Senior Environmental Engineer

ABOUT MARIANA MINERALS Mariana Minerals is a software-first, vertically integrated minerals company on a mission to supply the critical minerals powering modern energy, AI, and defense technologies. We’re reimagining the minerals supply chain by combining deep industry expertise with advanced software, automation, and data-driven decision-making. THE ROLE Mariana Minerals is hiring a Senior Environmental Engineer to provide technical environmental engineering support across our U.S. mining, processing, and refining project sites in a fast-paced, multi-project environment. Reporting to the Global Environmental Permitting Lead, you will apply your engineering background to environmental studies, permitting technical support, monitoring program design, and the integration of environmental requirements into engineering and design decisions across FEL 1–3, detailed design, construction, and operations. This role requires the ability to move quickly across multiple concurrent projects, prioritize effectively, and deliver high-quality technical work under compressed timelines. You will also support due diligence and sustainability initiatives, and work closely with the Global Environmental Permitting Lead, the Regional Permitting and Compliance Environmental Engineer, and internal stakeholders (process engineering, operations, legal, and executive leadership) as needed. WHAT YOU'LL DO Technical Environmental Engineering - Conduct and oversee environmental technical studies (air quality modeling, water quality/hydrology assessments, stormwater design, waste characterization) supporting permitting and compliance across multiple concurrent projects. - Design and implement environmental monitoring programs (air, water, stormwater, wildlife) and analyze results to support compliance reporting and technical decision-making. - Support integration of environmental requirements into FEL 1–3 and detailed design, partnering with process and civil engineering teams on technical trade-offs. - Prepare technical sections of permit applications, EIS/EA chapters, and supporting engineering documentation. EMS & Compliance Technical Support - Support development, implementation, and continuous improvement of site-level Environmental Management Systems (EMS). - Provide technical support for stormwater, spill prevention, waste management, and pollution-control programs, including field inspections as needed. - Assist in developing remediation and corrective action plans, applying sound engineering judgment to resolve issues quickly. Cross-Project & Fast-Paced Delivery - Flex across multiple active projects and shifting priorities, delivering quality technical work under compressed timelines and with limited advance notice. - Support due diligence technical reviews for acquisitions and new project development, including environmental data review and site assessments. - Contribute technical data and analysis to corporate sustainability and ESG reporting. Stakeholder Collaboration - Partner with process engineering, operations, and legal on technical environmental questions, and communicate clearly with the Global Environmental Permitting Lead and project teams. - Support the Global Environmental Permitting Lead and Regional Permitting and Compliance Environmental Engineer with technical analysis, data, and documentation as needed. QUALIFICATIONS Required - Bachelor's or master's degree in Environmental Engineering, Civil/Environmental Engineering, Environmental Science, or a related field. - 5+ years of environmental engineering experience in mining, energy, or large infrastructure, with a demonstrated ability to work effectively in a fast-paced, multi-project environment. - Working technical knowledge of environmental studies and modeling (air, water, stormwater) and monitoring program design. - Familiarity with U.S. environmental regulations (CAA, CWA, RCRA, ESA, EPCRA) and their technical/engineering implications. - Experience supporting permit applications, EIS/EA technical sections, or environmental engineering design packages. - Strong analytical, technical writing, and project-prioritization skills. Preferred - Experience with critical minerals (lithium, nickel, graphite, etc.) or refining/processing facilities. - Experience with EMS design or implementation (ISO 14001 or similar frameworks). - Familiarity with IFC/Equator Principles or ESG data reporting. - EIT/PE, or progress toward professional engineering licensure. OUR CULTURE IS BUILT ON FOUR PRINCIPLES: Everyone Gets Home Safe. We never put speed or cost ahead of people. Extreme Ownership. We take full responsibility for outcomes, relentlessly driving toward solutions. Engineer Out Requirements, then Automate. We simplify, optimize, and then automate for scale. Share Your Legos. We collaborate openly, share knowledge, and empower each other to build bigger, better solutions. Join us as we build the future of responsible mineral sourcing and supply!