The Keystone pipeline system, an addition to which has been the subject of environmental protests for years, leaked about 383,000 gallons of crude oil in North Dakota, covering an estimated half-acre of wetland, state environmental regulators said.
The spill, which has been contained, occurred in a low-gradient drainage area near the small town of Edinburg in northeast North Dakota, less than 50 miles from the Canadian border, according to Karl Rockeman, the director of the state Department of Environmental Quality’s division of water quality.
“It is one of the larger spills in the state,” he said in an email on Thursday.
There are no residences near the site and the wetland is not a source of drinking water, he said. State regulators and cleanup equipment are on site, but Mr. Rockeman could not say whether cleanup had begun.
The leak occurred along a stretch of the existing Keystone pipeline system, not the 1,179-mile-long addition to that system known as the Keystone XL pipeline, he said. Keystone XL has been the subject of environmental protests for years. President Barack Obama denied it a permit in 2015, but just days after taking office President Trump cleared a path for its operator, TC Energy, formerly known as TransCanada, to proceed.
Catherine Collentine, an associate director with the Sierra Club, which opposes the Keystone XL addition, said in a statement that this week’s leak is further proof that such spills are inevitable.
“We don’t yet know the extent of the damage from this latest tar sands spill, but what we do know is that this is not the first time this pipeline has spilled toxic tar sands, and it won’t be the last,” she said. “We’ve always said it’s not a question of whether a pipeline will spill, but when, and once again TC Energy has made our case for us.”
In a statement, TC Energy said the pipeline was shut down after the spill was detected at about 9:20 p.m. local time on Tuesday. The cause of the spill will not be known, the statement said, until an internal investigation is complete and the pipeline is analyzed by federal officials.
“We are establishing air quality, water and wildlife monitoring and will continue monitoring throughout the response,” the statement said.
In 2017, a spill along the Keystone pipeline system coated a stretch of grassland in South Dakota with more than 407,000 gallons of leaked Canadian crude oil, which was nearly twice as much as originally estimated, according to the company. The pipeline also leaked about 16,000 gallons each in spills in 2011 in North Dakota and in 2016 in South Dakota.
The original Keystone pipeline system began operation in 2010 and carries crude oil from Alberta, Canada, south to Texas. The system contains 2,687 miles of pipeline.