Plan for soil cleanup near Mackenzie River worries Dehcho First Nations

A proposal to remediate the site of a former Shell fuel facility in Fort Simpson is being opposed by the Dehcho First Nations. The site has sat vacant for 40 years and contains soil contaminated by hydrocarbons.

The First Nations say remediating soil on site at former Shell facility could pollute Fort Simpson air, water

The sun sets over the Mackenzie River at Fort Simpson, N.W.T. The Dehcho First Nations have come out in opposition to a soil remediation project near the river, fearing - among other things - that it could release contaminants into the water. (submitted by Laurell Villeneuve)

The Dehcho First Nations have expressed their opposition to a soil remediation plan in Fort Simpson in a letter to the Mackenzie Valley Land and Water Board. 

The soil in question is on a site formerly home to a Shell fuel facility, which has sat vacant for 40 years due to containing soil contaminated by hydrocarbons.

The First Nations' opposition centres around the project's location. According to the proposal, the soil would be kept on site throughout the process, where it would be dug up and tilled to let contaminants evaporate.

The letter says the process could contaminate air and water in Fort Simpson — or the Mackenzie River itself — and the First Nations want the soil brought off the island. 

"The proposed location of the [land treatment facility] poses a threat to the environment and the health and safety of residents in Fort Simpsons [sic]," the letter reads. 

We're trying to do the right thing.- Mark Underwood

Mark Underwood, a field technician with CANURE, the group proposing the remediation project, says he is surprised by the opposition. 

"We're trying to do the right thing," he says. 

"We're trying to remediate it after sitting for 40 years."

An environmental review conducted at the site found that the contamination goes about 1.5 metres deep, meaning the total amount of soil to be dug up would be around 1,600 cubic metres, or about the volume of a public swimming pool.

"The logical thing to do is to treat it on site, and it's a relatively modest volume of soil," says Underwood.

Contamination concerns

The Dehcho letter says it is concerned about contamination of the air and water.

"Contaminated soils within the LTF [Land Treatment Facility] could leach into the surface water or groundwater or be transported by wind and impact adjacent soils, vegetation and the Mackenzie River," the letter reads. "Aerating petroleum-contaminated soils in the LTF could create noxious fumes, which directly impact the health and safety of the residents of Fort Simpson."

Underwood, however, insists he has his bases covered. Regarding the air, he says the total impact would be similar to "a few gallons" of gasoline equivalent.

To contain water runoff within the site, the proposal includes a metre-high wall of soil around it, and has a clay layer below to prevent it from leaking into the ground.

As for the Mackenzie, the Dehcho letter says other jurisdictions require a large buffer between these kinds of sites and bodies of water — in Manitoba, it's 500 metres. The CANURE site sits about 50 metres from the Mackenzie River.

But Underwood says the same goes for the river as the groundwater. 

"We're engineering it to make it suitable," he says. "We built the cell to accommodate a year's worth of rainfall as if there was no evaporation."

Though he was originally required to reply to the comments by Friday, Underwood has asked for an extension in order to address the First Nations' concerns. He says he is not planning to relocate the site.

"Somehow it seems that perspective is lost," he says. "Trying to heal it on site is a reasonable thing to do." 

About the Author

Jimmy Thomson is a former reporter for CBC North.