For the first time in a week, crude oil is flowing again through most of the 2,687-mile Keystone Pipeline, but a section of the conduit in Kansas that leaked nearly 600,000 gallons remained shut off as an investigation of what caused the damage continues, officials said.
TC Energy, the Canadian operator of the aboveground pipeline, announced Wednesday evening it is resuming operations of the system that was unaffected by the spill last week in Washington County, Kansas.
"The affected segment of the Keystone Pipeline System remains safely isolated as investigation, recovery, repair and remediation continue to advance," the company said in a statement Thursday morning.
The company said it is "safely restarting" the section of the pipeline running from Canada to Patoka, Illinois.
"This restart facilitates safe transportation of the energy that customers and North Americans rely on," TC Energy said in its statement.
Emergency crews work to clean up the largest U.S. crude oil spill in nearly a decade, following the leak at the Keystone pipeline operated by TC Energy in rural Washington County, Kansas, Dec. 9, 2022.
Drone Base/Reuters
At full operation, the pipeline normally pumps about 622,000 barrels, or more than 26 million gallons of oil per day from Alberta, Canada, to refineries in Texas, Illinois and Oklahoma. A barrel of oil is equivalent to 42 gallons, or about the size of a typical bathtub, according to industry standards.
The pipeline's damaged "Cushing Extension" which runs from Washington County to Cushing, Oklahoma, remained closed Thursday as the investigation and cleanup goes on, the company said.
The Pipeline and Hazardous Materials Safety Administration, a division of the U.S. Department of Transportation, must grant regulatory approval before the Cushing Extension can reopen, according to the company.
The Kansas oil leak is now the biggest in the United States in more than a decade and the largest in the 12-year history of the Keystone Pipeline.
The leak in Kansas was first detected just after 9 p.m. on Dec. 7, about 20 miles south of a pipeline's Steele City, Nebraska, terminal. The leak in the 36-inch diameter pipeline spilled down a hill and into Mill Creek in Washington County, prompting TC Energy to shut down the entire line.
The spill was "contained" by about 300 people working at the site, according to TC Energy.
5 top Keystone Pipeline oil spills
ABC News / U.S. Government Accountability Office
It remains unclear what caused the leak or when the repairs to the section of the pipeline will be completed. TC Energy officials said no timeline has been established for restarting the flow of crude oil through the area.
Third-party environmental specialists were among the hundreds of people who responded to clean up the mess using multiple vacuum trucks, booms, and additional resources, the company said. As of Wednesday evening, the company said it had recovered about 127,470 gallons of oil from Mill Creek and rescued wildlife, including a beaver affected by the spill.
The company said air quality monitoring has found "no indication of adverse health or public concerns."
The leak was the latest in a series of accidents on the pipeline. A federal report released last year showed the conduit recorded 22 accidents between 2010 and 2020 and found the severity of spills has "worsened" in recent years. The report conducted by the U.S. Government Accountability Office showed the previous incidents leaked a total of 11,975 barrels of crude oil, or a little over 500,000 gallons.
The report found that four of the biggest Keystone Pipeline oil spills between 2010 and 2020 were caused by issues related to the original design, manufacturing of the pipe or construction of the pipeline.
