Cincinnati
Cincinnati, OH water profile — supply sources, drought status, wastewater reuse, and the key water issues facing the city.
cincinnati public water system
surface water (rivers/reservoirs) · local government · PWSID OH3102612
Below EPA's 15 ppb lead action level at last testing.
Source: EPA Safe Drinking Water Information System (SDWIS) · 2026 Q1
Cincinnati is a large city and the 3rd-largest in Ohio, home to roughly 296,943 residents. Cincinnati's drinking water comes largely from the same regional sources that serve Ohio: Lake Erie, Ohio River, and aquifers.
As elsewhere in Ohio, the central challenge is aging infrastructure. Lake Erie algal blooms, which once shut off Toledo's water, are a recurring quality threat.
Ohio reuses an estimated 3% of its treated wastewater and maintains minimal reuse programs; Cincinnati tracks no meaningful drought conditions on the U.S. Drought Monitor scale.
Explore the Ohio profile for statewide context, or dig into the water issues shaping Cincinnati below.
Hamilton County water quality
Source: EPA SDWIS · 2026 Q1
At a glance
- Population ~296,943 (3rd-largest in Ohio)
- Primary sources: Lake Erie, Ohio River, and aquifers
- Drought: no meaningful conditions
- State reuse rate: ~3% of wastewater
Common questions
Is tap water safe in Cincinnati?
Cincinnati's largest water system, CINCINNATI PUBLIC WATER SYSTEM, serves about 750,200 people. EPA records show 0 health-based violation(s) since 2016 and a most-recent 90th-percentile lead level of 1.4 ppb (EPA action level is 15 ppb). Always check your own provider's annual Consumer Confidence Report.
Where does Cincinnati get its water?
CINCINNATI PUBLIC WATER SYSTEM draws primarily from surface water (rivers/reservoirs), part of Ohio's supply from Lake Erie, Ohio River, 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.
ExplorePFAS Contamination
Per- and polyfluoroalkyl substances persist in water supplies for decades. New federal limits are forcing utilities nationwide to invest in advanced treatment.
ExploreAlgal Blooms
Nutrient pollution and warming water are fueling toxic algae outbreaks that can shut down drinking-water intakes — as Toledo learned in 2014.
ExploreLead Contamination
Millions of lead service lines still connect homes to water mains. After Flint, a national push — backed by new EPA rules — aims to rip them all out.
Explore