ESTIMATES OF SHALE ENERGY WASTEWATER DISCHARGE LOADING TO SELECT RECEIVING STREAMS IN SOUTHWESTERN PENNSYLVANIA

A common concern with shale energy development has been potential impacts to surface water resource quality via permitted discharges or accidental releases to receiving streams and rivers. In Pennsylvania permitted discharges are now required to have effluent of a higher quality with a total dissolved solids (TDS) concentration of less than 500 mg/L, though there were historic discharges until about May 2011 of shale-derived fluids with much higher concentrations of TDS. Constituents of concern in this waste stream include barium, strontium, chlorides, bromide, radionuclides, and fracturing fluid additives. Energy companies that were discharging shale wastewater to permitted treatment plant were required to characterize the fluids according to the Pennsylvania Department of Environmental Protection’s Form 26R parameters, which included 51 shale-related analytes. Form 26R data from PaDEP files were acquired to evaluate parameter loading (with a primary focus on total dissolved solids, bromide, and chloride) to select receiving streams. Available USGS streamflow data were also utilized for flow values along with PaDEP’s waste production reporting database to provide estimates of the volume of wastes discharged from a given location. This presentation will provide a first-order assessment of whether levels of concern would have been expected downstream of these discharges under seasonally varying streamflow conditions.