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Line 5 in Michigan
Line 5 in Michigan
Line 5 Tunnel Project Proposal Enbridge Energy Limited Partnership is currently seeking approval to build a utility tunnel and to replace and relocate the portion of the Line 5 pipeline that runs beneath the Straits of Mackinac. The proposed tunnel would house the replacement segment for the Line 5 petroleum pipeline that sits on the bottom of the Straits.
Review and permitting decisions for the proposed project involve multiple state agencies and the U.S. Army Corps of Engineers. This website is intended to provide an overview of the routine regulatory permitting process that the proposed project will require.
Michigan Public Service Commission
The MPSC authorizes proposals for energy infrastructure including intrastate and interstate crude oil and petroleum product pipelines by authority of Public Act 16 of 1929 and operates in a quasi-judicial manner with the Commission making final decisions through a formal evidentiary hearing process, otherwise known as a contested case proceeding. The MPSC will consider Enbridge’s request to replace and relocate the portion of the Line 5 pipeline crossing the Straits of Mackinac into a tunnel beneath the Straits.
Department of Environment, Great Lakes, and Energy
The principal laws EGLE considers when evaluating pipeline projects that impact water resources fall under the Natural Resources and Environmental Protection Act of 1994 (NREPA). Enbridge has submitted permit applications for work within wetland areas, water discharges and under the submerged lands portions of NREPA.
Mackinac Straits Corridor Authority (MSCA)
The Mackinac Straits Corridor Authority (MSCA) within the Michigan Department of Transportation (MDOT) is responsible for overseeing construction and operation of a tunnel in bedrock beneath the waters of the Straits of Mackinac. The tunnel will house a replacement segment for the Line 5 petroleum pipelines that currently sit on the bottom of the Straits and will accommodate other utilities to improve infrastructure connections between the peninsulas. MSCA will own the tunnel after its construction and provide independent oversight throughout its life.
US Army Corps of Engineers
The U.S. Army Corps of Engineers, Detroit District, is conducting an independent review of the proposed Line 5 pipeline tunnel project in accordance with federal regulations. The Corps of Engineers will prepare an environmental impact statement (EIS) that considers potential impacts and reasonable alternatives to the project which will inform its permit decision on Enbridge’s application with the Corps. There is no specific timeframe for the Corps' decision.
Public Comment Opportunities
Public comment on the EGLE permits closed on October 19, 2020.
Public Information Session on Enbridge Line 5 Application for National Pollutant Discharge Elimination System Wastewater Permit
Public Hearing on Enbridge Line 5 Application for National Pollutant Discharge Elimination System (NPDES) Wastewater Permit
Public Information Session on Enbridge Line 5 Application for Proposed Tunnel Construction Involving Potential Wetlands Impacts
Public Hearing on Enbridge Line 5 Application for Proposed Tunnel Construction Involving Potential Wetlands Impacts
- MDOT Question on Geotechnical Investigation, January 2021
- MDOT Question on Collapses in Terms of Loss of Face Control, January 2021
- MDOT Question on Risk Mitigation, January 2021
- MDOT Question on Gas Encounters, January 2021
- MDOT Question on Vibrations, January 2021
- MDOT Question on Slurry Containment, January 2021
- EGLE Permit Decision Documents
- EGLE's NPDES Permitting Presentation
- Tunnel Agreement (MSCA/Enbridge Energy)
- Line 5 Replacement and Tunnel Project: Geotechnical Data Report
- Letter Agreement Regarding Technical Specifications (Enbridge Energy/MSCA)
- Assignment of Easement Rights for Utility Tunnel (MSCA/Enbridge)
- Easement to Construct and Maintain Underground Utility Tunnel at the Straits of Mackinac (MDNR)
- Second Agreement between the State of Michigan, MDEQ, and MDNR and Enbridge Energy
- Third Agreement Between the State of Michigan, MDEQ, and MDNR and Enbridge Energy
- The Great Lakes Tunnel Project - Geotechnical Data Report - Summary (Enbridge)
- Agreement Between the State of Michigan and Enbridge Energy, Limited Partnership and Enbridge Energy Company, Inc.
- Straits of Mackinac Pipe Line Easement Conservation Commission of the State of Michigan to Lakehead Pipe Line Company, Inc.
- Alternatives for replacing Enbridge's dual Line 5 pipelines crossing the Straits of Mackinac (Report to the State of Michigan from Enbridge)
- More information about the tunnel project including an animated video describing the tunneling process in more detail is available on Enbridge's website.