New York Times: In something resembling a bottle return program, Detroits enormous petroleum coke pile, a byproduct of Canadian oil sands, is making its way back to Canada. A Canadian electrical power plant, owned by Nova Scotia Power, is chipping away at the three-story-high, blocklong pile of petroleum coke on Detroits waterfront. The company is burning the high-carbon, high-sulfur waste product because it is cheaper than natural gas. The uncovered black pile, which has angered and upset some residents of...