Modelling the impact of mining operations on surface water and groundwater
Mount Isa Mines is a copper and lead/zinc mining complex, consisting of multiple orebodies, in northwest Queensland, Australia. Since 2010, KCB has completed various groundwater and geochemical assessments at this mining complex.
KCB assessed the potential impacts of a series of mine expansions and pit closures, and associated waste rock dumps, on the levels and quality of local surface water and groundwater systems.
Groundwater assessments included:
- Review of the existing hydrological, hydrogeological and geological data for the development of a conceptual groundwater model.
- Ground truthing the conceptual model through field investigations including drilling and bore installations, groundwater sampling, packer and infiltration testing, and test pumping.
- Development of an integrated water balance model, including groundwater and geochemical modeling, for the tailings storage facility using GoldSim software.
- Development of a mass transport model to predict potential seepage from the tailings storage facility.
- Development of a groundwater management plan for mining operations, including expansions to mine pits, waste rock dumps and the tailings storage facility.
Geochemical assessments included:
- Geochemical characterization and modelling of potential seepage from mine waste materials, including the potential for acid and metalliferous drainage from pit walls, waste rock dumps and the tailings storage facility.
- Development of predictive water quality models based on static and kinetic laboratory tests and sampled water quality data.
- Development of sampling guidelines to identify and classify acid and metalliferous-producing geological units.
- Recommendations for the ongoing monitoring of potential seepage from mine waste materials.