Hydrogeological Testing and Characterization: Fresnillo Mine, Zacatecas, Mexico

The Fresnillo Mine, operated by Fresnillo PLC and located in Zacatecas State in central Mexico, is one of the largest silver mines in the world.  Geofirma was contracted by Mine Design Engineering (MDEng) to complete a hydrogeological study in conjunction with the geotechnical site investigation program for the proposed extension of the San Carlos shaft from its current elevation of approximately 550 metres below ground surface to approximately 1000 metres.

The primary object of Geofirma’s work was to characterize the groundwater conditions along the proposed shaft horizons, particularly to provide an estimate of hydraulic conductivity and groundwater pressures that may be encountered during construction of the shaft.  Hydrogeological work included fracture logging and borehole geophysics to identify potential zones of high inflow as well as the completion of step – injection tests using specialized deep borehole packer testing equipment.  In total, 25 test intervals were completed and analyzed using nSIGHTS software to determine a representative permeability and pressure profile along the shaft alignment.

For additional information, please contact Sean Sterling, M.Sc., P.Eng., P.Geo.