David Hatfield, an Arkansas wildlife photographer and minister, rose before dawn on Monday and headed to Lake Conway.
Even though he had lived nearby for 25 years, Hatfield never knew of the threat now oozing near this 6,700-acre habitat 25 miles north of Little Rock, the largest game and wildlife commission reservoir in the United States.
"It surprised me that we had a pipeline here," he said.
But ExxonMobil's Pegasus pipeline has been buried here for more than six decades, quietly propelling oil between Texas and Illinois beneath the backyards of Mayflower, Arkansas. Pegasus' years in obscurity ended March 29, when it ruptured, spilling at least 12,000 barrels (504,000 gallons/1.9 million liters) of heavy Canadian crude oil and water into the neighborhood. (See related "Pictures: Arkansas Oil Spill Darkens Backyards, Driveways.")
Now, the broken conduit is at the center of a national debate—the plan to transport much larger volumes of heavy oil from the Canadian tar sands through the United States, through both older pipelines like Pegasus and new ones like the proposed Keystone XL. (See related interactive map: "Keystone XL: Mapping the Flow of Tar Sands Oil.") The line break in Arkansas may provide a real-world test of a hotly contested issue: Is tar sands oil more corrosive and damaging than other types of crude? . (See related story: "Keystone XL Pipeline Path Marks New Battle Line in Oklahoma.")
Although the U.S. State Department's environmental impact analysis last month concluded that there was no evidence that tar sands oil was worse than other forms of crude oil, it noted the issue was still under study. The results of a National Academies of Science review of the literature are due in July. But with President Barack Obama's decision on a permit for Keystone XL expected sooner than that, the Arkansas spill is providing new ammunition for foes of the project.
"The tragedy is a lot of these issues haven't been given the attention they merit," said Anthony Swift, an attorney with the international program of the environmental group, the Natural Resources Defense Council (NRDC). In the wake of the Arkansas spill, he and other opponents intend to make sure questions they have long been raising about tar sands oil—the risks to pipeline integrity, and the challenges for cleanup—get a greater hearing.
Oiled Ducks, Uncertain Risks
As Hatfield approached Lake Conway on Monday morning, a couple of miles from the line break, he saw children at a bus stop holding hankies or towels to their faces. "The smell of oil was almost overwhelming," he said. "I grew up in Oklahoma, so it's a familiar smell." But by afternoon, Hatfield said, the odor had been eliminated. Also, he didn't see any oil encroaching on the lake itself, just plenty of workers in hazmat suits, digging contaminated soil.
The oil sullied backyards and poured down at least one storm sewer, and 22 homes were evacuated. But emergency workers said they stopped the flow before it reached Lake Conway. Still, 16 ducks, two turtles, and a muskrat were oiled. Before an ExxonMobil contractor, Wildlife Response Services of Seabrook, Texas, took over the rescue effort, a local all-volunteer nonprofit group, the HAWK Center (Helping Arkansas Wild "Kritters"), washed and cared for the animals, posting some photos on its Facebook page. Lynne Slater, HAWK Center founder and director, said it was impossible to identify some of the ducks (there were gadwalls, mallards, and blue-wing teals) until some of the oil was removed with dishwashing soap. "It was really like removing peanut butter and tar mixed together," she said. "It was super, super sticky."
But it's an open question whether heavy Canadian oil—and specifically, oil from Alberta's tar sands—is any worse than conventional crude, which has proven its ability to cause damage whether in Prince William Sound, the Gulf of Mexico, or the sands of Kuwait.
The raw product extracted from Alberta's tar sands is known as bitumen, and it is as viscous as cold molasses. It can't be transported in pipelines unless it is processed or diluted. (Exxon Mobil says the oil that spilled in Mayflower was not diluted bitumen, but heavy Canadian oil. But there may be little practical difference between the two, since the company did confirm the presence of dilutants in the oil. And Canada's National Energy Board says western Canada heavy crude contains some bitumen.)
Questions on the properties of diluted bitumen, known as dilbit, first came to the fore in 2010 when a pipeline operated by Calgary's Enbridge burst near Michigan's Kalamazoo River, contaminating 40 miles of river and wetlands with dilbit. Workers are still cleaning up the site, at a tab now running north of $800 million, making it the costliest onshore oil spill in U.S. history.
Oil typically floats on water, so booms were deployed at the surface to contain the damage to the Kalamazoo, Swift said. But the barriers proved useless when the heavy oil sank beneath them.
In the wake of Kalamazoo, NRDC conducted its own analysis of U.S. pipeline spill statistics, concluding that pipelines in the northern Midwest, which have been carrying dilbit since the late 1990s, longer than other pipelines in the United States, spilled 3.6 times as much crude per mile than the national average between 2010 and 2012. Swift and his colleagues at NRDC argue that the influx of tar sands on the U.S. pipeline network will pose greater risks to pipeline integrity and challenges for leak detection systems, and will significantly increase impacts to sensitive water resources when spilled. "It's thicker, it's heavier, it moves at higher temperatures because it generates friction," Swift said.
But other studies have reached different conclusions.
A study released this year by consultants for the Canadian Energy Pipeline Association (CEPA) concluded that dilbit "is no more corrosive than comparable heavy sour crudes and in many cases may be less corrosive." The report argued that the industry need not take any additional measures for corrosion control "over and above what is already standard practice."
That study has been derided by some critics for its affiliation with CEPA, a pipeline industry group, but the findings largely have been corroborated by researchers at the University of Washington. That report addresses the "highly debated topic with oil sands products . . . the degree of corrosivity with respect to pipeline transport." That report, too, concludes that "ongoing research suggest that oil sands products are not more corrosive than standard crude oils and thus do not pose an increased risk for transmission pipeline corrosion."
In its environmental impact statement (EIS) for the proposed Keystone XL pipeline, the U.S. State Department examined Alberta's crude oil pipelines, which carry massive amounts of diluted bitumen. The study found that corrosion is indeed the main case of pipeline spills, accounting for 37.7 percent. But the report found that percentage not significantly greater than in the United States, where it's 34.4 percent. "Therefore no evidence is found that Alberta's pipeline contents are more corrosive than average crude oil."
The study has not yet been completed, so there is much anticipation—from environmental and industry groups alike—around the National Academies' effort. Results are expected this July; in the meantime, committee members aren't talking. If the study finds that dilbit is more corrosive than traditional crude, a second phase will endeavor to figure out what to do about it.
Kevin Garrity, past president of an association of corrosion engineers called NACE International, said his group is keeping a close on the process. "We at NACE want to know if we need to do anything different so that we can develop the standards and test measures to address that."
Heavy and Sticky
But the National Academies study will look only at the corrosion issue, not the equally contentious question of whether dilbit behaves differently in the environment. The State Department's EIS on the Keystone XL pipeline says that diluted bitumen is lighter than water, and would tend to float like crude oil. But once dilbit spills from a pipeline, says Swift, "it doesn't stay in combination for long." The heavy bitumen separates from its dilutants, which are natural gas liquids like benzene that evaporate easily.
"It's very hard to get off," said Steve Hamilton, a professor of ecosystem ecology and biogeochemistry at Michigan State University, who advised the U.S. Environmental Protection Agency and Enbridge on the Kalamazoo spill. Because the river was high, the bitumen eventually coated a vast expanse of land as the water dropped. "The only way to get it off was to harvest all the vegetation and scrape the soil," Hamilton said. At one point, the enterprise occupied more than 2,000 workers. "People literally were going in with shovels and clippers and plastic bags collecting all this stuff." Detergents were ineffective, Hamilton said. And dispersants work only in saltwater.
Today, bitumen still lies on the river bottom, and when it is disturbed, sheens appear on the surface. Nevertheless, wildlife and vegetation are returning.
Hamilton believes accidents like the one in Kalamazoo need more oversight and scrutiny, but those are only short-term answers. In the long run, he is more concerned about the source of the bitumen—Alberta's tar sands. "It's an immense reserve of fossil fuel," he said. "I think the most serious issues involving this material is its ultimate effect on climate." (See related photos: "Satellite Views of Canada's Tar Sands Over Time.")
But climate activists believe that how Alberta's oil gets to market will have a decisive impact on the climate question. Keystone XL, with a capacity of 800,000 barrels per day, would be the first direct pipeline connection to the advanced-technology refineries of the Texas Gulf Coast. ExxonMobil's now-closed Pegasus pipeline, with a capacity to move 90,000 barrels a day, has been one of the few circuitous routes for moving tar sands oil to the Gulf refineries until now. Pegasus long had transported Texas oil into the Midwest, but in 2006, Exxon reversed its direction to send northern oil south. The EPA issued a corrective action order on Pegasus this week, ordering ExxonMobil to find the cause of the spill, noting that a change in direction of flow can affect the hydraulic and stress demands on the pipeline.
If so, it's yet another risk connected to the influx of Canadian oil. Other pipeline reversals to move heavy Canadian oil south and east are being contemplated or have taken place—the largest was the reversal earlier this year of Enbridge's Seaway pipeline, which now has capacity to move 295,000 barrels per day from Oklahoma to Texas.
There are other hazards. Already, some tar sands oil is moving by train; a train derailed in western Minnesota and spilled 350 barrels (14,700 gallons/55,566 liters) two days before the Arkansas spill. (See related story: "Oil Train Revival: North Dakota Relies on Rail to Deliver Its Crude.") And there will be a push for other conduits, because Canada plans to triple oil sands production to 5.1 million barrels per day by 2035.
That's why those concerned about the atmospheric impact of tar sands development are focusing attention on what happens on the ground.
This story is part of a special series that explores energy issues. For more, visit The Great Energy Challenge.