Salinity in the northern segment of the Brazos River Alluvium Aquifer : a hydro-forensic approach.
The Brazos River Alluvium Aquifer is a minor aquifer in central and east Texas under water table conditions. It is an underutilized resource and may be considered a supplemental water source. However, variability in salinity occurs throughout the Brazos River Alluvium Aquifer and the source of this variability is unclear. The objective of this study is to characterize the variability of salinity in the northern segment of the Brazos River Alluvium Aquifer and evaluate potential sources of elevated salinity. Three potential sources of elevated salinity were evaluated: Interactions between the aquifer and the river, concentration from irrigation, and brine contamination from historic oil and gas fields. Based on the ionic and isotopic composition of aquifer and river samples, in-situ water samples, core descriptions, batch leaching of sediment, and hydrographs, the Brazos River and historic oil and gas fields do not appear to be the source of elevated salinity for the aquifer; although, irrigation could impact aquifer salinity.