(December 13, 2017) Enbridge Inc. (Calgary) recently entered into an agreement with the state of Michigan laying out a path forward for addressing the future of the company’s Line 5. The agreement increases collaboration and coordination between the state and Enbridge and contains key actions that move toward a long-term solution. Line 5 is a 645-mile, 30-in.-dia. pipeline that originates in Superior, Wis. and terminates in Sarnia, Ont. It transports as much as 540,000 bbld of light crude oil and natural gas liquids.

Environmentalists, Indian tribes, and state officials have focused on the segment that lies beneath the Straits of Mackinac, a five-mile-long waterway, alleging that the underwater portion installed in 1953 is deteriorating and is a threat to the environment. They have called for the closure of the line. Enbridge maintains the segment is in good condition, is regularly monitored, and has never leaked, but nonetheless has agreed to a program to drive down risk.

By June 2018, the company will have evaluated three options for the eventual replacement of the dual pipelines in the Straights of Mackinac. Options evaluated with the state include placing a new pipeline in a tunnel under the straits, installing a new pipeline below the lakebed of the straits using horizontal directional drilling, and creating a trench on the bottom and placing a new pipeline in a secondary containment structure or system.

Enbridge has also agreed to temporarily shut down Line 5 operations when adverse weather conditions create sustained waves higher than eight feet in the straits; put into place additional safety measures to further mitigate a potential anchor strike from boats; and evaluate additional tools and underwater technologies that could help inspect and maintain the line, and assess the condition of the coating on the twin pipelines.

The company-state pact also provides for work with the state to enhance safety and reduce the potential impacts at other Line 5 water crossings, as well as replacing the St. Clair River crossing as soon as federal and state approvals are received. Finally, coordination will be increased with Michigan regarding operations, maintenance, and the future of Line 5 in order to promote transparency. State representatives will have access to Enbridge’s data and studies.

The agreement does not represent a dinal decision regarding Line 5’s future. The evaluation of the pipeline called for by the Michigan Petroleum Pipeline Task Force Report will continue. The evaluation is being conducted by the Michigan Agency for Energy, the Michigan Department of Environmental Quality, and the Michigan Department of Natural Resources, with advice from the Pipeline Safety Advisory Board. A contract for a separate, independent risk analysis, led by Michigan Technological University, is being finalized. The studies, along with public input and the new agreement, will shape a final recommendation from the state on the future of Line 5.