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 Group updated Runoff Control Plans (RCPs) for the Castle Rock Ops and Gailen Buck facilities to reflect site improvements that affect each site’s stormwater management system. Tierra Group also authored a new Runoff Control Plan (RCP) for the Moore Road Parcel to document all site stormwater controls that are in place for the protection of the water quality of local receiving waters. The Moore Road Parcel will eventually include a public works yard as well as the County’s Emergency Vehicle Operations Center (EVOC).
Tierra Group provided a feasibility-level Tailings Storage Facility (TSF) design for Condor Gold’s La India Project permitting, a planned 2,000 tpd open pit mine in western Nicaragua. TSF embankments used rockfill from the open pit and a geomembrane liner for…
Tierra Group engineers designed La Esperanza TSF, a 2.1-km long, 35-m high, earthfill tailings dam with an HDPE lined impoundment footprint of 840,000 m2. Tierra Group designed and provided Construction Quality Assurance (CQA) for all subsequent downstream dam stages. Stage…
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…
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 completed an annual dam safety inspection (DSI) to meet both Nevada Division of Water Resources (NDWR) Dam Safety and the client's requirements. The DSI included reviewing monitoring data, a dam and appurtenant structures inspection, and a DSI report.
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…
Tierra Group conducted an Independent Technical review of Vista Gold Corp’s Mt. Todd Tailings Storage Facility Expansion in Northern Territory, Australia. Tierra Group assisted the 2025 Mt. Todd feasibility study project providing TSF and waste rock dump design and water…
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…
Creston Mascota Mine is located in Chihuahua, Mexico and is owned and operated by Agnico Eagle Mexico. Tierra Group designed the Phase 4 heap leach pad, buttress, which included geotechnical investigations, slope stability analyses and a water balance for Agnico…
Tierra Group provided Tailings Stewardship Services for TSFs and water dams at the Cadia, Terfer, and Red Chris properties. Responsibilities included data/report review; identifying and assisting the client with managing risks, liabilities, controls, and reporting; evaluating progress towards GISTM compliance;…
Tierra Group provided a desktop and field review of B2Gold’s Santa Pancha Mine hydrogeology. The review identified data gaps in site data and provided recommendations for improve an existing site hydrogeology model and improve underground water management. The hydrogeologic model…
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 provided a feasibility-level Tailings Storage Facility (TSF) design for Condor Gold’s La India Project permitting, a planned 2,000 tpd open pit mine in western Nicaragua. TSF embankments used rockfill from the open pit and a geomembrane liner for…
Tierra Group engineers designed La Esperanza TSF, a 2.1-km long, 35-m high, earthfill tailings dam with an HDPE lined impoundment footprint of 840,000 m2. Tierra Group designed and provided Construction Quality Assurance (CQA) for all subsequent downstream dam stages. Stage…
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…
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 completed an annual dam safety inspection (DSI) to meet both Nevada Division of Water Resources (NDWR) Dam Safety and the client's requirements. The DSI included reviewing monitoring data, a dam and appurtenant structures inspection, and a DSI report.
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…
Tierra Group conducted an Independent Technical review of Vista Gold Corp’s Mt. Todd Tailings Storage Facility Expansion in Northern Territory, Australia. Tierra Group assisted the 2025 Mt. Todd feasibility study project providing TSF and waste rock dump design and water…
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…
Creston Mascota Mine is located in Chihuahua, Mexico and is owned and operated by Agnico Eagle Mexico. Tierra Group designed the Phase 4 heap leach pad, buttress, which included geotechnical investigations, slope stability analyses and a water balance for Agnico…
Tierra Group provided Tailings Stewardship Services for TSFs and water dams at the Cadia, Terfer, and Red Chris properties. Responsibilities included data/report review; identifying and assisting the client with managing risks, liabilities, controls, and reporting; evaluating progress towards GISTM compliance;…
Tierra Group provided a desktop and field review of B2Gold’s Santa Pancha Mine hydrogeology. The review identified data gaps in site data and provided recommendations for improve an existing site hydrogeology model and improve underground water management. The hydrogeologic model…
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 provided a feasibility-level Tailings Storage Facility (TSF) design for Condor Gold’s La India Project permitting, a planned 2,000 tpd open pit mine in western Nicaragua. TSF embankments used rockfill from the open pit and a geomembrane liner for…