A report has been released today regarding a pipeline rupture in Prince George that led to a fire.
The report found that stress corrosion cracking led to the pipe rupturing. There were deficiencies in predicting the extent of cracking and a deferred inspection led to a hazard being undetected prior to the rupture.
The coating on the surface of the pipe had deteriorated over time. This allowed soil moisture to contact the pipe surface that led to corrosion and cracking. The cracks reduced the load bearing capacity of the pipeline at normal operating pressures.
Following the occurrence, the Transportation Safety Board issued a Pipeline Safety Advisory Letter to Westcoast Energy Inc. regarding the management of stress corrosion cracking of susceptible pipelines. The letter suggested that the operator may wish to review its stress corrosion cracking management practices, including inspection intervals, to mitigate the risks associated with polyethylene tape-coated pipe.
