Letter: Fact, diluted bitumen floats

Letter to the Editor from Kevin Demas detailing some of the science of diluted bitumen's behaviour.

Editor, The Gazette:

The “Public in the Dark about Pipeline” letter by Susan Wilkin has a very disputable fact that needs to be corrected…and the 209 conditions the panel set out more than cover the other points put forward.

A lengthy discussion on the subject of diluted bitumen’s behaviour in sea water took place in Prince Rupert last week at the Joint Review Panel hearings examining Northern Gateway’s marine emergency response planning. Evidence on the record shows that diluted bitumen acts like many other common oil types in water.

There are significant adverse effects when crude oil is spilled in the ocean. Diluted bitumen is less dense than water and therefore floats. Project opponents have said that diluted bitumen sinks in open water and is therefore next to impossible to clean up. This isn’t true and there is no evidence on the record to support this claim.

Dr. Alan Maki, an oil spill response expert testifying at the JRP hearings in Prince Rupert on Feb. 5, 2013, told the hearing, “It’s fundamental physics that everything has a specific gravity relative to water. Water is 1.0. All the compounds we’re talking about range from .75 up to .92, .93. It is an immutable fact of physics that they will float.”

The products Dr. Maki was referring to are the crude oil products Northern Gateway intends to ship: diluted bitumen and synthetic crude oil. It’s also important to note that sea water’s density is higher than 1.0, more like 1.02. Compounds with densities lower than 1.02 will float.

But there are other factors at play here as well. All oils weather when exposed to the environment. Oil’s physical properties are changed by wind, waves, sunlight and other environmental exposures over time. As oil weathers, it can become denser. So what matters is the answer to this question: Does weathered diluted bitumen become denser than sea water?

Some have suggested that diluted bitumen weathers rapidly, with diluent evaporating, leaving bitumen behind to sink. This isn’t true. Diluted bitumen does not weather to a pure bitumen state.

Northern Gateway conducted tests to measure the density of weathered diluted bitumen under simulated conditions. At no time during the two-week-long tests did diluted bitumen weather to a density greater than water.

It’s also a fact that pockets of submerged crude oil have occurred when crude oil—oil types including, but not specifically isolated to, diluted bitumen—has been spilled into moving bodies of water like oceans, lakes, rivers and streams.

Water in the “real world” is not plain water. Sediments are often suspended in water because of energetic physical motions like waves.

Agitation will separate oil from sediment; the oil then floats back to the surface. This has been a successful tactic for cleaning up submerged oil in the Kalamazoo River.

Northern Gateway’s first priority is to ensure that oil is not spilled. In the unlikely event of a spill, Northern Gateway’s world-class, science-based emergency response planning will be there to act quickly to minimize any adverse environmental effects.

Kevin Demas,

Grand Forks


Grand Forks Gazette