Environmental Negatives of the Alberta Tar Sands:Tailings Ponds
A tailings pond is an engineered dam and dyke system that is used as a settling basin/storage container for what is left over (a mixture of water sand, clay, and residual oil) after oil sands processing. Once in the pond, the sand sicks to the bottom and the water from the top three metres is recycled. Tailings lakes took up 176 square kilometers in 2010 and are expected to expand by nearly 50% in area by 2020 to 250 square kilometers. Tailings ponds present a number of environmental challenges:
Contaminants of the tailings ponds include naphthenic acids, polycyclic aromatic hydrocarbons, phenolic compounds, ammonia, mercury and other trace metals. Between 2006 and 2010, the total amountof mercury added to all tailings ponds per year increased by 80%, lead by 50% and arsenic by 21%. In response, the Government of Alberta requires that all oil sands operators to have plans to convert fine tailings into reclaimable land. While this may help with reclaiming the land, it does not guarantee that the plan will follow through. |
Keystone XL Pipeline:Environmental Positives of the Alberta Tar Sands:I have done an extremely thorough search for the environmental positives of the tar sands of Alberta and I could not find anything that claimed the extraction of oil was good for the environment. However, There is many economical positives to the Athabasca tar sands.
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Water Impacts
The Alberta oil sands are responsible for many extreme changes in Alberta's natural water. When the water is messed with, it causes everything that relies on it for survival, witch would be anything living around it, to change and not for the better. The oil sands mining operations are subject to a zero-discharge policy due to the toxins in the waste water. Around 40-70% of waste water used in the oil sands operations is recycled back to the extraction process. Any waste water that is not recycled is stored in tailings ponds. This means that oil sands operations cannot return all of the water that they use to the natural cycle. The extraction and upgrade of mining ans in situ techniques require approximately 0.8 to 2.4 barrels of fresh water for each barrel of bitumen or oil. the annual water consumption in 2011 was:
These volumes are in addition to water that is recycled through that processes. The majority of the water used for mining is taken from the Athabasca River. Current and proposed projects could withdraw more than 15% of the Athabasca River's water flow during its lowest flow periods, according to the awarded water licenses. Water withdraws during low-flow periods in the winter pose a threat to the fish population of the river. It reduces the availability of fish habitat and could reduce the health of the river's ecosystem. In the past year, oil sands pollution has been linked to elevated cancer rates in Fort Chipewyan for the first time. Fort Chipewyan, as well as other communities, are located downwind from the oil sands development. which leaves them more vulnerable to the effects of what's left over form the oil mining process. The University of Manitoba conducted a study that found fish and animals eaten as a traditional diet of the people in the area of the tar sands contained unusually high concentrations of contaminants emitted during the extraction and upgrading of bitumen. out of 94 people interviewed as part of the three year study, 23 cases of cancer were reported. Samples take from the wildlife contained high concentrations of carcinogenic polycyclic aromatic hydrocarbons along with levels of arsenic, mercury, cadmium and selenium high enough to be of danger to young children. |
Air Pollution
Along with many greenhouse gases, the operation of oil sands release mass volumes of pollutants into the Earth's atmosphere. These pollutants include nitrogen oxides, sulfur dioxide, volatile organic compounds and particulate matter. If you haven't already guessed, these chemicals are known to affect human health in a negative way. Just the production of a single barrel of bitumen generates more than twice as much nitrogen oxides and sulfur dioxide emissions as producing a barrel of conventional oil. Emissions intensity (grams of pollutant per barrel of bitumen or SCO produced) are:5
However, in an Environment Alberta video, an expert suggests that the air in Fort McKay and Fort McMurray near the oil sands production sites is less polluted than in major Canadian cities, such as Edmonton. The graph on the left displays this. Sulfur dioxide and nitrogen oxides are major contributors to acid rain production. This is shown to us in Northern Saskatchewan and Manitoba because they are highly sensitive to acid rain. It is connected to the oil sands because they are located down wind from them. Which brings me to my next environmental issue; water impacts. |