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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.
Water quality scores for 60 cities in Illinois
See the top 20 cities with the cleanest, safest drinking water
Complete water quality rankings for every city in Illinois
39,983 residents
149,013 residents
113,150 residents
39,164 residents
38,785 residents
150,362 residents
55,971 residents
34,084 residents
36,033 residents
37,983 residents
39,463 residents
77,676 residents
88,302 residents
42,017 residents
41,105 residents
29,141 residents
54,016 residents
75,201 residents
27,549 residents
55,245 residents
39,584 residents
78,723 residents
47,686 residents
29,128 residents
39,711 residents
58,364 residents
42,909 residents
78,110 residents
59,717 residents
2,746,388 residents
70,522 residents
49,540 residents
148,655 residents
114,394 residents
89,321 residents
53,970 residents
48,705 residents
114,797 residents
42,214 residents
30,479 residents
80,796 residents
30,706 residents
44,048 residents
36,650 residents
54,264 residents
78,680 residents
37,651 residents
39,577 residents
31,630 residents
56,265 residents
67,824 residents
43,849 residents
54,318 residents
44,762 residents
51,895 residents
177,564 residents
41,097 residents
69,350 residents
34,485 residents
38,510 residents
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.
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.
These contaminants have been detected in various Illinois water systems
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.
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.
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.
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.
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.
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.
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.
Lead can be present in Illinois water, primarily from older plumbing infrastructure. Homes built before 1986 may have lead pipes or lead solder. While water treatment plants remove lead, it can leach into water from service lines and home plumbing. Check your city's specific report for lead testing data, and consider having your tap water tested if you live in an older home.
PFAS ("forever chemicals") have been detected in water systems across the United States, including in Illinois. These chemicals are associated with industrial sites, military bases, and firefighting foam use. The EPA has set new PFAS limits effective 2024. Check individual Illinois city reports for PFAS testing results in your area.
Based on our analysis, Hanover Park has the highest water quality score in Illinois at 47/100 (Grade F). However, "best" depends on your specific health concerns. View our Best Water Quality in Illinois page for a complete ranking.
Public water systems in Illinois are required by the EPA to test water regularly. Testing frequency depends on the contaminant: bacteria testing occurs daily to weekly, while chemical contaminants may be tested quarterly or annually. Results are published in annual Consumer Confidence Reports. Our site aggregates this data from EPA's SDWIS database.
Compare water quality across counties and find data for your area