Naperville
Naperville, IL water profile — supply sources, drought status, wastewater reuse, and the key water issues facing the city.
naperville
surface water (rivers/reservoirs) · local government · PWSID IL0434670
Below EPA's 15 ppb lead action level at last testing.
Source: EPA Safe Drinking Water Information System (SDWIS) · 2026 Q1
With about 147,100 residents, Naperville ranks as the 5th-largest city in Illinois and a mid-sized city. Water in Naperville is sourced chiefly from Lake Michigan, Mississippi River, and deep aquifers, the backbone of Illinois's supply.
The defining water pressure here mirrors the state's: aging infrastructure. Lake Michigan provides Chicago abundant supply, but suburban communities pumping deep aquifers face declining levels.
Statewide, Illinois recycles about 5% of its wastewater with minimal reuse programs. Locally, Naperville faces abnormally dry to moderate drought conditions.
The Illinois state profile covers the regional supply outlook; the issues below detail what's driving Naperville's water future.
DuPage County water quality
Source: EPA SDWIS · 2026 Q1
At a glance
- Population ~147,100 (5th-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 Naperville?
Naperville's largest water system, NAPERVILLE, serves about 156,406 people. EPA records show 0 health-based violation(s) since 2016 and a most-recent 90th-percentile lead level of 7.1 ppb (EPA action level is 15 ppb). Always check your own provider's annual Consumer Confidence Report.
Where does Naperville get its water?
NAPERVILLE 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.
Explore