Enbridge Plans Line 5 Anchoring, Coating Checks


Michigan’s Department of Environmental Quality has given Enbridge Energy a permit to install 22 new anchors on the floor of the Straits of Mackinac to help stabilize the company’s controversial Line 5 pipeline.

Anchoring and the loss of the pipeline’s protective coating have been the two main concerns raised by opponents of the line, who hope to see it shut down. Line 5 is the only oil pipeline running under the Great Lakes.

The new anchors are an effort, the DEQ says, for Enbridge to ensure it is in compliance with its original easement in the Straits, as well as the more recent consent degree the company entered into with the federal government after two spills elsewhere in its network.

The easement calls for no unsupported stretch of pipeline under the Straits running longer than 75 feet. Last June, media reports revealed documentation that indicated in more than 200 instances, the maximum length was exceeded. Stretches of up to 286 feet were left without support in some cases.

Enbridge said it had added four new screw anchors in 2016 to address segments of pipeline that had gone unsupported due to erosion. The company said at the time that it intended to add 18 more.

Coating Work Included

In addition to adding 22 new anchors—which represent one of the three forms of support called for in the easement—Enbridge must, according to the DEQ, inspect the protective coating on the pipeline in the areas where the anchor work is done, and repair any areas of coating loss.

Besides screw anchors, some parts of the pipeline are supported by sandbags or by the lake bed itself.

Line 5 supports

Besides screw anchors, some parts of the pipeline are supported by sandbags or by the lake bed itself.

The new anchors are being installed as a separate measure, unrelated to the agreement Enbridge came to last year with Gov. Rick Snyder, which will involve a report on alternatives to the pipeline, to prepare for its eventual replacement. The agreement also includes the replacement of the section of line 5 running under the St. Clair River, which is underway now.

Pipeline Background

Enbridge has been under increasing fire over the past year from citizens, activists and lawmakers in Michigan who are concerned about the condition of the 65-year-old dual pipeline under the Straits. In November, Snyder publicly called on Enbridge to be more transparent about the line after a series of revelations of coating damage on the pipes under the Straits.

In February 2017, Enbridge denied reports of coating loss on the pipeline. The following month, the company acknowledged that there were areas of coating loss, but that they only affected the outer layer of the coating system.

More recently, it was revealed that there were areas of bare metal on the line under the Straits, and some Enbridge personnel knew about the gaps soon after they were created in 2014, but the company hadn’t acknowledged their existence for three years. In November, Enbridge revealed that, rather than the three gaps in the coating that the company originally reported, there were dozens of areas of bare metal, some larger than one square foot in area.

Enbridge has held that the pipeline’s integrity has never been compromised, citing the recent pressure test as evidence that the coating gaps and unsupported stretches have not led to any increased risk at this time.


Tagged categories: Government; Infrastructure; NA; North America; Oil and Gas; Pipelines; Protective Coatings; Quality Control

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