Update on the condition of the Kalamazoo River following the 2010 Enbridge oil spill

Olga Bonfiglio
College of Arts and Sciences staff writer

Boat on Kalamazoo River

Submerged oil recovery on the Kalamazoo River. Photo credit: EPA

On July 25, 2010, people living along the Kalamazoo River from Marshall east about 35 miles to Galesburg smelled a peculiar odor. They contacted the authorities who at first couldn't figure out what was wrong. Eventually, they discovered that a 40-year-old oil pipeline had ruptured. Over the next 17 hours it would gush out 843,000 gallons of oil—enough to fill half a high school gymnasium. This incident turned out to be the largest inland oil spill in US history—and the costliest because no one knew how to clean it up.  

This oil wasn't like most oil that travels through the nation’s 2.5 million miles of pipelines. It was diluted bitumen , a heavy crude oil from the tar sands of Alberta, Canada. This oil is thick and black like tar or asphalt instead of liquid and in order to transport it through conventional pipelines, it is diluted with lighter hydrocarbons to make diluted bitumen or “dilbit.”

Enbridge Energy, who owns and operates this pipeline, makes a business of transporting, distributing and generating energy primarily in North America through 29,000 miles of pipeline in Canada and the United States. The energy delivery company based in Calgary, Canada, is the largest transporter of crude oil in Canada with 2.2 million barrels per day. It was eventually held responsible for the spill for 22 probable violations in its pipeline operations, including never informing the EPA of the product distinction of dilbit from other crude, according to Inside Climate News.

Much of the oil Michigan uses comes from this tar sands oil product, which is the same one that would pass through the Keystone XL Pipeline should it be built. This oil spill on the Kalamazoo River was the first major release of dilbit into a freshwater environment.

“The clean-up set in motion amazingly fast,” said Steve Hamilton, professor at the Kellogg Biological Station, Michigan State University at a recent weekly Lyceum talk on water held at the Lee Honors College.

“Miles and miles of absorbent booms were set up to recover the oil. Hundreds of volunteers saved oiled wildlife while thousands of people helped clean up oil deposited on the land, to excavate ‘hot spots’ and to manually harvest oiled vegetation and soils.”

The US Environmental Protection Agency oversaw the clean-up 2010-2014. Governor Jennifer Granholm requested the EPA’s assistance since the Michigan Department of Environmental Quality was not up to the task.

Because of torrential summer downpours, the oil was spilled during a high water peak, so the spill ran not only into the river channel but also into riparian and flood plain land. Talmadge Creek, a tributary of the Kalamazoo River where Line 6B burst, was excavated and completely rebuilt—twice. The oil also went downstream to the Ceresco Dam, the Mill Ponds area in Battle Creek, and Morrow Lake, all of which trapped oil. Oil flowed into undeveloped flood plain swamps, and some of it submerged to the river’s bottom.

“This was a formidable challenge and it took a monumental clean-up,” said Hamilton. “Sometimes 2,000 people were working at one time.”

Submerged oil was particularly difficult to capture because dilbit, like all crude oil, floats in water and eventually sinks. Sunken oil can produce sheen for a long time. Whenever sheen appears from an oil spill, federal regulations require the EPA to go after it until it disappears.

“Even a little oil can produce a lot of sheen,” said Hamilton, “so workers used some unproven techniques to recover submerged oil and stop the sheening.”

To find the submerged oil, a technique was developed called “poling.” A long pole was stuck into the riverbed to stir up the sediments and record the amounts of sheen and globules that floated to the surface. More than 20,000 points were poled in the affected areas. This was the first time the EPA used this technique, but it was necessary because quick lab analyses had been found to be unreliable.

To recover submerged oil, workers also experimented with “agitation” from fall 2010 through 2011, but its efficacy was unproven. Agitation involves stirring up the sediments to capture oil that rises to the surface.

Dredging proved to be the best solution for ridding the water of sheening, even though it is the most destructive and expensive.

Several hundred acres of the area were dredged. At three locations dredge spoils were processed on land for “dewatering,” that is, separating river water from the sediment and oil.

The Ceresco Dam, which was in serious disrepair, was removed in an attempt to restore the natural channel of the river and recreate the original floodplain, even though some people objected.

“The dam was not generating power, but it was a symbol of the community,” said Hamilton, “so the residents of Ceresco objected to its removal.”

Today, the river is in pretty good shape, reported Hamilton. Overbank oil is virtually gone and oil in the river is invisible in most places. The best guess is that less than 10 percent of the spilled oil remains submerged in the river and reservoirs. The sheening in the “hot spots” has ceased. There are no known hazards to human health, and the river is now open for recreation with the MDEQ back in charge.

“Life in the river has recovered remarkably well, too,” said Hamilton. “Bottom dwelling invertebrates seem to have recovered although we would expect that full recovery of aquatic plants and mussels would be more delayed. Flood plains are coming back to normal. About 3,800 turtles were saved and released back into the wild.”

The clean-up cost $1.12 billion, and Enbridge is responsible for the entire cost. What made this oil spill so expensive was that a portion of the dilbit sank. In the process of responding to this incident, authorities learned much about dilbit spills on rivers, including:

  • Releases in water bodies are incredibly hard to clean up.
  • Submerged oil may sheen for a long time and recovering it is very difficult.
  • Bitumen sticks to surfaces and is hard to remove.
  • Sediments and soils may release small amounts of oil for a long time in the years to come.
  • A substantial fraction of oil (though less than 20 percent) sank, probably by association with river particulate matter.

Hamilton added that today the Michigan Department of Environmental Quality continues to oversee monitoring and ensure that the cleanup is complete, but the hope is that major clean-up operations are finished.

In addition to covering the costs incurred in the clean-up, Enbridge has settled with the state and agreed to provide $75 million toward environmental improvements and mitigation, including the restoration of 300 acres of wetland. In addition, nearly $4 million has been provided through a process called the Natural Resources Damage Assessment. The company had already constructed new river access points for paddlers and has established a foundation to support local projects. Enbridge has paid a federal fine of $3.7 million, and further federal penalties may be forthcoming under the Clean Water Act.

 “It is hard for oil to move into groundwater because the groundwater flows toward the river along most of the oiled reaches,” said Hamilton, “and, thankfully, there was no evidence of it seeping into the groundwater.”

As for the PCBs in the Kalamazoo River that were left over from the paper industry, Hamilton said they were not affected because the oil spill was stopped before it spread into that section of the river, which is around and downstream of Kalamazoo.

In the end, the oil spill definitely put the Kalamazoo River on the map, and the incident brought harsh criticism and recommendations for action.

The National Transportation Safety Board believed the dilbit spill was caused by “pervasive organizational failures” as well as “weak federal regulations.” It advocated that pipelines be made safer and that the technology is available to do that.

The National Academies of Sciences, Engineering and Medicine issued a scholarly document on the Kalamazoo River oil spill titled “Spills of Diluted Bitumen from Pipelines: A Comparative Study of Environmental Fate, Effects and Response” and stated the following:

“Diluted bitumen has been transported by pipeline in the United States for more than 40 years, with the amount increasing recently as a result of improved extraction technologies and resulting increases in production and exportation of Canadian diluted bitumen. The increased importation of Canadian diluted bitumen to the United States has strained the existing pipeline capacity and contributed to the expansion of pipeline mileage over the past 5 years. Although rising North American crude oil production has resulted in greater transport of crude oil by rail or tanker, oil pipelines continue to deliver the vast majority of crude oil supplies to U.S. refineries.”

Hamilton, who never thought he'd see an oil spill in Michigan, remained skeptical whether we are better prepared to respond to a dilbit spill now than we were in 2010.

“The National Academies report has a lot of good recommendations, but at this point in time, we still lack the tools and approaches to stop spilled oil from submerging in water bodies. So I am not sure what would be done differently if the same kind of spill happened today.”