Who is downstream? A case study of community drinking water system vulnerability to changing coal-fired power plants bromide loads in the Ohio River Basin

Wastewaters from energy-related activities, including oil and gas produced water and coal-fired power plant wet flue gas desulfurization (FGD) wastewater, often contain high concentrations of dissolved solids. Discharges of these wastewaters to surface waters can lead to levels of bromide that are problematic for drinking water systems due to toxic disinfection byproduct (DBP) formation during treatment. The extent of downstream bromide effects on drinking water depends on the pollution control configuration at the power plant, the type and amount of coal burned, whether halogen additives (i.e., bromine or iodine) have been applied to the coal, and the dilution capacity at the drinking water intake. 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. Although overall coal consumption at NAICS code 22 power plants in the Ohio River Basin has declined steadily in recent years (from 52 to 38 MMT), consumption of what is called “refined coal,” which is often treated with halogen additives, increased by 42% due to its perceived positive effect on air pollutant reductions and a federal tax credit (from 24 to 34 MMT). As a case study for evaluating the environmental justice implications of power plant changes on downstream drinking water sources, this paper analyzes the demographics, size, treatment plant processes, and publicly reported water quality data for community water systems downstream of coal-fired power plants in the Ohio River Basin, USA.