US probe raises doubts about weights on energy pipelines

Calgary

A US regulator's preliminary investigation into the biggest oil pipeline spill this year has raised a red flag that could trigger an extensive and costly inspection of tens of thousands of miles of underground energy lines.

The 5,000-barrel leak on TransCanada Corp's Keystone pipeline on Nov 16 in South Dakota might have stemmed from damage caused by a weight put in place when it was built in 2008, the Pipeline and Hazardous Materials Safety Administration (PHMSA) said in a report. Weights are used to prevent pipelines from moving and reduce the risk of damage or ruptures when water tables rise.