The Jasper gold mine operated from February 1990 to June 1991, producing approximately 135,000 tonnes of ore. The ore was hauled off-site for milling and tailings disposal at the nearby Star Lake mill site. In April 1991, a decommissioning and reclamation plan was submitted to the regulatory agencies. The plan was accepted and decommissioning commenced in June and was completed by September 1991. A minimum three year transition phase monitoring programme was then undertaken to monitor the effectiveness of decommissioning work performed and the progress of revegetation.
Decommissioning work performed included sealing access to the underground workings, removing all surface structures and associated facilities, and preparing disturbed areas for revegetation. The mine portal was sealed by backfilling with waste rock. Raise break-throughs to surface were sealed by installing reinforced concrete caps over the openings. The strategy applied for revegetation was the encouragement of natural revegetation while avoiding the permanent introduction of non-native plant species.
The invasion of native plant species on disturbed areas was encouraged by various means. The seeding of short-lived agronomic grasses was successful in stabilizing soil conditions and providing a catchment mechanism for native airborne seeds. Scarification and recontouring of disturbed areas has also proven effective. Slash and deadfall from surrounding areas was also pulled out onto disturbed areas that had not revegetated four years after decommissioning. All of these methods have been effective in encouraging natural revegetation. However, earlier application of the slash and deadfall may have allowed for the abandonment of the property in the third year of the transition phase. The concrete caps used to seal the raise break-throughs to surface have performed as designed. Approval to abandon the site is anticipated in 1996, five years after decommissioning and the start of revegetation.