Chicago, Illinois Water Quality Report
Population: 2,746,388 | Last Updated: 1/14/2024
Overall Water Quality Grade
Based on compliance rates, contaminant levels, and treatment effectiveness
Water Sources
Chicago receives its drinking water from one primary source:
Lake Michigan
100%Surface Water
Pristine Lake Michigan water drawn from intake cribs 2 miles offshore at depths of 20-30 feet
Detected Contaminants
All contaminants listed below are within legal limits, but some may exceed health guidelines.
| Contaminant | Detected Level | Legal Limit | Health Goal | Status | Trend |
|---|---|---|---|---|---|
| Lead | 3.8 ppb | 15 ppb | 0 ppb | Below Legal Limit | ↓ improving |
| Total Trihalomethanes (TTHMs) | 38 ppb | 80 ppb | 0 ppb | Below Legal Limit | → stable |
| Haloacetic Acids (HAA5) | 22 ppb | 60 ppb | 0 ppb | Below Legal Limit | → stable |
| Chlorine | 0.9 ppm | 4 ppm | 4 ppm | Optimal | → stable |
Comparison with Illinois State Average
Lead Compliance
4.0 points above state average
Bacterial Compliance
2.0 points above state average
Chemical Compliance
2.0 points above state average
Overall Score
6.0 points above state average
Water Quality Trends
Overall water quality score over the past 5 years
Water quality has improved by 3.0 points since 2019
Contamination History
Lead Service Line Concerns
Growing awareness of lead service lines throughout Chicago, estimated 400,000+ homes affected
Resolution:
Launched lead service line replacement program, free water testing for residents, corrosion control optimization
Microplastics Detection
Study found microplastics in Lake Michigan, Chicago's water source
Resolution:
Enhanced filtration systems proven effective at removing microplastics, ongoing monitoring program established
Frequently Asked Questions - Chicago Water Quality
Is Chicago tap water safe to drink?
Yes, Chicago's tap water is among the best in the country. Lake Michigan provides an excellent source, and the city operates two world-class treatment plants that process over 1 billion gallons daily. The water meets or exceeds all federal and state standards.
Does Chicago have a lead problem in its water?
The water leaving Chicago's treatment plants contains no lead. However, Chicago has approximately 400,000 lead service lines connecting homes to the water mains. The city adds orthophosphate for corrosion control and offers free water testing. A gradual replacement program is underway.
Why does my Chicago tap water sometimes taste like chlorine?
Chicago uses chlorine for disinfection to ensure water safety throughout its distribution system. Chlorine levels are carefully monitored and kept at safe levels (0.5-1.2 ppm). If taste is a concern, refrigerating water or using a carbon filter can reduce chlorine taste.
How does Chicago protect Lake Michigan water quality?
Chicago draws water from intake cribs located 2 miles offshore and 20-30 feet deep, away from shoreline pollution. The city also invests heavily in green infrastructure to reduce stormwater runoff and participates in Great Lakes protection initiatives.
Is Chicago water hard or soft?
Chicago water is moderately hard at about 135 mg/L. This hardness comes from natural minerals in Lake Michigan and is safe to drink. Hard water may leave mineral deposits on fixtures but provides beneficial calcium and magnesium.
Nearby Water Utilities
Compare water quality in nearby cities:
Evanston, IL
Oak Park, IL
Cicero, IL
Naperville, IL
Utility Information
Water Provider
Chicago Department of Water Management
Contact Information
Customer Service: 312-744-4420
Emergency: 311
Data Disclaimer
This water quality report is compiled from publicly available data and annual water quality reports. For the most current information, please contact your local water utility or visit their official website. Last updated: 1/14/2024.