Objectives and Initiatives

Since its inception, the Reclamation and Closure group has been focused on improving our institutional knowledge of our 33 closed sites. With a better knowledge of their unique geologies, histories, environmental condition and regulatory requirements, we will be better positioned to identify and manage the potential risks at each mine site.

On an annual basis, all operating and closed sites review – and revise as required – their closure assumptions regarding the physical work and costs that would be required to complete closure. This ensures that our closure objectives are current and that our closure planning accounts for any new or revised conditions at the operation, and any regulatory changes that may affect closure plans or require changes to the closure design.

Closure planning begins at the earliest phases of a project’s lifecycle and evolves as the project matures. Effective closure planning:

  • Includes active stakeholder participation
  • Understands and addresses the regulatory requirements
  • Improves project transparency
  • Identifies risks earlier so they can be mitigated
  • Reduces long-term liabilities, and moves the project towards passive care and custodial transfer
  • Recognizes and plans for potential post-closure land uses and opportunities

2018 Objective

Post-closure monitoring stage at El Sauzal

In 2016, we completed the closure of our El Sauzal mine in Mexico. During 2017, the focus was on monitoring the site and completing maintenance work in channels and tailings corona to control water runoff and erosion damages. Environmental federal inspectors visited the site at the end of the year to ensure that we were complying with the terms and conditions for the closure stage as they are outlined in the Environmental Impact Assessment permit (in Mexico called the Manifesto de Impact Assessment or MIA). This occurred after the site submitted the Final Closure report. As of December 31, 2017, the site has entered into post-closure monitoring as we continue to work on finalizing the site inspection and sign off process in the following years.

Continuing Closure of the Marlin Mine

Mining at the Marlin mine in Guatemala ended May 31, 2017. Progressive reclamation has been performed at the site since the start of operations in 2005. The Marlin pit backfill started in 2012, with a mixture of dry tailings, cement and rock used as fill material. This is a best-in-class technique that results in a stable, environmentally benign landscape. In December 2015, backfilling of the main pit was completed. In 2016, we began to cover the pit wall, which we completed in 2017. The tailings dam was completely filled by September 2017. We started the cover construction in December 2017 with a layer of geotextile. In 2018, a 1.5 m layer of coarse oxide will be set on top of geotextile and finally a 1.0 m layer of fine oxide will be set above to allow vegetation growth.

In 2017, the closure plan was also updated and submitted to the Ministry of Mining (MEM) and Ministry of Environment (MARN). Major community activities included land donation and continuity of water services projects. To support the transition of our employees and workers, we offered education, training and retraining opportunities to 1,500 employees and workers to help diversify their skill-sets and assist with career transitions as appropriate.

Marlin Mine Open Pit Closure

At our Marlin mine, both underground and open pit methods were used. We stopped open pit mining at Marlin in 2011 and continued underground mining until May 2017. When we closed Marlin’s open pit, our objective was to ensure productive post-closure use by producing a stable condition, both physically and geochemically. In 2012 we started the progressive reclamation of the Marlin mine open pit. In the backfill process, material was placed and compacted in a four-step process. The first step involved adding the base layer using filtered tailings with 2% of compacted cement to seal the floor of the pit. In the next stage, we added a layer of filtered tailings. We then added layers of waste rock material in the centre of the pit surrounded by a filtered tailings ring. Finally, the upper levels of the backfilling continued until it reached the highest part of the north wall. As of December 31, 2017, 20,000 m3 of oxides were left to be placed.

Water runoffs will continue their flow towards the natural drainage of the Tzalá River basin through a concrete-steel notch or spillway built for flood and runoff speed control before reaching the natural creek. The design considered a storm event of 250 years and 24 hrs.

Finally, 3,187 kilograms of Brachiaria grass seeds were hydroseeded – some of them above 1140 m2 of Ecomatrix (a green polypropylene mesh).

Mine closure sequence December 2011 January 2016
Mine closure sequence March 2017 September 2017