MI Hears Comments on Line 5 Tunnel


The Michigan Public Service Commission held a virtual public hearing last week for comments on the proposed Enbridge Line 5 tunnel, which if approved would run under the Straits of Mackinac.

The hearing was the latest step in a years-long battle debating the risks associated with Enbridge Energy’s Line 5 liquid pipeline.

Enbridge Pipeline Saga

In July 2017, Michigan Pipeline Safety Advisory Board released an assessment of Enbridge Energy’s Line 5 liquid pipeline that looked at the risks related to keeping the current pipeline—which was built in the 1950s and crosses under the Straits of Mackinac—as well as alternatives, including new lines in or around the straits, a new pipeline elsewhere or a complete abandonment of the line.

The assessment was prepared by Dynamic Risk Assessments Inc.

According to Dynamic Risk, the biggest threats to the existing pipeline are anchor hooking, incorrect operations, vortex-induced vibration and spanning stress. A spill in the straits, the firm contends, would likely incur $100-200 million in costs, about 60% of that covering environmental cleanup. Those figures account for what Dynamic Risk calls “objective assessments of credible risks,” and not a worst-case scenario.

By June 2018, Enbridge Energy released its report to the state of Michigan on possible replacement of its Line 5 pipeline, concluding that a tunnel or an open cut with secondary containment would be feasible methods for replacing the 65-year-old liquids pipeline.

In the report, Enbridge says its study, performed by independent consultants, showed a tunnel created by a tunnel-boring machine could be a feasible method of installing a new pipeline to replace Line 5. Such a tunnel would have a 10-foot inside diameter and would stretch four miles long, 100 feet below the deepest part of the Straits.

A tunnel would cost $350-500 million, Enbridge says, and if this alternative were chosen, the dual 20-inch pipelines comprising the current Line 5 would be replaced with one 30-inch line. The concrete tunnel would be lined with precast concrete tunnel lining; the annulus outside the tunnel lining would be filled with cement grout.

The other alternative the company says could work would be an open cut with a secondary-containment pipeline around a new 30-inch Line 5. This approach would cost $250-300 million and would involve trenching the pipeline for the first half-mile or so from the shoreline, then laying the majority of the line on the lakebed with an engineered protective cover.

The pipe-in-pipe system would involve a 30-inch steel pipeline surrounded by a 36-inch secondary-containment line with low-friction spacer rings in the space between. The outer pipeline would be engineered to withstand pressures greater than the line’s operating maximum.

However, a worst-case spill on Line 5, according to a risk analysis by Michigan Technological University, could affect more than 400 miles of shoreline on Lake Michigan and Lake Huron and come with a price tag of more than $1.8 billion.

A lawsuit filed at the end of August 2018 by the Environmental Law and Policy Center and the National Wildlife Fund alleged that a top Coast Guard official testified under oath in front of Congress the year before that the service was not adequately prepared for a worst-case spill on the line, though the Coast Guard does have a contingency plan in place to do just that.

In December, the Michigan Senate voted to create the three-member Mackinac Straights Corridor Authority, an entity that would oversee the construction of the replacement pipeline and a new utility tunnel.

According to Crain’s Detroit Business, creating the panel is an essential step toward replacing the underwater pipeline. The project is slated to take seven to 10 years to complete, and the cost of replacing the pipeline could range from $350-500 million, all paid for by Enbridge, but owned by the Mackinac Bridge Authority.

However, in May 2019, the law to create the three-member Mackinac Straights Corridor Authority was ruled unconstitutional by the state attorney general. Gretchen Whitmer, Michigan’s current governor, asked for Attorney General Dana Nessel's legal opinion. In Whitmer’s view, the law is invalid. Earlier last year, Whitmer halted state agencies’ attempts to facilitate construction on the tunnel.

State legislature Republicans have dismissed Whitmer’s opinion, citing that a judge has already allowed the law to be as is.

The state attorney general’s communications director, Kelly Rossman-McKinney, noted that the attorney general thinks the opinion will be upheld. If that happens, though, consumer groups are likely to sue, according to the Engineering News-Record, given that Upper Peninsula residents oppose measures that would take Line 5 out of service without replacement.

At the beginning of March, Enbridge announced that it hired Arup (London) to design the tunnel and Great Lakes Tunnel Constructors—a partnership between Jay Dee Contractors Inc. (Livonia, Michigan) and Obayashi Corp. (Tokyo)—to build it.

At the time of the announcement, the company was still continuing to seek construction permits from the Michigan Department of Environment, Great Lakes and Energy and the U.S. Army Corps of Engineers.

In mid-May, the Corps Detroit district office announced it would begin accepting public comments on Enbridge’s proposal to build an oil pipeline tunnel beneath Michigan’s Straits of Mackinac.

However, at the end of the month, Enbridge officials announced that while installing screw anchors to secure sections of its Line 5 in the channel they discovered four spots where protective coatings had worn away from the underwater oil pipeline.

Located on the east segment of Line 5—which divides into two pipes when crossing the bottom of the straits—are four spots measuring less than 6 square inches in size where protective coatings have failed, revealing exposed bare metal. Enbridge spokesperson Ryan Duffy reported at the time that the coatings would be repaired within 10 days following the discovery.

Spill Plan Approval

The Associated Press has reported in June that the federal court had overruled District Judge Mark Goldsmith’s ruling that Enbridge had to comply with both the Endangered Species and National Environmental Policy Acts in regard to its spill plans.

Previously, the company was sued by National Wildlife Federation for allegedly failing to prove that plans wouldn’t jeopardize endangered fish or wildlife and for not issuing an environmental impact statement. However, in the past five years Enbridge had submitted spill plans which were both approved by the federal Pipeline and Hazardous Materials Safety Administration.

In a 2-1 ruling, the 6th U.S. Circuit Court of Appeals said the agency could not consider them because the Clean Water Act has specific criteria “by which to evaluate the ‘correctness’ of the plans.”

Judges Amul Thapar and Joan Larsen stated in their majority opinion that Enbridge had met those standards and that the company plans to have enough personnel and equipment to respond to a worst-case discharge, as well as testing and drills.

“Enbridge has developed and implements very thoughtful and thorough emergency response plans to respond to any size of a release from Line 5, including any release at water crossings made by Line 5, such as at the Straits,” said Duffy. “Our policies and procedures demand that Enbridge pipelines and associated facilities are operated safely.”

However, Mike Shriberg, Great Lakes regional director for the wildlife federation is considering asking the entire 6th Circuit court to take the case or appeal to the Supreme Court.

“If you’ve got equipment in place that can’t be used, you’ve got to look at what the impacts would be to fish or wildlife like the piping plover, which is an endangered species that has critical nesting habitat in that area,” he said. “If the federal agency isn’t considering those things, they’re not doing their job.”

What Now

The hearing was part of the state’s review process of the project as both proponents and critics of the plans spoke last week.

Proponents of the tunnel, which included state representatives, business leaders, members of the United Steelworkers Union in Ohio and Enbridge employees, depicted the plan as a compromise—one that mitigates the greatest risk of an oil spill in the Great Lakes by moving the pipeline from the lakebed.

They argued that keeping that access to propane is vital for the region and would also preserve jobs in the safest way possible.

Critics, which include environmental groups, members from the Bay Mills Indian Community, other tribes, local landowners and Michigan residents aren’t convinced that the project has undergone sufficient environmental review and also look to the agreement’s 99-year lease, saying that the tunnel and pipeline would soon become obsolete.

The state is still collecting public comments and will begin hearing testimony from legal challengers next year.


Tagged categories: Environmental Controls; Lawsuits; NA; North America; Ongoing projects; Pipeline; Pipelines; Tunnel

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