Brenda Mines was officially closed, after 20 years of operation, in June 1990 due to depleted ore reserves. Site reclamation activities began in 1988. This included contouring and terracing of rock piles, aerial seeding and fertilization, and irrigation of newly planted areas.
Options were also evaluated for disposal of water collecting in the open pit. This required studies of drainage patterns, seismic stability of the dams, aquatic species, plants, forage crops and trees.
Two committees provided guidance during the evaluation: a Technical Committee of government representatives and a Public Surveillance Committee with local residents. A detailed closure plan was in place by 1993 and an amended Ministry of Environment permit to discharge was issued first in 1997 and then with further requirements in 1998. Between 1990 and 1997, important site closure and reclamation activities were completed. In 1998, the new water treatment facility was commissioned.
Aerial fertilization of tailings area