Keystone pipeline leak in S. Dakota about double previous estimate -paper

The Keystone crude oil pipeline leak inNovember in rural South Dakota was nearly double the originalestimate, making it one of the largest U.S. inland spills since2010, a newspaper report on Saturday said.

Robynn Tysver, a spokeswoman for Calgary-based TransCanadaCorp , which owns the pipeline, told the AberdeenAmerican News some 9,700 barrels of oil leaked in the Nov. 16spill, the South Dakota paper reported. The original estimatewas 5,000 barrels.

The spill gave further ammunition to environmental groupsand other U.S. opponents of another pipeline the company hasproposed, the long-delayed Keystone XL.

TransCanada had shut down the 590,000 barrel-per-daypipeline, one of Canada's main crude export routes linkingAlberta's oil fields to U.S. refineries, immediately followingthe spill. Operations were restarted less than two weeks later.

TransCanada officials were not immediately available forcomment.

The TransCanada spokeswoman told the newspaper repairs havebeen made on the pipeline and a clean-up conducted.

"We have replaced the last of the topsoil and have seededthe impacted area," Tysver said in an email sent to the AmericanNews 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 inrisk assessments before operations began in 2010, according todocuments reviewed by Reuters.

(Reporting by Jon Herskovitz in Austin, Texas, editing by GCrosse)