The Mackinac Center appreciates the opportunity to provide comments supporting the approval of the Line 5 Tunnel Project Proposal (Department of Environment, Great Lakes, and Energy application number HQ3-8BYB-N9DT1). The project ensures energy security, economic stability, and environmental protection for Michigan and the Midwest.

Project Overview

The Line 5 pipeline, operational since 1953, transports 540,000 barrels per day of light crude oil and natural gas liquids, supplying 55% of Michigan’s propane, 65% of Upper Peninsula propane, 45% of refinery feedstocks in Michigan, Ohio, Pennsylvania, Ontario, and Quebec, and jet fuel for airports like Detroit Metropolitan Wayne County and Toronto’s Pearson.[1]^{, [2]}

The tunnel project (Alternative 4b as described in the 2017 Dynamic Risk “Alternatives Analysis for the Straits Pipeline” report) relocates the pipeline into a concrete-lined tunnel 100 feet below the Straits of Mackinac, reducing environmental risks while maintaining energy reliability[3] (see also the U.S. Army Corps of Engineers Draft EIS, Volume 1, Section 2.2).[4] On page 9, the Dynamic Risk report identifies Alternative 4b as having negligible operational risk compared to other alternatives. In Volume 1, Chapter 1, the draft EIS document evaluates impacts, alternatives, and mitigation, meeting federal NEPA standards.

Economic Benefits

The tunnel project supports Michigan’s economy and regional energy security. The 2021 Consumer Energy Alliance report estimates that a Line 5 shutdown would result in $20.8 billion in annual economic losses across Michigan, Ohio, Indiana, and Pennsylvania, including $3.06 billion in Michigan’s economic activity, 6,692 jobs, and $56.8 million in tax revenues.[5] Michigan’s Upper Peninsula relies on Line 5 for 65% of the propane it uses and would face supply shortages without alternatives.[6] The 2020 Mackinac Center report, “Assessing the Costs of the U.P. Energy Task Force Committee Recommendations,” notes shutdowns could increase propane prices by $0.10–$0.35 per gallon, with historical spikes of 80% during shortages.[7] This finding was supported by the Dynamic Risk report, which noted:

The abandonment of Line 5 would cost about $200M and would also produce an increase of 10¢/gallon to 35¢/gallon for propane in the Michigan Upper Peninsula. The system would go into apportionment, causing supply squeeze and a higher product costs in Detroit/Toledo (462,000 barrels/day refinery capacity and major suppliers to Michigan). The local prices for refined petroleum products would be expected to increase by two cents per gallon for the 5.7 billion gallons of gas and refined petroleum product consumption each year in Michigan.[8]

The Dynamic Risk report estimates Line 5 contributes $80 million annually in Michigan, supporting 900 jobs, with the tunnel project adding 400–1,800 construction jobs (see page 9).

Safety and Legal Compliance

The U.S. Army Corps’ draft EIS acknowledges the potential for the tunnel project to enhance safety conditions by mitigating the risk of anchor strike. The tunnel eliminates the possibility of a strike, reducing it from the “No Action Alternative” potential of once every 1,300 years (see: page 4-188). [9]

The 2017 Dynamic Risk report notes negligible operational or environmental risks associated with pursuing the tunnel alternative (see page MS-3 for discussion of Alternative 4b).

Ongoing continuous monitoring, the positive results of the Environmental Protection Agency’s 2017 hydrostatic pressure test,[10] and robust tunnel design bolster a 68-year leak-free record for this section of the pipeline. The EIS document also confirms that the project complies with the National Environmental Protection Act and other federal standards (See EIS, Volume 1, Chapter 1).

Environmental Mitigation

The U.S. Army Corps’ draft EIS identifies several short-term impacts, including the loss of 19 acres of vegetation and 4.32 acres of wetland, potential impacts on water-based recreation, increased truck traffic during construction, and noise affecting 45 residences (Draft EIS, Volume 1, Section 4). Notably, many similar impacts would occur if this process led to the shutdown and decommissioning of the pipeline.

The Army Corps’ draft EIS document recognizes that mitigation efforts are expected to address or remediate those short-term impacts. Mitigation includes erosion controls, stormwater management, and revegetation. The draft EIS in Volume 2, Section 5, also recommends considering additional alternatives to mitigate environmental impacts. Long-term, the EIS Executive Summary document plainly states that the tunnel project will result in a “beneficial cumulative effect on reduced risks of a petroleum leak in the Straits and, when combined with one of the decommissioning sub-alternatives, improvements to water-based recreation.”

Other reports have made it clear that rejecting or shuttering the pipeline will not reduce the demand for the products it is used to transport. Instead, those products will be transported by other means, such as rail or truck. The 2017 Dynamic Risk report notes rail alternatives pose higher spill risks — 2.567 spills/year (see pages 7-18). The Consumer Energy Alliance report explains that a shutdown of the Line 5 offers no emissions reductions or cost benefits, “as refineries, chemical plants, and propane processors currently dependent on Line 5 will simply seek out higher cost suppliers of crude oil and natural gas liquids” (see page 15).

Both rail and truck entail higher risks of spills than pipelines. Furthermore, Mackinac Center testimony before the Michigan House Transportation Committee, “Estimating Some Costs of Closing Line 5,” indicated that “the total cost of replacing Line 5 with tanker trucks is $916,000 per day, or $334 million per year due to road damage, congestion, accidents and carbon dioxide emission.” This effort would require as many as 2,150 additional tanker trucks moving fuels across the Mackinac Bridge daily.[11]

Response to Opponent Concerns

Opponents, including "For the Love of Water," cite public opposition, inadequate review, safety risks, environmental impacts, tribal concerns, rising costs ($1.5 billion), minimal need, and political influence.[12]

• Public Opposition: Claims that the public is uniformly opposed to the construction of the tunnel are simply wrong on the facts. A broad, diverse coalition of the public, bipartisan elected officials, and business and labor organizations supports the continued operation of the pipeline and rapid construction of the tunnel. Along with the Mackinac Center, other groups that have publicly supported the project include,
  • Business Groups: The Michigan Chamber of Commerce,[13] The Detroit Regional Chamber[14], The Grand Rapids Chamber, InvestUP, Upper Peninsula Construction Council,[15] Michigan Manufacturers Association, Midland Business Alliance, Michigan Association of Convenience Stores,[16] [17] and the Small Business Association of Michigan[18]
  • Labor: Michigan Building and Construction Trades Council,[19] Pipeliners Union 798,[20] Laborers’ International Union of North America,[21] Canada’s Building Trade Unions,[22] Laborers’ Local 1329 – Iron Mountain,[23] Michigan Pipe Trades Association, and Operating Engineers 324[24]
  • Elected officials: The Michigan House of Representatives,[25] ^[26] The Canadian Federal Government,[27] Mike DeWine – Governor of Ohio, John Husted – Ohio Lieutenant Governor[28]
• Claims that the Review has been “Fast-Tracked”: Numerous processes, including the state’s initial (2023) review of the Enbridge application for state approval of the Line Tunnel Project, have considered the pipeline and the proposed tunnel. Additionally, the U.S. Army Corps EIS process incorporates a robust public input period through virtual meetings and public comment periods. The process of safety testing and considering alternatives for the pipeline has been ongoing for almost a decade, with the Dynamic Risk alternatives report and EPA hydrostatic pressure test both completed in 2017.In January 2025, the Council on Environmental Quality released a document considering “Environmental Impact Statement Timelines.”[29] The opening lines of this report indicate that “For final EISs issued in 2024, the median time from notice of intent (NOI) to final EIS was 2.2 years.” The federal NOI for the Line 5 Tunnel Project was published in the Federal Register (by the U.S. Army Corps of Engineers) on August 15, 2022. This represents a timeline of more than 1,000 days ago (or almost 3 years), with the final EIS not expected until fall 2025. While the USACE has expedited the EIS process (the final report was not previously scheduled until 2026), claims that the review process, at the state or federal level, has been fast-tracked are not supported by the timeline or facts.[30]Furthermore, the Line 5 Tunnel project has already received approval from the Michigan Public Service Commission after the agency completed a three-year-long review process. The MPSC considered input from the following intervenors: the Bay Mills Indian Community; the Environmental Law and Policy Center and Michigan Climate Action Network; For Love of Water; Grand Traverse Band of Ottawa and Chippewa Indians; Little Traverse Bad Bands of Odawa Indians; the Mackinac Straits Corridor Authority; Michigan Attorney General Dana Nessel; Michigan Environmental Council; Michigan Climate Action Network; Michigan Laborers District Council; Michigan Propane Gas Association; National Wildlife Federation; Nottawaseppi Huron Band of Potawatomi Indians, and Tip of the Mitt Watershed Council.[31]After this multi-year review and comment process was completed, the final ruling of the MPSC bluntly stated, “The Commission’s order determined there is a public need for the replacement section of Line 5 and the products it carries, finding that without the pipeline’s operation, suppliers would need to use higher-risk and costlier alternative fuel supply sources and transportation for Michigan customers, including those who use propane for home heating.”The Commission’s order goes on to recognize the value of the tunnel project for protecting the ecological, cultural, and natural resources of the Great Lakes and reiterates the increased potential for environmental harm caused by transitioning the movement of crude oil and natural gas liquids by rail and truck. The Commission ruled that “there are no feasible and prudent alternatives to the replacement project pursuant to the Michigan Environmental Protection Act (MEPA).”Given the intense scrutiny of the project over more than a decade, claims that the process has been fast-tracked or that public comment has somehow been restricted are absurd.
• Safety: Geotechnical testing ensures tunnel safety (U.S. Army Corps draft EIS, Volume 1, Section 5.3.1, Page 80). The Consumers Energy Alliance, Dynamic Risk ‘alternatives,’ and EPA’s “Line 5 Dual Pipelines Hydrostatic Pressure Tests” reports all confirm negligible risks of continued operation.
• Environmental Impact: As previously noted, predicted environmental impacts from the tunnel project are short-term and related to the construction period. The U.S. Army Corps’ draft EIS report notes these impacts will be mediated and restored, and, on balance, the tunnel project will have “a beneficial cumulative effect on reduced risks of a petroleum leak in the Straits and, when combined with one of the decommissioning sub-alternatives, improvements to water-based recreation.”Furthermore, the alternatives of doing nothing, partially burying the pipeline with gravel, or decommissioning the pipeline all carry the potential of environmental risk. As previously discussed, if the pipeline is closed, crude oil and natural gas liquids will still be demanded and will be transported by rail or truck. As noted previously in this comment, both the Army Corps’ draft EIS document and the Dynamic Risk report detail how trucking and rail pose greater risks than transportation by pipeline.
• Costs: When compared to the expenses already listed, the tunnel’s cost is justified. The loss of $20.8 billion throughout the regional economy and tens of thousands of direct and indirect jobs has not been supported by the arguments of the tunnel project’s detractors. Furthermore, taxpayers will not bear the cost to build the tunnel; the proponent (Enbridge Energy) will bear the cost of building the tunnel.The above-noted research by both the Consumer Energy Alliance and Mackinac Center highlights significant price impacts ($0.10–$0.35/gallon increase in propane prices) that will have broad and far-reaching impacts across the region and with the nation’s key trading partners.

Recommendation

The U.S. Army Corps’ draft EIS report, the 2017 Dynamic Risk, 2021 Consumer Energy Alliance, the 2020 Mackinac Center reports, and the 2023 MPSC ruling in favor of the tunnel project all confirm that the tunnel alternative safely and effectively balances energy, economic, and environmental needs.

The Mackinac Center urges the Michigan Department of Environment, Great Lakes, and Energy to approve the project, ensuring energy reliability and protecting the Great Lakes.

References:

Permission to reprint this blog post in whole or in part is hereby granted, provided that the author (or authors) and the Mackinac Center for Public Policy are properly cited.