EGL Ref: 9018 22 June 2022 Page 2 WAI-985-000-REP-LC-0006_Rev0.docx This report shall only be read in its entirety. Above the Northern Uphill Diversion Drain, a cut and fill platform will be created for a magazine (explosives storage) (Drawing 0715). This will require the relocation of the existing staff facilities adjacent to the loadout as they are in the blast zone. The new staff facilities will be located adjacent to the newly relocated Development Site Workshop. A new collection pond called NRS Collection Pond is required (Drawings 0715, 0761). A new perimeter drain (NRS Perimeter Drain) at the toe of the stockpile will collect and direct surface runoff to the NRS Collection Pond. Stockpiles for rehabilitation material are also required beyond the footprint of the NRS (Drawing 0715). The northern rehabilitation stockpiles are positioned adjacent to Golden Valley Road. This location of stockpiles also provides some benefit as a noise screen. 2.0 BACKGROUND AND CURRENT SITE FACILITIES 2.1. Location and existing stockpiles The existing Waihi gold mining operation operated by OGNZL is centred in and around the Waihi Township (Figure 1) and includes Martha Open Pit, and a series of underground mines including Trio Underground Mine, Favona Underground Mine, Correnso Underground Mine, and Martha Underground Mine (MUG). Martha Open Pit is located within the Waihi Township and the underground mines are located to the east and southeast of the pit at depth. Three main stockpiles: Northern, Central, and East Stockpiles are located on the Development Site which is located adjacent and east of the Ohinemuri River and north of the Ruahorehore Stream (Figure 2 and Figure 3). The Development Site is connected to the Martha Open Pit by a belt conveyor (Figure 2). A crusher located at Martha Open Pit crushes the rock before loading the material on to the conveyor belt. The operation includes the Processing Plant and a Water Treatment Plant. They are located to the southeast of the Waihi Township, adjacent and west of the Ohinemuri River (Figure 2). Any ore from Martha Open Pit is loaded off the existing conveyor at the ore Processing Plant. Adjacent to the Water Treatment Plant is the Polishing Pond Stockpile, which is used for the temporary stockpiling of ore or run of mine material. Overburden material from Martha Open Pit is conveyed past the Processing Plant to the Development Site. Lime is added to PAF material on the conveyor belt, ready to be placed in the TSF embankment or stockpiles. 2.2. Construction and operation In the late 1980s open pit mining of Martha Hill commenced. Open pit mining created a source of earth and rock fill (overburden) material to construct downstream embankment dams to store the tailings behind. The overburden material from open pit mining is a valuable resource for building TSF embankments and backfilling of underground operations. However, working stockpiles are required for temporary stockpiling and long-term storage of overburden materials. Construction of the initial TSF, Storage 2, in 1987 required a Northern Stockpile and a Southern Stockpile to manage materials delivered to the Development Site from Martha Open Pit. Both stockpiles were located against the Storage 2 embankments, to
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