A SAG D (Steam assisted Gravity Drainage) tar sands plant north of Fort McMurray. The Alberta tar sands are the largest industrial project on the planet, and the world's most environmentally destructive. SAG D is used to extract the bitumen from the tar sands when they are too deep to be strip mined. Although it has the benefit over strip mining, of not having to clear fell the Boreal forest, SAG D produced oil is the most carbon intensive fossil fuel on the planet, over three times more carbon intensive than conventional oil. This is due to the extraction process. Two pipelines are drilled vertically, one to the top of the tar sands layer and one to the bottom. They then spread out horizontally. Vast quantities of steam are pumped down the upper pipe