EVALUATING DEEP GROUNDWATER CONTRIBUTIONS TO SHORT TERM ELEMENT CYCLING

Calculations of fluxes in common elements (C, N, P, Fe, etc.) on the surface of Earth generally do not account for the contribution of deep confined groundwater mining. Deep confined groundwaters frequently do not exist in equilibrium with atmospheric conditions and would, if not for human removal, exist only in long term storage on geologic time scales. Human mining of such aquifers for water sources essentially removes dissolved gases and minerals from deep time sequestration and returns them to short term cycling. This project seeks to examine the rates of removal and the volumes of such minerals and gases removed from long term storage through water sampling at deep aquifer wells (using the Trinity Aquifer in Texas as an illustration) across the flow path of the aquifer and using the PHREEQ-C aqueous equilibrium program with the results of titrations and standard ion analyses.