Job Details: Job Location: Missoula, MT - Missoula, MT, Position Type: Full Time, Education Level: Graduate Degree, Salary Range: Undisclosed, GSI Environmental is seeking a Senior Geochemist to join our growing mining practice. This position offers the opportunity to work with experienced professionals on technically challenging mining projects involving mine waste, mine water, permitting, operations, and closure. The successful candidate will provide technical leadership for environmental geochemistry programs supporting hard rock and industrial mineral projects across the U.S. and internationally. The role will include study design, geochemical characterization, interpretation of complex datasets, mine water quality prediction, geochemical modeling, technical reporting, and close collaboration with hydrogeologists, engineers, and permitting specialists. Responsibilities:  Lead or support geochemical characterization programs for waste rock, tailings, ore, pit-wall materials, soils, sediments, and mine water. Design and interpret static and kinetic testing programs, including acid-base accounting, net acid generation, humidity cells, column tests, leach testing, mineralogy, and related laboratory programs. Evaluate acid rock drainage and metal leaching potential and develop defensible source term and mine water quality predictions for permitting, design, operations, and closure. Develop, apply, and/or review geochemical and hydrogeochemical models using PHREEQC, Geochemist’s Workbench, GoldSim, MIN3P, or comparable tools, as appropriate to project needs. Integrate geochemical results with hydrogeologic, hydrologic, water balance, and engineering analyses to evaluate seepage, contact water, pit lakes, tailings, waste rock facilities, and closure scenarios. Plan and oversee field sampling programs and coordinate laboratories, vendors, subcontractors, and QA/QC activities. Prepare and review technical reports, memoranda, permit support documents, work plans, proposals, and presentations. Communicate technical findings and uncertainty clearly to clients, regulators, project managers, and multidisciplinary teams. Manage technical tasks and projects, including scope, schedule, budget, quality, and staff coordination. Mentor junior and mid-level staff and contribute to technical standards, training, and practice growth within GSI’s. Support proposal development, client relationships, conference participation, and other activities that help grow GSI’s mining practice. Qualifications: Qualifications M.S. or Ph.D. in geochemistry, geology, hydrogeology, environmental engineering, environmental science, or a closely related discipline; exceptional candidates with a B.S. and substantial directly relevant experience will also be considered. 10 or more years of relevant professional experience, with strong preference for mining geochemistry or environmental consulting experience. Demonstrated expertise in mine waste characterization, acid rock drainage/metal leaching assessment, and mine water quality prediction. Experience designing, managing, and interpreting laboratory and field geochemistry programs. Strong technical writing, data interpretation, and presentation skills. Experience managing technical scopes, schedules, budgets, and multidisciplinary project interfaces. Ability to work independently while contributing effectively to cross disciplinary teams. Valid driver’s license and ability to travel domestically and occasionally internationally for project needs.   Job Perks Opportunities for ownership in a growing employee-owned company. Competitive salary and benefits with attractive year-end bonuses. Flexible work environment with potential for remote work. Participation in conferences, technical presentations, and publications. Collaborative atmosphere.   The base salary for this position will be determined by the candidate’s geographic location, education, relevant degree, related experience, and overall qualifications.