• Diluted bitumen previously thought to sink, hampering cleanup
  • Pipeline projects face opposition over spill concerns

The debate over what happens to oil-sands crude in a freshwater spill just got a new twist -- one that could help unlock stalled pipelines.

A study funded by the Canadian government shows diluted bitumen doesn’t sink as readily as conventional oil when spilled in fresh water, upending previous assumptions. Instead, it floats, unless exposed to high temperatures and weathering.

The results may help dispel some concern that a spill of diluted bitumen would be more difficult to clean up and help companies make the case for pipeline projects such as Kinder Morgan Inc.’s Trans Mountain expansion. Investors are watching closely, said Andrew Logan, director of the oil and gas program at Ceres, an investor network promoting sustainable business practices.

“This kind of study is important because there is a battle among crudes" to supply the market, said Logan. Ceres represents investors with $14 trillion worth of assets. More understanding of how to mitigate the risks of heavy oil in a spill would help make the crude more accepted, he added.

Facing Opposition

The Canadian government is preparing a decision on Trans Mountain, which crosses rivers in British Columbia on its route to the Pacific. The province has opposed that pipeline and Enbridge Inc.’s Northern Gateway because of inadequate spill preparation. The risks of spills also featured in the debate -- and ultimate failure -- of TransCanada Corp. to win approval for its Keystone XL line.

The study was funded by the Canadian government, while the oil industry provided the products to be tested and had no input in the design or interpretation of the research, said Heather Dettman, a researcher at Natural Resources Canada’s laboratory near Edmonton who led the study. The results were presented at an environmental contamination conference in Halifax earlier this month.

The study follows a 2015 report by the U.S. National Academy of Science that showed dilbit tended to quickly sink after being spilled in fresh water, requiring the use of dredgers or divers with vacuums to extract the oil from the sediment at the bottom of rivers.

“The question is always does dilbit float or sink,” said Dettman said. “What we found is that the oil was floating but we also found that the lighter oils mixed in with the water, like adding cream to coffee.” Clean-up crews would still have a narrow window to recover the spilled fuel before it causes damage.

Higher temperatures, which reached 29 degrees Celsius (84 Fahrenheit) during Enbridge’s 2010 spill on the Kalamazoo River in Michigan, accelerate the dispersal of heavy oil in water, according to the study. Cooler temperatures would allow more time to clean up a spill before the oil eventually settles on river bottoms.

Enbridge’s emergency response systems focus efforts on surface collection and absorption in the early stages of an event to help collect floating bitumen, said spokesman Graham White.

Pipeline Plans

Responders are currently poorly equipped to deal with such accidents, according to the 2015 report by the National Academy of Sciences, which called for “unique” approaches to diluted bitumen spills.

“The growth of heavy oil is relatively recent and regulators have been slow to recognize the threat it poses,” said Anthony Swift, a director at Natural Resources Defense Council. “For now, we are dealing with a regulatory regime that treats all oil the same.”

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