Independence Group Sustainability Report 2019

significant decreases in standing water level likely due to increased abstraction rates. No significant change in water quality was observed. The Tropicana Operation’s TSF is unlined and has an associated groundwater mound. Consequently, the site completes vegetation impact assessments to determine if either abstraction or mounding is causing tree stress or deaths. To date, vegetation monitoring indicates that neither has had an impact on the overlying bush. Surface water monitoring, undertaken after significant rain events, is also undertaken at the Tropicana Operation to determine the effectiveness of the site’s surface water management infrastructure. Results indicated that surface water management on site was effective. Tailings storage and waste management IGO’s mineral waste material includes tailings and waste rock, the two largest mining-related waste streams produced at our mining operations. Tailings are residues created as part of the mining process, with the storage of this waste material stored in reservoirs or dams known as tailing storage facilities. Mine tailings are the fine-grained waste rock material, suspended in a water slurry, that are discharged from an ore processing plant following the extraction of the desired metal or mineral. Inappropriate storage of tailings can lead to safety, health and / or environmental hazards. The management of IGO’s TSF is a top priority. As of June 2019, IGO manage one operating TSF at the Nova Operation, which is fully lined and has been engineered for the life of the mine. TSFs at IGO-operated assets are subject to our Environmental Group 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 also use independent external reviews to provide us with the confidence that our facilities are conforming to regulation. For example, in response to the 2015 Samarco dam failure, IGO undertook a high-impact function audit of its facilities. The audit was completed by Klohn Crippen Berger and they found no issues with respect to integrity of the dams. In November 2018, IGO commissioned SRK Consulting to complete a dam breach assessment at the Nova Operation. The purpose of this assessment was to examine various worse 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 prefeasibility study. The location of the TSF at the Nova Operation is remote from local communities and public infrastructure. The studies and audits conducted to date provides us with an acceptable level of assurance that impacts from a dam failure will 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 Standard for Emergency Preparedness and Business Continuity. Tailings generation has increased at the Nova Operation, with the mine operating at design capacity for the majority of FY19. The total amount of dry tailings deposited was 1,443,449.8t. During FY19 there have been no significant incidents associated with the Nova Operation TSF. 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. For example, during FY19, IGO received a letter from the Church of England Pensions Board on behalf of a range of large funds managers seeking the disclosure of tailings storage facilities management information. We, like many industry peers, elected to provide a response which is available on our website. Waste rock generated from our operations is stored and managed in accordance with statutory guidelines and IGO standards. This is to minimise the potential for environmental harm and to ensure the effective rehabilitation of our mine sites both progressively and at closure. The responsible management of landfill waste is an important aspect of our waste management strategy. Across the business, waste disposed to landfill has been increasing, reflective of the growth of the business in recent years. 44 — IGO SUSTAINABILITY REPORT 2019 SECTION 3 RESPONSIBLE OPERATIONS