TY - JOUR ID - 366 TI - Spatial Distribution of Solutes in Aquifer Outcrop Zones along the Brazos River, East-Central Texas JO - International Journal of Environmental Research JA - IJER LA - en SN - 1735-6865 AU - Hudak, P.F. AD - Department of Geography and Environmental Science Program, University of North Texas 1155 Union Circle #305279, Denton, TX 76203-5017, USA Y1 - 2011 PY - 2011 VL - 5 IS - 3 SP - 595 EP - 602 KW - Brazos River KW - Texas KW - Groundwater KW - agriculture KW - Oil/gas production DO - 10.22059/ijer.2011.366 N2 - Concentrations of several solutes – nitrate, arsenic, sulfate, boron, chloride, and bromide – along with total dissolved solids (TDS) in ten counties bordering the Brazos River in east-central Texas were compiled, mapped, and analyzed relative to regional land use and geology. Agriculture and oil/gas production are major activities and potential sources of groundwater contamination in the study area. Data were compiled from 104 water wells with a median depth of 446 ft (136 m) in the outcrop zones of six sedimentary aquifers: Carizzo-Wilcox, Queen City, Sparta, Yegua-Jackson, Gulf Coast, and Brazos Alluvium. Only two observations surpassed the 44.3 mg/L drinking water standard for nitrate, and four observations exceeded the 10 ug/L standard for arsenic. The median chloride concentration was 53 mg/L; however, the maximum level was almost three times the secondary drinking water standard of 250 mg/L. Chloride, bromide, sulfate, and boron concentrations resembled TDS patterns, with numerous samples exceeding secondary TDS drinking water standards in the Yegua-Jackson Aquifer. Most chloride/bromide ratios were between 100 and 300. Overall, results of this study suggest that natural processes exert a primary control on solute concentrations in the above aquifers, with a potential for modest anthropogenic impacts from agriculture and oil/gas production. UR - https://ijer.ut.ac.ir/article_366.html L1 - https://ijer.ut.ac.ir/article_366_d4f549e221e20923484fac6d360ba229.pdf ER -