Gold mining's toxic legacy raises concerns about Eastern Shore project
125 years ago, material contaminated with mercury and arsenic was simply dumped in waterways
A proposed gold mine on Nova Scotia's Eastern Shore has dredged up concerns about mercury and arsenic contamination in the area from 125 years ago.
Toronto-based Anaconda Mining Inc. wants to develop a 125-hectare surface and underground mine just outside Goldboro, N.S., about 250 kilometres east of Halifax.
The company submitted its environmental assessment last month, and on Sept. 19, Environment Minister Margaret Miller said it was not detailed enough for her to make a decision whether to approve the project.
Public and government feedback on the project shows that some are worried the mine's activities will disturb sites contaminated by gold mining as far back as 1893.
"Our experts warn us that disturbance to these contaminated surfaces may reintroduce this source of toxicity," reads a joint submission by the Nova Scotia Salmon Association and the Atlantic Salmon Federation, which goes on to note that Anaconda's report does not adequately address that concern.
History of contamination
The Goldboro area has been mined extensively through the years and historically, mercury and cyanide were used to extract gold from the rock.
In those early days, once the gold was extracted, the leftover material, called tailings, was simply dumped into nearby streams or wetlands. High levels of arsenic and mercury have been found in Gold Brook and the Upper Seal Harbour area as a result.
And it's not just the tailings — which are now largely covered in moss and relatively stabilized — that could still contain contaminants. Old mill sites and unidentified waste rock and ore storage sites could also have leached contaminants into the bedrock.
The province's senior hydrogeologist cautioned that the company "needs to ensure that remobilization of historical contamination does not occur."
The senior water quality specialist for the Environment Department suggested Anaconda develop a plan for dealing with any "legacy chemicals" so that surface water is protected.
Another Environment Department manager wrote, "Sufficient details have not been provided on how the historic tailings disturbed within the project area will be managed in accordance with the Nova Scotia Contaminated Site Regulations."
Will the old tailings be disturbed?
But it's unclear whether those historic sites will be disturbed by the mine's activities, and the company's own report appears to make contradictory statements.
The historic and current tailings "should not be allowed to mix," the company wrote, and in order to prevent that, Anaconda is considering building a containment cell or relocating the historic tailings — which would, of course, disturb them.
Anaconda did not make anyone available for an interview, but in a statement to CBC News on Friday, a spokesperson said if the company does relocate historic tailings, it will work with the province to determine the best way to do that, and it will receive approval from the province first.
Who would be liable for damage?
Anaconda says the pre-existing pollution is not its legal responsibility, as it has received an indemnification letter from the province absolving it of liability related to past mining and milling activities — as long as those areas are not disturbed.
The province could not immediately provide more details about that letter, but said it was issued several years ago.
The director of mineral management for the province's Energy and Mines Department, George MacPherson, was clear in his submission about the consequences of disturbing historical tailings: "If they touch it, we'll consider them responsible for it."
Anaconda acknowledged it will be responsible in that scenario. "We would assume liability for environmental remediation of that area," it said in a statement.
Other concerns raised in the responses to the environmental assessment include the report's lack of detail, the potential for acid rock drainage and the environmental impact on Newfoundland, where the gold will be processed. The Municipality of the District of Guysborough expressed support for the project.
"Anaconda will ensure that there are no long-lasting negative environmental effects due to our work performed on the site," the company's statement said. "When Anaconda is finished working in Goldboro, the area will be in better environmental condition than it is right now. That is our commitment."
About the project
The environment minister has asked the company to prepare a more detailed environmental study, and it will have one year to submit it. The company says it was disappointed with that delay, but respects Miller's decision.
Anaconda plans to begin construction in 2020 and wind up production in 2029.
The operation would begin as an open-pit mine and then become an underground mine by its third year. Anaconda plans to extract 575 tonnes of ore per day and process it through gravity and flotation before trucking the gold concentrate to the company's Point Rousse processing facility, near Baie Verte, N.L., via the North Sydney ferry.
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