THURSDAY, MAY 21, 2020
Starting last Friday (May 15), the U.S. Army Corps of Engineers 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.
The comment period follows the submission of a complete project application.
About the Enbridge Pipeline
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 lake bed 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.
Although, 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, 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.
What’s Happening Now
The news of Enbridge’s approved application and comment period opening arrives a little over one week after state officials announced that they would be delaying a permit for the project.
According to reports, the Water Resources Division of the Michigan Department of Environment, Great Lakes, and Energy requested more information on the project from Enbridge after finding that there were still issues with the project’s design and specifications.
"EGLE understands that design-build process is being used by overlapping the design phase and construction phase of this project," the associations stated in a letter. "This means that much of the exact dimensions and specifications of structures and tunnel location and design are to be determined as the project design is finalized."
Specifically, officials were seeking information on the exact diameter proposed for the pipeline, how mitigation issues would be addressed and suggested that relevant design products and specifications be implemented.
The Detroit News reports that the Corps responded to the information requests on May 4 and May 7. However, according to Scott Dean a spokesperson for EGLE, the Corps has until June 3 to respond to the last of its unanswered requests for more information, which the company reports it would comply.
Regardless, the Corps moved forward with opening a public comment period on May 15, and it is slated to last through June 4.
"We have not scheduled a public hearing, but commenters to the public notice may request a public hearing," said Katie Otanez, a regulatory project manager for the corps' Detroit District. "The corps will determine whether a public hearing is needed based on whether a hearing is likely to result in information that could not otherwise be gained."
Once the project recieves the green light, construction is scheduled to begin near year with a 2024 target completion date.
Tagged categories: Government contracts; Oil and Gas; Pipelines; Program/Project Management; Project Management; U.S. Army Corps of Engineers; Upcoming projects
