Although mining activities may occur over an extended period of time, in the long term ours is a temporary land use. Therefore, it is a priority for Centerra to plan for the closure of all of its operations through a fully integrated, dynamic and iterative process that takes into account social and economic considerations at an early stage of mine development; this includes ensuring that appropriate financial assurances are in place to sufficiently cover closure and rehabilitation.
All sites record appropriate (IFRS-compliant) asset retirement obligations (AROs) that are reviewed regularly and audited annually with our financial statements. These are estimates based on the risk-adjusted costs required to settle present obligations.1 Our AROs are approved by Centerra’s executive team.
In 1995, in connection with Centerra’s licence to mine in the Kyrgyz Republic, Kumtor set up a reclamation trust fund to pay for mine closure liabilities. As of December 31, 2019, the balance in the fund was US$41.0 million, with the remaining cost to be funded throughout the remaining mine life.
1 AROs are discounted using a pre-tax risk-free discount rate consistent with the time period of expected cash flows. These cash flows can represent third-party or internal costs assumed for work intended to be completed in conformity with each site’s agreed-upon closure plan.
Centerra strives to reclaim portions of its mine sites that are no longer required for current mining operations.
At Mount Milligan, we’ve progressively reclaimed land as it has become available. The end land use objective is to restore the area to land that is capable of supporting wildlife, recreation and traditional uses by First Nations. During the 2019 growing season, Twin Sisters Native Plant Nursery of Moberly Lake, British Columbia, grew approximately 5,040 Sitka alder and 2,000 fireweed seedlings for planting in a portion of the tailings dam slope in 2020. The remaining portion was allocated toward the reclamation trial area. Reclamation research trials began in 2019 with the spring planting of willow stakes within 12 plots across three trial blocks and the measurement of stake survival following the first growing season.
As part of Mount Milligan’s five-year reclamation plan, ongoing collaboration with First Nations groups on research trials will continue. The focus will be on species selection for continued seeding and sampling of native species, surface preparation and treatments, and follow-up effectiveness monitoring.
Similar to Mount Milligan, Öksüt will aim to progressively reclaim land when possible. Topsoil removed for operations has been stored in designated stockpiles. Areas cleared during construction will be progressively restored with the goal of establishing a stable vegetative cover to minimize erosion, dust and spreading of invasive alien species.
While our Endako Mine in British Columbia is on care and maintenance, some reclamation is ongoing. Tailings beaches are revegetated as they become available, and consequently most of the tailings area will be reclaimed before the mine closes.
In adherence with good practice, conceptual closure plans are updated at least every three years, depending on the project’s stage in the mining lifecycle. Closure plan reviews and updates not only involve technical experts but also consider the needs of local communities, Indigenous groups, governments and employees.
At Kumtor, to help reduce the associated impacts of social change on our communities, we plan and prepare for the social transition of mine closure. Through active engagement, we strive to identify and understand the concerns, aspirations, values and expectations of local communities and Indigenous groups regarding mine closure and social transition.
Community engagement provides the framework for developing a reclamation program that not only meets the approved end land use objectives, but also creates education, training and business opportunities throughout the process. At Mount Milligan, the collaborative effort between local nurseries, plant ecologists, Mount Milligan environmental staff and local First Nations is the foundation for returning the mine to a state capable of supporting wildlife and traditional First Nations activities.
At Mount Milligan, to re-establish pre-mining capability and productivity conditions to the following end land use objectives: wildlife and recreation and re-establishment of opportunities for traditional use of the land by First Nations.