Officials say 550 gallons of potentially toxic coolant fluid have leaked from electric power cables that run underwater where Lake Huron and Lake Michigan meet.
The owner of the cables, American Transmission Company, says the fluid is a mineral-based synthetic oil used for insulation that can be harmful if released into the environment.
American Transmission says the leak was discovered after the two cables tripped offline Sunday evening. The cables have been taken out of service.
The Michigan Department of Environmental Quality (MDEQ) says the extent of the damage in the Straits of Mackinac is unknown.
The U.S. Goast Guard says the risk to human health is very low, but the MDEQ advised nearby towns to monitor their drinking water.
This news comes during the debate over the future of Enbridge’s Line 5.
In January, Gov. Rick Snyder rejected a panel’s recommendation to shut down Line 5 temporarily.
The MDEQ issued a permit in March allowing Enbridge to install 22 more anchor supports along the twin pipelines at the bottom of the Straits.
Editor’s Note: Enbridge Energy is a financial supporter of Michigan Radio.