
Tierra Group proporcionó una revisión por terceros del diseño de depósito de relaves y una revisión de las actividades de construcción de las etapas 1 y 2 al proyecto Hermosa en Patagonia, Arizona.
Tierra Group provided engineering and permitting support to Douglas County Public Works Engineering for NPDES Phase II Program compliance. Tierra Group’s scope of work included developing Runoff Control Plans (RCPs) for new County facilities, updating RCPs at existing County facilities,…
Sweetwater Mine Permitting Tierra Group’s Team began work at the Sweetwater mine in 1993 assisting permitting and developing tailings impoundment management strategies for the mine. We successfully designed and installed an innovative internal seal for repair of the mine’s damaged…
Hollister Waste Rock Facility Storage Tierra Group performed a third-party peer review of a Waste Rock Storage Facility (WRSF) design at Klondex Mines’ (Klondex) Hollister Mine in northern Nevada. The WRSF, as designed, involved lining the mine’s existing West Pit…
Tierra Group conducted a geotechnical investigation program to provide data for pit slope design. Tierra Group provided field support through oriented core logging, pit wall mapping, selected samples for laboratory testing, and provided pit slope design recommendations for safe open…
Dry Stack Tailings Storage Facility Tierra Group designed a dry stack TSF to store excess tailings from the underground paste backfill. The dry stack TSF was challenging, given the limited land area, steep terrain, seasonal cold weather, and surface water…
Lode-Star Gold, Inc., in advance of their proposed mining operations, submited a Physical Separation Facility application with the State of Nevada for their Goldfield Bonanza Project located in Esmeralda County, Nevada. The mine, located in the historic high-grade gold-bearing district of…
Tierra Group updated the County’s Standard Operating Procedures (SOPs) for Municipal Operations to maintain the County’s compliance with the requirements for stormwater discharges from the County’s municipal separate storm sewer system (MS4) under the Colorado Discharge Permit System (CDPS). Tierra…
Sterling Mine is an underground gold mine in southern Nevada which recovers gold through heap leaching and a carbon adsorption-desorption-recovery (ADR) plant. Tierra Group team members have a long history at Sterling, starting with heap leach pad final permanent closure…
Tierra Group performed a technical peer review of the Isabella Pearl heap leach facility (HLF) owned by Gold Resource Corporation. Isabella Pearl mine is located at the west end of the Santa Fe mining district in the Walker Lane gold…
Tierra Group conducted a siting analysis for a new WRSF to support the mine’s future production increase as part of the Preliminary Feasibility Study (PFS). In addition to supporting the PFS, Tierra Group assisted in preparing and submitting several engineering…
Midas Gold’s project is located in the remote central Idaho Rockies near the town of Yellow Pine. It is a brownfields gold-antimony project featuring three open pits and an anticipated 22,000 tpd plant throughput, along with challenging terrain and environmental…
The Midas Mine is located in northern Nevada, and is owned and operated by Hecla Mining Company. The mine is an underground mine with an operating mill. The mine’s existing tailings facilities are nearing their end of operating life and…










