Enbridge Inc. will shut down and replace its Line 5 across the Straits of Mackinac with a multiuse utility tunnel that the Calgary energy transmission company will pay for, Michigan Gov. Rick Snyder (R) announced.
“The historic agreement will result in eliminating nearly every risk of an oil leak in the straits and provide added protections to the Great Lakes. It also will allow for multiple utilities to be housed and protected, better connecting our peninsulas, improving energy security and supporting economic development,” he said.
Under the agreement Enbridge will pay for design, construction, and maintenance of the tunnel for up to 99 years, subject to approvals by the Mackinac Bridge Authority, Snyder said. The tunnel’s construction will cost an estimated $350-500 million over 7-10 years, he said.
“The agreement protects the waters of the straits and the Great Lakes in several ways, and makes a safe pipeline even safer,” Enbridge said. The agreement also will increase coordination between the company and the state, improve safety on Line 5 water crossings other than the straits, and provide financial assurances from Enbridge to meet the costs under a straits worst-case spill scenario, it said.
Snyder said assessments to date confirm Line 5’s integrity as it crosses the straits, but the new agreement demands additional measures to reduce risks during the tunnel’s construction, which include:
• Assuring the straits pipeline is not operating when high waves would severely hamper response to a potential oil spill. The agreement requires that Enbridge staff be present at the straits to be able to shut down the line within 15 min—even if power is lost—when wave heights hit 6½ ft for at least 1 hr. Enbridge must continue to shut down the straits pipeline when wave heights hit 8 ft for at least 1 hr.
• Providing a new radar system to supply improved, real-time wave-height data at the straits.
• Assuring that Enbridge makes available at least $1.8 billion to respond to a potential oil spill in the straits or anywhere on Line 5 in Michigan and providing added protections as the tunnel’s construction is completed.
• Providing consistent state supervision of Line 5 through regular meetings between Enbridge and the state.
• Installing cameras, paid for by Enbridge, to support new US Coast Guard regulations prohibiting ships in the area from dropping anchors by monitoring vessels and notifying crews on board those operating in a dangerous manner.
Snyder said the new agreement prohibits heavy crude traveling through Line 5, and requires additional safety measures at 13 priority Line 5 water crossings, in addition to requiring actions at 68 other crossings as identified in a June 30 report.
US Sen. Gary C. Peters (D-Mich.) convened a field hearing in Traverse City on Aug. 20 to examine risks of a Line 5 spill after a barge let its anchor drag along the bottom of the straits, cutting utility lines and denting, but not breaching, Line 5 (OGJ Online, Sept. 3, 2018).
Michigan Petroleum Pipelines (MPP), the agency overseeing their operation in the state, said that in compliance with the 2017 agreement, Enbridge has applied for authorizations and approvals to replace the Line 5 crossing at the St. Clair River, a water body that provides drinking water to a large population in southeast Michigan. Work will begin upon the receipt of those authorizations and approvals, MPP said.