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Cleanup of 2010 Mich. Dilbit Spill Aims to Stop Spread of Submerged Oil

Enbridge agrees to comply with EPA order to dredge Kalamazoo River. Final cleanup costs could top $1 billion.

Mar 27, 2013
Oil cleanup on the Kalamazoo River.

If all goes well, the next oil removal operation on Michigan's Kalamazoo River will mark the beginning of the end for the cleanup of the largest oil pipeline spill in U.S. history

The spill, which occurred in July 2010, already has cost pipeline operator Enbridge Inc. more than $820 million in cleanup expenses. That figure could top $1 billion by the time the latest operation is carried out.

The goal of the new effort is to dredge three areas of the river where the U.S. Environmental Protection Agency says oil is still accumulating. When the EPA first proposed the idea in October, Enbridge asked the agency to delay its decision until it conducted more scientific studies. But Enbridge agreed to comply after the EPA issued an order on March 14.

The EPA fears that if the oil isn't removed, it could continue to spread and contaminate parts of the river that are currently clean.

Surveys "show that submerged oil can now be detected throughout the 2 mile long, 700 acre expanse of [Morrow] lake," the EPA said in a letter that accompanied the order. "By contrast, only 189 acres showed submerged oil impact in Fall 2011. In Spring 2012, the area of impact had progressed to 325 acres."

The cleanup of the Kalamazoo has been especially challenging because the pipeline that ruptured was carrying diluted bitumen, or dilbit, from Canada's oil sands region. That's the same type of oil that the Keystone XL pipeline would carry from Alberta, Canada to the U.S. Gulf Coast if the project if the Obama administration approves the project.

The dilbit that spilled in Michigan contained a mixture of oil-thinning chemicals, which soon evaporated, and heavy bitumen, which gradually sank. Much of the bitumen accumulated in the riverbed, where cleanup techniques used for spills of lighter, conventional oil weren't effective.

Enbridge is now developing a work plan for the dredging.

"While there are some issues related to the Order that still must be resolved, we are, as we have always been, focused on cooperation with the EPA and other authorities in doing what is best for the river and the environment based on analysis and sound science," said a statement posted on the company website. Spokesman Larry Springer said Enbridge had no comment beyond that post.

Steve Hamilton, an ecologist at Michigan State University, said the EPA will conduct a new survey in the spring to assess the extent of the submerged oil. Hamilton is part of a scientific committee advising the EPA on the Kalamazoo cleanup. He spoke to InsideClimate News as an independent scientist, not as an agency representative.

Hamilton said dredging is believed to be the "ultimate solution" for the Kalamazoo cleanup.

"If indeed most of the oil is in these hot spots, then dredging should work," Hamilton said. "On the other hand, if there's dispersed oil still coming in [from upstream] and accumulating, it's anybody's guess what's going to happen."

EPA's Lengthy Oversight Unusual

In addition to dredging the riverbed, the order directs Enbridge to clean and maintain sediment traps used to capture oil outside of the hot spots, and to continue gathering scientific data on the river's recovery.

"U.S. EPA has determined that these cleanup actions are the most consistent with protecting public health and welfare and the environment," said the letter signed by Ralph Dollhopf, who has been the federal on-scene coordinator since the spill occurred in 2010.

The EPA is working with state and local authorities but it remains the lead agency in the cleanup—an unusual situation that highlights the challenge of the Kalamazoo spill.

Matthew Allen, a spokesman in the EPA's Montana office, said the agency's jursidiction typically ends when it determines that the impact of a spill is "no longer an imminent threat to waters of [the] U.S."

That decision is made based on the presence of a "visible sheen on the water," he said. "So if we have a sheen on the water of a significant size identified [as] from a pollutant source, then we will stay and clean that up."

The EPA made the state of Montana the lead agency just two months after an oil pipeline burst near the Yellowstone River in 2011. That spill released 63,000 gallons of crude oil—less than 6 percent of the volume spilled in the Kalamazoo—but it contaminated 70 miles along the Yellowstone River, nearly twice as many river miles as the Kalamazoo spill. Still, the Yellowstone cleanup was easier, Allen said, because the oil that spilled was "significantly lighter" and didn't sink to the riverbed.

When InsideClimate News contacted Dollhopf and his colleague for comment on the latest efforts to clean up the Kalamazoo, they directed us to coordinate through EPA's Region 5 Public Affairs Office. In an email, spokesman Joshua Singer said the office would not make the scientists available for questions.

One Cleanup Technique May Have Helped Oil Spread

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