The company that operates twin oil pipelines in a Great Lakes waterway said Friday it knew three years ago that protective coating had been damaged in one area but didn't inform regulators, an acknowledgment that drew sharp criticism from Michigan officials.
Enbridge Inc. said four gaps were opened in enamel coating on a section of pipe in Michigan's Straits of Mackinac as a support anchor was installed in 2014 — one of eight spots where scratches or calcium carbonate deposits have been discovered. Environmental advocates say the gaps bolster their contention that the company's 64-year-old Line 5 should be shut down, although Enbridge insists they pose no safety threat and the pipes are in good shape.
Line 5 carries up to 23 million gallons (87 million liters) of light crude oil and liquid natural gas daily across parts of northern Wisconsin and Michigan to refineries in Sarnia, Ontario. The underwater section beneath the nearly 5-mile-long (8 kilometers) straits area is divided into two pipes.
Enbridge officials told the Michigan Pipeline Safety Advisory Board in March they knew of no places where bare metal was exposed on the underwater sections, which spokesman Ryan Duffy said was "accurate to the best of their awareness." The company first notified state regulators about the coating gaps in August, saying they had been found this summer during inspections required under an agreement with the federal government.
But on Friday, Enbridge said engineers in its pipeline integrity department had known since 2014 about the damage sustained during the support installation. The engineers concluded that the gaps, which together covered an area less than one square foot, had caused no corrosion and didn't pass the information up the chain of command, Duffy said.
"As our dialogue with the state continues, Enbridge has come to recognize that issues which do not present a threat to the safety of the pipeline can still present a strong concern to Michigan, and we are adjusting our communication approach accordingly," he said.
Valerie Brader, executive director of the Michigan Agency for Energy and co-chair of the Michigan Pipeline Safety Advisory Board, said Enbridge should apologize for not providing the information earlier.
"This issue is too important to the people of Michigan not to tell the truth in a timely manner, and right now any trust we had in Enbridge has been seriously eroded," Brader said.
"I am concerned by Enbridge's lack of transparency when it comes to Line 5," said Capt. Chris Kelenske, deputy state director of emergency management and homeland security.
Enbridge said it was submitting more information about the gaps to the state Department of Environmental Quality, which is reviewing the company's application to place more anchors on the lake floor. The DEQ said it was postponing its deadline for processing the application from Nov. 2 to March 2, 2018, to allow a more thorough review.
Crews have repaired five of eight areas found to have coating gaps or calcium carbonate deposits, which indicate places where coating could be thin or missing, and work continues on the others, Duffy said.