The site of a former gold mine that operated approximately 100 years ago will be remediated after an investment of more than $33.4 million from the federal and provincial governments.
An environmental site assessment confirmed the soil at Montague Mines, which was mined for gold from 1865 to 1940, is contaminated with mercury and arsenic. The contamination is primarily found in an area of approximately 363 acres where mine tailings were disposed. The goal of the project is to return the land and wetlands to a productive habitat similar to what it was before mining activities.
The cleanup will include excavating contaminated soils to a depth of two metres and placing the soil in impermeable containment cells that will be 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.
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.
