Guardian: 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...