“…Uranium sources, transport, and groundwater geochemistry all affect the ultimate concentrations of uranium in groundwater. Uranium in groundwater can be derived from natural aquifer materials or anthropogenic pollution, including pollution from uranium mining and milling operations, phosphate mining, fertilizer use, or inappropriate waste disposal (Guimond and Hardin, 1989;Barisic et al, 1992;Zielinski et al, 1997;Gómez et al, 2006;Wetterlind et al, 2012;Alam and Cheng, 2014;Kamp and Morrison, 2014;Wu et al, 2014;Liesch et al, 2015;Blake et al, 2019;Reiller and Descostes, 2020). Uranium's average abundance in the upper crustal abundance is modest at about 2.6 mg/kg (Hu and Gao, 2008), but it can occur at very high concentrations in a variety of geologic settings.…”