Jefferson County, Kentucky: drinking water report. Jefferson County – Louisville – serves about 780,000 residents.
Jefferson County – Louisville – serves about 780,000 residents. Louisville Water Company draws from the Ohio River, operating a treatment system that has earned national recognition for water quality. The utility was the first in the US to receive the Partnership for Safe Water's excellence award for 20 consecutive years – a track record that few utilities can match.
The Ohio River at Louisville carries the accumulated discharges of communities and industries upstream, but Louisville Water Company's advanced treatment – including riverbank filtration, ozone, and biologically active carbon – produces a finished product that consistently wins taste tests against other Ohio River communities.
UCMR5 data shows low-level PFAS detections in the Louisville system. Kentucky does not have state-specific PFAS MCLs. According to the Kentucky Division of Water's 2024 compliance data, Louisville Water Company met all federal standards with significant margin. The utility's proactive treatment approach means it handles emerging contaminants that many other Ohio River utilities do not yet address.
Louisville Water Company's treatment is among the best on the Ohio River. The main household variable is your building's internal plumbing.
Check your water for data in your area. For most Louisville residents, the supply is clean. A basic carbon filter improves chlorine taste. Our water filter guide covers options. Pull your detailed report, and visit our Kentucky page for statewide data.