Geohydrology and susceptibility of major aquifers to surface contamination in Alabama; area 3

This report delineates and describes the geohydrology and the susceptibility to contamination of the major aquifers in Area 3--Cullman, Fayette, Lamar, Marion, Walker, and Winston Counties , Alabama. The major aquifers in the study area are the Tuscaloosa, Pottsville, and Bangor aquifers. The Pottsville aquifer is the most extensively used in the study area. The aquifer consists of sandstones and conglomerates with fractures and bedding plane openings. The Tuscaloosa aquifer, primarily used in the west and southwest part of the study area, is composed of sands and gravels in the Tuscaloosa Group. The Bangor aquifer, the least used aquifer in the study area, consists of limestone with bedding planes, solution cavaties, and fractures. All three aquifers are recharged throughout their outcrop areas and are susceptible to contamination from the surface within these areas. The Tuscaloosa aquifer is the most susceptible aquifer to contamination within the study area because of the absence of confining layers, shallow depth to the water surface, and relatively uniform porosity and permeability of aquifer materials. The Pottsville and Bangor aquifers are less susceptible to surface contamination than the Tuscaloosa aquifer; generally having lower permeability and receiving less recharge than the Tuscaloosa aquifer thereby making surface contamination less likely. (USGS)