Load Modeling Approach for Evaluating Selenium Stream Standards Compliance

Regional scale selenium loading associated with surface coal mining, Elk Valley, British Columbia, Canada

“…It is not clear which of these processes are important in the context of watershed scale Se fate and transport, particularly as it related to mine design guidance. The few studies which have simulated Se fate and transport at a watershed scale have focused on groundwater (Hanna and Loftis, 2007;Myers, 2013;Bailey et al, 2014), with only one study focused on a surface mining context (Myers, 2013).…”

“…Previous conceptual models assigned concentrations of Se in water released from waste rock piles or agricultural soils on the basis of effluent concentrations measured in seeps (Hanna and Loftis, 2007;Myers, 2013). This is despite the fact that such concentrations have been documented to vary significantly among waste rock dumps (Table 1 in Myers, 2013).…”

“…A number of mathematical models of Se have assumed conservative transport of Se (Hanna and Loftis, 2007;Myers, 2013). Bailey et al (2014) show that Se can be released as SeO 4 2− from shale formations containing selenopyrite in the presence of oxygen or nitrate.…”

“…What work has been done has typically focused on the enrichment of Se in groundwater associated with irrigation in the American West. Hanna and Loftis (2007) use a conceptual approach based on a water balance and linear reservoirs coupled to conservative transport of Se. Myers (2013) used MODFLOW, a process based, finite element groundwater model, and assumed conservative transport of Se.…”