U.S. officials have rejected Exxon Mobil Corp.'s request to reconsider a $1 million penalty imposed against the oil giant over a 63,000-gallon crude spill into Montana's Yellowstone River.
The U.S. Department of Transportation on Friday ordered the Texas company to pay the penalty within 20 days.
Safety regulators said Exxon Mobil failed to adequately heed warnings that its 20-year-old Silvertip Pipeline was at risk from flooding. They said the company lacked procedures to minimize the spill when the line broke.
The 2011 spill left oil along an 85-mile stretch of the Yellowstone, killing fish and wildlife and prompting a cleanup that took months.
Exxon attorneys had asked the Department of Transportation to withdraw three of its four findings of pipeline safety violations. It also sought to reduce the penalty.