The Michigan Department of Environmental Quality granted a permit to Enbridge Energy Partners LP for the installation of anchor support on the underwater twin segments of the Line 5 oil pipeline running under the Straits of Mackinac.
The permit would allow 22 anchor support structures to be fixed into the lake bed to support the pipelines amid shifting underwater landscapes caused by strong currents between Lake Michigan and Lake Huron. The anchors would also minimize the potential of having pipeline spans that are unsupported for more than 75 feet, according to a March 23 news release.
The permit also includes conditions requiring documentation of the state of the protective coating along the pipeline and fixing any damage found.
The underwater segments already have 127 support anchors, where most of the pipeline coating gaps were discovered during inspections. Enbridge acknowledged that the coating gaps were likely to have been created during installation of the support anchors.
The work is part of the Enbridge Inc. subsidiary's obligations under a bottomlands easement with the state and a federal consent decree with the U.S. Environmental Protection Agency, reached in 2016 in response to a 2010 crude spill from Enbridge's Line 6B in Marshall, Mich.