Chicago
Chicago, IL water profile — supply sources, drought status, wastewater reuse, and the key water issues facing the city.
chicago
surface water (rivers/reservoirs) · local government · PWSID IL0316000
Below EPA's 15 ppb lead action level at last testing.
Source: EPA Safe Drinking Water Information System (SDWIS) · 2026 Q1
Chicago, IL is one of the largest cities in the United States, with a population near 2,720,546 and the largest community in Illinois. Like much of Illinois, Chicago draws its water primarily from Lake Michigan, Mississippi River, and deep aquifers.
Chicago's water outlook is shaped most by aging infrastructure — the issue that dominates planning across Illinois. Lake Michigan provides Chicago abundant supply, but suburban communities pumping deep aquifers face declining levels.
Chicago sits in a state that reuses roughly 5% of treated wastewater (minimal programs) and currently experiences abnormally dry to moderate drought.
For the bigger picture, see the Illinois state water profile and the related issues below.
Cook County water quality
Source: EPA SDWIS · 2026 Q1
At a glance
- Population ~2,720,546 (largest in Illinois)
- Primary sources: Lake Michigan, Mississippi River, and deep aquifers
- Drought: abnormally dry to moderate conditions
- State reuse rate: ~5% of wastewater
Statewide drought history
% of Illinois in severe+ drought (Moderate (D1) now).
Source: U.S. Drought Monitor
Common questions
Is tap water safe in Chicago?
Chicago's largest water system, CHICAGO, serves about 2,746,388 people. EPA records show 0 health-based violation(s) since 2016 and a most-recent 90th-percentile lead level of 8.8 ppb (EPA action level is 15 ppb). Always check your own provider's annual Consumer Confidence Report.
Where does Chicago get its water?
CHICAGO draws primarily from surface water (rivers/reservoirs), part of Illinois's supply from Lake Michigan, Mississippi River, deep aquifers.
Related water issues
Aging Infrastructure
Much of America's water infrastructure is decades past its design life, leaking trillions of gallons a year and demanding hundreds of billions in reinvestment.
ExploreGroundwater Depletion
Aquifers from the Central Valley to the Ogallala are being pumped faster than they recharge, causing land subsidence and threatening long-term supply.
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