Crews say hundreds of gallons of a coolant have leaked from power cables into the Straits of Mackinac.

American Transmission Company says that two of their six electric cables that run under the Straits of Mackinac have leaked fluid that’s used for insulation.

What it’s leaking can be harmful when released into the environment.

It’s believed about 550 gallons of this synthetic oil has spilled in the Straits, but they believe for the most part they have mitigated any more spilling.

Lt. Rachel Wellman of the U.S. Coast Guard sector Sault says they were contacted about the spill Monday night and have been responding since.

On Sunday evening the company noticed their pressure levels dropping in those two cables, while addressing the situation, this cold weather and snow prevented them from fully investigating it at that point.

They contacted the Coast Guard.

They still don’t know the cause of the leak but narrowed it down to a spot midway between Mackinaw City and St. Ignace.

The two cables have been shutdown and they are attempting to drain them fully of all their coolant, without spilling any more.

“Based on the difficulty in nature it was diagnosing the problem and the extreme weather conditions they were facing we made the decision to turn the cables off,” Jackie Olson of ATC said.

The Coast Guard says there’s no concern that this spill could directly harm humans, but the coolant is potentially toxic to the environment.

According to the DEQ, at this time it’s unknown how much damage this has done to the waterway, but that’s something we will we be looking into much deeper.