Prepared an EIS Hydrogeologic Work Plan that contains a description of the proposed EIS modeling effort and a methodology for analyzing pumping tests conducted in fractured rock. The modeling effort considered the effects of the mine pumping, the resulting pit lakes, a drainage adit, and surrounding streams and springs. Implemented the Work Plan and constructed the groundwater model.
Managed the development of baseline hydrogeologic characterization and environmental impact analysis of proposed mine pit expansion on groundwater hydrology. Work included compilation of existing well logs, aquifer test data, water quality and stream flow data and performance of qualitative assessment of impact potential.
Managed a surface and groundwater sampling program and characterization program for a historic mine site near Ely, Nevada. The scope of work included bi-weekly sampling of surface waters and lakes, monthly sampling of monitoring wells, and quarterly sampling of domestic off-site wells. The field data were used to characterize water quality impacts from historic and ongoing mining practices and to develop a conceptual model of the hydrogeologic conditions at the site. Detailed sampling protocols and an extensive QA/QC program were developed to ensure representative samples were collected.
Managed site characterization and restoration design for historic abandoned copper mine located in Sierra Nevada Mountains. Worked in conjunction with CRWQB to evaluate existing acid mine drainage, develop remediation alternatives including wetlands treatment of copper and zinc-rich waters, and prevent discharge to adjacent streams. Preliminary design criteria and costs were developed for a landfill, capped waste pile, vegetated waste pile, mine backfilling, constructed wetlands, and chemical precipitation remedial options.
Managed and implemented a hydrogeologic and geochemical characterization program for cyanide gold-leaching operations in support of an environmental assessment and environmental impact study. The study consisted of characterizing the groundwater flow system, developing a groundwater flow model using MODFLOW to predict dewatering and pit refill characteristics, use of the MINTEQ geochemical model to evaluate pit geochemistry and characterization of mine waste dump geochemistry.
Evaluated geochemical test work (MWMT, Profile II metal analyses), Water Pollution Control Permit, and Closure Plan for developing a strategy for heap closure. A report summarizing cyanide bio-detoxification and metal removal strategies, as well as process water geochemistry, and water management concerns was prepared for inclusion in the amended Closure Plan.
Prepared an in-house site assessment of all permitting and public agency records related to clean-up, closure, and reclamation of a cyanide heap leach facility. The site assessment included reviewing local, state, and federal records, informal interviews with regulatory officials, and data review of all pertinent in-house records. Information was used to prepare a Health Risk Assessment Report of the mining waste units at the site.
Conducted microbial and vegetation site assessments at the mine site to investigate the distribution of acid producing bacteria and to establish impacts acid rock drainage may have on local plant ecosystems. Developed a soil sampling design and performed soil collection. Isolated and enumerated autotrophic acidophilic microbial populations using an MPN method. Prepared a final report summarizing population distributions and how they relate to impacts associated with acidic discharge at the mine site.
Prepared a closure work plan and managed the project designed to characterize the high TDS groundwater situation in “compartmentalized” fractured rock at the site. Potential sources of the high TDS groundwater included potential leachate drain down from adjacent former leach dumps and an existing beneficiation pond. Recommended interim and long-term remedial actions.
Provided third party evaluation of potential for mass transport migration and pit lake formation.