Feasibility Study and Technical Report - Pretivm

Figure 18.5Access Road Avalanche HazardsOne area (Path AR8) is affected by ice fall (blocks falling off bluffs above the road).Several avalanche paths on the southwest and northeast side of the Knipple Glaciercould affect the road if it is realigned to avoid crevasses. Potential consequences ofavalanches reaching the access road include damage to vehicles, occupant injury orfatality, and traffic delays for avalanche debris clean up. Avalanche path characteristicsfor the Knipple Glacier segment are expected to change as the glacier changes over time,so this segment will be re-assessed regularly.Areas within Paths AR4, AR8, and KG1 have increased hazard and consequences due tothe high frequency of avalanches and ice falls reaching the affected areas, as well asmagnitudes large enough to severely damage vehicles, injure occupants, and delay theflow of traffic during storms, when avalanche control is not feasible.KNIPPLE TRANSFER STATIONThe Knipple Transfer Station is located at the valley bottom near the confluence of theSalmon and Knipple valleys. Extreme avalanches to Size 4 occurring in Path AR7 (Table18.6) are estimated to reach the west end (approximately 20%) of the Knipple TransferStation pad with an estimated return period of at least 100 years. Avalanches are notexpected to reach the eastern side of the Knipple Transfer Station pad where primaryfixed facilities (camp) are located. Potential consequences of avalanches reaching thesite include damage to infrastructure, and injury or fatality for any personnel located inthe runout area.Pretium Resources Inc. 18-21 1291990200-REP-R0012-02Feasibility Study and Technical Report on the BrucejackProject, Stewart, BC