environmental impact
Development of the Athabasca oil sands has resulted in extensive environmental degradation of pristine boreal forests and wetlands. Bitumen strip mining not only renders large areas of land uninhabitable even after reclamation efforts, but is also known to introduce hazardous chemicals into the local environment through the production and storage of tailings (i.e., waste byproducts). This method of mining is incredibly energy and water intensive, using enormous quantities of diesel fuel, gasoline, natural gas, and freshwater for everything from construction equipment, to fleet vehicles and bitumen processing. An often overlooked impact of Athabasca mining is the significant externalized air emissions once the bitumen is refined, sold, and used by consumers.
watershed & river
Oil sands mining is water intensive, impacting water resources through the drainage of wetlands and overburden, aquifer dewatering, withdrawal from the Athabasca River, tailings management, and bitumen processing (2). Less than 10% of the water approved for withdrawal is returned to the river, which has dramatic impacts to downstream aquatic, flood plain, and
deltaic ecosystems. Currently 590,000,000 cubic meters of water per year has been approved for withdrawal for Athabasca mining. This volume is sufficient to meet the needs of approximately 3 million people or a city the size of Chicago (17). The
oil sands are transported to a processing facility where the bitumen is washed from the sands using hot water (4). Approximately four barrels of water (636 liters of water) is required to extract one barrel of bitumen (17).
The management of acutely toxic bitumen tailings is a major environmental concern with Athabasca oil sands mining (2). The water used for extraction and washing of oil sands is pumped into tailings ponds – a mixture of bitumen, water, sand, silt and fine clay particles (2) (Figure 2-4). The bitumen constituents within the tailings ponds are of most concern and include naphthenic acids, PAHs, benzene, lead, mercury and other trace metals (18). Total levels of mercury across all tailings ponds at the Site increased by 63%, lead by 29%, and arsenic by 28% between 2006 and 2009 (18). Tailings ponds through all Alberta mining operations exceeded an area of 176 km2 as of 2010 and are projected to grow 50% by 2020 (18). Athabasca tailings ponds currently cover more than 50 km (2) (Figure 2-5). Tailings produced at the Site by Syncrude and Suncor is expected to exceed one billion m3 by 2020, which is sufficient to fill 400,000 Olympic-sized swimming pools (2).
Enormous dykes and dams constructed from excavated overburden are used to trap the tailings in “ponds.” These engineered structures are so large that Syncrude’s Southwest Sand Storage Facility is considered one of the three largest dams in the
world (2). Horizontal migration through dykes and dams is largely mitigated by ensuring sufficiently low hydraulic conductivities and through internal drainage pipes. However, vertical migration through the underlying geological formation and aquifer, and subsequent lateral migration toward natural bodies of water, is a major concern (Figure 2-6). Elaborate seepage and contaminant monitoring systems have been constructed between tailings ponds and the Athabasca River as illustrated in Figure 2-6 (19). Despite operating under a zero-discharge regulation seeking to prevent the migration of contaminants into natural waterways, it has been reported through analytical sampling that tailings are in fact leaking into the Athabasca River (20).
Long-term tailings management has historically involved the passive approach of waiting for fines to settle, recycling the water, and excavating and removing the mature fine tailings for additional bitumen extraction (4) (Figure 2-7). While technology is being developed to expedite this process, it currently takes anywhere from a decade to a century for the mature fines to settle (4). Mining companies are currently lobbying Canadian regulatory agencies for permission to place the fluid mine tailings into “capped” mine pits upon mining completion (2). They claim that any lateral movement will sufficiently dilute contaminants prior to draining into the Athabasca River (2).
deltaic ecosystems. Currently 590,000,000 cubic meters of water per year has been approved for withdrawal for Athabasca mining. This volume is sufficient to meet the needs of approximately 3 million people or a city the size of Chicago (17). The
oil sands are transported to a processing facility where the bitumen is washed from the sands using hot water (4). Approximately four barrels of water (636 liters of water) is required to extract one barrel of bitumen (17).
The management of acutely toxic bitumen tailings is a major environmental concern with Athabasca oil sands mining (2). The water used for extraction and washing of oil sands is pumped into tailings ponds – a mixture of bitumen, water, sand, silt and fine clay particles (2) (Figure 2-4). The bitumen constituents within the tailings ponds are of most concern and include naphthenic acids, PAHs, benzene, lead, mercury and other trace metals (18). Total levels of mercury across all tailings ponds at the Site increased by 63%, lead by 29%, and arsenic by 28% between 2006 and 2009 (18). Tailings ponds through all Alberta mining operations exceeded an area of 176 km2 as of 2010 and are projected to grow 50% by 2020 (18). Athabasca tailings ponds currently cover more than 50 km (2) (Figure 2-5). Tailings produced at the Site by Syncrude and Suncor is expected to exceed one billion m3 by 2020, which is sufficient to fill 400,000 Olympic-sized swimming pools (2).
Enormous dykes and dams constructed from excavated overburden are used to trap the tailings in “ponds.” These engineered structures are so large that Syncrude’s Southwest Sand Storage Facility is considered one of the three largest dams in the
world (2). Horizontal migration through dykes and dams is largely mitigated by ensuring sufficiently low hydraulic conductivities and through internal drainage pipes. However, vertical migration through the underlying geological formation and aquifer, and subsequent lateral migration toward natural bodies of water, is a major concern (Figure 2-6). Elaborate seepage and contaminant monitoring systems have been constructed between tailings ponds and the Athabasca River as illustrated in Figure 2-6 (19). Despite operating under a zero-discharge regulation seeking to prevent the migration of contaminants into natural waterways, it has been reported through analytical sampling that tailings are in fact leaking into the Athabasca River (20).
Long-term tailings management has historically involved the passive approach of waiting for fines to settle, recycling the water, and excavating and removing the mature fine tailings for additional bitumen extraction (4) (Figure 2-7). While technology is being developed to expedite this process, it currently takes anywhere from a decade to a century for the mature fines to settle (4). Mining companies are currently lobbying Canadian regulatory agencies for permission to place the fluid mine tailings into “capped” mine pits upon mining completion (2). They claim that any lateral movement will sufficiently dilute contaminants prior to draining into the Athabasca River (2).
Oil Sand mines alberta
land issues
Canada has over 310 million hectares of boreal forest containing 35% of the world’s wetlands and the largest coverage of peatlands – known as muskeg – in the world (2). The Athabasca oil sands are wholly overlain by boreal forests and wetlands and mining progression is clearly detected by Landsat imagery (2) (Figures 2-9 & 2-10). The mining process begins by clear cutting and removing all surface vegetation and draining the wetlands (2) . Wetlands are excavated to a depth of one to three meters followed by the removal of overburden – clay, silt, and sand – until the oil sands are exposed (Figure 2-11). Overburden at the site has largely been used for geotechnical purposes including the construction of dams and dykes to prevent contaminant migration from tailings ponds (5). Approximately 4,000 kg of overburden and oil sands must be mined to produce one barrel of oil (5). The material is removed by some of the largest hydraulic shovels in the world, capable of scoop capacities exceeding 40 cubic meters, and transferred to processing facilities by dump trucks (5) (Figure 2-12).
The diversion of rivers, draining of wetland complexes, and removal of vegetation and thin boreal forest soils has resulted in habitat reduction, fragmentation, and a general decrease in biodiversity of wildlife (Figures 2-13 & 2-14). The wetlands and peatlands are not only home to thousands of species of plants and animals, but also regulate surface and groundwater flows and filter out contaminants prior to aquifer and water-body recharge. “In the coming decades, almost 10% of the region’s wetlands will be converted, mostly by oil sands and operations, and permanently removed from the landscape (2).” Surface mining of the Athabasca oil sands will result in irreversible impact to the entire watershed as it has not been proven to reclaim areas to the former boreal-wetland ecosystem (2). Instead, reclaimed mines will likely resemble upland landscapes, an undesirable endpoint for a process that will not even begin for 20-30 years after initial mining operations begin at a respective location. Suncor claims to have reclaimed 858 hectares of land since it began mining operations in the late 1960s, which accounts for less than 9% of its disturbed land to date. Syncrude claims to have reclaimed 4,055 hectares, which accounts for 21% of its disturbed land. However, since mining began with Suncor operations in 1967, none of the reclaimed lands have been certified as reclaimed by Canadian regulatory authorities (2).
The diversion of rivers, draining of wetland complexes, and removal of vegetation and thin boreal forest soils has resulted in habitat reduction, fragmentation, and a general decrease in biodiversity of wildlife (Figures 2-13 & 2-14). The wetlands and peatlands are not only home to thousands of species of plants and animals, but also regulate surface and groundwater flows and filter out contaminants prior to aquifer and water-body recharge. “In the coming decades, almost 10% of the region’s wetlands will be converted, mostly by oil sands and operations, and permanently removed from the landscape (2).” Surface mining of the Athabasca oil sands will result in irreversible impact to the entire watershed as it has not been proven to reclaim areas to the former boreal-wetland ecosystem (2). Instead, reclaimed mines will likely resemble upland landscapes, an undesirable endpoint for a process that will not even begin for 20-30 years after initial mining operations begin at a respective location. Suncor claims to have reclaimed 858 hectares of land since it began mining operations in the late 1960s, which accounts for less than 9% of its disturbed land to date. Syncrude claims to have reclaimed 4,055 hectares, which accounts for 21% of its disturbed land. However, since mining began with Suncor operations in 1967, none of the reclaimed lands have been certified as reclaimed by Canadian regulatory authorities (2).
The cumulative land disturbance at the Site from 1967 to 2006 from oil sands development was approximately 480 km2. This includes open pit mines, tailings ponds, overburden piles, dykes, dams, processing facilities, pipelines and other infrastructure development including access roads, commercial properties, and housing (16). Figure 2-15 contrasts the development between 1974 and 2004. Refer to the Remote Sensing section for additional images depicting developmental progress and land use changes since 1967.
air emissions
Air pollution and greenhouse gas emissions have a direct local and regional impact from mining operations, and an indirect, longer-term impact from the eventual combustion of the refined bitumen (Figure 2-15). The production of synthetic crude oil from the oil sands represents a 33% higher greenhouse gas intensity when compared to conventional oil production on a kg CO2eq/barrel of oil basis (2). Producing a barrel of bitumen also has a 100% increase in NOx and SOx emissions when compared to producing a barrel of conventional oil (2). Between 2006 and 2015, NOx and SOx emissions from Athabasca mining operations are projected to increase over 500% and 130%, respectively. NOx and SOx are not only directly harmful to biological life, but lead to the production of acid rain and tropospheric ozone (i.e., smog). In addition to NOx and SOx, volatile organic compounds (VOCs) are a major
concern with oil sands operations. In 2006, 122,000 kg of VOCs were emitted from Athabasca mining operations, which is expected to increase to 600,000 kg by 2015 (21).
concern with oil sands operations. In 2006, 122,000 kg of VOCs were emitted from Athabasca mining operations, which is expected to increase to 600,000 kg by 2015 (21).