Detroit's mountains of petroleum coke are 'dirtier than the dirtiest fuel'

It was the dirty secret of Alberta's tar sands – until the black mountain of petroleum coke on the banks of the Detroit River grew to occupy an entire city block three storeys high.

Now it could become a familiar feature at storage yards and water fronts across the country as the oil industry in the US and Canada struggles to deal with a glut of waste from Alberta's tar sands production.

"This is dirtier than the dirtiest fuel," Gary Peters, a Michigan Democrat who represents the area where the pet-coke mountain has been accumulating, told the Guardian.

Peters has been pressing for full exposure of the potential health and environmental risks associated with petroleum coke, a byproduct of tar sands production.

"We need to know more about this material and the impact on communities," he said. "I don't think enough is known. "

Peters (pictured) has introduced a bill in the House of Representatives calling for an investigation into pet-coke.

Pet-coke is made up almost entirely of carbon, which means that it produces more greenhouse gas emissions than tar sands oil or even coal if it is used for electricity.

Some pet-coke can be used to make steel, but the pet-coke piling up in Detroit is low-grade and high in sulphur and impurities which means it can only be used for electricity – and that comes at a heavy cost to the climate and for air quality.

This particular pile is owned by Koch Carbon, which is controlled by the Koch brothers, oil billionaires and backers of ultra-conservative groups, including those which work to discredit climate science and block action on climate change.

Koch Carbon did not respond to requests for comment.

The growing eyesore has generated growing concern in Detroit and Windsor, the Canadian city across the river. Residents complained about clouds of black dust blowing off the mounds, which were left uncovered.

"People around that area especially in windy conditions say the material can be blown around and they say it is ending up in houses," Peters said. "What is going to happen when rainwater is on the material which is high in sulphur, high in heavy metals, when it runs off into that river?"

This week, the state environmental authority in Michigan disclosed that an adjacent drain had been left open, raising the possibility pet-coke had been washing into the river and the Great Lakes system. "We just don't know," Peters said.

That may be about to change. Peters and others are pressing for greater oversight of the hodgepodge of regulations governing the storage and transport of pet-coke. Some states, such as California, require pet-coke be kept covered. Others have far less specific guidelines.

But it's unclear whether those efforts can keep pace with the growing mounds of pet-coke building up in Canada and in the US.

Expanded production from the tar sands has dramatically increased the amount of pet-coke entering the refining system – and US refineries are overwhelmed, said Deborah Gordon, an energy and climate analyst at the Carnegie Endowment for International Peace.

Every barrel of crude that comes out of the Alberta tar sands throws off between 60-130lbs of pet-coke. By May 2012, Alberta had stockpiled 70m metric tons of the stuff, driving down prices.

"They are drowning in it. It just can't be absorbed any more in the refining process," Gordon said.

Until now, the industry had shipped pet-coke off to Asia or southern Europe as a cheaper alternative to coal.

Most power plants in the US or Canada will not burn pet-coke for fuel because it is so polluting. Burning pet-coke for electricity require expensive equipment to clean up the sulphur – although a plant in Nova Scotia announced this week it would begin chipping away at the mound in Detroit.

"It is a waste product that is almost free for the taking, and the Koch brothers are probably thinking: 'please somebody take this from us. Give us a little something for transport, and just take it'," Gordon said.

Peters said he feared similar piles accumulating at other locations in the US, as tar sands production continues to expand. "One of my main concerns with the Keystone pipeline is that we will be seeing piles of pet-coke in a lot of other places in the US, because it is a main byproduct of refining Canadian oil," he said. "What we are seeing in Detroit now will be dwarfed by more oil coming through here with Keystone."

"This is just a glimpse of that future reality."