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Alyeska to deal with waterway threats Work this summer will involve installing protections to keep shifting river, creek from exposing buried sections of oil pipeline Wesley Loy For Petroleum News
The operator of the trans-Alaska oil pipeline is seeking state approval for two projects to protect the line from shifting waterways.
One project will be far north, along the Sagavanirktok (Sag) River, with the other project at Sheep Creek near the south end of the 800-mile pipeline.
Both projects will require amendments to the pipeline’s right-of-way lease over state lands.
The operator, Alyeska Pipeline Service Co., has a rivers and flood plains program to make sure the line is protected, spokeswoman Michelle Egan said.
The annual spend for the program is about $4 million to $5 million per year, and the upcoming projects are “fairly typical,” she said. Alyeska is an Anchorage-based consortium that runs the pipeline on behalf of owners BP, ConocoPhillips, ExxonMobil and Chevron.
The Sag River project Alyeska is applying to the state Department of Natural Resources, State Pipeline Coordinator’s Office, to add 41.5 acres of state land in the Sag River flood plain to the right-of-way lease.
The project site is about 25 miles south of Deadhorse and 33 miles north of Pump Station 2. The pipeline and the Dalton Highway follow the west side of the Sag River at this location.
The river is braided with many channels across the active flood plain. The concern is that the naturally occurring migration of the river, combined with a major flood event, could outflank an existing armored gravel structure built at the time of pipeline construction in the 1970s, Alyeska said.
Alyeska wants to prevent flows that could expose the shallow buried pipeline.
The project will involve extending the armored structure using bulldozers, excavators and other equipment.
The work is expected to take 18 days, and will be done between June 1 and Oct. 31, Alyeska said.
The Sheep Creek project Alyeska is seeking to add 6.2 acres of state land to the pipeline right-of-way lease at Sheep Creek, about 20 miles north of Valdez.
The company plans to install two structures at the pipeline crossing of the creek. The structures will protect the integrity of the pipeline by preserving the depth of cover should the creek channel migrate, Alyeska said.
Coho salmon inhabit Sheep Creek, but Alyeska said it doesn’t expect much of the work to be in the stream. However, a small temporary diversion on a subchannel might be needed.
Again, the work will involve bulldozers, rock trucks and other equipment. The job is scheduled to be done between June 1 and the end of November.
Information on both projects is available on the State Pipeline Coordinator’s Office website, dnr.alaska.gov/commis/pco
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