Millions of megagrams of coal combustion byproducts (CCBs) are produced annually in the United States. Certain CCBs have physical and chemical characteristics that provide potential for use as a soil amendment. The objective of this experiment was to examine the effect of land application of a dry flue gas desulfurization (DFGD) by-product on runoff water quality. Dry FGD by-product was applied to a managed grassland in May of 2015 and trace element concentrations in runoff water were measured following each runoff-producing event for a 2-mo period. There were no significant differences in cumulative runoff volume or cumulative loading of As, Be, Cd, Co, Cr, Cs, Cu, Ni, Pb, Rb V, and U between the amended and unamended plots. Cumulative loading of Se was significantly higher in amended plots compared to the unamended control. Additional research is needed to fully understand the environmental impacts of land applying coal combustion by-products, but our results suggest that runoff water quality from DFGD-amended grassland is very similar to that from unamended grassland.