The project, proposed by Atlantic Gold (Atlantic Gold was purchased by St Barbara, an Australian gold mining company, last year. St Barbara now runs Atlantic Gold Operations in Nova Scotia), would involve the construction of an open-pit gold mine one kilometre long, half a kilometre wide and a maximum of 170 metres deep alongside the river. In total, the project would involve some 240 hectares (roughly 450 football fields).
The initial processing at Cochrane Hill would result in tailings ponds on site, contained behind dams perched above the St. Mary’s watershed. Any treated effluent would be discharged into the Cameron Lakes, which drain through McKeens Brook, arguably the most productive spawning habitat on the river, according to Beaver.
Modern open-pit gold mines operate differently, aiming to extract only small flakes of gold diffused throughout tonnes of rock. Rock is excavated, crushed and treated to leach out gold. The remnants are then deposited in a waste pile and resulting chemical muds are stored in tailings ponds, which remain long after the life of a mine.