B-3 – Area 3 - Assessment of Environmental Effects 19 Development of the Wharekirauponga Access Tunnel will take place over approximately 16 months. The tunnel development cycle consists of scaling and rock bolting, rebogging (clean-up), face drilling, charging, firing and finally bogging in preparation for the start of the next cycle. These activities are performed with standard underground mining equipment. The development cycle timeframe for the Wharekirauponga Access Tunnel will be approximately 12 hours. Any development ore intercepted during construction of the northern extent of the tunnel will be stockpiled in the Willows Rock Stack for later transport to the Processing Plant. Any development ore intercepted during construction of the southern extent of the tunnel will be transported directly to the Run of Mine stockpile. 3.4 FORWARD DRILLING PROGRAM As construction of the tunnels advances drilling may be required ahead of the development face. Retrieved drill cores will be oriented, boxed, and subjected to geological and geotechnical logging and analysis. The forward drilling will provide geotechnical and hydrogeological information for ground several hundred metres ahead of tunnelling to inform geotechnical and water management requirements for the corresponding length of tunnel. 3.5 WATER MANAGEMENT Water encountered during tunnel construction or mining operations will drain to sumps. Water not recycled for drilling purposes will be pumped via the mine services to the WTP for treatment and discharge. Engineering controls, including sealing and grouting tunnels and shafts during development with grout or shotcrete, may be required to manage water ingress.
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