Supporting Technical Assessments

Rory McNeill Reference No. 20148384_7407-012-LR-RevA_DRAFT OceanaGold Corporation 08 September 2021 2 2.0 ALIGNMENT OPTIONS OceanaGold has provided Golder with five tunnel alignment options for the Portal to Willows Connection (refer Figure 1). An additional tunnel alignment option was provided from Northern Portal to Willows Connection; however, it is Golder’s understanding that this option is not being investigation further. Each of the five provided plan tunnel alignments have a shallow or deep option for vertical alignment. Each alignment option takes into consideration the surface landholders, geotechnical conditions, interaction with MUG/GOP works, interaction with old workings and LOM material handling. The five options are outlined below:  Option 1 is a straight-line tunnel from Portal to Willows Connection, approximately 4.8 km in length. Option 1 does not consider any other planned infrastructure in the area and passes beneath several residential properties at depths of 40 – 85 m. OceanaGold has determined that Option 1 is unlikely to be considered viable due to the large number of potentially affected land owners.  Options 2, 3 and 4 tunnel alignments, which are each approximately 5.0 km in length, take into consideration planned MUG Portal development, Favona capital development, utilise existing surface air shafts and pass beneath OceanaGold land to avoid a number of residential properties.  Option 5 heads north-east initially to utilise OceanaGold owned land before heading towards Willows Connection. The alignment is estimated to be 5.3 km and passes beneath the Ohinemuri River on numerous occasions and runs parallel with the river for approximately 250 m; therefore, OceanaGold has determined that this option is unlikely to be viable. Figure 1: Proposed tunnel alignment options between Waihi and Willows Connection (supplied by OceanaGold). D R A F T

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