Skip to main content

Vessels used in response to a hazardous spill sit on the waters of Vancouver Harbour as the federal government announces changes to improve oil tanker safety on Monday March 18, 2013. One of the country’s top oil spill experts says exports of heavy crude pose added risks to the West Coast, since some oil sands blends are likely to sink in the case of a spill, complicating potential cleanup efforts.DARRYL DYCK/The Canadian Press

Natural Resources Minister Joe Oliver this week told a Vancouver audience that British Columbians have nothing to fear from Pacific exports of Canadian oil sands crude.

"We have taken significant measures to protect against a spill," the minister said.

But one of the country's top oil spill experts says exports of heavy crude pose added risks to the West Coast, since some oil sands blends are likely to sink in the case of a spill, complicating potential cleanup efforts.

Years of research make clear that some kinds of diluted bitumen will not float in an accident, says Merv Fingas, the former chief of research and development for a group at Environment Canada that specialized in oil spills. Instead, the oil-thinning diluent in the crude will evaporate. The remaining bitumen, if it is heavy enough, will drop through the water, where the highly sticky substance can adhere to rocks and other sediments, making cleanup difficult.

Determining whether spilled oil sands crude will float is a key question for those weighing shipments of oil to Pacific markets. Critics say the possibility of a product that sinks increases the environmental risks of such oil shipments, raising another obstacle for industry's ambitions.

But Enbridge Inc., the pipeline builder seeking to build the Northern Gateway pipeline, has sought to assure the National Energy Board that the products it intends to carry west will stay on the surface, where they can be cleaned up using skimmers and other tools.

"It is an immutable fact of physics that they will float. They simply cannot sink in water," Dr. Alan Maki, who holds a Master's in aquatic biology and has served as a witness for Enbridge, told the NEB in February.

In an interview, Mr. Fingas said "that's not true." The diluent, he said, "comes off fairly rapidly, so you really have to look at the density of the base compound, the bitumen underneath it."

Bitumen is different depending on its source, but some has a higher specific gravity than seawater, Mr. Fingas said. "So some bitumen will sink and some will not," he said. He added: "Every time we did get a sample of any kind of bitumen in the laboratory and analyzed it, it always sank."

Mr. Fingas holds a PhD in environmental physics, plus three Master's and two undergraduate degrees. He has been involved with over 800 papers and publications, as well as six books on spills. He was one of three scientists chosen by the U.S. National Oceanic and Atmospheric Administration to estimate the amount of oil spilled in the Gulf of Mexico in 2010.

Mr. Fingas supports Pacific oil sands exports, saying it's economically necessary for Canada. And bitumen, he said, has fewer soluble toxins than light oil, making it much safer to aquatic life if spilled.

But the possibility that bitumen won't float has raised alarm in B.C. Sinking bitumen makes an already "really messy situation" in the case of a spill "orders of magnitude more difficult," said Eric Swanson, a director for the Victoria-based Dogwood Initiative. Art Sterritt, executive-director with Vancouver-based Coastal First Nations, said heavy crude could deal a double blow in case of an accident: "It's going to float for a while and it's going to wipe out the foreshore, then it's going to sink and it's going to wipe out the bottom," he said.

Enbridge has presented research to the NEB that tested two types of diluted bitumen. While some 15 per cent of the oil fell 10 centimetres below the surface of the test facility, "at no point was oil found to submerge, sink, and stick to the bottom of the flume," the report found.

In a statement, Enbridge spokesman Todd Nogier said making diluted bitumen creates "a new product" that is "not likely to sink in areas away from the shoreline in marine environments." He added that oil "may sink" near shore if it "interacts with sediments." Enbridge has been ordered to dredge parts of the Kalamazoo River after remnants of a heavy oil spill remain in the Michigan waterway.

A 1999 study by the U.S. National Research Council found that in heavy oil spills, 20 per cent of the crude sank, compared to 4 per cent in all spills. Ottawa has pledged more study. On Monday, Natural Resources Minister Mr. Oliver said the government will examine how bitumen behaves "when spilled in the marine environment."

Environment Canada's studies of bitumen in spills date back to 1995, Mr. Fingas said. The current government, however, has substantially cut back that work. Mr. Fingas spent 33 years with Environment Canada before quitting in 2006, ahead of cuts that he said trimmed its environmental emergencies research work force from 45 to roughly 15, and eliminated the two aircraft it used for studies. That has hamstrung capabilities Mr. Fingas worked to build.

Report an error

Editorial code of conduct

Tickers mentioned in this story

Study and track financial data on any traded entity: click to open the full quote page. Data updated as of 23/02/24 4:10pm EST.

SymbolName% changeLast
Enbridge Inc
Enbridge Inc

Follow related authors and topics

Authors and topics you follow will be added to your personal news feed in Following.

Interact with The Globe