BILLINGS, Mont. – Federal regulators proposed $1.7 million in civil penalties against Exxon Mobil Corp. on Monday for safety violations linked to a pipeline rupture that spilled an estimated 63,000 gallons of crude oil into Montana’s scenic Yellowstone River.
In a notice sent to the company, U.S. Department of Transportation regulators alleged a chain of bad decisions by Exxon leading up to the spill and in its immediate aftermath. That included Exxon employees’ failure to close an upstream safety valve, which could have significantly reduced the size of the spill after it was first detected.
As a result, the agency said, oil continued gushing into the flooding river for almost an hour after the break was noticed by pipeline controllers in Houston.
The agency also faulted the company for not addressing flood risks and not taking adequate measures to prevent a spill.
The July 2011 rupture of the 12-inch pipeline under the river near Laurel fouled 70 miles of the Yellowstone River’s banks, killing fish and wildlife and prompting a massive, months-long cleanup.
Investigators chalked up the immediate cause to floodwaters that damaged the line and left it exposed. It ruptured under pressure from debris washing downriver.
Exxon spokesman Patrick Henretty said the company was disappointed in the government’s findings, which he said appeared to contradict an investigative report released in December that said Exxon took “reasonable precautions to address the flooding.”
Henretty added that Exxon was still reviewing Monday’s notice. He said the Irving, Texas-based company has already altered its training program and procedures on the use of remote-control valves that can be used to shut down pipelines quickly when accidents occur.
Investigators previously said the size of the spill could have been reduced by about two-thirds if pipeline controllers had acted more quickly.
In Monday’s notice, the agency said there had been “numerous indications” that the 20-year-old Silvertip pipeline had been installed in an area prone to seasonal flooding and erosion.
Nevertheless, when the Yellowstone was flooding in 2011, Exxon chose to keep its pipeline operating even as at least one other company decided to shut down another line in the same area, the agency said.
Exxon’s “failure over an extended period of time to recognize those threats ... was a major cause of the failure,” Transportation officials said in Monday’s notice.