ABSTRACT
The city of Midland, TX is prone to drought and has resorted to the use of groundwater to meet its water demand. However, due to naturally occurring arsenic in aquifer sediments, arsenic concentrations in the extracted groundwater are often above the US EPA maximum contaminant limit of 10 µg/L. The aim of this study is to identify biogeochemical factors which control the mobilization of arsenic from the sediment to the groundwater. Aquifer sediments were collected at a well site up to a depth of 643 ft. Geological and total elemental analyses using XRF and ICPMS indicated co-occurrence of As and Fe, along with S in certain sediment strata. Arsenic speciation and microbial community analyses will be performed to identify the driving factors of As mobilization.
