The Chronicles of Dilbit, Part 2

This is Part 2 in a series. For Part 1, click here. 

The Canadian Energy Pipeline Association isn’t the only company trying to salvage diluted bitumen's – aka dilbit's – public image.

Amidst the controversy surrounding the Joint Review Panel hearings on the Enbridge Northern Gateway Pipeline, Enbridge reached out directly to some of its most vocal opponents on Twitter, including Vancouver-based author John Vaillant, activist Bill Hiller and UBC mathematician Mark Maclean.

The company claimed it had a report that would give the final word on whether dilbit sinks or floats in seawater: "crude oils, including diluted bitumen are less dense than water and therefore float."

This claim was a direct contradiction to observations described in the National Transportation Safety Board’s (NTSB) report on the 2010 Kalamazoo River spill, which observed, “Once the crude oil mixture (oil and diluents) enters the environment, weather factors, volatility, and physical agitation affect the composition, thus allowing some of the oil to sink into river sediments and collect on the river bottom.”

In response to one commenter on the website, Enbridge wrote “when oil combines with sediments, it can sink. This is what happened in Kalamazoo. However, it should be noted that only a small amount of the oil that was released from Line 6B ended up submerged.”

This again contradicted the findings in the NTSB report, which described a significant amount of oil – moderate-to-heavy contamination – was still present in the river bed one year after the spill.

“Enbridge began collecting sediment samples on July 27 to determine the impact of the spill on the river system,” the report recounts. “By August 2010, field personnel noticed the presence of submerged oil. Starting in September 2010 and continuing throughout the winter, Enbridge removed the submerged oil by dredging, excavating, and aeration. In spring 2011, an EPA-directed reassessment found a moderate-to-heavy contamination covering over 200 acres of the river bottom. In August 2011, the EPA directed Enbridge to remove the remaining submerged oil.”

The NTSB report went on to say, “The large volume of oil that escaped the source area also contributed greatly to the estimated $767 million cleanup for this accident. Nearly 2 years after the accident, crews are still removing submerged oil and contaminated soils miles from the release site.”

Given the overwhelming evidence of the NTSB report, even TransCanada was forced to acknowledge that, “Crude oil does sink if it is allowed to weather and mix with dirt over time, making a swift response to a spill in water critical. In turbulent water, it is typically driven to the bottom of the river where it tends to stick to rocks, which can make clean-up more difficult.”

So what could account for the difference between Enbridge’s lab tests and the NTSB’s observations?

Anthony Swift of the National Resource Defense Council says it might come down to a case of mistaken identity. He points out that crude oils often go by one name for technical purposes and another name for marketing purposes. He contends that the Cold Lake crude that Enbridge tested in their lab was not the same as the crude that ended up in the Kalamazoo River. Chances are, it wasn’t even dilbit.

“Enbridge in its study said it evaluated Cold Lake crude,” says Swift. “The problem with Cold Lake crude is it’s a name under which several blends of diluted heavy crudes are marketed. Some of them are diluted bitumen and some of them are diluted heavy crudes. Cold Lake is also a technical name for a blend of crude which is a conventional heavy crude.”

He explains that diluted bitumen under pressure in a pipeline is lighter than water, but when that mixture is exposed to air, as it was in the Kalamazoo River spill, the diluent—often a natural gas condensate—evaporates, leaving behind the much heavier bitumen to sink to the bottom.

Although there are few independent studies into the characteristics of bitumen, a chapter in the UNESCO Encyclopedia of Life Support Systems by Wyoming researcher Dr. James G. Speight puts the average density of tar sands bitumen at 8 API, which is heavier than water’s 10 API and therefore sinkable.

Swift says that the “issue with the Enbridge study was, given the importance of knowing the heaviness of the bitumen they were working with, they didn't mention that, which is a bit of a tell. The omission of the key fact that they should be testing for is a problem.”

“If one were inclined to be disingenuous, one could do so fairly easily,” he says.

He believes that the key to ending the spin on dilbit is transparency, including independent studies into its characteristics that are not spearheaded by industry.

“Ideally we would have had studies evaluating the behaviour of diluted bitumen before it was being moved in pipelines,” says Swift. “What's really shocking is we still don't have an independent study evaluating the behaviour of diluted bitumen nearly three years after the worst onshore pipeline accident in US history revealed the problem.”

Image Credit: Environmental Protection Agency