In March, the National Energy Board (NEB) approved the reversal of Enbridge’s Line 9, a pipeline running from Sarnia to Montréal. Critics such as Environmental Defence and West Coast Environmental Law have pointed out flaws in the regulatory process. The project was not required to undergo a comprehensive environmental assessment and members of the public were subject to an onerous process in order to submit a comment.
The 38-year-old pipeline will carry heavy crude, including diluted bitumen (dilbit), from the Alberta oil sands. Critics say that dilbit is more corrosive than other forms of crude; Enbridge assures the public it is not, and cites studies by the National Academy of Sciences and Natural Resources Canada.
Simple corrosiveness is not the problem, however. International pipeline safety expert Richard Kuprewicz warns of extensive stress corrosion cracking in pipelines. This occurs as a result of a different mechanism than chemical corrosion. Ordinary variations in operating pressure within a pipeline, called pressure cycling, increase with dilbit because the substance varies more in composition than conventional oil. The greater swings in pressure inside the pipeline can create cracks or worsen existing ones.
Kuprewicz analyzed Enbridge’s assessments of Line 9 and found evidence of extensive stress corrosion cracking, which he detailed along with other concerns in a technical report filed as part of the NEB review. The researcher found the same problems on Enbridge’s Line 6B pipeline after it ruptured and spilled dilbit into the Kalamazoo River in 2010.
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The Goodman Group (TGG) assessed Enbridge’s liability insurance as completely inadequate for the densely populated area that Line 9 runs through and its proximity to drinking water sources. TGG claims Enbridge has overestimated the benefits and underestimated the risks, entirely ignoring the costs of a rupture. They conclude that the potential economic costs could greatly exceed any potential benefits.