2006 Project Alternatives Pit and Dike Risk Evaluation MEADOWBANK GOLD PROJECT

2006 Failure Mode ConsequenceMonitoring/Action Overtopping Water spill into pitDike Freeboard, Lake outflow channels inspected Internal Erosion Till core progressive erosion by void or defect in construct with minor to major toe seepage Regular walk-over inspections Remedial action reverse filter and rockfill buttress Seepage within Foundation Failure by pore pressure induced instability.Observed during initial dewatering or very shortly thereafter. Heightened inspection frequency during dewatering and first year Piezometer monitoring, expected to draw down phreatic surface as open pit deepens Slope Instability Foundation failure would cause a rotational slip in the wide rockfill shell Earthquake loading for this site is a low, limited dike displacements expected Mechanism in foundation soils expected to develop slowly Monitor for settlement and cracks in the dike crest. Walk-over inspection. Unexpected Settlements Could lead to water flowing over rockfill shells.Freeboard and No enhanced monitoring required, as excessive settlement would be apparent from the seepage. Pit Slope Failure Involving Pt slope and Dike Localized to Pit Slope Minimum set back distance for Dike toe to Pit wall Localized pit stability monitored by prisms during mining operations. Potential Risks, Mitigation, and Monitoring Pits and Dikes MEADOWBANK GOLD PROJECT

2006 Potential Risks, Mitigation, and Monitoring Pits and Dikes – Goose Island Section MEADOWBANK GOLD PROJECT

2006 Project Alternatives Other Issues MEADOWBANK GOLD PROJECT

2006  Disposal to pits – Cleaned and stripped of potential pollutants  Disposal in landfill area – Decontaminated items that could not be cleaned sufficiently for disposal in pits  Disposal off-site/returned to supplier – Chemicals, batteries, insulation  Develop Operations/Maintenance Manual for operation of landfill site Disposal of Non-Salvageable Items MEADOWBANK GOLD PROJECT