title: In-situ bitumen extraction associated with increased petrogenic polycyclic aromatic compounds in lake sediments from the Cold Lake heavy oil fields (Alberta, Canada).
abstract: Most future growth in the Alberta bituminous sands will be based on thermal in-situ recovery technologies. To date, however, most attention on the environmental effects of bitumen recovery has focused on surface mining in the Athabasca region. Recent uncontrolled bitumen flow-to-surface incidents (FTS; appearance at the surface of bitumen emulsions from deep subsurface recovery zones) reported at the Cold Lake heavy oil fields highlight the need to better understand the potential role of in-situ extraction as a source of contaminants to landscapes and surface waters. We analyzed sediment cores from a lake located ∼2 km away from a recent bitumen FTS incident to provide a long-term perspective on the delivery of metals, polycyclic aromatic compounds (PACs), and polychlorinated biphenyls (PCBs) to surface freshwaters, and to assess whether the onset of local in-situ bitumen extraction can be linked to contaminant increases in nearby lakes. An increase in alkyl PACs coincided with the onset and expansion of commercial in-situ bitumen extraction, and multiple lines of evidence indicate a petrogenic source for recent alkyl PAC enrichment. However, no coincident increase in vanadium (enriched in bitumen) occurred that would suggest the source of petrogenic PAC enrichment is direct input of bituminous particles. Our results show that, similar to surface mining in the Athabasca region, activities associated with in-situ extraction can increase the burden of petrogenic PACs in nearby lakes, but many questions still remain regarding the exact sources and pathways of PACs into the environment. Given that more than 80% of Alberta's bitumen reserves can only be accessed using in-situ technologies, we recommend that this be made a research priority.
authors.affiliation: 30 Marie Curie Pvt., Department of Biology, University of Ottawa, Ottawa, Ontario, K1N 6N5, Canada.
authors.forename: Jennifer B
authors.initials: JB
authors.lastname: Korosi
authors.affiliation: Environmental Monitoring and Science Division, Alberta Environment and Parks, 9888 Jasper Ave., Edmonton, Alberta, T5J 5C6, Canada; Department of Earth and Atmospheric Sciences, 1-26 Earth Sciences Building, University of Alberta, Edmonton, Alberta, T6G 2E3, Canada.
authors.forename: Colin A
authors.initials: CA
authors.lastname: Cooke
authors.affiliation: 30 Marie Curie Pvt., Department of Biology, University of Ottawa, Ottawa, Ontario, K1N 6N5, Canada.
authors.forename: David C
authors.initials: DC
authors.lastname: Eickmeyer
authors.affiliation: 30 Marie Curie Pvt., Department of Biology, University of Ottawa, Ottawa, Ontario, K1N 6N5, Canada.
authors.forename: Linda E
authors.initials: LE
authors.lastname: Kimpe
authors.affiliation: 30 Marie Curie Pvt., Department of Biology, University of Ottawa, Ottawa, Ontario, K1N 6N5, Canada. Electronic address: Jules.blais@uottawa.ca.
authors.forename: Jules M
authors.initials: JM
authors.lastname: Blais
mesh_terms: D000416:Alberta; D004784:Environmental Monitoring / Q000379:methods; D019015:Geologic Sediments / Q000737:chemistry*; D006838:Hydrocarbons / Q000737:chemistry; D060106:Lakes / Q000737:chemistry*; D008906:Mining; D061329:Oil and Gas Fields; D059392:Petroleum Pollution / Q000032:analysis*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D006838:Hydrocarbons; D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical; C006647:asphalt
keywords: Alberta; Cold lake; High-pressure cyclic steam stimulation; Metals; Organic contaminants; Paleolimnology