Vulnerability assessment of the Trinity Aquifer in Texas due to sulfonamides antibiotics leaching to groundwater for

Texas has the largest population of cattle farming and the highest production of poultry farming across the United States. In northeastern region, antibiotics have been widely used in Concentrated Animal Feeding Operations (CAFO) as veterinary pharmaceuticals (VP). Not fully metabolized and excreted antibiotics have caused soil pollution and resulted groundwater contamination. Sulfonamides’ high excretion rate from animals, low sorption to soils, and impact on nitrate-reducing bacteria for nitrate reduction capabilities, enhance leaching and secondary pollution from inherent nitrate-N contamination. However, there is a limited understanding of sulfonamides transport from the surface to groundwater. This research assessed the Trinity Aquifer vulnerability by incorporating major hydrogeological factors that affect and control the groundwater contamination using GIS-based DRASTIC along with major chemical factors using HYDRUS solute transport modeling. The study reclassified and refined subareas with different vulnerability potentials by overlaying various spatially referenced digital data layers. Additionally, sulfonamides transport was simulated for different vulnerable scenarios to estimate persistence of the antibiotic and potential concentrations reaching the aquifer, developing predicted methods to prevent, mitigate and remediate groundwater contamination caused by sulfonamides antibiotics.