Proceedings of the 2022 Mississippi Water Resources Conference

Year: 2022 Authors: Chao X., Zhang Y., Al-Hamdan M.

Large quantities of stored coal ash nationwide pose a serious threat to the environment and wildlife when accidently released into surface water systems. On February 2, 2014, the failure of a storm water pipe under the primary coal ash pond of the Dan River Steam Station owned by the Duke Energy released about 39,000 tons of coal ash and 27 million gallons of pond water into the Dan River near Eden, N.C., about 130 miles upstream of the Kerr Reservoir. Together with the coal ash, a number of contaminants attached to the particles and dissolved in the pond water were also released into Dan River.

Numerical model is an effective tool to simulate the transport processes of coal ash and associated chemical contaminants in river flow. In this case, the entire study reach of the river-reservoir system extends from the USGS Wentworth gauge on Dan River, about 22 km upstream of the spill location to the Kerr Dam, about 182 km downstream of the spill location. For such a long river-reservoir system, the CCHE1D model developed by National Center for Computational Hydroscience and Engineering at the University of Mississippi was applied to simulate the fate and transport of contaminants due to the Dan River coal ash spill accident. The processes of advection, diffusion, sedimentation, and adsorption/desorption of contaminants were considered in the model. Several chemical contaminants, including arsenic (As), mercury (Hg), and selenium (Se) were simulated, and their concentration distributions in water column and bed sediment were obtained. The simulated results were validated using the measured data obtained from EPA. Those results provide useful information for water environment evaluation and water resource management.