The proposed Energy East Pipeline would entail the conversion in Manitoba and Northwestern Ontario of a decades-old natural gas pipeline to transport heavy crude, or tar sands oil, diluted with natural gas products to make a product called Diluted Bitumen (DilBit). The pipeline that would be converted was not built to transport Alberta Dilbit.
In Marshall, Michigan in July 2010, an Enbridge pipeline carrying Alberta DilBit leaked over 1,000,000 barrels of DilBit into the Kalamazoo River. A study was done by the Natural Resources Defense Council in the U.S. on tar sands pipeline safety risks and found that DilBit is highly corrosive and acidic, creating significant risks for pipeline leaks. Corrosion was found to be a major factor in the spill in Marshall, Michigan. High heat and increased pressure is also required to transport DilBit through the pipes. Currently the NEB does not have any specific regulations for transporting DilBit through pipelines).
The NRDC report found that the Alberta pipeline system, which transports DilBit, has experienced 16 times as many spills due to the internal corrosion of the pipes. DilBit spills are also more difficult to detect due to the gas dilutants creating a gas bubbles within the pipe that slows the flow of oil. The Marshall, Michigan spill took Enbridge 12 hours to determine a leak had occurred and another seven hours to inform emergency responders.
To date, TransCanada has not claimed that there will be specific measures to mitigate the risks to pipelines posed in particular by DilBit, in the areas of pipeline technology, spill detection, and emergency response planning. An addition, a safety audit done by the NEB found TransCanada to be non-compliant in the areas of hazard identification, risk assessment and control; operational control in upset or abnormal operating conditions; inspection, measurement and monitoring; and management review.