Illinois Water Quality Reports
Comprehensive water quality reports for major cities in Illinois. Access Consumer Confidence Reports, contaminant data, EPA compliance information, and historical trends for water systems across the state.
Illinois Water Quality Overview
Water Sources
Illinois relies primarily on Lake Michigan for Chicago and northeastern suburbs. Central and southern Illinois use the Illinois and Mississippi Rivers, along with groundwater from deep sandstone aquifers. The state has abundant water resources.
Treatment Infrastructure
Chicago operates one of the world's largest water treatment plants using Lake Michigan. Other cities employ conventional filtration and disinfection. Lead service line replacement is a major infrastructure priority across the state.
Key Statistics
Common Contaminants in Illinois
Lead
Major concern in Chicago and older cities with lead service lines. Illinois has aggressive lead service line replacement programs and enhanced monitoring.
Disinfection Byproducts (TTHMs/HAA5)
Common in Lake Michigan and river water systems. Formed when chlorine reacts with organic matter in source water, particularly during warm months.
Radium
Naturally occurring in deep groundwater aquifers. More common in northern Illinois communities using deep sandstone aquifer wells.
Nitrates
Agricultural runoff affects rural areas with shallow wells. Central and southern Illinois agricultural regions most impacted.
PFAS (Forever Chemicals)
Found near military installations, airports, and industrial areas. State has enhanced monitoring and working toward treatment solutions.
Illinois-Specific Regulations
Illinois follows federal EPA regulations and has additional state requirements through the Illinois Environmental Protection Agency:
Lead Service Line Inventory
Requires all community water systems to create comprehensive inventories of lead service lines and prioritize replacement in high-risk areas.
Enhanced Corrosion Control
Stricter requirements for corrosion control treatment to minimize lead leaching from pipes and plumbing fixtures.
Source Water Protection
Enhanced protection for Lake Michigan intake structures and groundwater wellhead protection areas to prevent contamination.
Top 10 Cities - Water Quality Reports
Click any city to view detailed water quality report and Consumer Confidence Report
Historical Water Quality Trends
2020-2024 Improvements
- Accelerated lead service line replacement in Chicago and surrounding communities
- Enhanced PFAS monitoring and treatment upgrades at impacted systems
- Improved radium removal technologies for deep aquifer systems
- Better coordination between water utilities and state regulators
Ongoing Challenges
- Hundreds of thousands of lead service lines still require replacement statewide
- Small rural systems face compliance challenges with radium and nitrate standards
- Climate change affecting Lake Michigan water levels and quality
- Aging water mains and distribution systems need significant investment
Illinois Water Quality Agency Contact
Illinois Environmental Protection Agency
Bureau of Water
1021 North Grand Avenue East
Springfield, IL 62794-9276
Contact Information
Phone: (217) 782-3397
Email: epa.water@illinois.gov
Website: epa.illinois.gov/topics/water-quality
EPA Region 5 (Great Lakes)
77 West Jackson Boulevard, Chicago, IL 60604
Phone: (312) 353-2000 | Toll-free: (800) 621-8431
Frequently Asked Questions
How do I find my Illinois city water quality report?
Select your city from the list above to view its detailed water quality report. Each report includes contaminant levels, source water information, treatment methods, and links to official Consumer Confidence Reports from your local water utility.
What are common water quality issues in Illinois?
Illinois water systems commonly monitor for lead, disinfection byproducts (TTHMs and HAA5), radium, nitrates, and PFAS. Lead from aging infrastructure is a major concern in Chicago and older cities.
Who regulates water quality in Illinois?
Water quality in Illinois is regulated by the Illinois Environmental Protection Agency (EPA), working in conjunction with the federal EPA to ensure drinking water safety standards are met.