"Residents of the central Arkansas town of Mayflower were preparing for a calm Easter weekend when their plans unexpectedly changed. On Friday, March 29, the Exxon Pegasus pipeline burst, flooding this tiny Little Rock suburb with as much as 200,000 gallons of tar sands crude. Many residents say they didn’t even know about the pipeline, which carries Canadian petroleum from Illinois to Texas.
"We could see oil running down the road like a river," a Mayflower resident told TV station KTHV. A week later, 22 homes remain evacuated, while cleanup efforts have been complicated by bad weather and the unique characteristics of tar sands crude.
As the Natural Resources Defense Council’s Anthony Swift explains, '[T]he Pegasus line was carrying Wabasca Heavy diluted bitumen — a toxic climate mix of heavy tar sands bitumen and volatile petrochemical diluents,' like benzene, a toxic and carcinogenic solvent that helps keep the bitumen in liquid form. At room temperatures, undiluted bitumen is a solid (asphalt is mostly bitumen).
Once this mixture is exposed to air, the solvents begin to outgas, creating toxic fumes that are a danger to wildlife and human health. And if the thick slurry makes it to a waterway, problems compound fast. Unlike light crude, tar sands crude sinks, rendering conventional clean-up approaches — skimmers, vacuums, and floating booms — irrelevant."
Stacie Boschma reports for Mother Nature Network April 5, 2013.