Our Ref: 9215 23 June 2022 This report shall only be read in its entirety. File: WAI-985-000-REP-LC-0002_Rev0.docx TABLE A2. SCORING FOR OPTION 2 Option 2: Maximise Storage 3 Tailings Slurry TSF to RL160 and GOP Lake Category Subcategory Category Weighting Subcategory Weighting Score Weighted score Category Score Final Score Comments Technical Future ore resource 0.25 0.1 3 0.3 Storage 3 will not impact future ore resources. Small risk that GOP TSF may affect future underground mining. Geotechnical 0.15 5 0.75 Storage 3 and Northern Rock Stack sites have some weak material in foundations but it will be removed. Geochemistry 0.15 5 0.75 Storage 3 and Northern Rock Stack will have controls for potential geochemistry effects that have been effective to date and have been adopted and proven to work at other projects. GOP is a lake and so will not store tailings, but has partial backfill with some PAF rock as for GOP TSF. Constructability 0.1 5 0.5 Experience with existing TSFs indicates that they can be constructed to meet Specifications. Similar materials will be used for Storage 3 and the NRS. Operability 0.1 5 0.5 Storage 3 and GOP TSF can be operated in all conditions and without interference from other site functions. Assumes haul road from Northern stockpile to GOP TSF will be independent of existing access road/bridge to Process Plant. Storage capacity and expansion potential 0.15 5 0.75 Storage 3 can be expanded, but not to the same extent as with Option 1. Project schedule 0.25 5 1.25 Assessment indicates project scheduling requirements can be met. 4.8 1.2 Environmental Terrestrial ecosystem 0.25 0.2 3 0.6 Some short term impact on on-site terrestrial ecosystem associated with construction and operation of Storage 3 TSF and NRS. Biodiversity associated with closure plan would provide long-term mitigation. Aquatic ecosystem 0.2 3 0.6 Minor impact on aquatic ecosystem No known historical impact Groundwater 0.15 5 0.75 Potential groundwater impacts expected to be controlled with proposed design for facilities and considering performance of existing facilities Surface water 0.15 5 0.75 Potential surface water impacts expected to be controlled with proposed design for facilities and considering performance of existing facilities Impact on SNA 0.1 3 0.3 Storage 3 has small impact on SNA Dust 0.1 5 0.5 Control measures required and operating history indicates that air discharge standards will be met. Noise 0.1 3 0.3 Storage 3 is new TSF, located closer to some rural properties east of the Development Site. Expect minor noise effects, but no operating history at this location. 3.8 0.95 Socio-economic and permitting Social impact 0.25 0.15 5 0.75 Low social impact Mana Whenua 0.25 0 0 Consultation undertaken, but Mana Whenua prefer backfilling of GOP TSF to recreate maunga rather than use as a TSF. Economic 0.1 5 0.5 Project has considerable economic benefit to community and other parties Recreation 0.1 5 0.5 No impact on recreational users Regulatory approval 0.2 0 0 Backfill of GOP with water may not get regulatory approval Archaeological/heritage 0.1 5 0.5 Some remnants of historical mining activities at GOP TSF, but not significant Landscape and visual 0.1 3 0.3 Some visual impact from construction of Storage 3 and Northern Rock Stack, but rehabilitation provides long-term mitigation 2.55 0.6375 Project Economics Land ownership 0.25 0.1 5 0.5 OGNZL owns all the land required Capital cost 0.35 5 1.75 Ranks in top third Operating cost 0.35 3 1.05 Ranks in middle third Closure and post-closure cost 0.2 4 0.8 Ranks 2nd = and score reflects this 4.1 1.025 TOTAL WEIGHTED SCORE: 3.813
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