EGL Ref: 9215 23 June 2022 Page 4 This report shall only be read in its entirety. File: WAI-985-000-REP-LC-0002_Rev0.docx. FIGURE 3: AERIAL PHOTO OF STORAGE 2 (LEFT) AND STORAGE 1A (RIGHT) WHICH CURRENTLY STORE THE TAILINGS AT THE WAIHI OPERATION The existing TSFs approximately 3 km south-east of the Waihi Township are connected to the Martha Open Pit by a conveyor indicated on Figure 1, which transports rock and soil between the two areas without truck movements. At Martha Open Pit a crusher breaks the rock down before being placed on the conveyor. Material can be offloaded at the Process Plant or at the Loadout which is located up at the level of the crest of Storage 2. This provides an effective location to then transport the earth and rock fill to the TSFs or stockpile via haul routes on or behind the TSFs. Both existing TSFs are formed by construction of ‘U shaped’ embankments which abut the naturally rising land to the northeast, to form the impoundments which store the tailings. The embankments provide the disposal location for rock from the pits. Storage 2 was constructed first, starting in 1987, followed by Storage 1A with preliminary works starting in 1998 and first tailings discharge in 2001. Since May 2001, virtually all tailings produced on site have been disposed into Storage 1A. Between 2001 and 2005 a small amount of tailings were deposited within Storage 2 and since July 2005 no tailings have been deposited in Storage 2. Storage 2 has been successfully rehabilitated and water in the pond of Storage 2 is now clean and able to be discharged direct to the Ohinemuri River. Raising of Storage 2 to RL160.7 is within the consented Life of Mine (LOM) works and will see the embankment crest raised up to 4.7m above its current level. Tailings deposition will resume into Storage 2 and supernatant water in the tailings pond will be pumped back to the Water Treatment Plant for processing before discharge to the Ohinemuri River. Following completion of tailings discharge Storage 2 will again be rehabilitated so the water is clean for discharge direct to the Ohinemuri River. Storage 1A has a crest level of RL173.6 as of March 2021 and it is consented for raising to RL182 to provide storage for the resource associated with the Martha Underground and MOP4.
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