The coal-fired power generation sector in the United States has experienced substantial changes over the last decade due to regulatory (i.e., increased environmental regulation) and market (e.g., changing tax policies and increasing competition from alternative fuels) drivers. While environmental impacts to air quality and ecology from coal-fired power plants have been discussed in and widely studied for many decades, the potential human health effects associated with downstream, subsequent use of receiving waters as drinking water sources have received attention only recently. Coal-fired power plant wet flue gas desulfurization (FGD) wastewater contains high concentrations of dissolved solids, and discharges of these wastewaters to surface waters can lead to levels of bromide that are problematic for drinking water systems due to disinfection byproduct (DBP) formation during treatment. Although feedstock coal consumption at NAICS code 22 power plants in the United States has declined steadily in recent years from 443.9 to 239.5 million metric tons (MMT), consumption of what is called “refined coal” increased by 19.7% due to its perceived positive effect on air pollutant reductions and a federal tax credit (from 99.34 to 118.9 MMT). This increase in refined coal consumption combined with incomplete information on the nature and quantity of chemical additives used in refining increase uncertainty in the effect of this practice on drinking water systems downstream of power plants. The present work evaluates how refined coal consumption associated with U.S. wet FGD systems has changed over the period 2016-2020 and quantifies the uncertainty associated with potential increases in surface water bromide loads from the consumption of refined coal.
