Line 5 and potential transportation impacts

Location: National

Summary of Issue/Background

  • In November 2020, the State of Michigan announced that it would seek to revoke an easement used by Enbridge’s Line 5 pipeline that allows it to run through the Straits of Mackinac, removing the pipeline’s ability to operate.

  • Beginning in Superior, Wisconsin Line 5 moves 540 million barrels per day of crude oil and liquid natural gas products though Michigan into Ontario. The liquid natural gas and much of the crude feed refineries in Sarnia and Westover, Ontario, and the remaining crude is shipped to Quebec and Pennsylvania via Enbridge Line 7.

  • The issue is currently in U.S. federal court. In April 2021, the U.S. federal court ordered a mediation process be undertaken between Michigan and Enbridge in order to reach a negotiated solution. The most recent mediation took place in early September.

  • Contingency planning and solutions in the event of a shutdown are being considered by both industry and government. These solutions may involve increased use of rail, road and/or marine transportation modes.

  • Medium-term plans are underway to build the Great Lakes Tunnel, a $500-million private investment by Enbridge in Michigan, which will replace the segment of Line 5 in the Straights and reduce the chances of a pipeline incident in the area significantly. However, this project is several years from completion.

  • Line 5 is governed by the provisions of the 1977 Agreement between the Government of Canada and the Government of the United States of America Concerning Transit Pipelines, which guarantees the uninterrupted transit of light crude oil and natural gas liquids between the two countries. On October 4, 2021, Canada formally invoked a dispute resolution process as per Article Six of the 1977 Canada-U.S. Transit Pipeline Treaty.

  • The U.S. federal court has been asked to delay any decisions on Line 5 in order to facilitate negotiations between the two countries.


  • The Government of Canada considers Line 5 vital to Canada’s energy security and economic prosperity.

  • The Government of Canada continues to engage with the United States in support of a negotiated resolution to this issue.