The Transportation Safety Board determination of the cause of a pipeline rupture and explosion near Shelley in 2018 is ‘jaw dropping,’ according to the Lheidli T’enneh.
The board determined that stress corrosion cracking led to the pipeline rupture resulting in an explosion and fire near Prince George in 2018. The explosion resulted in the evacuation of several Lheidli T’enneh homes.
“My community understandably remains very concerned about Enbridge’s operations through our territory, and for good reason,” said Lheidli T’enneh Dayi Clayton Pountney. “The TSB report is clear in its findings that Enbridge’s operations were lacking. They didn’t follow their own protocols with respect to safety inspection deferment. Data from 2003 identified nine cracks above the set reporting criteria.”
The TSB investigation found that the pipeline ruptured due to stress corrosion cracks on the outside surface of the pipe; and that the polyethylene tape coating applied to the exterior surface of the pipe as a measure to protect it from corrosion deteriorated over time. This allowed soil moisture to come into contact with the pipe surface, leading to corrosion and cracking. Growing and merging over time, the cracks reduced the load-bearing capacity of the pipeline at normal operating pressures.
Enbridge had a stress corrosion cracking hazard management plan in place for this pipeline. However, the extent of the existing cracking on the segment of pipe that ruptured was not identified, according to the report. The model used to predict crack growth did not take into account all potential uncertainties in the predicted crack growth. This resulted in cracks growing at higher rates than the model predicted. Additionally, an inspection of this pipeline segment scheduled for 2017 was deferred until the fall of 2018. As such, the existing cracks remained undetected, according to the report.
“It is my expectation that decision makers and investors in Calgary and elsewhere would agree with my community’s assessment that this is unacceptable,” said Pountney. “This does not amount to the safe, world class transportation of hydrocarbons through our territory. Enbridge advises that this is critical infrastructure which is relied upon in B.C. and south of the border, and if this is the case, it is time to operate the lines as such. Step one is enforcing and implementing proper transportation and safety protocol.”
In February, 2019, the Lheidli T’enneh sought a court injunction to halt the flow of natural gas through its traditional territory.
“We stated from the beginning that our key concern was the safety of our members and other people living close to the gas pipelines,” said Pountney. “We launched our lawsuit against Enbridge because we weren’t getting adequate and transparent answers. We now have some answers. It is time for Canada to learn and improve from these mistakes.”