Coast Guard: 'Good fortune' that Straits spill was minor
Lansing — An early April fluid spill in the Straits of Mackinac was deemed minor by state and federal response agencies, but raised concerns Monday from state advisers and the public about what could have happened if Enbridge Energy’s Line 5 had ruptured.
Fluid from an electricity transmission line by American Transmission Co. was apparently hit by an anchor, according to the offices of Gov. Rick Snyder and Attorney General Bill Schuette.
“It did nothing to alleviate my concern that this pipeline should be shut down now because it’s clear that as we know more, we have more and more concerns about what’s happening there,” said Anne Woiwode, a Sierra Club volunteer.
Michigan Department of Environment Quality Director Heidi Grether said the argument is a familiar one.
“People keep saying shut them down, shut them down; part of the question is, under what authority?” Grether told reporters Monday during a break at the Michigan Pipeline Safety Advisory Board meeting.
Jerry Popiel, incident management adviser for the U.S. Coast Guard, and the Michigan Department of Environment Quality’s Scott Schaefer fielded questions from the advisory board and public for nearly two hours concerning the state and federal response to an April 1 leak from electrical transmission lines beneath the straits.
“This spill was a minor spill, “ Popiel said. “We’d call this some pretty good fortune in terms of what could have happened.”
The Pewaukee, Wisconsin-based American Transmission Company contacted the DEQ April 2 to inform the agency of decreased pressure in its electric lines.
The company later learned that an estimated 600 gallons of dielectric fluid, a type of mineral oil, had leaked due to a suspected anchor strike that severed two lines. Neither PCBs nor benzene compounds were found in the fluid, Schaefer said, and no sheen was ever observed on the water surface, likely because of the depth of the line and wave action.
U.S. Coast Guard officials have released little information as they investigate what caused the leak, but Gov. Rick Snyder has said it was a suspected anchor strike.
Popiel said it is not illegal for ships to drop anchor in the Straits of Mackinac, though several signs discourage it. Attorney General Bill Schuette filed suit against Escanaba-based VanEnkevort Tug and Barge Inc. in April, claiming its tug was responsible for the alleged anchor strike that ruptured the ATC lines.
The leak was stopped, Schaefer said, when ATC began to extract the oil from the line, creating a vacuum on the line that continued for roughly a month until the lines were completely emptied and capped.
Within a few days of the leak, officials determined the suspected anchor strike also severed abandoned Consumers Energy lines and dented the east and west pipelines of Enbridge Energy’s Line 5.
"It was sort of a slow-rolling response because, with the vacuum operations, we were able to eliminate the threat,” Schaefer said.
Board member Tony England, a University of Michigan electrical engineering and computer science professor, pressed Schaefer on how the agency would have handled the situation in worse weather conditions or in the event of a worse release.
“If we were trying to respond to a (crude) oil release on April 2, what would the situation have been?” England said.
Traven Michaels, environmental response specialist with the Little Traverse Bay Bands of Odawa Indians, voiced similar concerns. Michaels, who was involved in the joint response, said he was concerned about how the unwieldy weather in early April would have hindered a larger spill.
“This would have been a tough response,” he said.
Peter Holran, director of U.S. government affairs for Enbridge, said Enbridge discovered dents in Line 5 in a second interior assessment nearly a week after the ATC leak.
The company performed an interior assessment shortly after the leak, checking for indentations that would affect the integrity of the line, Holran said. The inspection showed no damage, but a second assessment performed with a more detailed tool indicated the dents that would later be documented from the exterior by underwater remote operated vehicles and divers, he said.
Holran said the company has reduced the maximum pressure and put in a temporary fix. It is working on a plan for longer-lasting repairs.
“We are leaning toward a composite sleeve at this point,” he said.
Board members asked Holran what type of information the agency intended to provide concerning the damage to the line and intended repairs.
"I think our presence here is an indication of our willingness to speak about the incident," Holran said.
Grether said the state’s cyber security prevents the DEQ from posting additional images or footage of the damaged lines on file-sharing programs such as DropBox.
“We have not been able to post ROV (remote-operated vehicle) footage and I don’t think we’re going to be able to,” she said.
Enbridge Energy will deliver a report to the state in June that will evaluate underwater technology to enhance leak detection, ways to stop anchor strikes, water crossings for Line 5 other than the Straits of Mackinac and the potential for placement of the pipeline within a tunnel or trench.
Michigan Technological University students who studied the possibility of a tunnel for a senior project estimated a 21-foot inter-diameter tunnel beneath the Straits would cost roughly $589 million for construction alone and take several years to complete.