Nova Scotia has announced that a former Dartmouth gold mine, which began production in 1865, will undergo remediation after a combined government investment of more than $33.4 million.
While production ceased at the Montague Gold Mines in 1940, it remains contaminated with mercury and arsenic, particularly in a roughly 147-hectare tailings disposal area, according to an announcement from Housing, Infrastructure and Communities Canada.
The goal of the remediation project is to return the land and wetlands to a productive habitat similar to what it was before mining activities, federal officials said.
Phase 1 and Phase 2 Environmental Site Assessments were completed in 2022, including Human Health and Ecological Risk assessments.
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“The start of remediation at the historic gold mine site in Montague Mines marks a major step forward in protecting both the environment and public health,” announced Nova Scotia Minister of Public Works, Fred Tilley. “This work reflects our dedication to responsible environmental stewardship and our commitment to addressing the legacy of past industrial activity.”
The cleanup will include excavating contaminated soils to a depth of two metres and placing the soil in impermeable containment cells constructed on site. The estimated volume of material expected to be contained within the cells is 120,000 m³. A treatment system will also be required to collect and treat any leachate from the constructed containment cells. Clean backfill will replace removed soil.
A low-permeability cover will be placed on areas of the site with lower levels of contamination to keep precipitation from creating contaminated runoff. These areas will also be covered with clean backfill, provincial officials noted.
Since 1991, provincial legislation in Nova Scotia requires mining companies to provide funds for reclamation — such as cash or bonds — before mining begins to cover full reclamation costs. This ensures sites can be effectively reclaimed even if a company defaults, preventing an abandoned or contaminated site.
