Tierra Group implemented a corporate Tailings Stewardship Strategy (TSS) at all of ASARCO Grupo Mexico’s mines in Arizona, USA (Hayden, Mission and Ray mines). Tierra Group conducted a site visit to each site to perform dam safety inspections, interview operations staff, and review each operations’ TSF for conformance with design, construction, operations, and closure Best Management Practices (BMPs). Tierra Group also developed a Operating, Maintenance and Surveillance Manual for Hayden Operations.