Enbridge Energy's initiative to construct a protective tunnel surrounding an aging pipeline beneath a significant waterway connecting two of the Great Lakes has been allowed to proceed, following a ruling from the Michigan Court of Appeals. The court affirmed that the state's Public Service Commission (PSC) rightly granted the necessary permits for the $500 million project, dismissing challenges posed by environmental organizations and Native American tribes.
The proposed tunnel is designed to enclose a 4-mile (6-kilometer) stretch of Line 5, which runs along the floor of the Straits of Mackinac, the channel that links Lake Michigan and Lake Huron. Enbridge has been utilizing this pipeline since 1953 to carry crude oil and natural gas liquids between Superior, Wisconsin, and Sarnia, Ontario.
Concerns about a potential environmental disaster in the straits have intensified since 2017, when Enbridge officials disclosed that engineers had identified gaps in the pipeline's protective coating as early as 2014. The situation escalated further in 2018 when the pipeline was damaged by an anchor from a boat, raising alarms about the possibility of a spill.
Despite Enbridge's assurance regarding the structural integrity of the pipeline, the company reached an agreement with former Michigan Governor Rick Snyder’s administration in 2018 that mandates the construction of the protective tunnel. This arrangement is intended to enhance the safety of the existing pipeline.
In December 2023, the Michigan Public Service Commission issued the necessary permits for the construction project. However, numerous environmental groups, including the Michigan Environmental Council and the National Wildlife Federation, along with various Native American tribes such as the Little Traverse Bay Bands of Odawa Indians and the Bay Mills Indian Community, challenged the PSC's decision in the appellate court.
The plaintiffs contended that the commission had improperly focused solely on the immediate need for the tunnel while neglecting to evaluate the overall necessity of the entire Line 5 pipeline. They also criticized the PSC for failing to adequately assess the greenhouse gas emissions associated with petroleum products transported through the pipeline.
Ultimately, the appellate court concluded that the PSC's analysis was comprehensive and reasonable, ruling that there was no justification to overturn the decision or require the commission to revisit its findings. In response to the ruling, David Scott, a senior attorney representing environmental organizations involved in the case, expressed disappointment and mentioned the possibility of further legal actions without offering specific details.
Despite the ruling, the legal controversy surrounding the tunnel is far from over. Michigan's current governor, Gretchen Whitmer, a Democrat, opposes the continued operation of Line 5, regardless of the planned tunnel encasement. In 2019, Democratic Attorney General Dana Nessel initiated a lawsuit aimed at revoking the easement that permits the pipeline to traverse beneath the straits. This case remains active in the Ingham County state court, with a potential ruling pending.
Furthermore, Enbridge must secure federal construction permits from the U.S. Army Corps of Engineers before commencing with the tunnel project. Environmental advocates are apprehensive that the Trump administration may expedite this permitting process, especially following President Trump’s declaration of a national energy emergency on his first day in office.
