Kalamazoo River Oil Spill: Facts and Environmental Impact

The Kalamazoo River oil spill was one of the largest inland oil spills in U.S. history. Also known as the Enbridge pipeline oil spill, the environmental disaster started on July 25, 2010 in Marshall, Michigan, when a major pipeline managed by Enbridge Energy Partners, LLC. ruptured. As a result, around 1.2 million gallons of crude oil were spilled into Talmadge Creek and the Kalamazoo River.

Cleanup efforts took more than four years and required excavation and dredging of the riverbed, permanently altering the ecosystem. Learn about the oil spill, the component that made it so catastrophic, and its impact on the habitat and the community.

One of the Largest Inland Oil Spills in US History

Endbridge's pipeline 6B ruptured on the night of July 25, 2010, but the resulting oil spill wasn't reported until 17 hours later. The smell and oil sightings finally drove residents to complain and authorities to investigate. After the initial confusion, the area was evacuated on July 29 due to toxic levels of chemicals in the air.

When the first EPA personnel arrived on-site, they "observed oil flowing in such amounts that water was not observable," and a helicopter assessment revealed that "Talmadge Creek and the Kalamazoo River (...) were covered with bank-to-bank oil. Significant oil was also observed in the floodplain," according to the agency's report.

The pipeline carried diluted bitumen, a type of heavy crude oil derived from oil sands and mixed with light hydrocarbons to help it flow. Diluted bitumen, also known as Dilbit, is a thicker, viscous petroleum product, which makes it very difficult to clean.

The black, toxic sludge leaked from a 6-foot tear in the old pipeline (built in 1969) and slowly creeped down Talmadge Creek, contaminating the water but also sinking and blanketing the bottom of the stream, floodplains, and riverbanks. In addition, hydrocarbons used in the mixture evaporated, creating the toxic fumes that the residents smelled — and inhaled.

Enbridge estimated that 843,000 gallons had been released, but cleanup efforts revealed the number to be closer to 1.2 million gallons.

Heavy rains the week before the spill increased the river flow and complicated the situation, and the oil-contaminated water spilled over dams and extended over 38 miles downstream on the Kalamazoo River.

The Cleanup

The spill was unlike anything local and environmental authorities had ever dealt with. According to the U.S. Fish and Wildlife Service (FWS), the oil impacted over 1,560 acres of stream and river habitat, as well as floodplain and upland areas. More than 1,500 spill responders were mobilized and efforts to remove the oil took more than four years, but the water and surrounding land will always have some evidence of the toxins.

One major issue that responders faced was lack of detailed knowledge. Authorities treated the spill like they would any other disaster caused by "light" crude oil (which mostly sits on top of the water) instead of DilBit. After initial efforts showed mixed results, the true magnitude of the problem became evident.

When the DilBit spilled, the toxic chemicals used to dilute the bitumen evaporated and the heavy sludge sunk to the bottom, so cleanup and containment strategies used in other major oil spills were not sufficient. Spill response required the use of heavy equipment, dredges, and vacuum equipment, in addition to absorbent materials and containment booms, according to FWS. Containment efforts did manage to spare the remaining 80 miles of the river stream and avoid the oil reaching Lake Michigan.

First, they had to dredge the riverbed to remove the affected sediment that had sunk and settled at the bottom. Then they had to figure out where the oil had extended to other parts of the creek and river. In some parts, they had to completely rebuild areas where the oil had done the most catastrophic damage. In 2010 and 2011 alone, Enbridge spent more than $765 million in clean up costs, according to the company's financial reports.

In the fall of 2014, Enbridge completed the clean up mandated by the EPA, including sediment removal by dredging. Management of the site was transferred to the Michigan Department of Environmental Quality

Environmental Impact

At the beginning of the disaster, more than 4.000 animals were collected for cleaning and rehabilitation, ranging from birds, mammals, and amphibians, to crustaceans and reptiles. Most of these animals were successfully released back to their habitats. The impact on local wildlife, however, is hard to estimate, as many fish died after coming in contact with the oil and the sunken sludge damaged aquatic organisms and plants, altering the food chain.

To remove the sunken bitumen, Talmadge Creek and sections of the Kalamazoo River had to be — literally — dug out and reconstructed. According to the Kalamazoo River Watershed Council, "the Talmadge Creek corridor was almost completely excavated, with clean fill returned to more or less re-create the original wetlands and stream channel (...) This involved more shoreline stabilization and planting of native species and plants."

In addition, access to the river and the creation of work areas caused further damage to the surrounding ecosystem. According to FWS, "the oil, and efforts to recover the oil, damaged 1,560 acres of in-stream habitat, 2,887 acres of floodplain forests, and 185 acres of upland habitats."

Also affected were the Match-E-Be-Nash-She-Wish Band and the Nottawaseppi Huron Band of the Potawatomi Tribe. Both indigenous groups have traditionally considered the Kalamazoo River part of their natural and cultural heritage. In addition, they grow wild rice along its shores and participate in the conservation and rehabilitation efforts of local wildlife, including the threatened lake sturgeon.

The contaminated tract of the Kalamazoo River remained closed until June 2012, when sections were reopened for recreational use. Enbridge pipeline 6B, which is routed all the way to Canada, was rebuilt and reinforced in January 2013 and continues in operation to this day.