University of Tehran International Journal of Environmental Research 1735-6865 6 3 2012 06 15 Nitrate and Chloride Concentrations in Groundwater beneath a Portion of the Trinity Group Outcrop Zone, Texas663 668 en P.E. Hudak Department of Geography and Environmental Science Program, University of North Texas, 1155 Union Circle #305279, Denton, TX 76203-5017, USA 2012 06 15