Robinson Mine Tailings Impoundment Audit

Prior to joining Tierra Group, our Team completed a third-party tailings impoundment audit. The audit included reviewing operational procedures, monitoring, design, and future tailings storage planning. Produced an audit report for company’s internal use. (Tetra Tech, 2008)

Trade-off Studies

Tierra Group completed a trade-off study to evaluate raising the existing Tailings Storage Facility (TSF) or building a new TSF. An Alternatives Decision Matrix (ADM) was developed using weighted qualitative and quantitative parameters to evaluate the two options. A site visit was conducted to understand operational practices and challenges informing ADM development. Tierra Group worked collaboratively with the tailings operations and environmental teams ensuring TSF expansion option evaluations included institutional knowledge from “boots on the ground” team members.

2022 TSF Expansion Design Review

Tierra Group reviewed a TSF expansion design prepared by others. The third-party review aims to ensure conformance with the Nevada Division of Water Resources (NDWR) and Nevada Division of Environmental Protection (NDEP) regulations and industry best practices for tailings dam design. The design included a centerline raise of an existing cyclone sand embankment, raises to existing earthen embankments, and expansion of a geosynthetic-lined water retention area (Barge Operating Channel).