Officials: Enbridge Knew About Line 5 Coating Gaps


Canadian energy company Enbridge is facing further controversy related to its Line 5 pipeline under the Straits of Mackinac after reports revealed the company knew in 2014 about areas of coating damage on the underwater oil pipes, but didn’t acknowledge the damage to the public or officials until last month.

The Michigan Department of Environmental Quality said Friday (Oct. 27) that the DEQ, along with the state’s Agency for Energy and Department of Natural Resources, “expressed concerns that Enbridge knew of damage in the protective coating on a portion of Line 5 in the Straits of Mackinac.”

Three-Year Gap

Enbridge allegedly had documentation of the damage, reportedly inflicted in part by maintenance work on the pipeline, in 2014. The coating loss was only publicly disclosed in September 2017, when Enbridge said routine studies of the underwater pipeline conducted over the summer had uncovered three small areas of coating loss.

Later in September, state officials said that in fact there were more than three areas of coating loss, and that some were much larger than Enbridge had originally suggested. The director of the DEQ said that what Enbridge had previously disclosed was “not … the truth nor was it really accurate.”

An Enbridge spokesperson told WMUK News that the areas of coating loss were not a safety issue and that engineers did not report them because they were not a threat. Enbridge’s Ryan Duffy told the radio station that “the safety of the pipeline was never compromised.”

Line 5 Concerns

Line 5, which crosses under the Straits of Mackinac between the Upper and Lower Peninsula of Michigan, has been under fire from residents, activists and lawmakers over concerns that the 64-year-old dual pipeline could rupture, threatening the body of water.

Line 5 map

Enbridge's Line 5 conveys crude oil and natural gas liquids from Alberta to Sarnia, Ontario, crossing through Michigan en route; it has never experienced a leak, and recently passed a pressure test.

The pipeline, which conveys crude oil and natural gas liquids from Alberta to Sarnia, Ontario, crossing through Michigan en route, has never experienced a leak. But it has been under a microscope in recent years, especially after the 2010 rupture of Enbridge’s Line 6B, which released more than 843,000 gallons of oil, much of it into the Kalamazoo River.

In February, a local newspaper reported on environmental research on the pipeline that indicated areas of coating delamination. At the time, Enbridge said that the report was a study, not a description of the pipeline’s current state. “The pipe is in good condition and the fiber-reinforced enamel coating is intact,” Enbridge said at the time.

In March, the company admitted there were 18 areas of coating delamination on the pipeline, but said that only the outer layer was affected, and that the company would not take steps to make repairs because the main coating was still intact. The company said at that time that there were no holidays, or areas of bare metal, on the pipeline.

The revelation in August that there were a number of areas of bare metal, some as large as one square foot, came with a promise that the company was working on repairs.

Coating Controversy

Earlier this year, a state lawmaker proposed legislation that would require a third-party assessment of the pipeline, and would shut it down if the assessment determined there was sufficient risk. In July, an assessment performed by Dynamic Risk Assessments Inc. held that there was no indication of coating delamination on the pipeline.

Enbridge has held, and Dynamic Risk Assessments agreed, that the coating on the 193 pipeline is coal tar enamel. A report authored by engineer Edward Timm and released by the National Wildlife Federation called that assumption into question earlier this year, though.

Timm said in his report that while coal tar enamel was called for in the order for the pipeline, it’s not clear that that’s what was ultimately used to coat the pipe. Timm concluded it’s more likely it was “a solvent-based asphalt primer, two layers of asphalt-saturated glass fiber fabric and a white protective overlayer of white craft paper bonded with asphalt enamel.”

In June, the pipeline passed a pressure test in which it was subjected to pressures of 1,200 psi, eight times its normal operating pressure.


Tagged categories: Environmental Protection; Government; NA; North America; Oil and Gas; Pipeline; Quality Control

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