Union County had an estimated population of 14,824 (5,865 households) in 1999; projected population is 17,300 (6,600 households) in 2020. Public water is provided to about 90 percent of the county's residents. In areas of the county not served by public water, nearly all the households rely on private domestic wells. One customer will be added to public water service through proposed new line extensions from 2000 to 2020. If all the proposed water line extensions are made, about 10 percent of the county will still rely on private water supplies in the year 2020.
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.