Enbridge refines best-laid pipeline plans
Horizontal drilling process will create tunnel under environmentally sensitive Morice River
Pushing the proposed Enbridge Inc. Northern Gateway pipeline across the environmentally sensitive Morice River will involve drilling a 1.7-kilometre tunnel deep beneath the stream bed, according to project documents made public Friday.
The Morice, a tributary of the Skeena River, is one of 10 rivers on the proposed line’s 1,172-kilometre route that Enbridge has proposed to cross using a technique called horizontal, directional drilling (HDD).
And Enbridge’s initial plans for those crossings have been made available on the National Energy Board’s website as part of the company’s application for federal approval of the $5.5-billion project.
For the Morice, Enbridge picked directional drilling because of concerns raised by community groups and aboriginal communities about the project’s impact on salmon in the river, according to Jason Harris, a fisheries biologist with Enbridge Northern Gateway Pipelines, the entity Enbridge formed to build the project.
“Some of the things we’re looking at are [salmon] species present and the timing of their life stages, spawning for example,” Harris said.
He said the plans Enbridge has filed are only preliminary and the scope of the Morice project will change in terms of the crossing length or depth of the drill based on detailed geotechnical engineering.
However, the preliminary plan is for the line to cross the Morice at a spot 50 kilometres southwest of Houston, which lies west of Prince George.
The length of the drilling path would be 1,772 metres, according to the plan, and, at its deepest, 95 metres below the Morice River’s stream bed.
There would be two tunnels drilled, one for the 914-millilitre oil pipeline, and one for the 508-millilitre condensate pipeline that is part of the project.
However, the deep-drilled method does little to mitigate the concerns of project opponents who fear the possibility of a rupture of the oil line, which is being designed to pump 83.5 million litres of oilsands bitumen per day from a spot just north of Edmonton to Kitimat on B.C.‘s coast.
“It’s not so much the crossing or style of crossing, it’s what’s downstream of the crossing which is important,” said Greg Brown, who speaks for the Friends of Wild Salmon, a coalition of conservation groups in the northwest.
Downstream of Enbridge’s crossing, the Morice is braided in a warren of side channels and eddies, Brown said, where log jams form that are important rearing habitat for juvenile salmon.
He added that the area is an important spawning habitat for steelhead, pink, chinook and coho salmon.
“A Kalamazoo River-style rupture would be just disastrous for the Morice,” Brown said, referring to the July rupture of an Enbridge pipeline in Michigan that spilled 19,500 barrels of oil into the stream.
Of the nine other stream locations that Enbridge has proposed to cross using horizontal, directional drilling, five are in B.C.
The first is at Hook Creek, a 672-metre crossing 602 kilometres into the route, on the east slope of the Rocky Mountains; the next is a 576-metre crossing of the Parsnip River 671 kilometres farther along.
The others are a 696-metre crossing of the Stuart River near Fort St. James; a kilometre-long crossing of Hunter Creek 1,099 kilometres along the route; and a 1.2-kilometre crossing of Wedeene River, 1,145 kilometres into the route.
The Northern Gateway pipeline route crosses 773 streams in total.
depenner@vancouversun.com