Land, groundwater, and surface water could be at risk due to a plan to replace Line 5 in Straits of Mackinac.
A federal report released hours ago has prompted people on both sides of the issue to scramble to make sense of concerning findings.
A significant development involving the future of Line 5 has emerged. The U.S. Army Corps of Engineers has released its draft environmental impact statement on Enbridge Energy’s controversial proposal to build a 3.6-mile tunnel beneath the Straits of Mackinac.
This tunnel would house a new oil and gas pipeline to replace the aging Line 5 infrastructure, which has drawn growing concern over the past decade.
According to the report, the tunnel project would cause direct, detrimental effects on the environment.
Those include the loss of trees and wetlands, disruption of surface and groundwater systems, and impacts to both wildlife and public recreation during construction.
While the majority of these negative impacts are expected to occur only during the construction phase, lasting up to six years, the Army Corps concludes that many could be significant and have lasting effects.
Among the most concerning findings are the potential for erosion and sedimentation, the release of drilling fluids into the water, and daily truck traffic that would clog public roads and heighten safety risks, especially during peak travel seasons.
Despite these challenges, the corps report also acknowledges potential long-term benefits.
If completed, the tunnel would reduce the risk of a catastrophic pipeline leak in the open waters of the Great Lakes.
It could also facilitate the decommissioning of the twin pipelines currently lying exposed on the lake bottom—pipelines constructed over 70 years ago.
Enbridge maintains that the new tunnel would provide a safer, more modern solution for transporting over 20 million gallons of oil and natural gas liquids daily through Michigan.
The company also points to the extensive permit review process, which it states has been ongoing for over five years.
However, the project remains deeply divisive. Environmental groups are calling for a full and independent review under Michigan’s Submerged Lands Act, arguing that the project poses a threat to public trust resources.
The debate now shifts to the public. The Army Corps of Engineers is inviting public comments on the environmental impact study through June 30.
They will hold two virtual public meetings this summer to discuss the findings.
