Enbridge resumes partial operation of Line 5, Gov. calls for another shutdown, review

Enbridge has resumed partial operation of Line 5 under the Straits of Mackinac, a company spokesman said Saturday, despite the request of Gov. Gretchen Whitmer to keep the pipeline shut down. 

Line 5 was shut down by the company on Thursday after "significant damage" was discovered in an anchor support during routine maintenance.   

Whitmer on Saturday sent a second letter to Al Monaco, CEO of Enbridge, asking the company immediately shut down the dual pipeline running through the Straits of Mackinac until the damage is investigated, assessed and preventative measures are put in place, according to a release from the governor's office. 

“Given the gravity of this matter, I was taken aback to learn the company has unilaterally resumed operation of the west leg without even opportunity for discussion,” said Governor Whitmer. “At this moment, Enbridge is pumping crude through the Great Lakes on state-owned bottomlands without any explanation for the cause of this damage to the pipeline structure and no assurance that Enbridge has taken sufficient steps to mitigate future harm.

"This disregard for the safety and well-being of our Great Lakes, and Enbridge’s due care obligations under the 1953 Easement, is unacceptable.” 

In addition to Whitmer's request, she also asked Enbridge to provide a full report as to the cause of the damage and measures Enbridge will put in place to prevent it from happening again, according to the release.

Once the state, or a third-party selected by the state, has reviewed the information, the state and Enbridge can discuss when normal operations can resume, the release said.

When operating, Line 5 transports up to 540,000 barrels per day of light crude oil, light synthetic crude, and natural gas liquids, according to Enbridge.

Operation of the west leg of the pipeline was restarted at about 2 p.m. Saturday, after inspections by a remote-operated vehicle determined there was no damage to that part of Line 5, according to Enbridge spokesman Ryan Duffy.

More:Whitmer: Line 5 shut down after 'significant damage' to anchor support

Line 5 in the Straits consists of two 20-inch pipelines, an east leg and west leg. The legs run parallel to each other for four-and-a-half miles across the lake bed, Duffy noted. 

"The issue with the screw anchor assembly observed on Thursday is isolated to the east leg, which we will continue to investigate and evaluate over the weekend," he said in an email to The Detroit News. 

"The east leg will remain shut down. Our federal regulator, PHMSA (Pipeline and Hazardous Materials Safety Administration), has no objections to this plan."

In a letter to Monaco on Friday, Whitmer said the damage to the anchor support was reported to the state on Thursday night. Whitmer's office released the letter Friday evening.

According to Duffy, the company discovered during seasonal maintenance that a screw anchor support had shifted from its original position.

"There was no damage to the pipeline itself," Duffy said. "There are about 200 of these anchor supports." 

The pipeline was totally shut down as a precaution while the entire pipeline was inspected by divers and with remotely operated vehicles, he added.

In her letter on Friday, the governor requested Enbridge turn over "all relevant information about this most recent damage."

Whitmer also asked the company to "provide affirmative evidence, including appropriate diagnostic testing, that establishes the integrity of the dual pipelines in the Straits of Mackinac."

Monaco responded to Whitmer on Saturday, and confirmed that Enbridge is committed to sharing what is learned about the incident with the screw anchor assembly on the east leg with PHMSA and the state of Michigan, Duffy said. 

News of the shutdown was the latest development in a years-long debate about the 66-year-old Line 5 in the Straits of Mackinac as environmental groups have voiced concern about the potential for a rupture and called for the line to be shuttered.

kbouffard@detroitnews.com

Twitter: @kbouffardDN