Coast Guard: Enbridge-contracted vessels likely scraped Line 5

A U.S. Coast Guard official told environmental groups Friday that damage discovered to Line 5 earlier this year likely was caused by Enbridge-contracted vessels conducting work in the area to prepare for the construction of a utility tunnel.

Enbridge earlier this year noted in a report that it had narrowed down to five the list of "small to moderately sized" vessels that could have dragged a cable in a north south direction over Line 5, scraped the east leg and damaged an anchor support. 

Four out of the five boats, Enbridge said at the time, had been contracted by the Canadian oil giant. 

Coast Guard Captain Anthony R. Jones of Port Sault Sainte Marie said his staff conducted its own review and came to similar conclusions. 

"I have concluded that the disturbances found by Enbridge Energy are reasonably attributed to incidental contact by cables or other equipment deployed or handled by vessels contracted by Enbridge to conduct work within the submerged pipeline area," Jones wrote Friday. 

Enbridge Energy still is reviewing the incident and hasn't reached a final determination about the cause, company spokesman Ryan Duffy said Tuesday.

The company has implemented safety protocols to avoid vessel-induced damage to the line, including the identification of vessels traveling through the straits, patrol boats in the area, contact with at-risk vessels asking them to lift anchor or avoid crossing the straits, or a temporary shutdown of Line 5.

"We have interviewed our own contractors working in the areas as part of our thorough investigation," Duffy said. "As of now we can’t rule out their involvement."

Line 5, which transports up to 540,000 barrels a day of light crude oil, light synthetic crude and natural gas liquids, has been the subject of a years-long dispute over a possible rupture of the 67-year-old pipeline in the Great Lakes. The Canadian company is engineering a tunnel to house the pipeline along the Straits and was performing geotechnical work along the planned construction area when the damage allegedly took place. 

The contacts with the line are outside the Coast Guard's purview, which focuses on traffic management to avoid anchor strikes along the pipeline, Jones said. 

The captain had been asked by environmental groups to review the Regulated Navigation Area within the Straits of Mackinac, within which certain vessels are banned from anchoring or loitering in the area unless Jones grants them permission. 

Jones said he determined no vessels or barges anchored in the straits from October 2018 onward in a way that was in violation with the Regulated Navigation Area. 

The damage discovered by Enbridge along the line earlier this year was not enough to be considered a marine casualty and rise to the level of Coast Guard review, Jones said. 

"While I do not intend to take action related to instituting a temporary rule or seeking to amend the current rule, I will use this opportunity to continue to advance our safety posture and improve the way we implement (Regulated Navigation Area) requirements," he wrote to the groups.

For the environmental groups requesting the review, Jones' response came as confirmation of the alternatives left to ensure the pipeline's safety.

"It just goes on to confirm that there’s no safe way for this pipeline to operate in the Straits," said Sean McBrearty, Michigan legislative and policy director for Clean Water Action.

When Enbridge discovered the scrapes and damaged anchor support along the line in early summer, a judge ruled a segment of the pipeline should be closed down until the Pipeline and Hazardous Materials Safety Administration could assess the pipeline's safety. 

That review is ongoing. 

eleblanc@detroitnews.com