An investigation conducted by pipeline operator TC Energy Corp may have uncovered the cause of the Keystone oil spill. According to TC Energy, the “failure occurred due to a combination of factors, including bending stress on the pipe and a weld flaw at a pipe to fitting girth weld that was completed at a fabrication facility.” The company insists that the welding was inspected and tested and found to be up to all necessary codes and standards. Despite this, the flaw eventually developed into a crack over time, leading to the spill.
TC Energy also says that their original estimate of 14,000 barrels of oil released during the spill has been revised to 12,937 barrels, and they estimate cleanup costs at about $480 million.