Oil and Natural Gas - Energy Policy Analysis: A Conceptual Framework - page 86

deposits underground. These processes can use more water and require larger amounts of energy
than conventional oil extraction. In the Athabasca tar sands of Alberta, there are very large amounts
of bitumen covered by little overburden, making surface mining the most efficient method of ex-
tracting it. Overburden consists of water-laden muskeg (peat bog) over clay and sand. Athabasca
oil sands are typically forty to sixty meters deep, sitting on top of flat limestone rock, mined with
truck and shovel operations using some of the largest power shovels (100 or more tons) and dump
trucks (400 tons) in the world. Surface mining with such large equipment has held production costs
to around $27 per barrel of synthetic crude oil despite rising energy and labor costs (Canadian Oil
Sands Trust 2007). Consequently, surface mining tar sands entails environmental degradation of
land similar to that described for coal strip mining in Chapter 2.
After excavation, hot water and caustic soda (NaOH) are added to the sand, and the resulting
slurry is piped to an extraction plant where it is agitated and oil skimmed from the top. Bitumen
separates from sand and clay, and small air bubbles attach to bitumen droplets. Bitumen froth
floats to the top in separation vessels and is further treated to remove residual water and fine solids.
Bitumen is much thicker than conventional crude oil, so it must be mixed with lighter petroleum
(either liquid or gas) or chemically split before it can be transported by pipeline for upgrading into
synthetic crude oil. Extraction plants can recover over 90 percent of the bitumen from the sand.
About two tons of oil sands are required to produce one barrel (roughly one-eighth of a ton) of
oil. After oil extraction, the spent sand and other materials are usually returned to a mine, which
is eventually reclaimed.
Heavy metals such as vanadium, nickel, lead, cobalt, mercury, chromium, cadmium, arsenic,
selenium, copper, manganese, iron, and zinc are present in Athabasca oil sands (Kelly et al. 2009).
Some but not all are removed during the extraction process, and the remainder must be removed
before or during refining. Air monitoring has shown significant increases in violations of hydrogen
sulfide (H 2 S) standards both in the Fort McMurray area and near oil sands upgraders. Hydrogen
sulfide, a significant safety hazard, is a colorless, toxic, flammable gas responsible for the foul
odor of rotten eggs. A major hindrance to monitoring produced waters from oil sands has been
the lack of identification of individual compounds present in the effluent. Better understanding of
the complex mixture of compounds, including napthenic acids, would make it possible to moni-
tor rivers for leachate and to remove toxic components (Rowland et al. 2011). In 2007 a study
of Lake Athabasca, downstream of the oil sands, was initiated due to occurrence of deformities
and tumors found in fish caught there (Weber 2010). High deformity rates in fish embryos in the
Athabasca River and its tributaries were attributed to aromatic polycyclic compounds, some of
which are known carcinogens (Kelly et al. 2009).
In spring 2008, a reported 1,600 waterfowl died in the oily tailings waste of a tar sands mine
in Alberta (Dyer and Simieritsch 2010). Tailings ponds now cover fifty square miles and contain
190 billion gallons of toxic liquid by-products from oil sands mining, including acids, ammonia,
mercury, and other compounds and trace metals (Nix and Martin 1992) toxic to aquatic organisms
and mammals (MacKinnon and Boerger 1986). Woodland caribou herds in Alberta have declined
and are now considered non-self-sustaining, partly due to habitat loss from oil sands development
(Environment Canada 2008). Researchers project that over the next thirty to fifty years, over 160
million boreal songbirds with be lost due to habitat loss and fragmentation, tailings pond deaths,
loss of wetlands, toxin accumulations, and impacts from climate change (Dyer and Simieritsch
2010; Wells et al. 2008).
The Keystone Pipeline System transports synthetic crude oil and diluted bitumen from north-
eastern Alberta through Montana, South Dakota, Nebraska, Kansas, and Oklahoma to refineries in
Illinois, Oklahoma, and the Gulf Coast of Texas. It consists of the Keystone Pipeline, completed in