The Michigan Department of Environmental Quality (MDEQ), Michigan Department of Natural Resources (MDNR) and the Michigan Agency for Energy (MAE) are notifying residents near the Straits of Mackinac to increased activity related to damage to American Transmission Co.’s electrical transmission lines and Enbridge Energy’s Line 5.
Crews are expected soon to launch remotely operated vehicles (ROVs) to evaluate infrastructure conditions, according to the Unified Command (UC). The UC, consisting of the U.S. Coast Guard, MDEQ, ATC, and a tribal representative, was established to address a mineral oil release from the ATC cables.
At the same time, additional crews near Mackinaw City and St. Ignace, at the direction of the UC, are continuing to vacuum any remaining mineral oils from ATC’s electrical cables that connect the Lower and Upper Peninsulas through the Straits. Two of the six lines were damaged earlier this month and resulted in the release of nearly 600 gallons of mineral oil. The Coast Guard, which is the lead agency in the UC, has identified vessel activity as one of the potential causes for the mineral oil release.
According to the UC, the next step in the response to the ATC cable damage is the launch of a working class ROV, weather permitting. A barge has been prepared to assist workers in this inspection. After an assessment is completed, a plan will be developed and executed to determine the best method to mitigate future environmental impacts.
During the same time frame, Enbridge will deploy an ROV for a visual assessment of Line 5, which is adjacent to the ATC cables. Line 5 is believed to have sustained small dents to its twin, 20-inch lines, possibly from the same vessel activity that potentially damaged ATC’s cables.
The UC says there has been no major environmental impact on the Straits or wildlife from the ATC leakage.
Enbridge has run tests to assess damage to Line 5. Company officials state they have found no evidence of fluid loss and have confidence in the pipeline’s structural integrity.
Gov. Rick Snyder has called on Enbridge to accelerate the identification of anchor strike mitigation measures and the evaluation of alternatives to replace pipelines, both of which are required under the state’s November agreement with Enbridge. The studies are scheduled to be completed in June. Snyder also said the state will expedite a review of other actions to protect the Straits as well as working with federal partners to expedite the permitting process to allow for protective measures to be installed in the Straits.