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Pipelines vs rail for moving oil safely - a close call
Notwithstanding the appalling train disaster in Quebec this month, U.S. government accident data show both railroads and pipelines are relatively safe ways to move crude oil and other hazardous liquids over long distances.
The Canadian derailment and subsequent explosion, which killed at least 15 people and left dozens more unaccounted for, has sparked a renewed debate about whether it is safer to move crude and other hazardous liquids by tank car or pipeline.
Back in May, Canada’s Prime Minister Stephen Harper warned that rejection of the proposed Keystone XL Pipeline would lead to an increase in oil shipments by rail, which he called “more environmentally challenging” than pipelines.
Keystone supporters are poised to cite the derailment as evidence that pipelines are safer. But the rail industry has already begun to push back. “Rail has fewer spills that release less crude oil than other transportation modes,” according to the Association of American Railroads (AAR).
The association has published a battery of statistics to show pipelines have more and bigger spills than rail operators. It estimates railroads spill just 0.38 gallons for every million barrel-miles of crude moved, compared with an estimated spill rate of 0.88 gallons on the pipeline network.
A barrel-mile is measure of through-put that signifies one barrel moved one mile.
So who is right? Is it safer to ship crude by pipeline rather than tank car? The answer: it depends.
Amount Spilled is Small
The first and most important point is that the amount of crude and other dangerous liquids spilled on both the railroads and the pipeline network is small when compared with the enormous volume of crude and other flammable, explosive and toxic liquids they carry every year.
In the United States, there are over 182,000 miles of pipelines carrying hazardous liquids, according to the Pipeline and Hazardous Materials Safety Administration (PHMSA), which regulates both the pipelines and dangerous materials carried on any other mode of transport such road, rail, air and sea.
In 2011, the total volume of hazardous liquids transported on the pipeline network hit a record 5,888 billion barrel miles.
Crude accounted for accounted for around 30 percent of the volume transported (1,813 billion barrel-miles).
But hazardous pipelines also carried refined products (1,602 billion barrel-miles), highly volatile liquids like propane (539 billion barrel-miles), and carbon dioxide (1,932 billion barrel-miles) which is toxic in high concentrations.
Over the last decade, U.S. hazardous liquid pipelines have spilled fewer than 30 barrels of crude and other hazardous liquids for every billion barrel-miles transported.
The number of fatalities as a result of serious and significant incidents has averaged fewer than two a year (with five more injuries). Damage to property has averaged $218 million.
The government does not publish directly comparable statistics on the volume of crude and other hazardous liquids carried on U.S. freight trains, so it is difficult to provide precise comparisons for the railways. Most estimates are based on a confidential sample of waybills (transit records) obtained from the Surface Transportation Board, which regulates freight rates in the rail industry.
Historically, the volume of hazardous liquids moved by train has been 1-2 orders of magnitude smaller than by pipeline. But the AAR statistics, which are based on its own proprietary data and waybill-derived volume estimates, suggest the spill rate is very similar to the pipelines, and the industry operates very safely in general.
PIPELINES MUST SHUT PROMPTLY
Which method of transport is “safer” depends on whether the object is to minimise the number of spills (in which case pipelines have the advantage) or their size when they do occur (in which case rail freight is better).
Pipelines are very safe but they move enormous volum
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