Tailings Management

Tailings management, dealing with the residue from minerals processing, is one of the most critical areas of environmental management for mining operations. It continues to receive global attention and we treat it very seriously. Notably, there is a renewed emphasis on the part of mining companies – and the mining sector as a whole – to demonstrate to stakeholders that they are managing their tailings facilities responsibly.

Our operations manage their tailings facilities according to site-specific conditions and applicable local laws and regulations as well as applicable international standards. Tailings management is a key component of EIAs and corresponding management plans.

At the Seabee Gold Operation, we use two tailings management facilities (TMF), namely the East Lake TMF and the Triangle Lake TMF. Tailings deposition alternates between the two facilities with summer deposition occurring in the former and winter deposition occurring in the latter. We will be expanding the Triangle Lake TMF beginning in 2019 with expected completion in 2020.

We operate the Seabee Gold Operation facilities in accordance with a Tailings Operation Maintenance and Surveillance Manual, which was developed by recognized independent engineering experts. We also follow the Canadian Dam Association Safety Guidelines.

In 2017, we installed a water treatment plant at the East Lake TMF to treat and settle the solids and separate the water at both of the TMFs. We use an extensive treatment process to treat water to the acceptable provincial levels, as defined in the Saskatchewan Environmental Quality Standards for Surface Water. The treated water discharges to a settling pond, which flows through a series of wetlands before discharging to the northern arm of Laonil Lake.

At Puna Operations, we optimized the design of the operations to reduce costs, limit our overall environmental footprint, and minimize the potential impacts on the environment. Specifically, we process ore from the Chinchillas mine at the existing Pirquitas facilities and dispose tailings in the mined-out Pirquitas pit. This approach eliminated the need for constructing an expanded TMF, which reduces our overall environmental footprint. The reagent scheme used for processing Chinchillas ore avoids the use of cyanide in the lead flotation stage, thus eliminating any cyanide concerns within the tailings.

We continue to operate our existing TMF at the Pirquitas facilities. The TMF serves as a backup to the pit disposal and we may use it as a water treatment pond.

The Marigold mine became a heap leach operation in 1994 at which time the TMF was decommissioned and reclaimed. The only remaining activity concerning the TMF is ongoing well monitoring.

In 2006, the Marigold mine became the first mine in the world to be certified under the International Cyanide Management Code (ICMC). The mine continues to maintain certification under the ICMC.

We conduct extensive monitoring at all of our TMFs as part of our regular environmental monitoring programs. In 2018, we were in full compliance with all internal and external requirements.

The following table provides an overview of the quantity of tailings we produced at our operations in 2018.

Table 10. Tailings Volumes

Operation m3
Seabee Gold Operation 195,555
Puna Operations 756,191

Throughout 2019, we will develop an enterprise-level tailings management policy. In addition, we will augment existing third-party reviews of tailings facilities with a formal Independent Tailings Review Board. The mandate of this review board will be to review and assess the management and condition of our TMFs. The review board will be comprised of recognized experts from relevant disciplines including geotechnical, water, and mine closure. Lastly, we will review the requirements for adopting the MAC Tailings Management Protocol.

In 2006, the Marigold mine became the first mine in the world to become certified under the International Cyanide Management Code (ICMC). The mine continues to maintain certification under the ICMC.