BIOACCUMULATION OF ALKALINE EARTH METALS ASSOCIATED WITH OIL AND GAS OPERATIONS

Oil & gas (O&G) wastewater is released to environment in several areas of the Appalachian Basin, through road spreading and permitted discharges. These releases lead to increased concentrations of alkaline earth metals in waterways and sediments that could pose risks to human health and environmental health. Elemental concentrations measured in sediments downstream of O&G wastewater discharge facilities identify intervals with higher Sr, Ba and Ra (3-4 times background). Multiple isotopic tracers (²²⁶Ra/²²⁸Ra and ⁸⁷Sr/⁸⁶Sr) indicate upstream disposal of Marcellus produced waters is the source of the elevated concentrations. ²¹⁰Pb and ⁷Be age-dating indicates that the interval corresponds to a period of time of maximum volume of unconventional (i.e., Marcellus) wastewater disposal (2009-2011). While sediments appear to preserve the unique chemistry of O&G wastewater that can be used as forensic tools to record discharges of effluent over time, little is known about the potential accumulation and/or long-term risks of these contaminants for freshwater species. Similar to sediments, bivalve shells record the water chemistry of streams and may be used to evaluate changes in water quality through time. Feathers are commonly used for sampling exposure to pollutants as many pollutants become incorporated into the feather structure. Analyses of biomonitors will help quantify risks and guide future O&G wastewater management strategies.