What Michigan’s Small Businesses Need to Know About Enbridge’s Great Lakes Tunnel Project

Q: What is the Great Lakes Tunnel Project? 
A: The Great Lakes Tunnel is a private infrastructure project proposed by Enbridge, the energy company that operates Line 5 – a pipeline that has delivered light crude oil and natural gas liquids to Michigan and the Great Lakes region for more than 70 years. Enbridge plans to bore a tunnel deep beneath the Straits of Mackinac, connecting the upper and lower peninsulas, to house a replacement segment of Line 5. The tunnel could also accommodate third-party utilities, including electric and fiber optic cable. 

Q: Why is the tunnel being proposed? 
A: Environmental protection and energy reliability. The current dual pipelines are buried to a depth of 65 feet and then rest on the lakebed, making them more vulnerable to anchor strikes. The tunnel would move pipeline operations to approximately 350 feet underground, virtually eliminating the risk of a release and increasing long-term system reliability – all while ensuring Michigan homes and businesses continue to have access to the energy they need. 

Q: What is the current permitting status for the Great Lakes Tunnel project? 
A: Enbridge continues to make progress toward securing the state and federal permits required to build the Great Lakes Tunnel. In 2023, the Michigan Public Service Commission (MPSC) issued its permit approving Enbridge’s application to construct a Line 5 replacement segment within the Great Lakes Tunnel. Earlier this year, Enbridge submitted updated permit applications to the Michigan Department of Environment, Great Lakes, and Energy (EGLE). These applications seek re-issuance of permits that EGLE originally issued in 2021 and have a five-year term; Enbridge is reapplying to avoid any lapse in permit coverage. Finally, the project is under federal review by the U.S. Army Corps of Engineers (USACE), which released a draft Environmental Impact Statement (EIS) on May 30, 2025, with its public comment period closing on June 30, 2025. 

Q: What does this mean for small businesses? 
A: Line 5 and the energy products it transports to Michigan and the region are vital to powering Michigan’s small business engine. Line 5 is critical for providing the inputs that are refined into the gasoline, diesel and jet fuel used throughout Michigan and the Great Lakes region, and it supplies more than half of the propane used in the Upper Peninsula, as well as rural downstate. The Great Lakes Tunnel Project will help to ensure a reliable and affordable supply of energy for the businesses that need it. Especially in rural areas, businesses rely on these fuels for deliveries, equipment, heating and more. Disruption to Line 5 will mean higher costs for everything from manufacturing costs and shipping to shelf prices. 

Q: Is the project funded by the state or federal government? 
A: No. The tunnel is a privately funded project by Enbridge. Construction and operating costs will be covered by the company, not taxpayers. 

Q: Is the project safe and environmentally responsible? 
A: Yes, the MPSC concluded that Line 5 is needed and that the tunnel is the appropriate location to house Line 5. The USACE recently released a draft EIS, which had the benefit of public review and comment. The tunnel will be built with the latest tunnel boring technology, and modern environmental protections, including real-time leak detection. It is infrastructure for the next generation. 

Q: What’s the potential economic impact? 
A: The Great Lakes Tunnel project represents a significant private investment in Michigan’s energy infrastructure, designed to serve the state and region for decades to come. It will safely house the Line 5 pipeline, and will also enable other utilities to utilize it, providing efficient and protected connectivity between Michigan’s peninsulas. The project is expected to create construction jobs and business opportunities for Michigan workers and firms, as well as significant economic benefits for northern Michigan during construction. Labor groups have voiced support, citing job opportunities for local workers and contractors. For small businesses, the broader benefit is energy stability – avoiding the volatility that would come with a pipeline shutdown. 

Q: Are there concerns? 
A: Some have raised concerns about long-term dependence on fossil fuels and the potential impact of tunnel construction on local wetlands, cultural sites and local ecosystems. Others argue that Michigan should invest in renewables and transition away from fossil fuels altogether. The regulatory process is designed to weigh these issues and determine whether the project can meet environmental standards. 

Q: Who supports the Great Lakes Tunnel Project? 
A: Supporters include Michigan’s major business associations, multiple labor unions, business organizations and energy associations. These groups view the project as a sensible modernization of existing infrastructure – one that balances environmental protection with energy access. Health systems and manufacturers have also weighed in, citing concerns about fuel shortages if Line 5 is interrupted. Regional refineries are supportive, as Line 5 provides a significant amount of feedstock they need to produce transportation fuels, propane, and petrochemicals used throughout the region’s manufacturing and agricultural industries. 

Small Business Association of Michigan is a member of the Great Lakes Michigan Jobs coalition, which helps support the Great Lakes Tunnel Project in key ways, like taking part in the public comment periods on permit applications. Hundreds of small businesspeople have also joined the Great Lakes Michigan Jobs efforts; you can too! Go to Great Lakes Michigan Jobs to learn more and to lend your support: Build the Tunnel — Great Lakes. Michigan Jobs.  

The Great Lakes Tunnel Project is about more than a pipeline – it’s about protecting energy access, environmental safety and economic stability for the long haul. Whether you support or question the project, small businesses deserve a seat at the table. This is your moment to weigh in – because the future of Michigan’s energy infrastructure affects us all. 

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