Particulate matter emissions associated with marcellus shale drilling waste disposal and transport

Emissions quantities and neighboring exposure concentrations of six airborne pollutants, including PM₁₀, PM_2.5, crystalline silica, arsenic, uranium, and barium, which resulted from the disposal of Marcellus shale drill cuttings waste during the 2011–2017 period were assessed. Using these predicted exposures, current setback distances required in Pennsylvania from waste facilities were investigated. For potential residents living at the perimeter of the current setback distance, 274 m (900 ft), a waste disposal rate of 612.4 metric ton/day at landfills (the 99th percentile in record) did not result in exceedances of the exposure limits for any of the six investigated pollutants. However, the current setback distance could result in exceedance with respect to the 24-hr daily concentration standards for PM₁₀ and PM_2.5 established in the NAAQS, if daily waste disposal rate surpasses 900 metric ton/day. Dry depositions of barium-containing and uranium-containing particulate matter should not be a danger to public health based on these results. The air quality impacts of waste transportation and the potential for reductions were studied using an optimization of landfill locations in Pennsylvania indicating the potential benefits in reduced environmental health hazard level possible by decreasing the distance traveled by waste disposal trucks. This strategy could reduce annual emissions of PM₁₀ and PM_2.5 by a mean of 64% and reduce the expected number of annual fatal accidents by nearly half, and should be considered a potential risk management goal in the long run. Policy to limit or encourage reduction of distances traveled by waste removal trucks and manage setback distances as a function of delivered waste quantities is merited.