Feasibility Study and Technical Report - Pretivm

• reporting and feedback mechanisms.20.1.7 WATER MANAGEMENTGENERALWater management will be a critical component of the Project design in this high runoffenvironment. The most likely avenue for transport of contaminants into the naturalenvironment will be through surface or groundwater. As such, through its consultants,Pretivm has developed a water management plan that applies to all mining activitiesundertaken during all phases of the Project. The goals of this management plan will beto:• provide a basis for management of freshwater on site, especially with thechanges to flow pathways and drainage areas• protect ecologically sensitive sites and resources, and avoid harmful impacts onfish and wildlife habitat• provide and retain water for mine operations• define required environmental control structures• manage water to ensure that any discharges are in compliance with theapplicable water quality levels and guidelines.Strategies for water management include:• protecting disturbed areas from water erosion, and collecting surface water fromdisturbed areas and treating it to meet discharge standards prior to release• minimizing the use of fresh water through recycling of water whenever possible• monitoring the composition of release water and treating it to remove or controlcontaminants as required to meet discharge standards• constructing diversion channels to direct undisturbed runoff away from miningactivities.WATER MANAGEMENT OVERVIEWThe Brucejack deposit, located west of Brucejack Lake on the east side of the SulphuretsValley, is proposed to have an underground mine and associated facilities. Theunderground facility will be mined over a 22-year period. As mining progresses, 2.4 Mt ofwaste rock that was excavated from the underground mine prior to operations andapproximately 2.2 Mt of blasted rock from plant site excavations during construction willbe deposited into Brucejack Lake, along with 9.5 Mt of flotation tailings duringoperations. An additional 8.6 Mt of tailings paste backfill and 2.0 Mt of waste rock will bedeposited in the underground mine during operations. Of the total processedmineralized material, 8% (approximately 1.6 Mt) will be trucked to an off-site facility asconcentrate for secondary processing.Pretium Resources Inc. 20-16 1291990200-REP-R0012-02Feasibility Study and Technical Report on the BrucejackProject, Stewart, BC