Independence Group Sustainability Report 2019

Water management The increasing pressure on global freshwater resources is a well recognised concern for many stakeholders. Water is an important resource for IGO’s mining activities. We use water in all parts of our business, including exploration drilling, the mining process, ore processing, dust suppression, and for drinking and domestic use in our accommodation camps. The location of the Nova Operation is remote to any public water infrastructure, which means we need to rely on available groundwater. The Great Western Woodland (GWW) surrounding the Nova Operation is characterised by low relief paleo drainage systems, with no defined rivers, and several ephemeral creeks and watercourses. Salt lakes are relatively common across the GWW. Groundwater is typically in aquifers close to the surface, recharging by direct rainfall infiltration. Groundwater is typically saline to hypersaline. There are no competing users of the water resource in the vicinity of the Nova Operation with the nearest other users being pastoralists approximately 25km from the mine. The ongoing responsible management of water is key to the sustainability of our operations. At the Nova Operation, water is supplied from groundwater bores and water is recovered from the underground mine, which sits below the groundwater table. In Western Australia, water abstraction is subject to a licence issued by the Department of Water and Environmental Regulation. Each licence states our annual water entitlement and conditions to ensure we appropriately manage abstraction over the life of our mining activities. To meet these requirements, abstraction volumes and groundwater levels are monitored. We systematically track and map our plant water usage. It is standard practice across IGO operations to maximise the volume of water recycled. Unintended safety and environmental impacts can result from both poorly managed groundwater abstraction and the uncontrolled release of contaminated water, particularly where salinity or contaminant levels are elevated. Water releases from mining operations can take various forms including stormwater discharge, process and mine dewatering discharges, water delivery line breakages, and seepage from storage facilities such as dams and tailings storage facilities. IGO has established processes for water management and the management of water-related risk at the Nova Operation. However, it is noted that the Nova Operation is yet to develop an accurate all-of-site water balance, which we expect to complete in FY20. Based on available science, the woodlands surrounding the mine are not dependent on tapping into the saline aquifers utilised by the mine. We complete annual vegetation impact assessments to determine if our abstraction is causing tree stress or deaths. Similarly, we monitor groundwater levels to check for changes in groundwater levels and chemistry. Unlike unlined tailings storage facilities (TSF), which typically have associated groundwater mounds beneath and around them, the fully plastic-lined tailings storage facility at the Nova Operation has no associated groundwater mound. To date, vegetation monitoring indicates that neither groundwater drawdown nor mounding has had an impact on the overlying forest. Further, as the groundwater is hypersaline, it is likely that few higher organisms, if any, are dependent on groundwater as a water source. Wastewater is managed by a recycled water scheme with the approval of the Western Australian Department of Health. A wastewater treatment plant has been installed to recycle all grey and black water produced by the accommodation camp, power plant, paste plant and other non-processing infrastructure on site. The treatment process enables this water to be reused on site for dust suppression and effluent irrigation. Since commissioning, a majority of the recycled water has been directed to the licensed effluent irrigation area or stored in the TSF for further use. The Nova Operation has an ongoing challenge to achieve the efficient disposal of the bio-solids produced by our sewage treatment plant. At present, these solids are trucked to Esperance for landfill disposal. During FY19 we continued to work through options for a permanent and local disposal solution. In FY19, at the Nova Operation we consumed 1,733.4ML of water. Total water consumption at the Nova Operation decreased in FY19, attributed to new initiatives being employed to reduce groundwater consumption such as by converting the paste plant to recycled tailings storage water. We can confirm that we operated in accordance with our licence conditions. During FY19, IGO had no significant material spills or unapproved discharges from our operations. At the Tropicana Operation, 6,310.8ML of water was withdrawn from groundwater bores. Groundwater monitoring is completed to measure any effect that abstraction is having on the surrounding water table, including water levels and water chemistry. The standing water levels in FY19 were generally stable, although there were some exceptions which saw IGO SUSTAINABILITY REPORT 2019 — 43