Canada's Fraser Institute has published a study which finds that transporting oil by pipelines is more than twice as safe as using rail, and marine tankers are safer still with a markedly improved safety record over the past 40 years.
While oil shipped by tanker has increased from 1.4 billion tons in 1970 to 2.9 billion tons in 2015, the amount of spillage has plummeted by 98 percent.
The report Safety First: Intermodal Safety for Oil and Gas Transportation notes the contentiousness of the planned Trans Mountain, Line 3, and Keystone XL pipelines, and the study evaluated marine tanker safety in light of the additional oil tankers that will result from the expansion of the Trans Mountain pipeline.
“The evidence is clear. Building new pipelines and shipping oil by tanker is the safest and most environmentally responsible way to get Canadian oil to global markets,” said Kenneth Green, Fraser Institute’s senior director of energy and natural resource studies and co-author of the report.
Since the mid-1990s there has not been a single major spill from oil tankers or other vessels in Canadian waters. One recent study conducted by the federal government on marine oil spill preparedness estimated that a major spill of over 10,000 tons was exceedingly rare and likely to only occur once every 242 years. Likewise, a spill of 100 to 1,000 tons is expected to occur once every 69.2 years.
Marine safety has also improved dramatically since the 1970s. For example, when comparing the number of spills in the 1970s to the 2010s (up to 2016) using international data, the number of spills between seven and 700 tons has decreased from 543 to 35, and in this same period the number of large spills (>700 tons) has declined from 245 to 12. The amount of oil spilled has also dropped dramatically, falling from three million tons in the 1970s to only 39,000 tons in the 2010s.
In addition, compared to pipelines and rail, marine tanker transport is found to result in the fewest number of accidents per million barrels of oil transported. Overall, between 2004 and 2015, pipelines experienced approximately 0.05 occurrences per million barrels of oil equivalent (Mboe) transported.
The transportation of oil results in fewer occurrences than the transport of natural gas. Transporting petroleum products by pipelines resulted in approximately 0.04 occurrences per Mboe compared to 0.07 for natural gas products. This means that the rate of occurrences for transporting natural gas products was 1.67 times greater than the rate of occurrences for petroleum products.
However, occurrence rate only tells part of the story. In addition to having low occurrence rates, almost 70 percent of pipeline occurrences result in spills of less than one cubic meter (17 percent result in no spill). Only 17 percent of pipeline occurrences take place in the actual line pipe, meaning that the vast majority of spills occur in facilities that often have secondary containment mechanisms and procedures.
The results were similar for rail, where the transportation of oil was found to result in fewer accidents per Mboe transported than natural gas. Also similar to the data on pipelines, most rail accidents occurred in facilities rather than in transit.
The report is available here.