Keystone I, the first phase of TransCanada’s pipeline system that brings tar sands oil from Alberta, Canada to southern Illinois, has shut down once again after mechanical problems. Reuters reports that there is “no word yet on the extent of the problems affecting the 591,000 barrel a day pipeline.” This comes as controversy continues to grow over the approval process for the second phase of the project, Keystone XL, which will continue the line all the way to the Gulf Coast of Texas. Keystone I has been in operation for less than two years.