Sustainability Report 2021

MINERAL RESIDUE MANAGEMENT IGO’s mineral waste material includes tailings and waste rock, the two largest mining-related waste streams produced at our operations. Management and storage of waste rock and the processed mineral tailings is a critical issue for our industry. It represents a social, safety and environmental challenge that we are determined to meet. The effective management of the storage of tailings requires rigorous design practices, comprehensive monitoring and management programs, independent auditing and strict corporate governance oversight. IGO manages one operating Tailings Storage Facility (TSF) at the Nova Operation, which is fully lined and has been engineered for the life of the mine. Mineral waste management at IGO- operated assets are subject to our Group Environmental Standard 3 – Mineral Waste Management which applies to the management of waste rock and tailings. This standard requires the development of a tailings management plan, which includes a risk assessment completed in accordance with IGO’s Common Management System Standard 3 – Risk Management. As part of our ongoing tailings management process, IGO maintain an annual audit schedule to ensure that our practices at IGO-operated facilities conform to our Group standards and are being operated in accordance with the mine’s operating strategy, safety conditions, prescribed premises conditions, and mining tenement conditions. We use independent external reviews to provide us with the confidence that our facilities are conforming to regulations. During FY21, IGO commissioned SRK Consulting to review the ongoing operational, management and monitoring aspects of the Nova Operation TSF in line with IGO management standards and regulatory licence conditions. In previous financial years, SRK Consulting completed a dam breach assessment at Nova to examine various worst-case/credible-case dam breach scenarios and define the likely area of impact given a dam breach and the catastrophic release of tailings. This study validated the original dam breach assessment completed as part of the Operation’s pre-feasibility study. Finally, we have undertaken a high-impact function review, completed by Klohn Crippen Berger, in which no issues were identified with respect to integrity of the dam. The location of the TSF at the Nova Operation is remote from local communities and public infrastructure. The studies and reviews conducted to date provides us with an acceptable level of assurance that impacts from a dam failure would be contained within IGO’s mining lease boundaries. Risk management systems are in place for operational facilities to mitigate potential impacts on employees and contractors in the event of a dam failure. This includes maintaining current emergency response plans in accordance with our Common Management System Standard 13 – Emergency Preparedness and Business Continuity Planning. During FY21, the Nova Operation team have been completing a gap analysis of our current TSF practices and processes against the recently released ICMM Global industry Standard on Tailings Management, which sets the precedent for the safe management of tailings facilities towards the goal of zero harm. This program of work will be completed in FY22. The Nova Operation deposited 1,414,966t of dry tailings in FY21. There were no significant incidents associated with the Nova TSF during the financial year. Likewise, there were no uncontrolled releases from the facility, nor any associated material fauna losses. IGO supports the need for the public disclosure of TSF management practices, and actively participates in external requests for information. We continue to support the investor led Church of England Pensions Board Mining and Tailings Safety Initiative and have provided a response to its request for disclosure of TSF management information, which is available on our website. Waste rock generated from our operations is stored and managed in accordance with statutory guidelines and IGO standards. In FY21, the Nova Operation generated 165,787t of waste rock, a 11% decrease on FY20, representing improved management practices and the deliberate use of waste rock as backfill underground. Additional tailings and waste rock data can be found in the performance data on page 99. NON-MINERAL WASTE IGO takes a holistic approach to the way we manage our waste. We seek to positively influence environmental and social impacts of our products through the value chain, which includes the way we manage our waste products. We manage our waste in accordance with the IGO Group Environmental Standard 7 – General Waste Management. January 2020 saw the roll out of a group-wide, employee-led waste reduction initiative to reduce the amount of non-mineral waste that we generate and improve the way we manage it. This initiative was founded on the application of the waste-management hierarchy of ‘avoid, reduce, reuse, recycle.’ Environment IGO’s mineral waste material includes tailings and waste rock, the two largest mining-related waste streams produced at our operations. Nova Operation tailings storage facility 78 —IGO SUSTAINABILITY REPORT 2021