VARIATION IN THE EFFECTS OF UNCONVENTIONAL OIL AND GAS SPILLS IN THE WILLISTON BASIN

Waste materials from unconventional oil and gas (UOG) extraction have the potential to pose significant risks to human health and the environment from their unintentional release. Understanding the potential effects on human and ecosystem health is a critical research priority as waste materials often contain radioactive and carcinogenic elements from the geologic formations along with additives used in the UOG development and extraction processes. UOG waste may pose different risks to water quality, ecologic communities, and human health depending on its composition and pathway into the environment. To evaluate these risks, we developed a conceptual model linking UOG waste to its ultimate human and ecological health effects as a result of the environmental entry, system drivers, and ecosystem parameters. We use this framework to suggest a set of archetypical release scenarios which may impact the environment differently. Many of these system drivers and ecosystem parameters can be quantified using GIS while the composition of the waste material and the potential ecological health effects can be determined through laboratory and field analyses. This information can be used to identify and group comparable spills which will experience similar environmental issues and allow scientists and managers to better understand and address the effects of UOG waste in the environment. We tested our conceptual model in the Williston Basin at two field sites with different wastewater environmental pathways: Goose Lake, where ground water transport was the dominate pathway; and Blacktail Creek, a surface water dominated spill site. Our approach shows how the effects of UOG spills may differ substantially, identifies regions of greatest environmental risk as a result of continued UOG development, guides prioritization of future studies, and helps resource managers respond to new spills.