The oil sands comprise three major oil sands deposits in the Province of Alberta, Canada. These are the largest reserves of oil on the planet outside of Saudi Arabia and Venezuela. The largest deposits are the Athabasca oil sands, located north of Edmonton centered around the town of Fort McMurray. The other two deposits are the Cold Lake deposits south of Fort McMurray, and the Peace River. The map shows the massive scale of the oil sands.
The area currently being mined is 901 square kilometers, an area slightly larger than the city of Calgary. This entire landscape is marked by vast deforestation, strip mines, toxic wastewater “ponds,” and large-scale freshwater diversions.
Alberta’s oil sands are a mix of bitumen, clay minerals, water and silica sand. Bitumen, also known as asphalt, is a liquid or semi-solid form of petroleum. It is sticky, black and highly viscous, meaning it cannot easily flow to productions wells. To make it easier to transport by pipeline, once diluted bitumen is extracted from the tar sands it’s thinned with natural gas condensates, which can include hydrocarbons such as benzene, toluene, and hexane. The result is diluted bitumen, also known as dilbit. Diluted bitumen spills in water bodies are uniquely difficult to clean up: as soon as the volatile compounds evaporate, the remaining dense, viscous residue sinks to the bottom.
Two methods are used to extract bitumen: in situ extraction and surface strip mining. The in situ method is used when bitumen is deeper underground. Machines are used to inject high-pressure steam to heat the sands and reduce bitumen viscosity so it can be extracted like conventional oil. The process uses a huge amount of water and natural gas. Eighty percent of the oil sands’ bitumen is being extracted this way. The remaining 20% is available closer to the surface and open surface strip mining techniques are used. These include excavation of the land using hydraulic power shovels to rip away boreal forests and giant hauler trucks (the biggest vehicles on the earth) which themselves cause severe land degradation in the middle of the remaining boreal forest.
Oil sands companies also use great volumes of water in the process of separating oil from the clay and sand. The magnitude of these withdrawals is dramatically altering the water cycle of the vast Athabasca River Basin. The wastewater from the processes of mining and refining contains a stew of pollutants, including corrosive naphthenic acid and cancer-causing alkyl-substituted polycyclic aromatic hydrocarbon, along with clay and sand. From 3 to 5 cubic metres of polluted wastewater sludge, or “tailings,” is generated for every cubic metre of bitumen extracted. These tailings are stored in large engineered dams and dyke systems called tailings ponds. The Alberta oil sands tailings ponds are reportedly the largest toxic impoundments on the planet.
The oil produced by either method produces more greenhouse gas emissions than any other oil. It’s the largest and fastest growing single source of carbon in Canada. While emissions in most of Canada have been slowly coming down over the last 20 years, those in Alberta have increased significantly, mainly because of tar sands extraction, making it extremely unlikely that Canada will meet its international emission reduction targets.
From 2005 to 2017 Canada’s emissions went down by 2% and Ontario’s went down by 22%, while Alberta’s went up by 18%, primarily as a result of oil and gas exploration. Alberta is now responsible for almost 40% of Canada’s emissions.
National Inventory Report 1990-2017: Greenhouse Gas Sources and Sinks in Canada. Canada’s Submission to the UN Framework Convention on Climate Change
The True Cost of Oil, Garth Lenz, TEDxVictoria
What are the Oil Sands? Canada Oil Sands
Oil Sand Companies in Athabasca Oil Sands, Wikipedia
Oil Sands Facts & Statistics, Alberta
“Diluted bitumen spills in water bodies are uniquely difficult to clean up: as soon as the volatile compounds evaporate, the remaining dense, viscous residue sinks to the bottom.”
“The Oil Industry and That Amazing Floating Tar Sands Oil” by DeSmog (citing “Spills of Diluted Bitumen from Pipelines: A Comparative Study of Environmental Fate, Effects, and Response,” (2016), National Academies of Science (USA)
“Oil sands companies also use great volumes of water in the process of separating oil from the clay and sand. The magnitude of these withdrawals is dramatically altering the water cycle of the vast Athabasca River Basin. The wastewater from the processes of mining and refining contains a stew of pollutants, including corrosive naphthenic acid and cancer-causing alkyl-substituted polycyclic aromatic hydrocarbon, along with clay and sand. From three to five cubic metres of polluted wastewater sludge, or “tailings,” is generated for every cubic metre of bitumen extracted.”
A Line in the Tar Sands: Struggles for Environmentalism Justice, Stephen D’Arcy, Toban Black, Tony Weis, and Joshua Kahn Russell, Eds., 2014, Between the Lines, p. 28.