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, and reviewing, developing, and updating stormwater standard operating procedures (SOPs) for use at County facilities and projects.
Tierra Group conducted geo-electrical testing to locate leaks present in the geomembrane liners underlying a Solution Conveyance Canal, Sumps 1 and 2, and the Intermediate Pond at Timmins Gold Corp’s San Francisco Mine in Sonora, Mexico. Leak detection testing procedures…
Tierra Group advanced the TSF design to a Feasibility Level according to the Canadian National Instrument NI 43-101 and the U.S. Security and Exchange Commission’s Subpart SK-1300 regulation. Tierra Group’s scope of work included a geotechnical investigation, engineering analysis, and TSF…
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…
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…
Tierra Group performed a site visit and visual inspection of a dam to assess its overall condition and provide the Owner recommendations for continued maintenance, monitoring, and improvements. The assessment was a follow-up to previous work completed by Tierra Group…
Tierra Group provided a raise design for Doe Run's Brushy Creek tailings embankment, a facility first commissioned in 1973. Cone penetration testing, liquefaction analysis, seepage modeling, and slope stability modeling were performed for the embankment. Hydrology, spillway design, and impoundment layout…
The Fire Creek Mine, located in north-central Nevada, is owned and operated by Klondex Gold & Silver Mining Company. The mine is an underground mine that is operating a bulk sampling program and has recently submitted its Preliminary Feasibility Study. As…
The Stibnite 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…
Tierra Group performed an independent engineering design review of a Cemented Tailings Facility (CTF) and multiple processes and freshwater ponds. Tailings will be mixed with cement at the paste plant and deposited in the CTF along with underground mine development…
Tierra Group completed the design for two 3-meter upstream raises to an existing paste tailings storage facility at New Jersey Mining Company’s New Jersey Mill site near Kellogg, Idaho. Work included performing a cone penetration testing (CPT) investigation of the…
Tierra Group International, Ltd. participated as the geotechnical lead engineering firm for the Copperstone Project Pre-Feasibility Study (PFS) in Arizona, U.S.A. Tierra Group was responsible for tailings and waste rock storage, water management and underground geotechnics design and cost estimates…
Dam Breach Analyses Tierra Group prepared a DBA to evaluate potential downstream impacts due to a hypothetical failure (breach) in three components of Empire State Mines (ESM) tailings storage facility (TSF): North Dam (ND), South Dam (SD), and West Perimeter…