We work to minimise the impact of the mineral and non-mineral waste our activities produce. We focus on the need to store waste safely, particularly mineral waste and tailings.
Our operations are required to continually review their waste management procedures and plans and identify opportunities for improvement.
Most of the waste our activities generate is waste rock and residues from our production processes. We design our assets to ensure the responsible management of our mineral wastes and implement systems to responsibly manage and dispose of all our non-mineral wastes.
Wherever possible, we reuse waste rock and other types of mineral waste to reduce our operational footprint – such as in backfilling mines and building roads.
We assess the hazards of waste from our activities in accordance with relevant regulatory systems and Good International Industry Practices and manage their reuse, recycling or disposal in a safe and responsible manner.
Most of the waste Glencore generates is mineral and includes tailings, slag and waste rock.
The design, construction, operation and closure of our waste storage facilities aligns with the requirements of environmental assessments and government approvals. These are received prior to the start of operations and maintained throughout the life of an asset.
In addition, throughout an asset’s lifecycle it undertakes monitoring of the environmental conditions of waste storage facilities and reports the data to regulators. We reuse as much inert waste as possible. For example, where possible, we use waste rock to backfill our mines, and fill roads with non-hazardous mineral wastes.
A potential risk associated with waste rock dumps and tailings storage is acid rock drainage (ARD). While not present in every rock type, ARD can occur from the exposure of certain types of rock, particularly those containing sulphide, to oxygen and water leading to the formation of atmospheric sulphuric acid. This has the potential to leach heavy metals (such as lead, zinc and cadmium) from the ore in the waste rock. Geochemical assessments are conducted on our waste rock to inform proper design of our storage facilities to minimise long-term potential impacts. We also conduct routine monitoring.
Assets are required to reduce the risk of ARD via a number of waste management technologies, including:
- segregating non-acid generating and potentially acid generating rock types;
- efficient mining practices to reduce the volume of waste rock; and
- capping of waste rock dumps to reduce contact with air, precipitation and sensitive water bodies.
The effectiveness of these design and management controls are monitored and updated to support the management and mitigation of potential impacts.