Contonga, a 990 tpd underground Zinc mine located in Perú’s Ancash Region, has been in operation for more than 25 years. Tierra Group team members assisted Nyrstar’s acquisition due diligence team by performing a fatal flaw analysis of Contonga’s Tucush Tailings Storage Facility (TSF) in 2009. Following the acquisition, Tierra Group’s team developed a modification plan to the 40-m high cyclone tailings dam to meet regulatory requirements and to allow the mine to continue operating. Two subsequent dam raise designs have been developed, which will allow Contoga Mine to continue operating through 2015, at which time a new TSF will be required. In anticipation of Tucush’s closure, Tierra Group has initiated a siting study to identify a new TSF location, and conceptual closure and reclamation planning has begun. Tierra Group’s current contracted work includes expansion design for the Tucush TSF, providing operations support, and designing a foundation for a new crusher.