A leak from the Pegasus pipeline was discovered near Mayflower, Arkansas on Friday, leading to an estimated spill of over 10,000 barrels of Canadian Dilbit. Reports state that the pipeline was carrying Wabasca Heavy crude from western Canada when it ruptured. Wabasca Heavy is a type of diluted bitumen (a type of crude oil that is heavier than most conventional crude oil) from Alberta’s tar sands region.