WASHINGTON — An oil spill that polluted an Arkansas town is drawing new scrutiny to the risks of transporting fuel across a national labyrinth of pipelines as President Barack Obama weighs whether to approve Keystone XL.
Environmental groups point to the rupture of the Exxon Mobil pipe on March 29 in Mayflower, Ark., about 22 miles northwest of Little Rock, as a reason why Obama should reject Keystone. Industry groups contend that pipelines remain the safest way to transport oil and other fuels, and that existing regulations are adequate.
"Without question, this underscores the risks of transporting this stuff," Jim Murphy, senior counsel at the National Wildlife Federation, said in a phone interview.
The State Department is weighing whether to recommend that Obama approve the Keystone project. The agency is reviewing the plan because it crosses an international border. White House press secretary Jay Carney said Monday the White House takes the safety of the pipeline system "very seriously." He said the Environmental Protection Agency is working with local officials and Exxon on the Arkansas spill.
Republicans and some Democrats in Congress argue Keystone will create thousands of jobs and improve U.S. energy security. The Senate on March 22 approved 62-37 a non-binding resolution encouraging development of the project. If built, the pipeline each day could carry more than 800,000 barrels of diluted bitumen, or dilbit, from Alberta to refineries along the Gulf Coast.
Exxon's pipeline, known as Pegasus, can carry 96,000 barrels a day. The 20-inch line runs to Nederland, Texas, from Patoka, Ill.
Michael Brune, executive director of the Sierra Club, a San Francisco-based environmental group, in a statement called the spill "another reminder that oil companies cannot be trusted to transport toxic tar-sands crude through Americans' backyards, farmlands and watersheds."
One question central to the debate is whether the diluted bitumen is more corrosive than conventional heavy crude.
Crude from Alberta's oil sands can pose a greater risk if it is transported at a higher temperature or under greater pressure, Richard Kuprewicz, president of Accufacts Inc., a Redmond, Wash.-based pipeline safety consultant, said today in a phone interview.
Operators using modern pipeline-safety techniques can manage any increased corrosion potential by cleaning out the line more frequently or carefully monitoring how the bitumen is diluted, he said.
"You just don't write off the corrosion threat, you've got to be sure you're managing it," he said. "There isn't a yes or no answer here. Have you identified the risk and are you dealing with it? Corrosion is just one bank of risk threats associated with dilbit."
The National Wildlife Federation, based in Reston, Va., asked the U.S. government last month to develop stronger standards for transporting tar-sands oil.
The group said in a statement that the fuel from the tar sands has the consistency of "gritty peanut butter." Because it's heavier than conventional crude, it is often tougher to clean up, particularly if it leaks into water bodies where it sinks to the bottom rather than floating on top, Murphy said.
The Environmental Protection Agency last month directed Enbridge Inc. to perform more dredging in Michigan's Kalamazoo River as part of a cleanup from a July 2010 rupture of a 30-inch pipeline that also carried heavy crude.
More than 843,000 gallons spilled during the leak. The oil flowed into Talmadge Creek before entering the Kalamazoo River, coating birds, muskrats and turtles in an oily residue.
Last year, there were 364 spills from pipelines that released about 54,000 barrels of oil and refined products, according to the Pipeline & Hazardous Materials Safety Administration, a division within the Department of Transportation. Any incident in which more than five gallons of fuel leaked is counted as a spill.
Each year, about 11.9 billion barrels of oil, gasoline and other refined products are pumped across the network of pipelines, said John Stoody, director of government and public relations for the Association of Oil Pipe Lines, a Washington- based group whose members own about 85 percent of the liquid pipelines in the U.S.
"Incidents do happen, but they're rare," Stoody said. There are 119,000 miles of pipelines carrying crude oil and refined products in the U.S., Stoody said.
"The properties of Canadian oil sands crude are similar to other heavy crudes from California, Venezuela and other places and transported safely across the U.S. for decades," Stoody said in an email.
In Arkansas, Exxon has said it collected about 12,000 barrels of oil and water, according to a statement Sunday from the Mayflower Incident Unified Command Joint Information Center. The town recommended that 22 homes be evacuated, it said. Exxon said no oil had reached nearby Lake Conway.
Shawn Howard, a spokesman for TransCanada, said the company has agreed to higher safety standards with U.S. regulators for the Keystone XL, such as increasing the number of shutoff valves, boosting inspections and burying the pipe deeper in the ground.
The Arkansas spill "is an unfortunate circumstance and demonstrates the pipeline industry must continue to focus on the safe, reliable operation of its energy infrastructure," Howard said in an email. "Americans consume 15 million barrels of oil every day to heat their homes, cook their food and start their cars. Oil and petroleum products are part of our daily lives."