The Sparta aquifer is Union County's only source of municipal and industrial ground water. Since development began in the early 1920's ground-water levels have declined more than 390 feet in some areas. As a result, Union was among five southern Arkansas counties designated as the state's first "Critical Ground Water Area" in 1996.
The U.S. Geological Survey, in partnership with the Union County Water Conservation Board that formed in 1999 and the Union County Conservation District, is conducting a 5-year Sparta Aquifer Recovery Study in southern Arkansas and northern Louisiana. Collecting data from 29 study wells in the five South Arkansas Critical Water counties and four contiguous North Louisiana parishes, the Study is documenting aquifer recovery resulting from completion of the Board's Ouachita River Alternative Water Supply Project. In 2004 and 2005, the project converted two major industrial users from ground to surface water, and partially converted a third. The project, along with other conservation measures that have been implemented in Union County, Arkansas over the past several years, have reduced ground water consumption by approximately 50 percent, and are designed to restore the aquifer to a sustainable level.