Exxon Mobil Corp's near 70-year-old Pegasus oil pipeline leaked a small amount of crude into a residential yard in Ripley County, Missouri on Tuesday, a month after the same pipe spewed thousands of barrels of crude in Arkansas.
A resident notified the company of the spill after spotting a patch of oil and dead vegetation seven miles south of Doniphan in the southeast of the state, Exxon and state officials said on Wednesday.
About one barrel of crude leaked and the cleanup is "close to completion", an Exxon spokeswoman said.
Tuesday's spill occurred 200 miles north of Mayflower, Arkansas, where about 5,000 barrels of crude spilled from the Pegasus pipe into a residential area on March 29, prompting a giant clean-up operation that is still ongoing.
The Mayflower spill stoked a fractious national debate about the effect of shipping increasing amounts of tarry Canadian crude across the United States, including through residential areas and in aging pipelines.
The Pegasus line, which can carry more than 90,000 barrels a day of crude from Illinois to Texas, was built in the late 1940s. It was shut after the Arkansas spill and was not in operation when the Missouri spill occurred.
"The release occurred from the installation of a guide wire for a power line pipe that was installed approximately 30 years ago," a spokeswoman for the Missouri Department of Natural Resources said on Wednesday. "The guide wire was located almost directly on top of the pipeline and has worn down over the years."
The Exxon spokeswoman said the cause was under investigation.
Exxon has not offered a timeline for when Pegasus will restart, which requires regulatory approval. The Pipeline and Hazardous Materials Safety Administration, which is responsible for approving pipeline restarts, was not immediately available for comment on Wednesday and it was unclear if the second spill would slow the restart process.
(Reporting by Edward McAllister and Robert Gibbons in New York; Additional reporting by Arpan Varghese in Bangalore; Editing by Gerald E. McCormick, Dale Hudson and Bernard Orr)