A Spill in the Straits

A Spill in the Straits
April 4, 2018 Mary Ellen Geist
Mackinac Bridge from Straits of Mackinac during tour on the Straits Area Tour - Photo courtesy of Gregory Varnum via Wikimedia Commons

A multi-agency command post has been set up in Mackinaw City, Michigan to monitor a spill of di-electric fluid caused by a break in two underwater power lines that extend from the Upper Peninsula to the Lower Peninsula in the Straits of Mackinac. The lines are owned by American Transmission Company (ATC) located in Pewaukee, Wisconsin.

Spokesperson for ATC Jackie Olson tells Great Lakes Now the lines have been shut down and the spill has topped out at just under 600 gallons. She says no further fluid is leaking into the spot where Lake Michigan and Lake Huron join near the Mackinac Bridge.

Olson says the company knew there was a problem starting late Sunday night or Monday morning but officials couldn’t identify it as coming from under the water until Monday afternoon.

Olson describes the coolant fluid like this: “It is a mineral based oil that serves as a coolant in the cables – the oil you inject into the cables to keep the current running. It acts as an insulator.”  Olson says it does not contain PCB’s.

Olson tells Great Lakes Now, “We have monitoring systems on all of our transmission facilities, and there was an alarm indication late Sunday night or Monday morning that there could be a leak. We investigated on Monday morning to try to trace the leak. Our early indications were that the leak was occurring in some of our above ground facilities. The cables went out of service, and we actually had an excavator on site. We flew an aerial patrol to look for a sheen, so we were doing research and investigating. When we didn’t find any trace of oil leakage…… that’s when we realized that the oil leak could be coming from under the water.”

Olson says clean-up was hampered yesterday by blizzard conditions and eleven inches of snow. Olson says the emergency responders are now vacuuming the substance out of the cables to make sure there are no further leaks.

Olson says all six of the lines have been de-energized.

She says she’s not qualified to answer whether a spill of 600 gallons of coolant fluid in the Great Lakes can cause a danger to the water, to wildlife or to human beings.

The National Wildlife Federation’s Beth Wallace tells Great Lakes Now, “The estimated size of the spill almost always grows during these events and shows the lack of control and understanding when there are releases. This is alarming and shows major gaps in our ability to address and fully assess releases. Key industry indicators for spills, like sheen on the surface water, are not adequate, especially in this location. This same issue arose during the 2010 spill/clean up near Kalamazoo when Enbridge and the EPA later discovered that oil was traveling below the surface of the water, not causing sheen, unless agitated. The spill continued to spread because they used sheen as the main indicator for oil being present. There’s also ice still in the straits, which will make this indicator even less accurate.”

Wallace says weather is a big issue.  She says, “All of these weather factors need to be strongly noted by agencies, including the snow.” She adds, “I’m not only concerned about wildlife, but also the water intakes that are in the area and how they are monitoring for contamination. This situation very much represents what it would be like to have a significant spill on Line 5.”

Officials say The Enbridge Line 5 Pipeline is not reported to be affected and is unrelated to this response.

The agencies responding are the U.S. Coast Guard, U.S. Environmental Protection Agency, National Oceanographic and Atmospheric Administration, U.S. Fish and Wildlife Service, Michigan Department of Environmental Quality, Department of Natural Resources, Michigan State Police Emergency Management and Homeland Security Division and Michigan Public Service Commission as well as multiple state agencies.

DPTV’s Great Lakes Bureau will continue to monitor this situation and will bring you updates as they become available.

(From Great Lakes Bureau Chief Mary Ellen Geist: to find out more about what would happen if there were a major oil spill in the Straits of Mackinac, watch our upcoming documentary “Beneath the Surface: The Line 5 Pipeline in the Great Lakes”  #GLNline5doc  which will air on Detroit Public Television Wednesday, April 25th at 10pm) 


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