Diluted bitumen tar sands study answers the wrong question

The Pipeline and Hazardous Materials Safety Administration (PHMSA) has released its study of the safety of diluted bitumen tar sands pipelines, conducted by the National Academy of Sciences (NAS). Unfortunately, the federal pipeline regulators gave the NAS a very limited scope of study, excluding many of the pressing environmental risks associated with diluted bitumen tar sands pipelines from consideration. The NAS literature review compared tar sands to similar heavy thick crudes coming from Canada that have similar properties and risks, rather than comparing them to the lighter oils historically transported in the U.S. pipeline system. The study did not account for the greater spill pipeline rates observed in states moving the largest volumes of diluted bitumen over the longest time period in the United States and ignored the behavior of diluted bitumen when spilled in water bodies.  As NRDC has said for years, there is still a need for better information on the risks of diluted bitumen tar sands pipelines to our lands and waters.

The NAS concluded that diluted bitumen tar sands and heavy crude present similar to risks to pipelines. NRDC reached a similar conclusion years ago before the diluted bitumen study was commissioned by Congress. As we said then, “like diluted bitumen, the production and export in pipelines of large volumes of heavy Canadian crudes is a relatively recent development which has not been accompanied by adequate due diligence on the part of regulators and the industry.” It appears that PHMSA did not ask the NAS to consider the more relevant and useful question at hand. Does the recent influx of Canadian heavy crudes and diluted bitumen tar sands flooding the U.S. pipeline system presents an increased risk to the nation’s communities, waters and lands? Unfortunately, the NAS findings shed no light on that question.  

It should be noted that Congress asked PHMSA for a much broader study. In the “Pipeline Safety, Regulatory Certainty, and Job Creation Act of 2011,” Congress required pipeline regulators to:

[C]omplete a comprehensive review of hazardous liquid pipeline facility regulations to determine whether the regulations are sufficient to regulate pipeline facilities used for the transportation of diluted bitumen. 

This provision came over a year after emergency spill responders were confounded by the Kalamazoo tar sands spill, as submerged heavy tar sands bitumen sank below the water surface, rendering conventional spill response methods and contaminating nearly 40 miles of the river. There were concerns that moving thick, viscous crudes created additional leak detection challenges. And there were concerns that pipelines moving thick heavy crudes, including diluted bitumen, operated at higher temperatures, increasing risks of corrosion.

PHMSA did not deliver on this charge. The agency limited NAS’s scope of work to whether the transportation of diluted bitumen by transmission pipeline has an increased likelihood of release compared with pipeline transportation of crude oils with “similar density and viscosity.” The finding that diluted bitumen tar sands doesn’t pose a greater risk than other thick heavy crude provides little comfort.

The U.S. does refine thick heavy crudes from Venezuela and Mexico – but these crudes are brought in by tanker and processed at coastal refineries. California has a small section of pipelines move heavy crudes at higher temperatures, but as the NAS noted, this system does not include large transmission pipelines and has a higher failure rate. Moreover, northern Midwestern states with the longest history of transporting both tar sand diluted bitumen and Canadian heavy crudes have spilled 3.6 times as much crude oil over the last three years as the national average.

Finally, PHMSA’s failure to task the NAS with evaluating the impacts of diluted bitumen spill presents a major shortcoming. As the NAS concluded:

Future pipeline releases can be expected to occur, and some will involve diluted bitumen. All pipeline releases can be consequential. As explained at the outset of this report, the committee was not asked or constituted to study whether pipeline releases of diluted bitumen and other crude oils differ in their consequences or to determine whether such a study is warranted.

After the tar sands spill in Mayflower, Arkansas and three years after the Kalamazoo tar sands spill, regulators have done the public an injustice by excluding an evaluation of the health and environmental risks of tar sands spills in our rivers and communities. 

Photo: Tar sands spill in Mayflower, Arkansas, March 29, 2013, courtesy of KARK 4 News

About the Authors

Anthony Swift

Director, Canada Project, International program

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