Why it's called 'dirty oil'

1. Tailings ponds

Called the largest project on earth, Alberta's oilsands produce over 1.3 million barrels of crude oil daily. But it has become more famous for the toxic wastewater it generates than its oil — 1.8 billion litres daily. The wastewater known as tailings, are stored in ponds are so large they can be seen by the naked eye from space. More »

2. Greenhouse gas emissions

The oilsands are Canada's fastest growing source of carbon dioxide, emitting five per cent of Canada greenhouse gases. Large amounts of energy are used to extract and covert the oilsands to crude oil, producing three times more greenhouse gases than a conventional barrel of oil. More »

3. Water pollution

Alberta's oilsands need water for mining and processing, using enough water for two cities the size of Calgary annually. The toxic wastewater that cannot be recycled is stored in large open-air tailings ponds. Fears of tailings seeping into ground water and nearby rivers is a growing problem in northeastern Alberta. More »

4. Air pollution

Oilsands upgraders in the Fort McMurray area consistently rank among the top 10 most polluting facilities in Canada. But the story doesn't end there. The oilsands industry needs a tremendous amount of energy and in Alberta, a lot of that energy comes from coal-fired plants — some of the worst polluters in the country. More »

5. Boreal forests

About five hundred square kilometres of boreal forest were cleared or mined by the end of 2007, transforming the landscape in northeastern Alberta. Industry promises to return the forest after extracting the oilsands, but it has never been proven that the forests' complex ecosystem can be reclaimed. Meanwhile, threatened species like the woodland caribou continue to dwindle. More »