Canada's National Energy Board approved the $7 billion project in March 2010.

U.S. approval has been more problematic. The decision rests with the State Department, but the U.S. Environmental Protection Agency has been chastising the State Department's environmental review, pushing for further review and public hearings.

In a June 2011 letter to the State Department the EPA said it remains concerned about risk of oil spills that could affect drinking water and sensitive ecosystems, as well as greenhouse gas emissions associated with the Keystone XL pipeline. The pipeline enables Alberta oil sands expansion, the most emissions intense oil production on the planet.

The State Department has promised a decision by the end of 2011. Statements by Secretary of State Hillary Clinton and President Barrack Obama, along with leaked cables from the U.S. Embassy in Ottawa, suggest the State Department maybe in favour of the project.

But recent pipeline oil spills, including at least 12 reported spills on TransCanada owned pipelines since May 2010, has increased public scrutiny on the proposed Keystone XL.

University of Nebraska-Lincoln engineering professor John Stansbury, who teaches U.S. Army Corps of Engineers how to do risk assessments, predicts the pipeline would have 91 significant spills over 50 years, not the 11 spills TransCanada predicts. Stansbury observes that neither TransCanada nor the regulators evaluating the proposed Keystone XL pipeline have properly considered the risks.

350.org founder Bill McKibben and supporters are issuing a call to action for three weeks of peaceful demonstrations in Washington DC between August 20 and September 3, 2011 to convince President Obama not to approve the TransCanada Keystone XL pipeline.