 residents
Galesburg
29,141 residents
Berwyn
54,016 residents
Bolingbrook
75,201 residents
Granite City
27,549 residents
Oak Lawn
55,245 residents
Park Ridge
39,584 residents
Schaumburg
78,723 residents
Elmhurst
47,686 residents
North Chicago
29,128 residents
Carol Stream
39,711 residents
Des Plaines
58,364 residents
Buffalo Grove
42,909 residents
Evanston
78,110 residents
Orland Park
59,717 residents
Chicago
2,746,388 residents
Decatur
70,522 residents
Downers Grove
49,540 residents
Rockford
148,655 residents
Springfield
114,394 residents
Waukegan
89,321 residents
Wheaton
53,970 residents
Glenview
48,705 residents
Elgin
114,797 residents
Urbana
42,214 residents
Danville
30,479 residents
Cicero
80,796 residents
Gurnee
30,706 residents
Lombard
44,048 residents
Addison
36,650 residents
Normal
54,264 residents
Bloomington
78,680 residents
Rock Island
37,651 residents
Streamwood
39,577 residents
Algonquin
31,630 residents
Mount Prospect
56,265 residents
Skokie
67,824 residents
DeKalb
43,849 residents
Oak Park
54,318 residents
Plainfield
44,762 residents
Hoffman Estates
51,895 residents
Aurora
177,564 residents
Belleville
41,097 residents
Palatine
69,350 residents
Oswego
34,485 residents
Hanover Park
38,510 residents
About Illinois Water Quality
Illinois water quality varies from Chicago's treated Lake Michigan water to rural communities relying on groundwater. The state's agricultural industry significantly impacts water quality in many regions, while older urban areas face infrastructure challenges. Illinois has been working to address both legacy contamination and emerging concerns.
Based on our analysis of 60 cities in Illinois, the average water quality score is 79/100. 15 cities have water quality scores below 70, indicating potential concerns that residents should be aware of. The highest-rated city is Hanover Park with a score of 47/100, while Romeoville has the most room for improvement at 98/100.
Water Sources in Illinois
Lake Michigan provides high-quality source water for Chicago and many suburban communities. The Illinois and Mississippi rivers serve other regions. Central and southern Illinois rely more heavily on groundwater and smaller surface water sources. Private wells serve many rural residents.
Common Water Contaminants in Illinois
These contaminants have been detected in various Illinois water systems
Illinois Water Regulations
Illinois EPA manages drinking water programs with standards generally aligned with federal requirements. The state has made significant investments in lead service line replacement, particularly in Chicago. Illinois has been addressing PFAS contamination and improving notification requirements.
Health Considerations
Chicago and other older communities face significant lead service line concerns. Agricultural regions should monitor nitrate and pesticide levels. Some areas have naturally occurring radium in groundwater. Industrial areas may have specific contamination issues requiring attention.
Recommendations for Illinois Residents
Illinois residents in older homes should determine if they have lead service lines and consider certified lead removal filters. Rural residents should test private wells annually. Consider activated carbon filtration for agricultural chemical removal. Stay informed about your local water utility's infrastructure improvement plans.
Frequently Asked Questions About Illinois Water Quality
Is Illinois's tap water safe to drink?
Water quality in Illinois varies by location. Our analysis shows an average score of 79/100 across 60 cities, with 15 cities showing potential concerns. We recommend checking your specific city's water quality report and considering filtration if needed.
What are the main water quality concerns in Illinois?
The most common water quality concerns in Illinois include lead (aging infrastructure), atrazine (agricultural runoff), nitrates (agricultural areas). These contaminants can come from natural sources, industrial activities, or aging infrastructure. Review your city's specific report to see which contaminants affect your area.
Should I use a water filter in Illinois?
Whether you need a water filter depends on your specific location and health concerns. With 15 cities in Illinois showing elevated contaminant levels, residents in those areas may benefit from filtration. Look for filters certified by NSF/ANSI to remove the specific contaminants found in your area.
Where can I find my Illinois water quality report?
Public water systems in Illinois are required to provide annual Consumer Confidence Reports (CCRs) to residents. You can usually find your report on your water utility's website, request it by phone, or access it through the EPA's database. Our city-level reports above summarize key information from these official sources.