Tailings Storage Facilities (TSFs)
Our metal and coal assets generate tailings (residues of mineral processing), which are stored in purpose-built tailings storage facilities (TSFs). TSFs are specially designed reservoirs ﬁlled with tailings and water. We remove water through drains or evaporation while the tailings settle, gradually ﬁlling the reservoir. At this point, we cap, seal and rehabilitate the TSF.
Our assets have management systems and dedicated facilities to dispose of mineral residues while preventing environmental contamination. Through our group-wide dam integrity and safety assurance programme, we require our TSFs to be audited by (KCB), one of the world’s leading experts on integrity and safety of tailing storage facilities.
Dam failure is the greatest risk for our TSFs, as disclosed in our Annual Report. Our dam safety assurance programme assesses our tailings and water dams in line with international leading practice.
Our assets are required to assess natural phenomena such as extreme flooding and seismic events, as well as operational criteria, and incorporate these factors into their TSF designs. Since 2016, our corporate dam integrity and safety assurance programme has detailed our approach towards the group-wide review on the integrity of our TSFs. This involves an assessment against more than 100 dam safety and governance leading practice criteria.
There are three levels of governance and assurance we require our assets to undertake on TSFs:
- 1. Regular surveillance – assets are expected to monitor their TSFs on an ongoing basis using piezometers, slope monitoring and other equipment, with results assessed by the management team of that asset.
- 2. Dam safety inspections (DSI) – external engineers carry out periodic DSI for operating assets and closed TSFs. A DSI evaluates and observes potential deficiencies in a TSF’s current and past condition, performance and operation; DSI findings are typically overseen by the asset management team.
- 3. Dam safety audits – KCB, one of the world’s leading experts, audits the integrity and safety of our TSFs. The results of these audits are reported to Glencore’s senior management and the HSEC Committee of our Board of Directors, and findings are followed up through regular independent verification audits.
The different levels of assurance are undertaken on the basis of national regulations; as well as, where appropriate, criteria aligned with international guidelines from the Canadian Dam Association, the Australian National Commission of Large Dams and the International Commission of Large Dams
In addition, where appropriate, assets conduct periodic dam safety reviews, which include reviewing maintenance, surveillance and monitoring, failure impact assessments, emergency management procedures, public safety and environmental management. The results are shared with asset and department management, and reviewed as part of the dam safety audits.
As technologies and knowledge evolves, we investigate and, when possible, implement new approaches to the management of our TSFs. For example, we are migrating some of our existing facilities to ﬁlter press tailings, which uses dewatering technologies to produce relatively ‘dry’ tailings that allow for stable and stackable storage. However, dry tailings are not suited to all environments and we continue to consider options to improve our TSFs management.
Tailings management protocol
We are committed to aligning the design, operation and closure of our TSFs with international best practices. We continually review and strengthen our TSFs management system through our catastrophic hazard evaluation programme.
As part of our ongoing approach to manage our TSFs safely from design through to closure, we strengthened our Group-wide TSFs Management Protocol in 2019.
Our revised Protocol reﬂects learnings from across the business and consultations with internal and external experts. It aligns with the and requires all our TSFs to meet the , currently considered one of the leading international guidelines for tailings dam design, operations and management.
Our TSFs Management Protocol requires all new tailings projects to assess alternative technologies that may reduce the dam’s consequence classiﬁcation or minimise its long-term risk.
In 2020, the Global Tailings Review, made up of the ICMM, UN Environmental Programme and Principles for Responsible Investment, published a new global industry standard on tailings management. Glencore participated in the development of the standard through the ICMM. We are mapping its requirements against our existing TSFs Management Protocol and will implement any variations.
We welcome the opportunity to participate in the Investor Mining & Tailings Safety Initiative and have responded to the Initiative’s request for information concerning TSFs. In response to this request, we have developed a , which is accessible here, accompanied by a .
Engaging with communities
We require our assets to undertake proactive, targeted stakeholder and community engagement across a broad range of operational topics, including TSFs where appropriate.
We expect our assets to develop and maintain emergency preparedness and response plans that are communicated with relevant stakeholders. Where appropriate, assets may also engage with local and regional emergency response services in scenario planning and practice exercises.
Decommissioning and closed assets
As the mine approaches the end of its life, closure plans are developed, which include the decommissioning of TSFs. These closure plans are developed in accordance with local and international guidelines and are approved through the regulatory process where required. We are also in the process of reviewing the latest guidance from ICMM in relation to mine closure plans.
When we decommission and close our TSFs, we require that assets put in place appropriate measures for physical and geochemical stability and that the rehabilitation of the land for appropriate post-mining land use in a manner that enhances stability. Where a landform for a closed TSF is not possible, closure plans must address physical stability and the control of geochemical stability in a manner that protects the environment.
Following closure, TSFs are inspected and monitored by dedicated teams on a regular basis. Our sites are required to have operational manuals that include instructions on actions in case of an abnormality, emergency response, monitoring, etc. Our corporate dam safety assurance program include closed assets.