Yellowstone Oil Spills Expose Threat to Pipelines Under Rivers Nationwide | Inside Clim... - 0 views
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At the time the Poplar pipeline ruptured, about 110 feet of it was completely uncovered along the bottom of the Yellowstone River, exposing it to damage.
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Bridger Pipeline LLC was so sure its Poplar oil line was safely buried below the Yellowstone River that it planned to wait five years to recheck it. But last month, 3.5 years later, the Poplar wasn't eight feet under the river anymore. It was substantially exposed on the river bottom—and leaking more than 30,000 gallons of oil upstream from Glendive, Montana. An ExxonMobil pipeline wasn't buried deeply enough for the Yellowstone River, either. High floodwaters in 2011 uncovered the Silvertip pipe, leaving it defenseless against the fast-moving current and traveling debris. It broke apart in July, and sent 63,000 gallons of oil into the river near Laurel, Montana.
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Both companies underestimated the river's power and its penchant for scouring away the earth that's covering and protecting their pipelines. That miscalculation led to the Exxon Silvertip spill and it's likely to be declared a significant factor, at a minimum, in the Poplar spill. Such misjudgments have potentially troubling implications nationwide, since pipelines carrying crude oil and petroleum products pass beneath rivers and other bodies of water in more than 18,000 places across America. Many of them are buried only a few feet below the water. "There were a lot of people who wanted to think that the last pipeline spill in the Yellowstone River in 2011 was a freak accident that would never happen again. After this most recent spill, no one believes that anymore," said Scott Bosse, Northern Rockies director for American Rivers. "The truth is, there are probably hundreds of pipelines across the country that are at considerable risk of rupturing under our rivers."
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While corrosion is the No. 1 cause of pipeline spills, a sizable number of pipelines at water crossings have ruptured or been endangered by river scour. Among them: ► The Poplar (Jan. 2015) and Silvertip (July 2011) pipeline failures on the Yellowstone River. ► More than 20 pipeline river crossings in Montana were found to be "dangerously close to exposure" during inspections of nearly 90 pipeline crossings in 2011, according to one report. Many of them have since been reburied significantly deeper. The Poplar pipeline was not among the crossings tagged as being close to exposure. ► Nearly half of the 55 oil and gas pipelines that cross the Missouri River were found to have sections buried 10 feet or less below the riverbed, according to the Wall Street Journal. A study by the U.S. Geological Survey, meanwhile, found that the Missouri riverbed had deepened by nine to 41 feet in 27 places because of severe scouring during the 2011 floods. ► An Enterprise Products Partners LLP pipeline that was uncovered by river scouring and ruptured in August 2011. The line spilled more than 28,350 gallons of a gasoline additive into the Missouri River in Iowa. ► A June 2012 spill in Alberta, Canada, where an oil pipeline owned by Plains Midstream Canada failed along the Red Deer River and released more than 122,000 gallons of light crude. Investigators concluded that the pipe was uncovered by scour during high flood waters and subjected to vibrations from the river flow that led a weld to fail.
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Three Enbridge Corp. crude oil pipelines crossing Minnesota's Tamarac River were exposed by floodwater erosion years ago, and were still exposed in mid-2014. None of the pipes had failed at that point, but one was being propped up by steel legs, according to an MPR News account. Federal regulations aren't much help. The only rule that addresses pipe burial at major river crossings requires petroleum pipelines to be laid at least four feet below the riverbed at the time of construction. Once a pipeline's installed, there are no requirements regarding burial depth. There is no rule requiring exposed pipelines to be reburied, though a spill under those conditions would invite regulatory penalties for leaving the line exposed to hazards. What's more, federal rules put the pipeline companies in charge of identifying all threats that could cause a spill in highly populated or environmentally sensitive areas, and the companies get wide latitude in deciding what to do about them, according to Rebecca Craven, program manager at the Pipeline Safety Trust, a nonprofit group that tracks pipeline risks and regulations.
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Indeed, the required four-foot minimum initial burial depth for pipelines can be completely eliminated by natural erosion over time or by a single flood event. Active free-flowing rivers can carve with enough ferocity to lower their riverbeds by 20 feet or shift the waterway onto an entirely new path, which can add new stresses to the pipeline or put the river over pipe that has less cover or lacks reinforcement or protective cement casings. The hotly debated Keystone XL oil pipeline project would cross nearly 2,000 rivers, streams and reservoirs in Montana, South Dakota and Nebraska, according to one estimate. The route takes the pipe across the Missouri and Yellowstone rivers, where owner TransCanada has pledged to install the pipeline 35 feet below the riverbeds.
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See Also: Ruptured Yellowstone Oil Pipeline Was Built With Faulty Welding in 1950sIce Hinders Cleanup of Yellowstone Oil Pipeline SpillExxon Overlooked, Masked Safety Threats in Years Before Pegasus Pipeline BurstDilbit in Exxon's Pegasus May Have Contributed to Pipeline's Rupture