Feasibility Study and Technical Report - Pretivm

frequent basis, but they will be larger avalanches. Both low-frequency large avalanchesand higher-frequency small avalanches may affect a road crossing that is higher up in theavalanche path.18.6.2 BRUCEJACK AVALANCHE HAZARDAvalanche paths and hazard areas that affect the Project were identified by reviewingtopographic relief and vegetation features on maps and aerial photos, as well asavailable Google Earth ortho-imagery and digital elevation models (DEM). In addition,field reconnaissance (helicopter overview flights and ground based survey) wascompleted on March 19, 2012, and from April 28 to 29, 2013.Approximately 15 avalanche paths or hazard areas reach (or potentially reach) projectinfrastructure or access roads, and many locations are estimated to be affected on anannual basis. Drawings for the avalanche paths and hazard areas are illustrated in theAlpine Solutions technical report entitled “Brucejack Project Avalanche HazardAssessment” (Alpine Solutions 2013). Avalanche paths are labelled according to Table18.2, referring to the element at risk, with the exception of paths along the KnippleGlacier, which may affect both the transmission line and access road.Table 18.4Avalanche Path or Area Label and Corresponding Element at RiskAvalanche Pathor Area LabelTL1, TL2, …, TLxAR1, AR2, …, ARxMS1, MS2, …, MSxKG1, KG2, …, KGxMain Facility at RiskPreferred transmission line alignmentAccess road and Knipple Transfer StationFacilities at or near the mine siteAccess road and transmission line corridor on glacierDetails of avalanche hazards and potential consequences are outlined in the followingsections for the mine site, access road, Knipple Transfer Station, and transmission line.MINE SITEThe mine site is located on a broad alpine plateau in undulating terrain on the southwestside of Brucejack Lake. The area is bounded by the Knipple Glacier to the east andsouth, the Sulphurets Glacier to the west, and rising alpine slopes to the north. Elevationof avalanche terrain at the mine site area ranges from 1,350 m to over 2,000 m. Theproposed facilities assessed in the mine site area near Brucejack Lake include:• two explosives and storage facilities – preliminary position• detonator storage – preliminary position• topsoil stockpile• substation• water treatment plantPretium Resources Inc. 18-16 1291990200-REP-R0012-02Feasibility Study and Technical Report on the BrucejackProject, Stewart, BC