It took two years to complete the Pentagon and four years to complete the Space Shuttle Discovery, but the energy giant TransCanada Corporation (NYSE:TRP), the company proposing to build the controversial Keystone XL pipeline, has been waiting five years for an approval by the Obama administration.

The Keystone XL project is an 875-mile pipeline that will bring crude oil from Alberta, Canada, and the Bakken Shale Formation, to refineries in the U.S. Gulf Coast. The State Department is currently reviewing the environmental impacts after which President Barack Obama would make a decision.

Environmental groups have been fighting the proposed pipeline because of the type of oil coming from western Canada, known as oil sands (also referred to as tar sands). Tar sands are permeated with bitumen, a form of petroleum in solid or semi-solid form that is blended in clay, sand and water. Two ways of extracting the bitumen are by surface (i.e., strip) mining or the injection of steam into underground formations that pump the bitumen to the surface through wells.

While the debate continues, check out some major projects that Oil Sands Fact Check found that were completed in five years or less.