Exxon Pegasus Pipeline Floods Mayflower, Arkansas, With Low-Grade Oil

On Saturday, Exxon Mobil’s Pegasus pipeline, which carries up to around 90,000 barrels per day of Canadian crude oil from Illinois to Texas, developed a leak and caused thousands of gallons of low-grade bitumen oil to gush from the pipe. The thick black liquid flooded a suburban area of Mayflower, Arkansas, forcing twenty-two families to evacuate.

The Environmental Protection Agency classified the event as a "major spill;" as of Monday, 12,000 barrels had been recovered. According to the U.S. Transportation Department's Pipeline and Hazardous Safety Administration's order to fix the leak, the exact cause of the leak is still unknown. This leak comes only a few days after a train carrying Canadian oil spilled 15,000 gallons, and two years after Exxon was fined $1.7 million for a spill in the Yellowstone River.

The Pegasus pipeline carries low-quality oil from Canada’s oil-rich tar sands; according to environmentalists, this sort of oil is more corrosive than others, and for this reason pressure the Obama administration to reject the proposed Keystone XL pipeline. A report from Penspen, a consulting firm working for the Canadian Energy Pipeline Association, denied this allegation, stating that the "diluted bitumen" oil in the Pegasus pipe was no more corrosive than other heavy crude. In any case, this latest accident is sure to intensify concerns about current safety policy involving oil pipelines, especially regarding the proposed Keystone XL pipeline which would travel from Canada to the Gulf of Mexico.

What alternatives to oil pipelines do we have? Compared to the feasible alternatives — ships and trains — pipelines are clearly the most convenient method of oil transportation. With that in mind, some of the best ways of minimizing the damage potential include careful pipe placement and more frequent problem detection. In this regard, the nature of the Pegasus pipeline is somewhat dubious.

The pipeline, built in the late 1940s, travels across 13 miles of watershed land — an area which supplies much of Little Rock’s drinking water — and was last inspected, or "pigged," for flaws in the summer of 2010. There is a limit to what can be done to minimize risk, but systematic refurbishing of old lines, careful placement, and more frequent flaw detection are likely the best ways to minimize the inherent risks of oil pipelines. 

That said, the main cause for concern in this context is the alleged corrosive effects of tar sand oil; with contradictory evidence, it is difficult to know just what the corrosive properties actually are. Until this evidence is sorted out, the abovementioned efforts might be the best options in the effort to minimize the risks of oil transportation.