Scouring endangers U.S. river pipelines

Soil on the bed of the Missouri River was washed away by floodwaters, exposing and rupturing a natural gas pipeline, an energy company said.A pipeline owned by Enterprise Products Partners spilled about 3,300 barrels of natural gas liquids into a flooded area of the Missouri River last weekend in Iowa.Flooding along the river exposed several pipelines to danger after rushing waters swept away several feet of the river bed.State officials in North Dakota last month found evidence of scouring 30 feet deep. Federal law requires pipelines be buried 4 feet below the riverbed.Enterprise spokesman Rick Rainey was quoted by The Wall Street Journal as saying scouring exposed most of the pipeline near Onawa, Iowa."Over the top and underneath, all of the soil supporting the pipe has been eroded," he said.Magellan Midstream Partners, another pipeline company, announced it suspended operations at one of its pipelines crossing the Missouri River because of scouring fears.The U.S. Department of Transportation's Pipeline and Hazardous Materials Safety Administration in July called on pipeline operators to look into the potential effects of scouring.