The Yauricocha mine is a polymetallic (copper, lead, zinc) underground mine located in Yauyos Province, Lima, Peru. Tailings are deposited in the Yauricocha Tailings Storage Facility (TSF) located 3km from the process plant. Tierra Group was engaged in 2015 to serve as the engineer of record (EoR), and provided construction quality assurance (CQA) support for the Yauricocha TSF during construction of the Phase 4 dam raise. Tierra Group also reviewed dam raise alternatives in preparation of future dam raises.