Environment

Michigan and Enbridge to Replace Two 65-Year-Old Oil Lake Pipelines

Two aging crude oil pipes in a channel connecting Lakes Huron and Michigan are about to be replaced.

The bridge over the Straits of Mackinac in Michigan. The new Enbridge pipeline would run deep under the lake beds near here.

Agreements have finally been reached between the State of Michigan and Enbridge, a Canadian pipeline provider based in Calgary, to replace a pair of 65-year-old crude oil pipes with a single new one which would be place in a tunnel deep below the bottom of the lakes.

It had taken some time to arrange the replacements. Michigan had been concerned for some time that the two lines could leak at any time, through a combination of exposure to the harsh environment of the lakes, continuous use, some apparent gaps in proper coating of the pipes, and natural aging. Enbridge, as the company responsible for the current lines, said that they have “operated Line 5 safely and reliably for decades”.

Line 5 is the name for the entire existing pipeline system. That includes the twin lines which are being replaced by the new solution, as part of an overall 645 mile (1,038) channel running from Superior, Wisconsin, to Sarnia, Ontario, with a major part of the route running across northern Michigan.

Environmentalists have criticized the existing lines as well as most plans to build a new one, saying that any pipeline represents a continuing risk to the lake environment.

To satisfy as many concerns as possible, Enbridge’s new pipeline will run deep under the lake beds, provide for a built-in approach to inspect potential leaks on a continuous basis, and even pay the entire cost of building the new lines. Enbridge needs the pipeline as an important channel to bring Canadian oil into the United States.

The work would start with drilling a location where the pipeline would go through. That opening will be in bedrock some 100 feet (30 meters) under the Straits of Mackinac, a waterway running some 4 miles long where Lakes Michigan and Huron come together. The pipe will be inserted within the opening.

As part of the construction, Enbridge will put cameras at the Straits to watch for ship activity and make sure no one anchors their vessels in an area which might cause harm to the underground line. Electronic systems and regular underwater checks will be carried out to ensure the new line stays free from leaks. There will also be Enbridge personnel readily available during high wave periods and in the event the automatic shutoff systems fail when required.

Because of the underwater nature of the project and the importance of keeping it safe, the project is expected to take a minimum of 7 and up to 10 years to construct. It is estimated to cost between $350 million to $500 million.