Oily water flow on the Kalamazoo River downstream from an oil spill outside Marshall, Michigan, the United States, July 31, 2010. A 30 inch (76.2 cm) petroleum pipeline operated by Enbridge Energy of Canada (Calgary, Alberta) ruptured on July 26, spilling an estimated 1 million gallons (3.7 million liters) of raw crude oil into a tributary that feeds the Kalamazoo River near Marshall Township, Michigan. [Xinhua/Tony Ding]