Dozens of residents, tribal members and environmental groups used the Mackinac Straits Corridor Authority public-comment period on March 12 to press the authority and state and federal regulators to halt or further scrutinize the proposed Line 5 tunnel and related permits.

"The tunnel is a false solution," said Julie Griesinger of Oil and Water Don't Mix and the Sierra Club. "Enbridge keeps saying the tunnel will protect the Great Lakes, but all it does is extend the life of a 645 mile aging pipeline that has 33 documented spills." Griesinger and others urged the Corps to complete a full review under NEPA and to allow robust public participation.

Tribal speakers tied the matter to treaty rights and community survival. Denise Petoskey, speaking in her indigenous language and English, described the lakes as the basis of her community's livelihood and urged the authority to consider tribal concerns. Several speakers noted that all 12 Michigan tribes have opposed the tunnel and called for protection of sovereign rights.

Public-health and climate worries were a common thread. "Approving new fossil fuel infrastructure like the Line 5 tunnel ... locks us into decades of climate pollution," said Nada Robert, network manager with the Michigan Climate Action Network, who called for pausing approvals until a full review of climate and health impacts is completed. Denise Keel, executive director of the Michigan Climate Action Network, said experts estimate the project could increase carbon emissions substantially and cited pending appeals of prior administrative rulings.

Speakers raised contractor and safety concerns. Multiple commenters cited Barnard Construction Company and other contractors' past project problems, including underpaid workers and construction defects. "Barnard also has a history," said Sean McBrearty of Clean Water Action, enumerating contractor problems and saying the authority should scrutinize contractor selection and project oversight before the state assumes any long-term liability.

Community members stressed local and economic risks. Ashley Rudzinski of the Groundwork Center noted that the Great Lakes support tourism and commerce worth billions and said an oil spill could devastate shoreline communities and supply chains. Local residents recounted experiences from previous Enbridge spills and urged the authority to reject shortcuts in review or permitting.

Speakers also warned about broader social risks tied to temporary worker camps and alleged human-trafficking incidents connected to other pipeline projects. Commenters asked the authority to press permitting agencies to examine those risks and to clarify whether federal executive orders might alter public-comment opportunities.

What the public requested: speakers called for a full environmental review that includes climate impacts and public-health analysis, careful evaluation of contractor qualifications and labor practices, respect for tribal treaty rights, and transparency about state expenditures and oversight steps. Several speakers said they would pursue appeals in court or through administrative channels.

The authority did not respond with formal action during the public-comment period. The session closed after the scheduled speakers finished; the authority will continue to receive updates from the Army Corps, MDOT and Enbridge as the NEPA and permitting processes proceed.