WASHINGTON Jan 2 An Exxon Mobil
pipeline spill into the Yellowstone River in 2011 would have
been far less severe if the company had not delayed closing
valves, a report issued on Wednesday by federal pipeline
Exxon's Silvertip pipeline, which carries 40,000 barrels per
day of crude in Montana, leaked about 1,500 barrels of oil into
the Yellowstone River in July 2011 after the region suffered
Had Exxon Mobil Pipeline Company's shutdown procedures
required remote controlled valves to be closed immediately after
a leak, "the crude oil release volume would have been much
less," said a U.S. Pipeline and Hazardous Materials
Administration report obtained by Reuters on Wednesday.
Controllers closed some valves and pumps 10 minutes after
the spill. But workers then waited about 46 minutes before
shutting other valves, the report said. If the company had
responded faster the spill would have been about two-thirds
The report said erosion from the flooding exposed the
pipeline to debris that severed it and caused the leak. It did
not specify fault or express that Exxon violated any safety
regulations. A spokesman said the agency was reviewing the
report to determine if enforcement actions will be taken.
The Silvertip routinely transports oil sands crude from
Canada which environmentalists have said can corrode pipelines.
The oil industry has said the petroleum is no more corrosive
than other crude transported in pipelines. Exxon has said no
Canadian oil was in the line near the area that was affected by
After the spill, Exxon had installed a new quarter-mile
section of the line at least 40 feet under the river.
An Exxon spokeswoman said the company would not comment on
the report until it had more time to review and analyze its