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The Dilbit Disaster: Inside The Biggest Oil Spill You've Never Heard Of, Part 2

Days of confusion followed the spill. Officials thought they were cleaning up ordinary crude. It was an erroneous assumption Enbridge did not correct.

By Elizabeth McGowan and Lisa Song, InsideClimate News

Jun 27, 2012
Technicians prepare pipe before cutting and removing the section from the Enbrid

On Tuesday, July 27, 2010—the day after the biggest pipeline spill of Canadian dilbit in North America was detected—oil was still streaming from Talmadge Creek into the Kalamazoo River near Marshall, a community of 7,400 in southwestern Michigan. Some people had fled their riverside homes because of the overwhelming smell, like burning tar.

Six inches of rain between Thursday and Sunday had turned the normally sedate river into a roiling brown torrent that overflowed its banks by several feet. The creek, usually only five or six feet wide and a foot deep, was at least 100 feet wide.

The EPA officials who had gathered in Marshall still thought they were dealing with the light crude oil that usually flows through U.S. pipelines. As veterans of other spills, they were certain they were prepared for this one.

What they didn't know yet was that 6B, the pipeline that ruptured, was carrying bitumen from Canada's tar sands region. Bitumen is the heaviest oil in use today and is too thick to flow through pipelines. To remedy that problem it is thinned by about 30 percent with liquid chemicals, usually including benzene, which can cause cancer in humans.

This diluted bitumen, or dilbit, is the same type of oil that would be carried on the 1,702-mile Keystone XL pipeline if the controversial project is approved. When dilbit spills, most of the added chemicals evaporate, leaving the heavy bitumen to sink in water.

Pipeline 6B is owned by Enbridge Inc., Canada's largest transporter of crude oil. Enbridge's president and chief executive officer, Patrick Daniel, perpetuated the mistaken belief that this would be a routine cleanup. On Monday, Daniel had flown in from Enbridge's Calgary, Alberta, headquarters in the company jet. In an interview the next day, he said much of the oil could be sucked off the water's surface with vacuum trucks and that only a "minuscule" amount might sink below the surface.

"To tell you the truth, it's lighter than water so it sits on top of the water," he said.

Days of confusion followed the spill, with federal and state officials basing their cleanup decisions on the erroneous assumption that the oil was ordinary crude. It was an assumption that Enbridge did not correct. Federal regulations do not require pipeline operators to disclose the specific type of crude oil their lines carry. The nonprofit Pipeline Safety Trust and other organizations have urged the government to change that policy since Canadian dilbit was first pumped into the United States more than a decade ago.

Two deadlines the EPA set Tuesday reflected the agency's confidence in a quick turnaround. Enbridge was ordered to clean up the wetlands near the broken pipeline by Aug. 27. The creek, the river and all shorelines were expected to be oil-free by Sept. 27. Both of the orders mentioned only oil—not dilbit.

The agency's overarching objective was keeping the oil from reaching the spot where the Kalamazoo empties into Lake Michigan, about 115 river miles west of Marshall. Together with the other four Great Lakes, Lake Michigan is a drinking water source for at least 26 million Americans and almost 10 million Canadians.

The EPA was also concerned about a Superfund site near the city of Kalamazoo, about 43 river miles west of Marshall. Polychlorinated biphenyls, better known as PCBs, were embedded in the river, and nobody was sure what would happen if oil mixed with PCBs, which are known human carcinogens.

While the scientists worried about protecting Lake Michigan from the oil, health experts fretted about the oil's effect on people living along the Kalamazoo's banks.

Benzene readings picked up by hand-held monitors were still swinging wildly. Readings ranged from less than 50 parts per billion, a level that didn't worry the health experts, to 3,000 ppb. The highest readings were in areas where oil was being recovered.

Jim Rutherford, Calhoun County's public health director, huddled with state and federal health experts. They had no idea how long the benzene would linger. And they still hadn't found any clear guidelines on whether people should be evacuated in these circumstances.

Finally they decided to create their own benchmark for evacuation, based on their analysis of the available scientific information.

The Michigan Occupational Safety and Health Administration lists 500 ppb as the workplace benzene limit. Using that standard, plus the federal standards they had studied earlier—and taking into account differences between workers and a general population that included children, the sick and the elderly—they decided on Wednesday to set 200 ppb as the benchmark for evacuation.

Rutherford would order an evacuation Thursday if monitors continued to show benzene readings of 200 ppb or above, they agreed. As the county health director it was also up to him to make the final call and to decide if it should be a mandatory or voluntary evacuation.

That Wednesday night, before Rutherford headed home, the EPA reported that the size of the spill was at least 1 million gallons. That figure exceeded Enbridge's Monday estimate of 819,000 gallons.

Even after three days of working double shifts, sleep didn't come easily for Rutherford that night.

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