WESTERN AUSTRALIA PERTH FIGURE 11 LONG OPERATION (NI) IGO 100% MINING METHOD Underground – stoping FY18 PRODUCTION Ni in ore – 5,855t Cu in ore – 394t AREA DISTURBED 101ha AREA REHABILITATED 4ha WORKFORCE 50% FIFO 50% DIDO NATIVE TITLE Ngadju REMAINING MINE LIFE Care and Maintenance LONG OPERATION The Long Operation, approximately 3km east of Kambalda and 50km south-east of Kalgoorlie, is situated on the shores of Lake Lefroy. The Long Operation is comprised of both freehold land and mining leases. The area has long been disturbed by mining and mineral processing activities with BHP Nickel West’s Operation to the north, west and south, Mincor Resources to the north, and Gold Fields’ St Ives Gold Mine further south. Mining ceased at the Long Operation in June 2018, after 16 years of operation by IGO, and the site has been placed into care and maintenance while we consider its future. A comprehensive plan to prepare the site was implemented before operations ceased, including a site inspection and risk assessment to prioritise activities and minimise environmental impacts. Along with engaging and supporting employees who faced redundancy (see case study on page 55), IGO also initiated a site-wide clean-up program and mobilised a contractor to undertake rehabilitation of historical mining landforms. These included the run of mine (ROM) pads, two historic tailings storage facilities and portions of the waste rock dump. These works are still ongoing at the time of publication. A local contractor has been appointed to manage the site during the care and maintenance. They will undertake ongoing dewatering of the underground mine and regular maintenance of key infrastructure to ensure it remains in operating condition. CONSUMABLES The main consumables (in order of dollar value) at Long Operation in FY18 were electricity, water, backfill (tailings), shotcrete and explosives. The Long Operation sources electricity from BHP, which generates electricity from Trans Alta gas turbines located at BHP’s adjacent concentrator facility. Recovered groundwater was used in the backfill manufacturing process and the remainder was, and will continue to be, discharged (subject to licence conditions) onto the saltpan of Lake Lefroy. During care and maintenance, electricity will remain the largest consumable with power still being used to operate the dewatering pumps and ventilation fans. WASTE The relatively small mass of extracted waste rock was placed in a single waste rock dump. The majority of this material is classified as non-acid forming. During FY18, the Long Operation undertook a detailed material balance to quantify the amount of rock needed to complete closure activities. The site has a surplus of rock that will be made available to BHP Nickel West to assist them with their future closure activities. During FY18, the Long Operation successfully applied for approval to construct an on-site landfill for mine closure purposes. This will significantly reduce the cost of waste disposal during closure. 40 — IGO SUSTAINABILITY REPORT 2018