Pipeline repairs set for fall start
October finish in the cards for project after directional drilling, say Enbridge reps at public meeting
April Hudson
Northern News Services
Thursday, March 9, 2017
DEH CHO
Enbridge Pipelines is moving ahead with plans to drill under the Mackenzie River in order to replace up to 2,300 metres of the Line 21 pipeline.
Enbridge representatives gave a community update in Fort Simpson on Feb. 28. From left are Brian Cikaluk, supervisor pipelines; Bert Fillion, construction manager; Mark Gerlock, area supervisor; Chris Dickson, manager of community and indigenous engagement; Ann Marie Tout, regional manager for Enbridge; Sarah McKenzie, regulatory specialist; and David McWatt, project manager. - April Hudson/NNSL photo
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The pipeline running to Zama from Norman Wells was shut down in November as a precautionary measure after the south slope of the Mackenzie River along the pipeline began shifting at an increased rate.
Ann Marie Tout, regional manager for the Enbridge pipeline, said during a public meeting in Fort Simpson on Feb. 28 the affected section of the pipeline has been cleaned and capped at both ends with steel.
Now, Enbridge is proposing to leave that segment in place and use horizontal directional drilling to insert a new section under the river.
Tout said horizontal directional drilling is designed specifically to minimize environmental impact and is typically used under large rivers.
"We believe (this) is the best solution. It will ensure long-term protection of the river (and) it will optimize the safety of the pipeline from any instability along the river bank," she said.
The company would drill to a depth of between 70 and 100 metres, drilling from both slopes at the same time for between 45 and 60 days.
Pending regulatory and customer approval, Tout said drilling would begin in early August and wrap up in late October.
Over the past two months, Enbridge Pipelines has been completing survey work on the north and south slopes of the river.
Lights on the river mark where drilling rigs have been collecting core samples over the past couple weeks, as well.
Tout said there are approximately eight people currently involved in the work, which includes local contractors.
"These samples are collected just to confirm that our proposed solution is feasible and also to help us with the design," she said.
The company plans to file two applications this month with the National Energy Board - one for construction and the other to decommission the segment of pipeline that will be left in place under the river.
Enbridge Pipelines will also be applying to the Mackenzie Valley Land and Water Board for a land use permit and Type B water licence to support their drilling.
"We'd need about 70 to 80 people for this project, and we will be working with local businesses to optimize the benefits to the community without negatively impacting the community," Tout said, adding the company will need temporary work space on both sides of the river and may need additional land for their right of way.
Anticipating an August start to the work, Tout said the company hopes to barge its equipment to the North slope and stage it in June or July. Equipment will be trucked in to the south slope and staged in July.
Existing pipeline shouldn't cause concern
"Leaving (the existing) segment in place is the safest option and the least disruptive," Tout said.
"It avoids us having to try and excavate to remove the pipeline that's in the ground now, and it significantly reduces the risk of future instability."
The steel segment, which is buried four metres under the river, is encased in cement and is yellow-jacketed, meaning it has a polyethylene coating on it.
David McWatt, Enbridge's project manager overseeing the work on Line 21, said the cement casing goes up the banks of the river on both sides.
"It's been in since 1985. We've been monitoring it and there hasn't been anything in the river from the pipeline," McWatt said.
"I think that for the foreseeable future . it'll be cleaned again and it'll be filled with grout, so it'll be heavy and anchored where it is. I don't think we'll be having any issues with any toxins coming off the pipe."
As for the future of the pipeline, Tout said she is optimistic despite a decision by Imperial Oil to suspend production in Norman Wells.
"I think any buyer would want an operational pipeline because otherwise it's a stranded asset," she said.
"Our feeling is that regardless of who owns it, they would want to see the pipeline operational."
