Dome

aerial view, wisps of steam rise from a tailings pond in the early morning at the Suncor Energy tar sands processing plant about 20 miles north of Fort McMurray. Tailings are the waste materials left over after extracting pure bitumen from sand and clay with which it is found in deposits. The ponds contain a complex mixture of heavy metals and volatile organic compounds, many of which are considered toxic, 4/4/2014