The Athabasca oil sands are the second largest producer of crude oil in the world, with a surface area of approximately 100 000 square kilometres (Anderson, Giesy & Wiseman, 2010). The Alberta Energy and Utilities Board estimates that the oil sands contains approximately 1.7 trillion barrels of crude bitumen, however only 19% can be ultimately recovered (Raynolds, Severson-Baker & Woynillowicz, 2005; Humphries, 2008). The availability of recoverable bitumen makes Canada’s oil sands deposit larger even than that of Saudi Arabia (Czarnecki, Hamza, Masliyah, Xu & Zhou, 2004).The process of surface and in situ mining of the Athabasca oil sands is causing rapid and significant degradation of the regional environment surrounding Fort McMurray and the Athabasca River. Production is expected to increase to three million barrels per day by 2015 from approximately 2 million currently (Humphries, 2008). This increase will further exacerbate the existing environmental impacts of crude oil production. The Canadian oil and natural gas industry is extremely lucrative, but despite the short-term economic benefits of the mining of the Athabasca oil sands, the remediation of the negative environmental impacts of the extraction of oil on terrestrial and aquatic environments, biodiversity, and greenhouse gas emissions are a priority.
Background: Oil Sands and the Extraction Process
The extraction of crude oil from the Athabasca oil sands is carried out by surface mining and in situ mining. 90% of recoverable bitumen is located too deep to be recovered by surface mining (Mossop, 1980). Both techniques require invasive processes to successfully extract the bitumen from the subsurface and result in degradation of the land upon which they are located. In situ extraction involves the use of steam, which is injected into a well, to melt the bitumen which is subsequently pumped back up the well to the surface. The steam acts as a separating agent to isolate the bitumen from the other constituents (Anderson et al., 2010). Bitumen that is extracted by in situ processes is upgraded into more valuable synthetic crude and then refined into fuel for gasoline or diesel. The remaining bitumen is directly processed as raw (Bergenson, Charpentier, & MacLean, 2009).
Water Resources and the Athabasca River
The mining processes of the Athabasca oil sands directly affect water resources surrounding the mining pits, specifically the Athabasca River and its tributaries. Water use has been identified by the Alberta Chamber of Resources as a top four challenge of oil sands mining processes (Raynolds et al., 2005). The extraction of bitumen requires freshwater in large quantities, on a scale of 2-4 barrels of water for every barrel of oil produced (Anderson et al., 2010).
Tailings is what becomes of the water used in the extraction of oil. It is a slurry of bitumen, water, sand, silt and clay particles. Tailings ponds, which are actually man-made structures, take up more than...