Feasibility Study and Technical Report - Pretivm

26.5.8 WATER MANAGEMENT PLANWater management is considered to be a critical component of the Project design in thishigh precipitation environment. BGC makes the following recommendations for watermanagement at the next level of design:• Existing climate and hydrometric stations must continue to be monitored andmaintained with an appropriate level of quality control. The data from theclimate and hydrometric stations near Brucejack Lake should be reviewedduring the next stage of engineering design to confirm assumptions being usedfor precipitation and runoff.• The storage volume and pump requirements for the contact water pond shouldbe re-visited during detailed design.• Mitigations to address potential TSS exceedance during lake turnover need tobe investigated in more detail.• The water balance models and water management strategy need to be refinedto account for staging of the various mine facilities. This work should includeprobabilistic water balance modeling for the EIA process.The estimated cost for the above-mentioned recommended work is $100,000.26.5.9 MILL SITE LAYOUTTetra Tech recommends completing a trade-off study to assess potential cost savings inreduced earth-work by relocating the mill building further north and raising the padelevation. Information required to complete the trade-off study include:• additional geotechnical drilling and test pit excavations to further evaluatesubsurface conditions within the relocated mill building footprint• coordination with mining to review re-alignment of the portals.26.5.10 CONSTRUCTION CAMP CAPACITYThe estimated construction camp capacity is currently 450 beds. Tetra Techrecommends reviewing the construction manpower requirements in more detail todetermine if there is an opportunity to reduce the required capacity during construction.26.6 ENVIRONMENTALRescan recommends additional work to further develop the Project. This work includes:• Further water quality modelling of Brucejack Lake to provide direction on closureand post-closure monitoring and mitigation requirements (estimated cost at$50,000).Pretium Resources Inc. 26-10 1291990200-REP-R0012-02Feasibility Study and Technical Report on the BrucejackProject, Stewart, BC