Introduction The Sparta aquifer is an aquifer of regional importance within the Mississippi embayment aquifer system. It consists of varying amounts of unconsolidated sand, inter-stratified with silt and clay lenses within the Sparta Sand of the Claiborne Group. It extends from south Texas, north into Louisiana, Arkansas, and Tennessee, and eastward into Mississippi and Alabama (fig. 1). On both the west and east sides of the Mississippi embayment, the Sparta aquifer is exposed at the surface (outcrops) and is locally unconfined; it becomes confined as it dips toward the axis of the embayment, (generally corresponding with the Mississippi River) and southward toward the Gulf of Mexico where it is deeply buried in the subsurface (Hosman, 1968). Generalized ground-water flow in the Sparta aquifer is from the outcrop areas to the axis (center) of the embayment (fig. 2). In Arkansas, the Sparta aquifer outcrops parallel to the Fall Line at the western extreme of the Mississippi embayment (the Fall Line is a line dividing the mountainous highlands of Arkansas from the lowland area); and the formation dips from its outcrop area to the southeast. The Sparta aquifer supplies water for municipalities, industries such as paper production, and to a lesser degree, irrigation of agricultural crops (fig. 3). This report highlights hydrologic conditions of the aquifer in Arkansas County as an example of how water use is affecting water levels.