WASTE ROCK In FY18, the Nova Operation generated 748,808t of waste rock, with the majority of this material placed on the recently approved waste rock dump, adjacent to the underground portal. The remainder was placed around the tailings dam consistent with final closure design. The decision to develop the Bollinger deposit concurrent to the Nova deposit generated additional waste rock and necessitated a permanent storage facility. Nova continues to optimise waste generation and placement in its underground mine. Potentially acid forming waste rock is preferentially used underground as backfill and non-acid forming material is strategically placed at the storage facility to ensure it is available for rehabilitation purposes. During FY18, the Tropicana Operation produced 76.54Mt of waste rock. At the Long Operation, waste rock generation declined with reduced mining activity, with 22,712t brought to the surface in FY18. A detailed material balance was completed in the reporting period to identify waste rock requirements for closure. IGO is engaging with BHP Nickel West to discuss their potential use of our surplus rock for their own closure activities. A total of 163,269t of waste rock was mined from the Jaguar Operation’s Bentley Mine in FY18. Waste rock is brought to the surface, with potentially acid forming (PAF) material preferentially selected for aggregate production that is used underground to stabilise disused mining voids. As the majority of waste rock is non acid-forming this creates a neutralising environment for any PAF waste. Annual photo- monitoring records vegetation health surrounding the waste rock dumps to detect the presence or absence of acid mine drainage. TAILINGS The management of IGO’s TSFs is a top priority and all our facilities undergo an annual audit to ensure they are operated in accordance with the mine’s operating strategy, safety conditions, prescribed premises conditions, and mining tenement conditions. In addition to the annual audit process, IGO undertakes a periodic group tailings dam risk review, involving an internationally recognised specialist consultancy, Klohn Crippen Berger (KCB). This was last completed in FY17. In FY18, there were no uncontrolled releases from any waste facility, nor were there any material fauna losses associated with these facilities. Tailings generation increased at the Nova Operation, with the mine operating at design capacity for the majority of FY18. The total amount of dry tailings deposited was 1,235,478t. The Tropicana Operation has a single-cell tailing storage facility where all tailings from the Tropicana processing plant are deposited. In FY18, Tropicana deposited 7.63Mt of dry tailings into its storage facility. The Long Operation uses tailings from St Ives Gold Mine to produce a paste backfill material that is used to re-fill mined underground voids. In FY18, Long Operation used 40,097t of dry tailings to produce 60,229t of paste; a decrease from the 69,859t of tailings used in FY17. The Jaguar processing plant produced 391,874t of dry tailings that were deposited into TSF2 in FY18. As required by tenement conditions, both the disused TSF1 and the operational TSF2 were inspected and a qualified engineer produced an audit report. During FY18, recommendations for both tailing storage facilities relating to preventative maintenance measures were undertaken. IGO undertakes recycling programs at all our sites, with a focus on steel, hydrocarbons and cardboard. IGO SUSTAINABILITY REPORT 2018— 77