Jefferson County had an estimated population of 662,507 in 1999 with 99 percent on public water. The estimated 2008 population was 717,762 with 97 percent served by a water utility. In areas not served by public water, half the households use wells and half use other sources.
The Water Resource Development Commission has prepared a report on water-supply infrastructure in the county.
It is estimated that there are over 200,000 water wells in Kentucky.
The Kentucky Groundwater Data Repository, maintained by the Kentucky
Geological Survey, has information on over 50,000 of these wells. The
locations of wells and springs in the county for which data are available
is shown on the map
of wells and springs in the county. Certified well drillers in Kentucky.