WASHINGTON (Reuters) - A leak of thousands of barrels of crude oil into a North Dakota field from a pipeline operated by Tesoro Logistics LP late last month is the latest in a string of recent pipeline accidents that are a costly side effect of the North American oil boom.
The spill of about 20,600 barrels was first discovered on September 29, but little was known about it until Thursday when the company put out a press release. Federal government officials could not be immediately reached for comment amid the government shutdown.
The string of spills have stirred opposition from environmentalists to new pipeline projects such as TransCanada Corp's Keystone XL pipeline that would help link Canada's oil sands to refineries in Texas. Supporters of the projects argue that pipelines are much safer than rail and trucks.
Below are the major recent North American oil pipeline leaks:
September 29: The Tesoro Logistics LP pipeline spill was the biggest leak in North Dakota since 1 million barrels of salt water brine, a byproduct of oil production, leaked from a well site in 2006.
March 29: Exxon Mobil's Mayflower pipeline ruptured in a suburban neighborhood in Arkansas, forcing residents from homes. It spilled some 5,000 to 7,000 barrels of heavy crude from Canada.
June 2012: Enbridge Inc shut its 345,000 barrels per day Athabasca pipeline after 1,400 barrels of oil spilled in Northeast Alberta. The line was quickly restarted after the company bypassed a pump station.
July, 2011: Exxon Mobil's Silvertip pipeline leaked 1,500 barrels of crude into the Yellowstone River after heavy flooding in the region.
July 25, 2010: Enbridge Inc's 41-year-old 6B pipeline ruptured in Michigan, leaking 19,500 barrels of crude, of which about 8,500 spilled into the Kalamazoo River. The accident on the pipeline owned by the Calgary-based company was the largest onland oil spill in U.S. history and environmentalists complained it left lasting damage to the river. Regulators kept the line shut for more than eight weeks. The accident was one of three outages that summer for Enbridge, raising questions about the safety of pumping Canadian crude through the United States.
(Reporting by Timothy Gardner; Editing by Marguerita Choy)