This report delineates and describes the geohydrology and susceptibility of major aquifers to contamination in Area 10--Choctaw, Clarke, and Washington Counties in southwest Alabama. The major aquifers in the study area are the Nanafalia-Clayton, Lisbon, and Pliocene-Miocene aquifers of Tertiary age. The recharge areas for these aquifers generally coincide with their areas of use. Each aquifer is a source of public water supply in one or more of the three counties. All recharge areas for the major aquifers are susceptible to contamination from the surface. However, large parts of the recharge areas are rural areas that are used for timberlands, farms, and pastures; these areas have low potential for contamination and are several miles from pumping centers. (USGS)