Coast Guard, partners continue response in Straits of Mackinac

Mackinac Bridge Winter

MACKINAW CITY, Mich. – The Unified Command has been notified by Enbridge officials that further structural analysis conducted by Enbridge indicates that small dents exist in their pipeline infrastructure.

Enbridge has notified the Unified Command that the damage poses no threat to the overall integrity of their infrastructure.

The mineral oil leak from the American Transmission Company’s utility cables may have been caused by vessel activity and is under investigation.

Coast Guard Marine Science Technicians and Environmental Quality Analysts from Michigan’s Department of Environmental Quality have conducted daily surface surveys by boat and have not observed signs of pollution. Coast Guard Marine Science Technicians have also been present on overflights and have not seen any signs of an oil sheen.

The Unified Command is planning to deploy thermal scanning technology as well as a Remotely Operated Underwater Vehicle (ROV) to better assess the damage to the affected utility lines while efforts continue to extract the remaining product from two cables.

A commercial tug and barge are being outfitted to deploy the ROV equipment this weekend. Information from the thermal scans, as well as from the ROV will help inform the Unified Command’s salvage operations plan for the affected utility cables. The Unified Command is monitoring incoming weather patterns, which may impact future operations. Wind and wave height will be the primary factors that will determine if salvage operations can safely continue over the weekend.

American Transmission Company, a transmission-only electric utility, contracted North Shore Environmental to remove product from the cables. From a shore-side facility, North Shore Environmental is vacuuming the mineral oil from a less than one inch diameter void in the cables that stretch three and a half miles across the Straits of Mackinac.

To date, more than 250 gallons of the mineral oil have been extracted from one of the utility cables. Work to remove product from the second damaged cable commenced yesterday.

Additionally, wildlife biologists from the United States Department of Agriculture’s Animal and Plant Health Inspection Service (USDA-APHIS) Wildlife Services program, Michigan Department of Natural Resources, and personnel from the Michigan Department of Environmental Quality are surveying the area, on the water and from the shore and air, to look for any signs of pollution or impacted fish and wildlife. No impacts to the environment or wildlife have been identified.

“We are looking for any indications that birds or any other wildlife have come into contact with oil,” said a wildlife specialist with USDA-APHIS. “We encourage individuals who know of affected wildlife to report any sightings.”

The personnel surveying the area are trained to identify impacts on wildlife. More than 3,000 waterfowl, including Long-tailed ducks, Common Mergansers, Herring Gulls, Goldeneye, and eagles, have been observed over the course of the response from areas near Mackinac, Round and Boise Blanc Islands as well as on the shoreline near Mackinaw City, and west of the Mackinac Bridge. Personnel on scene have observed no abnormal bird behavior in the affected area.

The mineral oil in the cables acts as an insulator to ensure the integrity of the electricity within the cable.

All entities responsible for active utility lines that cross the Straits were notified by the Unified Command to ensure that all steps are taken to assess and mitigate any further damage to infrastructure or risk to public health and the environment. The utilities are continuing to conduct assessments of their infrastructure.

To report affected wildlife or animals acting abnormally please call the USDA at (517)-336-1928.

To report any oil sheen or pollution, please call the National Response Center at 1-800-424-8802.


  1. In other words the coast guard has no idea what caused the mineral oil to leak from the power cables.
    If they did they would have a definitive answer to this question instead of guessing.
    As far as the billionaire Enbridge company goes they claim their 65 year old pipelines, that were designed to last 50 years, are in pristine condition aside from a few new dents discovered, even though divers have videoed several damaged and missing supports on the lines. They are pushing more volume through these pipelines than ever and when they rupture (and they will) there will be catastrophic results causing irreparable damage to the great lakes and all because of corporate greed, instead of replacing the lines or finding an alternative way to move their oil and gas. There are too many palms being greased to stop these ‘past due’ lines from being shut down and there is going to be a disaster because of it, it’s not a matter of if, but when it will happen.

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