More than seven years have passed since an Enbridge oil pipeline ruptured and spilled more than a millionย gallons of tar sands oil, also known asย diluted bitumen,ย near a tributary leading toย Michigan’sย Kalamazoo River. Once in the water, the oilย โ which spill responders initially did not know was tar sands oil โ ended up sinking to the sediment onย the river bottom and causingย major environmental impactsย for wildlife andย plants.ย
Yet even today, the oil industry still claimsย that tar sands oilย floats.
For example,ย tar sands oil pipeline operator Kinder Morgan has anย FAQย pageย for its Trans Mountain pipeline, and according to that page, one of the company’s topย questions of 2017 was the following:ย โDoes diluted bitumen sink orย float?โ
Diluted bitumen (also known as dilbit) is the industry term for tar sands oil. Dilbit is a mixture of two distinct materials. One is the heavy tar-like bitumen that is mined from tar sands deposits. The other is a highly flammable natural gas condensate that is mixed with the bitumen toย allow aย product that starts out with theย consistency of peanut butter, once diluted,ย to flow through a pipeline or be pumped into a rail tankerย car.
Theย answer to this question of whether dilbit sinks or floats isnโt a simple yes or no. But the response on the Trans Mountainย FAQ page ends up beingย quiteย misleading:
โProducts carried in the Trans Mountain system must meet criteria for density (max 0.94) and viscosity (350 cst). That maximum density of 0.94 means that diluted bitumen is less dense than fresh water (density 1.00) and seawater (density 1.03). In fact, diluted bitumen (or dilbit) has the same spill-recovery characteristics as conventional heavyย oil.โ
Notice how Kinder Morganย didnโt answer the question directly but instead discussed the various densities of water and their products,ย implying that because diluted bitumen in the pipeline has aย density lowerย than water, it mustย float.
On a separate page on the Trans Mountain site, the same information appears under the heading:ย โMyth: Diluted bitumenย sinks.โ
However, a 2015 National Academy of Sciencesย conference on the Effects of Diluted Bitumen on the Environmentย madeย quite clear one keyย lesson of the Kalamazoo incident: Yes,ย diluted bitumen floats immediately afterย released,ย but as soon as it is exposed to the elements, the mixtureย begins changingย โ the light and volatile condensate diluting the bitumen evaporates โ and with timeย the remaining oil productย begins sinking.
Greg Powell of the U.S. Environmental Protection Agency was involved in the Kalamazoo cleanup and he explained this complex reality toย the conference attendees. โOnce the oil started to sink, it made things a lot more difficult on our recovery,โ heย said.
The oil industry has been sticking to itsย claim that diluted bitumen floats, but real-world experience seems to indicate that while dilbit floats for a short time, it soon interacts with the weather, water, and sediments, and ultimatelyย sinks.
In the Kalamazoo case, the oil began sinking within two weeks. And the cleanup took five years and costย over a billion dollars.
National Academyย of Sciences Contradicts Trans Mountainโs Claims โย Withย Science
The 2015 National Academyย of Sciences conferenceย on dilbit’s environmental effects was just one part of aย largerย research effort by the academy,ย which also resulted in a 2016 report on the topic. Thisย report makes clear that diluted bitumen spills in water are โuniqueโ and difficult to clean-up preciselyย because the bitumenย sinks:
โFor any crude oil spill, lighter, volatile compounds begin to evaporate promptly; in the case of diluted bitumen, a dense, viscous material with a strong tendency to adhere to surfaces begins to form as a residue. For this reason, spills of diluted bitumen pose particular challenges when they reach water bodies. In some cases, the residues can submerge or sink to the bottom of the water body.โ
Which is exactly what happened in the Kalamazoo River spill. Trans Mountain is correct that diluted bitumen is less dense than water, but that fact didnโt help the Kalamazoo River. Once exposed to the environment, dilbit breaks downย into its components and the heavy bitumen portionย sinks. And the National Academy found that this could occur even when the bitumen was still less dense thanย water:
โImportantly, the density of the residual oil does not necessarily need to reach or exceed the density of the surrounding water for this to occur. The crude oil may combine with particles present in the water column to submerge, and then remain in suspension orย sink.โ
This report comes to the same conclusions about dilbit sinking as the people working to contain and clean-up the Kalamazoo River spill. However, the reportย also directly contradicts Trans Mountainโs other claim that โdiluted bitumen (or dilbit) has the same spill-recovery characteristics as conventional heavy oil.โ A dilbit fact sheetย from the Canadian Energy Pipeline Association makes a similar case: โIn the event that diluted bitumen were to be spilled, the procedures for cleaning up the spill would be similar to cleaning up a conventional crudeย spill.โ
The National Academyย of Sciences reachesย a far different conclusion: โIn comparison to other commonly transported crude oils, many of the chemical and physical properties of diluted bitumen, especially those relevant to environmental impacts, are found to differ substantially from those of the other crude oils,โ and that โspills of diluted bitumen should elicit unique, immediateย actions.โ
In a move that spells trouble for Kinder Morgan’s Trans Mountain pipeline, the government of British Columbiaย this weekย took steps toย limit the growth of the tar sands oilย industry until scientists and officialsย reachย a better understanding of the impacts of dilbitย spills.
โWe are proposing we restrict the transport of diluted bitumen until we hear back from the B.C. scientific community about the impacts of a spill and what we would need to mitigate that,โ B.C. Environment Minister George Heyman told DeSmogย Canada.
Planning Isย Everything
The National Academy opens its report on diluted bitumen with a quote from President Dwight D.ย Eisenhower:
โI tell this story to illustrate the truth of the statement I heard long ago in the Army: Plans are worthless, but planning is everything. There is a very great distinction because when you are planning for an emergency you must start with this one thing: the very definition of โemergencyโ is that it is unexpected, therefore it is not going to happen the way you areย planning.โ
The recent sinking of the oil tanker Sanchi in the East China Sea is yet another example of how the oil industry moves various oil products across land, oceans, and rivers without having clear plans on how to deal with major spills. That spill involved a tanker full of condensate (the lighter component of diluted bitumen) and is the largest condensate spill ever.
Despite the oil and maritimeย industries’ experience transporting condensate for decades, theyย appear baffled aboutย how to deal with this disaster in the East China Sea. Spill expert Rick Steiner toldย Nature News: โThis is charting new ground, unfortunately. This is probably one of the most unique spillsย ever.โ
The oil industry has a long history of pushing forward recklessly in the pursuit of profit and then claiming ignorance when things go wrong, resulting inย โuniqueโย disasters.
After the deadlyย Bakken oil train disaster at Lac-Mรฉgantic, Quebec,ย the industry assured the public that Bakken oil was safe and no different than other oils. That wasย wrong.
When the Sanchi was initially on fire The Washington Post reported that the Chinese government said that much of the oil โwould probably evaporate in hours.โ That wasย wrong.
And the oil industry continues to claim that diluted bitumen floats in water and is no different to clean up than other oils โ despite the scientificย and real world evidence showing this isnโtย true.
Main image:ย Forward on Climate Rally in Washington, D.C.ย Credit: DCErica,ย CC BY–NCย 2.0
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