Pembina Institute

Dangerous goods: new report highlights risks of shipping raw oilsands

The Natural Resources Defense Council (NRDC) has shed new light on the dangers of shipping raw oilsands through pipelines today.

This major U.S. environmental organization's findings have implications for both the proposed TransCanada Keystone XL pipeline to the U.S. and the Enbridge Northern Gateway proposal, and should be heeded by governments and the public alike.

When raw oilsands are diluted with natural gas condensate, to make pipeline transportation easier, a mixture called diluted bitumen, or DilBit, is created. NRDC has analyzed this concoction, and found it to be highly corrosive and acidic, posing new and significant risks of pipeline leaks.

Worse, they found that high heat and increased pressure are required to transport the thick mixture more safely through pipelines — yet pipeline companies are using conventional pipeline technology to transport DilBit and U.S. safety and spill response standards are designed for conventional oil.

In Canada it is a similar story. The National Energy Board does not have any specific regulations to address DilBit pipelines. It is up to the pipeline operator to adhere to the more general onshore pipeline regulations and have an adequate safety management system. Moreover, in the Northern Gateway application there is no mention of how Enbridge will address the increased risks associated with shipping DilBit. These findings are alarming, and given the recent pattern of industry mishaps, is something that regulators and the public must begin to address.

NRDC found that the Alberta pipeline system — which routinely carries DilBit — has had about 16 times as many spills due to internal corrosion as the U.S. system.

Further, leaks in DilBit pipelines can be more difficult to detect because the natural gas condensate, the substance used to dilute raw bitumen, can change from a liquid to a gas, forming a gas bubble or "column separation" in the pipeline and slowing the flow of oil. This gas bubble presents many of the same signs as a pipeline leak, making it difficult to tell when a leak is actually happening. This is what is reported to have occurred in Enbridge's Kalamazoo River spill last summer. It took Enbridge 12 hours to notice that the "column separation" was actually a 20,000-barrel leak ($1.7 million of oil at today's price) and shut down the pipeline and another seven hours to notify emergency responders.   

Aside from presenting an increased risk of pipeline leaks, NRDC also found DilBit poses increased risks to the environment and human health. The natural gas condensate used to dilute bitumen has a low flash point and high vapour pressure, which causes it to be explosive even at sub-zero temperatures.  

DilBit also contains toxins, such as benzene, heavy metals and polycyclic aromatic hydrocarbons, which can be dangerous in the short term for the human central nervous system and carcinogenic over the long term. Reports indicate some of these health effects were demonstrated after Enbridge's Michigan spill. Sixty per cent of residents near the spill experienced respiratory, gastrointestinal and neurological symptoms consistent with acute exposure to DilBit.

To top it off, DilBit presents even more significant cleanup challenges in the case of a spill. Unlike conventional crude oil, which floats on top of water, DilBit is heavier than water and will sink into wetland or river sediments. Many of the conventional skimmers and booms will likely not be effective in cleaning up a spill of raw bitumen, which would settle into waterways and sediment. This risk is particularly notable in relation to the Northern Gateway pipeline, where the risk of a spill into salmon spawning waters is real.

These are all significant issues and should raise serious questions about the benefits of oilsands pipelines. These questions are particularly relevant for the Joint Review Panel that is currently considering Enbridge's proposal to build a pipeline that could potentially carry 525,000 barrels of DilBit per day from Alberta to B.C.'s Great Bear Rainforest.

What specific measures Enbridge has taken to mitigate the risks posed by DilBit - be it pipeline technology, leak detection or emergency planning? How will Enbridge ensure that the Kalamazoo River spill will not be repeated in the Skeena or Fraser watersheds?

And the danger doesn't end when the DilBit leaves the pipeline. What is the effect of corrosive, acidic DilBit on the oil tankers that will dock in Kitimat and travel through Canadian waters? Many of these tankers will carry eight times more oil than the Exxon Valdez. The responsibility to ensure safety and emergency response standards account for the unique risks posed by DilBit falls to the National Energy Board. 

Enbridge needs to acknowledge and address the increased threats of transporting diluted bitumen in trying to justify whether the Northern Gateway pipeline is in the public interest. Until then, there are more questions than answers.

Read more blogs relating to Alberta, British Columbia, Federal Action, Oil & Gas, Pipelines, USA.

Gerry Phillips — Jan 04, 2012 - 07:09 PM MT

You really don't understand physical chemistry to make the statements you have regarding the flammability of Dilbit. The flash point of the mixture will depend on the concentration of diluent and the inherent Flash Point of the diluent. Flash Point is another way of saying concentration. The total concentration of vapour above a homogeneous mixture is given by Raoult's Law as the sum of the partial pressures of the individual components. The concentration of any single component is the vapour pressure times the mol fraction. If the flash point of the diluent is -18 C, as given in the paper, the flash point of the mixture must be higher. The actual value will depend upon the concentration of the diluent and the bitumen. It's very possible that the mixture will not be flammable at the temperature it is being shipped.

James Chen — Apr 09, 2012 - 12:17 AM MT

It's also very possible that the mixture will be flammable at the temperature is proposed to be shipped, depending on the concentration, or at the temperature
of the mixture when something goes wrong. Your comment is rather narrow in scope.

Thomas Cheney — Sep 21, 2011 - 04:10 PM MT

Hi was wondering if Canadian pipelines are stronger than American ones. That was what I was reading in

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