Publication - October 20, 2010
The tar sands in the western Canadian province of Alberta are one of the largest deposits of oil in the world, second only to reserves in Saudi Arabia.

The tar sands are a complex mixture of sand, water, clay and bitumen—a thick tar-like substance that can only be made into synthetic crude oil through intensive processing. It takes huge amounts of energy, water and other resources to remove and refine the oil trapped in the sands2; extracting the oil has serious environmental, social and economic costs.

The tar sands lie underneath 140,800 square kilometres of forests and wetlands. To process them, much of this area – greater in size than Greece, or Portugal and Denmark combined – is being deforested, drained of clean water and polluted with toxic effluent. There has never been a comprehensive assessment of the negative impacts of developing the tar sands.

Despite the environmental destruction that results from extracting oil from tar sands, Canada’s “dirty oil” is sought after by the United States. Canada is considered much more stable and reliable than the Middle East and is now the number one exporter of oil to the U.S.  As a result, multinational oil corporations are proceeding at a frenetic pace to convert tar sands to dirty oil. But the costs are high.

They include:

Greenhouse gas emissions (GHGs)
The tar sands development is a major contributor to greenhouse gases, determining Canada’s role as one of the top 10 emitters of greenhouse gases in the world.

Loss of carbon storehouses
The boreal ecosystem holds 22 per cent of the total carbon on earth; destroying it removes a vital carbon depository – and releases huge amounts of GHGs into the atmosphere.

Loss of fresh water
One of North America’s most beautiful rivers, the Athabasca, flows through the tar sands region.9 Current tar sands projects remove about 370 million cubic metres of water each year.10 Much of it is contaminated with toxins and must be diverted to tailings ponds, depleting freshwater from the Athabasca-Peace-Mackenzie Delta – a World Heritage Site.

Devastated boreal wilderness
Pristine forests and wetlands, and the wildlife that live there, are damaged beyond recovery by tar sands operations.

Human health costs
Of the First Nations people who hunt and fish for their food, those living downstream from tar sands developments are seeing deformed fish and animals and experiencing rising rates of cancer in their communities.

Socio-economic costs
Rapid population growth in communities, such as Fort McMurray, which serve the tar sands industry and house workers, has caused severe shortages in housing and medical facilities and increases in homelessness, substance abuse and family violence.

Open pit mines
Twenty per cent of tar sands reserves are close enough to the surface to be mined using open-pit techniques. Even before the mining starts, waterways are diverted, wetlands are drained, the boreal forest is clear cut and the “overburden” of muskeg, soil and rocks above the deposit is scraped off and hauled away. Two tonnes of bitumen-rich material must be extracted for every one barrel of oil produced.

In situ drilling operations
At least 80 per cent of tar sands reserves are too deep to mine and must be extracted using in situ techniques. Supporting structures for these operations, such as seismic lines and pipelines, severely fragment the natural habitats of the bear, moose, caribou and birds that live there, resulting in their annihilation.

Toxic tailings lakes
Waste water from both in situ and open-pit mining operations is stored in tailings ponds, the world’s largest impoundments of toxic waste. These immense ponds, filled with acutely toxic chemicals known to cause cancer in humans and deformities in fish and animals, seep into the surrounding soil and the groundwater, which feeds lakes, rivers and aquifers.

The tar sands of Alberta - What and where they are
The tar sands, in northern Alberta, are naturally occurring deposits of sand, clay, water and bitumen - a form of crude oil so heavy and thick it won’t flow in its natural state.

Tar sands deposits exist around the world, but the largest known are in Alberta. The three main areas - Athabasca, Cold Lake and Peace River - cover more than 140,800 square kilometres, or 21 per cent of the province, an area the size of Greece, or of Portugal and Denmark combined.

Most of the tar sands are found under pristine boreal wilderness, and 37 per cent are within Alberta’s Boreal Forest Natural Region, an area with several internationally significant ecosystems.

Alberta’s deposits are buried at varying depths and are covered by muskeg, sandstone and shale, which are referred to as “overburden.”  To mine the deposits, oil companies strip away this overburden, destroying this wilderness forever.

How bitumen is processed

While conventional crude oil flows naturally or can be pumped from the ground, tar sands need to be intensively processed before the bitumen can be used by refineries. Deposits are mined from open-pit mines or, if reserves are too deep, extracted using in situ techniques. The deposits have to be processed through extraction and separation systems to remove the bitumen from the sand, clay and water. The bitumen needs to be upgraded before it can be refined. Then, because it is so viscous, it has to be diluted with lighter hydrocarbons to make it transportable by pipelines.

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