Environment & Science
3:13 pm
Fri March 15, 2013

Lots of unknowns as petroleum coke piles up along Detroit River

Large piles of petroleum coke along the Detroit River have sparked concern from citizens and environmental groups.

The “petcoke” is a byproduct of the crude oil refinement process. This petcoke comes from the nearby Marathon oil refinery.

It’s really started piling up on two sites along the Detroit River only recently, as the nearby Marathon oil refinery has expanded to process more crude oil from the Alberta tar sands.

But some scientists and regulators say it’s not clear if the substance is harmful.

Andy Hartz, southeast Michigan district supervisor with the Michigan Department of Environmental Quality, says the substance seems to fall into a regulatory gray area.

“The DEQ does not have any kind of specific regulations that regulates this type of land use,” Hartz says. “The product is a commodity. And because of that, it’s not a waste material.”

Petcoke can be used to generate energy and in industrial processes. Hartz says the DEQ has been told the petcoke will be shipped out once ice clears on the Detroit River.

DEQ officials have inspected the two major coke pile sites “to look at how they’re handling the material,” Hartz says.

He says the agency will “encourage” site owners to submit air quality management plans to deal with “fugitive dust,” and implement “best practices” to keep the material from seeping into the Detroit River and groundwater.

Those possibilities are major concern to environmentalists and area residents. Windsor residents protested the growing coke piles last week.

“The Friends of the Detroit River is very concerned with this issue,” Detroit Riverkeeper Bob Burns wrote in a recent email.

“The soils along the Detroit River are very susceptible to leaching due to the fact that so much of the shoreline along the upper Detroit River consists of porous fill. There are already a number of brownfield type sites along the river that were caused by the mishandling of waste materials in the past…If this material is not properly handled, we could be looking at the beginnings of other set of sites to add to our list in the future.”

It’s not clear whether or how harmful this petcoke would be to the surrounding environment, says Christopher Weisener, a Professor at the Great Lakes Institute for Environmental Research at the University of Windsor.

Weisener says pet coke is about 95% carbon, but also contains some sulfur and different trace metals, depending on where it was refined.

“The operations are all slightly different,” Weisener said. “So that will dictate some of those trace components.”

Weisener says this petcoke’s “toxicity is unknown at this point.” He says much more extensive study of the material and its interactions with the surrounding environment are needed to figure that out.