(Reuters) - The Keystone crude oil pipeline leak in November in rural South Dakota was nearly double the original estimate, making it one of the largest U.S. inland spills since 2010, a newspaper report on Saturday said.
Robynn Tysver, a spokeswoman for Calgary-based TransCanada Corp, which owns the pipeline, told the Aberdeen American News some 9,700 barrels of oil leaked in the Nov. 16 spill, the South Dakota paper reported. The original estimate was 5,000 barrels.
The spill gave further ammunition to environmental groups and other U.S. opponents of another pipeline the company has proposed, the long-delayed Keystone XL.
TransCanada had shut down the 590,000 barrel-per-day pipeline, one of Canada's main crude export routes linking Alberta's oil fields to U.S. refineries, immediately following the spill. Operations were restarted less than two weeks later.
TransCanada officials were not immediately available for comment.
The TransCanada spokeswoman told the newspaper repairs have been made on the pipeline and a clean-up conducted.
"We have replaced the last of the topsoil and have seeded the impacted area," Tysver said in an email sent to the American News late Friday evening, the paper said.
Keystone has leaked substantially more oil, and more often, in the United States than the company indicated to regulators in risk assessments before operations began in 2010, according to documents reviewed by Reuters.