Chicago drinking water comes from a mix of groundwater and surface water sources. Based on the most recent monitoring data, 9 contaminants have been detected in the water supply, including Lead, Nitrate, Arsenic, Copper, and 5 others. PFAS testing has been conducted with no detections. Water hardness is 136 mg/L (hard), which is within a typical range for the region.
Contaminants detected in Chicago water
9 total
Detection does not necessarily mean unsafe levels. See individual reports for concentrations and EPA limits.
Chicago tap water meets EPA legal standards (Maximum Contaminant Levels). However, 4 contaminants are present above independent health guidelines, which are often stricter than legal limits. 9 contaminants have been detected in the water supply, including Lead, Nitrate, Arsenic, Copper, Radium. View the detailed report for each water system to see specific levels and how they compare to both legal limits and health guidelines.
What contaminants are in Chicago water?
Monitoring has detected 9 contaminants in Chicago's water supply: Lead, Nitrate, Arsenic, Copper, Radium, Total Trihalomethanes, Haloacetic Acids (HAA5), Barium, Fluoride. 4 exceed health guidelines. See individual system reports for concentrations relative to EPA limits.
Does Chicago water have PFAS?
Chicago's water has been tested for PFAS compounds with no detections. Testing was conducted as part of the EPA's Unregulated Contaminant Monitoring Rule (UCMR5) program.
Is Chicago water hard?
Yes. Chicago water has a hardness of 136 mg/L (hard). Hard water is not a health concern but can cause scale buildup in water heaters and appliances, reduce soap effectiveness, and leave mineral deposits. Water softeners or conditioning systems can address hardness.
Where does Chicago get its drinking water?
Chicago's drinking water comes from a combination of groundwater and surface water sources. The water is treated and tested according to Illinois EPA and EPA requirements before distribution. Chicago is served by 11 water systems, the largest being CHICAGO (serving 2,721,308 people).
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