Enbridge: Line 5 Suffered 'Dents' in Straits Incident

FRIDAY, APRIL 13, 2018

Enbridge Energy told Michigan officials Tuesday that its Line 5 pipeline, originally thought to be unaffected by last week’s incident that damaged a nearby electric transmission cable, actually sustained small dents, likely caused by a passing ship.

Line 5, the 65-year-old liquids pipeline running under the Straits of Mackinac, was shut down temporarily last week after a leak of dielectric fluid from a nearby submerged electric line was found April 1, raising concerns that a ship anchor or other object may have damaged the cable’s housing. Anchor drops are prohibited in the area of the Straits where the lines are.

While the pipeline was restarted by April 4, it was revealed this week that Enbridge found damage to the pipeline, likely linked with the same incident. The company reportedly uncovered three small dents; officials say the dents do not compromise the line’s integrity.

Calls for Action

The team investigating the incident, headed by the Coast Guard and including state and local agencies, has not reported an official cause yet, but Lt. Gov. Brian Calley, acting as governor while Gov. Rick Snyder was traveling, called for legal action against the owner of whatever ship may have damaged the energy infrastructure.

Snyder also called on Enbridge to “accelerate the identification of anchor strike mitigation measures and the evaluation of alternatives to replace” the twin pipelines, part of an agreement between the governor’s office and Enbridge reached last fall.

Alternatives the company is exploring include installing a new pipeline in a tunnel, via horizontal directional drilling or in a trench with secondary containment.

Line 5 Controversy

Enbridge has been under increasing fire over the past year from citizens, activists and lawmakers in Michigan who are concerned about the condition of Line 5 and the risk of environmental damage to the Great Lakes should a release occur. In November, Gov. Rick Snyder publicly called on Enbridge to be more transparent about the line after a series of revelations regarding coating damage on the pipes under the Straits.

Last February, Enbridge denied reports of coating loss on the pipeline. In March, the company acknowledged that there were areas of coating loss, but that they only affected the outer layer of the coating system.

Later in the year, it was revealed that there were areas of bare metal on the line under the Straits, and some Enbridge personnel knew about the gaps soon after they were created in 2014, but the company hadn’t acknowledged their existence for three years. In November, Enbridge revealed that, rather than the three gaps in the coating that the company originally reported, there were dozens of areas of bare metal, some larger than one square foot in area.

Enbridge has held that the pipeline’s integrity has never been compromised. The line has never had a leak in over six decades of service, and last summer, it passed a pressure test ordered as part of the company’s consent agreement, established after the 2010 spill on its Line 6B.


Tagged categories: Infrastructure; NA; North America; Oil and Gas; Pipelines; Program/Project Management

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