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 A7. PROJECT ECONOMIC RANKING AND SCORING Project Economic Scoring Capital Cost Option Capital Cost Ranking Score Comments 1 1= 5 Requires initial development for Storage 3 and GOP TSFs and NRS 2 1= 5 Requires initial development for Storage 3 TSF and NRS and liner for GOP Lake. 3 6 0 Infrastructure for filered tailings is expensive and this option also requires initial development for Storage 3 and NRS. Requires larger drains and ponds to manage surface water than slurry TSF option. 4 3 3 High capital cost because Storage 2 needs to be raised to RL160.7 before any additional tailings storage is provided and existing infrastructure needs relocating. 5 4= 1.5 Paste plant and associated pumps/pipe infrastructure expensive and also requires NRS initial development 6 4= 1.5 Paste plant and associated pumps/pipe infrastructure expensive and also requires NRS initial development Operating Cost Option Operating Cost Ranking Score Comments 1 2 5 Similar to Option 2, but lower cost as less rock needs to be transported to Storage 3 which is longer haul and more expensive than to NRS. Tailings pumping costs less than Option 2 because less tailings are pumped to Storage 3. 2 3 3 Similar to Option 1, but has higher operating cost (see comments for Option1) 3 4 3 High operating cost for dry stack tailings 4 1 5 Close proximity to conveyor and short haul for rock to Storage 2 TSF and NRS. Small quantity of rock to raise Storage 2 above RL160.7. Storage 2 TSF in close proximity to Plant for tailings disposal 5 5= 0 High operating cost for paste 6 5= 0 High operating cost for paste Closure Cost Option Closure Cost Ranking Score Comments 1 4= 1.5 Requires capping of GOP TSF and partial capping of Storage 3 TSF. Capping of NRS is progressive during operation but NRS is almost depleted at end of project. Associated infrastructure (perimeter road drain and seepage collection system) could be removed to return land back to original state. 2 2= 4 Low cost because GOP Lake has minimal closure cost. Capping of NRS is progressive during operation but NRS is almost depleted at end of project. Associated infrastructure (perimeter road drain and seepage collection system) could be removed to return land back to original state. 3 4= 1.5 Requires capping of GOP TSF. Capping of Storage 3 TSF is progressive during operation. NRS has low closure cost as capping is progressive during operation. 4 2= 4 Low cost because GOP Lake has minimal closure cost, NRS has low closure cost as cap layer completed during operation and Storage 3 TSF only requires partial capping 5 6 0 Reinstatement of Gladstone Hill requires large quantity of rock to be transported from stockpile with large cost. NRS will need recapping after material removed for reinstating Gladstone Hill. 6 1 5 Low closure cost as Storage 1A and 2 and NRS will be capped progressively during operation.
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