Governor Rick Snyder announced Wednesday that his administration has reached an agreement with Enbridge Energy to replace Line 5, the 65 year old twin pipelines that run under the Straits of Mackinac connecting Lake Huron and Lake Michigan.
The agreement calls for a new pipeline that would run through a tunnel dug into bedrock below the lake bed.
The project is expected to take seven to ten years to complete and cost up to $500 million, which Enbridge would pay.
Supporters say the deal protects the lakes and ensures energy reliability.
But critics say the agreement will keep Line 5 open indefinitely while the tunnel is built, posing an unacceptable environmental and economic risk to the Great Lakes.
According to the National Wildlife Federation, Michigan does not need Line 5, citing studies that show closing it would impose no noticeable cost on consumers.
"While we will reserve judgment until we fully review the latest agreement, any agreement which does not begin with a plan to decommission Line 5 in the Straits within less than one year is a non-starter," said Mike Shriberg, Great Lakes Regional Director of the National Wildlife Federation and a member of Governor Snyder's Pipeline Safety Advisory Board, in a written statement. "We know that Line 5 is a threat to the Great Lakes and our way of life now, whereas a tunnel, if it is ever built, is many years away."
In a written statement, Michigan Attorney General and Republican gubernatorial candidate Bill Schuette expressed his support for the agreement, calling it "an important step forward in safeguarding our Great Lakes and ensuring that Upper Peninsula residents still have access to propane to heat their homes."
Gretchen Whitmer, Democratic candidate for governor, has called for immediate action to shut down Line 5.
Editor's note: Enbridge Energy is a corporate sponsor of Michigan Radio.