TC Energy says combination of factors caused Keystone pipeline leak

TC Energy Corp. says cleanup and remediation of the Keystone pipeline leak in December will cost an estimated US$480 million.

The Keystone pipeline system suffered the worst oil spill in its history on Dec. 7, when oil leaked into a creek in Washington County, Kansas.

The Calgary-based pipeline operator says the leak was due to a combination of factors, including bending stress on the pipe and a welding flaw.

It says the weld flaw led to a crack that grew over time as a result of bending stress fatigue, leading to the leak. The cause of the bending stress remains under investigation.

The company says a metallurgical analysis identified no issues with the strength or material properties of the pipe or manufactured fitting.

TC Energy also revised the size of the leak to 12,937 barrels from the original estimated maximum of 14,000 barrels.

This report by The Canadian Press was first published Feb. 9, 2023.