Prefeasibility Studies for the Resolution Mine
M&A characterizes several deep aquifer systems to evaluate the feasibility and potential impacts of proposed block-cave operations at an Arizona mine.
- Client: Resolution Copper, a member of the Rio Tinto Group
- Time frame: 2001–present
- Location: Near Superior, Arizona
This deep ore body — one of the largest copper resources ever identified in North America — will be mined using the block-cave method. It is located in the vicinity of the underground workings of the Magma Mine near Superior, Arizona. Dewatering has already begun as part of pre-feasibility study (PFS) activities.
M&A is providing hydrogeologic support for the PFS. Our work has entailed assessing the potential impacts of the proposed operations on nearby groundwater systems, characterizing hydrogeologic conditions, estimating the magnitude of groundwater inflow during mine operations, and modeling groundwater flow. It has also included extensive water level and hydrochemical monitoring. In addition, we have conducted a hydrogeologic assessment and modeling analyses to site a tailings storage facility.
- Designed and supervised the drilling and construction of more than 30 characterization wells to depths of up to 7,000 feet
- Conducted pumping, packer, and slug tests to determine hydraulic parameters for multiple zones within fractured-rock units
- Coordinated long-term, cross-borehole, pumping tests to improve estimates of hydraulic properties, to assess aquifer anisotropy, and to evaluate the flow and fault characteristics of the fracture network
- Analyzed available data to characterize regional and site-specific hydrogeologic conditions
- Integrated the hydrochemical, hydrologic, and geologic data collected during the exploration program to develop a conceptual model and characterize recharge / discharge relationships
- Used the hydrochemical data (which includes multi-parameter and isotopic data) to assess baseline conditions and groundwater flow pathways and to refine our understanding of groundwater–surface water interactions
- Designed and implemented a groundwater monitoring network to assess groundwater system response to dewatering
- Developed multiple groundwater flow models using MODFLOW and FEFLOW at regional, project, and facility scales
- Projected the depth and magnitude of potential groundwater inflow during the proposed shaft-sinking
- Implemented a long-term program to monitor groundwater levels, surface water flows, and water quality
- Conducted analyses and prepared submittals to support permitting for the infrastructure right-of-way
- Installed grouted annular instrumentation (fiber-optics and vibrating-wire piezometers) to depths of more than 6,000 feet to monitor rock stress and pore pressures in the ore zone and overlying aquitards / aquifers
- Developed a web-based data portal that allows mine staff to track groundwater levels and pore pressures in real time
- Installed packers within the production casing to permit the testing and monitoring of multiple aquifer zones within the ore body
- Developed and maintained a comprehensive database for the large, multi-parameter chemical data sets generated during testing and monitoring
- Conducted rigorous internal QA/QC reviews on laboratory data before digitally uploading them into the project database, following strict protocols for data verification and protection, in accordance with client requirements
- Developed a custom, web-based dashboard that provides remote access to data and graphical displays
- Allowed spatial and temporal data to be seamlessly integrated into GIS applications for easy analysis and display
Investigations are ongoing.