INDEPENDENCE GROUP NL SUSTAINABILITY REPORT 2018

TROPICANA OPERATION In FY18, a total of 5.5GL of water was abstracted from groundwater bores at Tropicana. Groundwater monitoring is completed to measure the effect (if any) that abstraction is having on the surrounding water table, including water levels and water chemistry. The standing water levels in FY18 were generally stable, although there were some exceptions which saw significant decreases in standing water level likely due to increased abstraction rates. No significant change in water quality was observed. Tropicana’s TSF is unlined and has an associated groundwater mound. Consequently, Tropicana 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 Tropicana to determine the effectiveness of the site's surface water management infrastructure. Results indicated that surface water management on site was effective. LONG OPERATION A total of 272ML was abstracted from groundwater sources and mine dewatering in FY18. Long generates a surplus of hyper-saline water which, following time in settling dams to remove sediment, is then discharged onto the salt pan of Lake Lefroy. Flow meters are used to accurately measure water use and discharge volumes to ensure compliance with licence conditions. A small percentage of the groundwater is extracted as water vapour and mist from underground by the mines ventilation fans. This aerosolised water is hypersaline and is toxic to plants, posing a threat to surrounding vegetation. To minimise the impact on local vegetation, vent fans have been redesigned to minimise the emission of the hypersaline mist. In FY19, a variable speed drive will be installed to further reduce the generation of mist. JAGUAR OPERATION Groundwater, sourced from production bores and the underground mine, accounts for all water consumption at the Jaguar Operation. In FY18, a total of 1.1GL was abstracted. Excess water is discharged into the historic Teutonic Bore pit. Of particular focus is the Operation’s effect on the water table and water quality within the surrounding pastoral leases. Water monitoring includes chemical analysis. No material changes to water chemistry nor water levels have been recorded at any of the pastoral bores to date with one exception. In previous years, a reduction in water levels was measured at the Wendy’s Borefield. Studies conducted in FY17 and FY18 indicate that there was no impact to surface vegetation nor the pastoralist's ability to access good quality water for stock. IGO SUSTAINABILITY REPORT 2018— 79