Consensus ecological risk assessment of potential transportation-related Bakken and dilbit crude oil spills in the Delaware Bay Watershed, USA

Abstract

Unconventionally-produced crude oils, i.e., Bakken oil and bitumen diluted for transport and known as dilbit, have become prominent components of the North American petroleum industry. Spills of these oils have occurred during transport from production areas to refineries via pipeline, rail, and barge. Some of their physical and chemical properties are distinct and present new challenges in mitigating spill impacts on people and the environment. This paper describes the adaptation of a qualitative risk assessment process to improve spill preparedness and response decisions for these oils when transported in an estuarine area. The application of this collaborative, interdisciplinary process drew upon a literature review, the local knowledge and experience of a broad set of decision makers, practitioners, and technical experts who developed consensus-based recommendations aimed at improving response to spills of these oils. Two emphasized components of this consensus ecological risk assessment (CERA) concerned risks: (1) to human health and safety and (2) from spilled oil and the associated response actions on endangered species. Participants in the process defined levels of concern associated with Bakken and dilbit oils relative to a set of response actions in freshwater, brackish and saltwater habitats and on resources at risk.