GEGOGAN LAKE — A new study showing that one of Guysborough County’s lakes remains polluted from a legacy of gold mining that occurred more than 80 years ago has taken at least one area environmentalist by surprise.
“I don’t think locals are aware that Gegogan Lake is as contaminated as environmental scientist Branaavan Sivarajah and his team’s work shows; I certainly wasn’t,” Scott Beaver told The Journal in an email following the release last month of the article in the Royal Society of Canada’s official journal, Facets. “We know not to use ... the Goldenville area, but the lake hasn’t had much attention, so this is shocking for sure,” he said.
The 2022 fieldwork for the study – led by Mount Allison University post-doctoral fellow Sivarajah – found that Gegogan Lake, situated approximately six kilometres south of Goldenville in the Municipality of the District of St. Mary’s, could contain levels of mercury (used in gold extraction) as high as were present during peak mining in the area during the late 19th century.
During the so-called “golden age,” of the industry, Nova Scotia produced 20,000-30,000 ounces of gold a year from mines, with one of the most prolific being Goldenville (210,152 ounces of output between 1862 and 1942).
According to the study, while “the average sedimentary concentrations of arsenic and mercury have decreased from peak concentrations at most of the downstream lakes ... nearly eight decades after historical gold mining activities ended in Nova Scotia ... notable exceptions include mercury in Gegogan Lake.” This suggests that “inputs from the watershed or contaminated sediments influenced ... recovery patterns.”
In an interview with The Journal, Sivarajah explained that because mercury does not readily “move through the sediment column” over time, the higher concentrations of the element in Gegogan Lake today indicate that “there still might be tailings washing in” as a result of off-road vehicle use or streaming in from “whatever’s in Gegogan Brook, which feeds the lake.”
He added: “We don’t have any samples from historic periods, in terms of measurements of mercury and arsenic, so we use the sediment, which is a good natural archive of past environmental conditions.”
Sivarajah could not say, definitively, whether his findings indicate a threat to human health in the area. “That would really depend on the type of mercury, such as [highly toxic] methylmercury,” he said. “We did not specifically look at methylmercury concentrations. We measured total mercury and were focussing primarily on aquatic ecosystems and recovery.”
Said Beaver: “It’s a shame, really, because Gegogan – a little drainage basin between St. Mary’s and Liscomb – is beautiful. With all this legacy toxic material in our waterways ... the question right now is how we’re going to clean this up and who [will be] responsible for that and for the costs.”
Last May, the provincial government issued tenders for an environmental consultant to study contamination at four former gold mining sites in Queens, Halifax and Guysborough counties, including West Side Country Harbour, north of Port Bickerton, and Miller Lake near the Liscomb River Wilderness Area.
The Goldenville site has been on the provincial clean-up list since 2019.
