Exxon Mobil was working to clean up thousands of barrels of oil in Mayflower, Arkansas, after a pipeline carrying heavy Canadian crude ruptured, a major spill likely to stoke debate over transporting Canada’s oil to the US.
Exxon shut the Pegasus pipeline, which can carry more than 90,000 barrels per day of crude oil from Pakota, Illinois, to Nederland, Texas, after the leak was discovered on Friday afternoon, the company said in a statement.
Exxon, hit with a US$1.7 million fine by regulators this week over a 2011 spill in the Yellowstone River, said a few thousand barrels of oil had been observed.
A company spokesman confirmed the line was carrying Canadian Wabasca Heavy crude. That grade is a heavy bitumen crude diluted with lighter liquids to allow it to flow through pipelines, according to the Canadian Energy Pipeline Association (CEPA), which referred to Wabasca as “oil sands” in a report.
The spill occurred as the US Department of State is considering the fate of the 800,000 barrels per day Keystone XL pipeline, which would carry crude from Canada’s oil sands to the US’ Gulf Coast. Environmentalists, concerned about the impact of developing the oil sands, have sought to block its approval.
Supporters say Keystone would help bring down the cost of fuel in the US.
The Arkansas spill was the second incident last week in which Canadian crude spilled in the US. On Wednesday, a train carrying Canadian crude derailed in Minnesota, spilling 56,000 liters of oil.
Exxon expanded the Pegasus pipeline in 2009 to carry more Canadian crude from the Midwest to the US’ Gulf Coast refining hub and installed what it called new “leak detection technology.”
Exxon said federal, state and local officials were on site and the company said it was staging a response for a spill of more than 10,000 barrels “to be conservative.”
Clean-up crews recovered about 4,500 barrels of oil and water.
“The air quality does not likely present a human health risk, with the exception of the high pooling areas, where clean-up crews are working with safety equipment,” Exxon said in a statement.
US media said the spill was in a subdivision. Mayflower city police said the oil had not reached Lake Conway nearby. The US Environmental Protection Agency categorized the rupture as a “major spill,” Exxon said, and 22 homes were evacuated following the incident.
A spokesman for the US Department of Transportation confirmed that an inspector from the Pipeline and Hazardous Materials Safety Administration had been sent to the scene to determine what caused the failure. The Environmental Protection Agency is the federal on-scene coordinator for the spill.
Several environmentalists say that oil sands crudes are more corrosive than conventional oil, although a CEPA report, put together by oil and gas consultancy Penspen, said diluted bitumen was no more corrosive than other heavy crude.
The US Department of Transportation last week proposed a fine of US$1.7 million for Exxon over pipeline safety violations relating to a 2011 oil spill in the Yellowstone River.
Exxon’s Silvertip pipeline, which carries 40,000 barrels per day of crude in Montana, leaked about 1,500 barrels of oil into the river in July 2011 after heavy flooding in the area.