A wall in a wetland: Inside the growing opposition to expansion of an oilsands mine

When Elder Barb Faichney flips through family photos, McClelland Lake is a recurring theme. Her family's trapline skirts the banks of the lake north of Fort McMurray, Alta., which has long been a special place for them to hunt, trap and gather.

This may not be the case for future generations, she said, if energy giant Suncor moves ahead with a plan to expand its Fort Hills oilsands facility to mine part of the lake's adjacent wetland.

"My grandchildren, they won't be able to enjoy McClelland Lake, they can't say, 'Look, Granny's footprints are all over here,'" said Faichney, who lives in and is a member of Fort McKay First Nation. "It'll be all gone."

McClelland Lake in northern Alberta is at once an important gathering place for local First Nations, a carbon sink, a wildlife habitat and a major potential source of bitumen.

Plans to mine it have been brewing since 2002, when the Alberta Energy and Utilities Board (a precursor to the Alberta Energy Regulator) allowed the company TrueNorth Energy to develop part of the wetland within its oilsands lease. Those plans kicked into high gear last fall, when the energy regulator gave current owner Suncor a green light to move ahead with its operational plan.

But permission to mine the McClelland Lake wetland comes with a caveat: The original 2002 approval hinged on the company agreeing to mine only about half the wetland while leaving the other half undisturbed.

Suncor says it will do this by building a wall — nearly 14 kilometres long and between 20 and 70 metres deep — to separate the two halves, a plan that's become the focus of growing opposition from wilderness advocates and scientists.

It's not just outside observers who are concerned. Some of Suncor's own scientific and First Nations advisers have also expressed hesitation about how the plan to expand the multibillion-dollar Fort Hills oilsands project is unfolding.

As an elder, Faichney has sat for years on a sustainability committee that advises Suncor on its operational plan, which lays out how the company will protect the unmined portion of the wetland. But she said she remains unconvinced that the plan will work and now wants it to be abandoned.

"My preference would be [they] pack up and get out of there," Faichney told CBC News in an interview.

Scientists who advise Suncor's sustainability committee have also raised concerns.

CBC News has obtained a copy of a recent presentation made by a technical advisory group for the project that expresses concern and frustration with how the company will monitor the unmined part of the wetland and ensure it's kept safe from the impacts of mining.

Suncor declined an interview with CBC News while the Alberta Energy Regulator considers a request from a conservation group to reconsider the project, but it has said in correspondence that its plan is based on years of consultation and expert knowledge.

The stakes are high for Suncor to keep the project afloat. The Fort Hills oilsands is a major priority for the company, which recently spent more than $1 billion to obtain full ownership. The facility, which opened five years ago, is expected to have a 50-year lifespan and has capacity to produce 194,000 barrels of bitumen per day.