A Michigan panel today approved Enbridge's $500mn plan to build a tunnel under the Straits of Mackinac to replace a section of its Line 5 pipeline.
The Mackinac Straits Corridor Authority, a new panel established to oversee the tunnel project, approved a proposed plan from Enbridge and the state of Michigan to build the structure to house Line 5.
The 540,000 b/d Line 5 crude and NGL pipeline will take five years to build, Enbridge said today.
The plan comes amid growing concern from environmental groups, local residents and some lawmakers that the 65-year-old pipeline system threatens the ecologically sensitive region.
The panel heard public testimony today both in favor and opposed to the plan. The hearing was held in St. Ignace, Michigan, which is on the Upper Peninsula.
Opponents to the project said that the approval process was being rushed to be completed during governor Rick Snyder's term in office and urged the panel to delay a decision. The incoming governor of Michigan, Democrat Gretchen Whitmer, has taken a hard stance against Line 5.
Opponents also said that Line 5 should be permanently decommissioned because of the risk to water supply and cited a 2010 spill on Enbridge's Line 6B which leaked 19,500 bl of crude and polluted the Kalamazoo river, which flows into Lake Michigan.
Proponents at the hearing said Line 5 has operated safely for decades, provides vital propane for heating and that building a tunnel will provide further protection from oil spills. Several Enbridge employees in Michigan spoke in favor of the project.
Line 5 carries light crude, light synthetic crude and NGLs under the straits that separate Lake Michigan and Lake Huron, running from Superior, Wisconsin, to Sarnia, Ontario. Some of the crude moves as far east as Montreal, Quebec, on Enbridge's 300,000 b/d Line 9.
As it travels under the Straits of Mackinac, Line 5 splits into two 20-inch-diameter, parallel pipelines. Line 5 also feeds refineries in Detroit, Michigan, and Toledo, Ohio. The system also carries NGLs for propane production to a facility in Rapid River, Michigan.
Concerns about a spill on Line 5 were exacerbated earlier this year when a boat anchor caused three small dents on the system. Enbridge said the structural integrity of the pipelines was not compromised.
Enbridge said that the tunnel will have one-foot-thick concrete walls, making the chances of a leak into the Straits "virtually zero."
The company is planning to begin collecting rock and soil samples from below the lakebed in the Straits in the spring of 2019, essentially starting the construction process. The target completion date for the tunnel is 2024.
Once a tunnel is built and placed into service, Enbridge would permanently deactivate the dual pipelines under the Straits. The plan approved today allows Enbridge to operate the current Line 5 until the tunnel is constructed.
Enbridge came to an agreement last year with Michigan to boost safety measures on Line 5, including replacing a portion of the system that crosses the St Clair river.
