WHAT WE OFFER

Your journey with Capstone Copper starts here. At Capstone, our people are the heart of our organization. We are focused on growth and are committed to unlocking the full potential of ourselves, our teams and our resources. We invest in our people to develop a skilled and engaged workforce, not only for today, but for the future. If you are looking for a purposeful, performance-driven and dynamic work environment, join us! Pinto Valley is an open-pit copper mine located at the west end of the historic Globe-Miami mining district of central Arizona, approximately 80 miles east of Phoenix. Pinto Valley has been in operation since 1972 and has produced more than four billion pounds of copper. Acquired by Capstone from BHP in 2013, the mine is fully permitted through 2039 and a study is underway to potentially extend the mine life through 2050. Our proximity to the Greater Phoenix metro area provides prospective employees with the option to live in communities such as Mesa, Apache Junction, Gilbert, Chandler, San Tan Valley, or Florence. Our location offers a unique work-life balance, blending the rewarding opportunities of the mining industry with easy access to the vibrant energy of Downtown Phoenix, making it an ideal choice for both individuals and their families. Capstone employees are eligible for an extensive total rewards package, designed to support your physical, mental, financial, and emotional well-being. This package includes, but is not limited to: 401(k) Savings Plan

• Eligible from day one, contribute up to 90% of your salary with a dollar-for-dollar company match up to 6%, fully vested immediately. Retirement Boost
• The company contributes 8.5% of your salary, with 100% immediate vesting. Employee Share Purchase Plan
• After three months, contribute 2% to 7% of your salary (max $5,000/year) to buy company shares, with a 50% company match, fully vested upon grant. Annual Short Term Incentive Bonus
• Up to 20% Affordable Medical, Dental, and Vision benefits (effective on start date), including Telehealth options and additional supplemental insurances Disability and Life Insurance (effective on start date) Paid time-off, including vacation, holidays, sick leave, and parental leave Employee Assistance Program Internal progression opportunities Tuition reimbursement Discounted insurance plans for pets, automobiles and homes We offer a 7-on, 7-off schedule that consists of one week of 12-hour day shifts followed by one week off, followed by one week of 12-hour night shifts.

We also have a 7-on, 7-off schedule that consists of all day shifts. These schedules offer a great work-life balance with ample time for rest and personal activities.

POSITION OVERVIEW

The Sr. Supervisor

• Tailings & Water provides leadership and oversight for daily Tailings Storage Facility (TSF), tailings deposition, and site water management activities.

This role is responsible for ensuring operations are conducted safely, efficiently, and in accordance with approved plans, regulatory requirements, company standards, and operational targets. The Sr. Supervisor leads employees and contractors, coordinates manpower, equipment, maintenance, and resources, and works closely with Engineering, Processing, Maintenance, Metallurgy, Planning, and HSEC. The role supports reliable tailings and water infrastructure, manages operational priorities and costs, develops personnel, and drives continuous improvement across the Tailings & Water function.

POSITION RESPONSIBILITIES

Safety & Compliance:

Ensure all employees and contractors comply with site safety standards, MSHA regulations, company policies, and applicable local, state, and federal requirements. Maintain compliance with the Collective Bargaining Agreement and applicable operating procedures.

Operational Leadership:

Direct and supervise tailings deposition, TSF activities, pump house operations, and site water management to achieve operational, reliability, quality, and cost objectives. Establish clear expectations and monitor performance against established KPIs.

Tailings & TSF Management:

Oversee daily tailings deposition and TSF activities in accordance with approved deposition plans, engineering requirements, operating procedures, and regulatory requirements.

Water Management:

Direct site water management activities, including pump houses, pumps, pipelines, ponds, reclaim systems, and related infrastructure to maintain reliable water movement and system performance.

Workforce Management:

Build and maintain an effective team through recruitment, training, development, and performance management. Ensure employees are properly trained and qualified for assigned tasks.

Training & Development:

Coordinate with the Training Coordinator to deliver required training programs aligned with current and future operational needs. Conduct performance reviews and provide ongoing coaching, feedback, and development.

Planning & Resource Allocation:

Develop and execute short

• and long-term work plans.

Allocate manpower, equipment, materials, and other resources to meet operational, project, schedule, and budget requirements.

Budget & Cost Control:

Provide input into departmental budgets and manage manpower, equipment, materials, and contractor resources to achieve planned activities within approved cost targets.

Project Execution:

Establish timelines and resource requirements for project readiness and field execution. Identify potential bottlenecks and implement corrective actions to maintain schedules and operational priorities.

Reporting & Data Management:

Ensure accurate capture of tailings, water management, equipment, safety, and operational data. Support preparation of daily, weekly, and monthly operational reports and performance updates.

Maintenance Coordination:

Work closely with Maintenance to identify and resolve equipment and infrastructure issues. Ensure maintenance plans and schedules align with operational requirements and short

• and long-term priorities.

Equipment & Infrastructure Reliability:

Ensure pumps, pipelines, water systems, and related equipment are operated and maintained in a manner that supports reliability, availability, and safe operation.

Cross-Functional Coordination:

Collaborate with Processing, SXEW, Metallurgy, Planning, Maintenance, Engineering, HSEC, and other departments to coordinate operational requirements and support site objectives.

Contractor Management:

Direct and monitor contractor activities to ensure compliance with safety, quality, productivity, schedule, and cost requirements.

Incident Management:

Investigate, document, and report incidents, near misses, and operational events in a timely and accurate manner. Ensure corrective actions are identified, assigned, and completed.

Field Leadership:

Maintain a strong field presence to monitor work activities, identify operational issues, reinforce safety and operating standards, and provide direction to employees and contractors.

Continuous Improvement:

Identify and implement improvements to tailings deposition, water management systems, work processes, equipment, and operating practices to improve safety, reliability, efficiency, and cost performance.

Leadership Support:

Provide guidance and operational input to site leadership on tailings and water planning, performance, resource requirements, operational risks, and improvement initiatives.

Additional Duties:

Perform other supervisory and operational responsibilities as assigned to support site operations.

POSITION REQUIREMENTS

Required High School Diploma or GED. Minimum 5 years of combined experience in supervision, maintenance, construction management, project management, and/or safety within a mining or heavy industrial environment. Demonstrated experience supervising employees and contractors in a field-based mining or heavy industrial environment. Strong working knowledge of tailings operations, Tailings Storage Facilities (TSFs), water management systems, pump houses, pumps, pipelines, ponds, and reclaim systems. Demonstrated ability to coordinate and execute operational plans involving manpower, equipment, maintenance, contractors, and other resources. Strong coordination and communication skills with the ability to work effectively across multiple departments. Effective time management skills and ability to manage multiple priorities and changing operational demands. Strong analytical, planning, organizational, and problem-solving skills. Intermediate computer skills, including Microsoft Office applications such as Excel and Outlook. Ability to understand and apply engineering plans, operating procedures, safety requirements, and regulatory standards. Ability to effectively communicate with employees, contractors, Engineering, Maintenance, Processing, HSEC, and other site departments. Ability to support budget management, cost control, operational reporting, and performance tracking. Valid Driver's License. Ability to read, write, and communicate effectively in English. Preferred Bachelor's degree in engineering, construction management, operations, or a related field. Direct supervisory experience with Tailings Storage Facility (TSF) operations. Experience with mine water management, reclaim water systems, pump stations, pipelines, or related infrastructure. Experience coordinating cross-functional mining, processing, construction, or infrastructure projects. Experience working within a unionized mining environment and familiarity with Collective Bargaining Agreements. Experience with maintenance management or operational systems such as SAP. Experience with operational KPIs, budgeting, cost control, and production or performance reporting.

WORK ENVIRONMENT / PHYSICAL DEMANDS

Primarily field-based role with routine exposure to active mining, processing, tailings, and water management operations. Approximately 70% field work and 30% office work. Regular walking on uneven ground and around operating equipment and active work areas. Regular climbing of stairs, ladders, and access structures associated with field and process equipment. Exposure to varying weather conditions, including heat, cold, wind, and precipitation. Exposure to dust, noise, moving equipment, pumps, pipelines, and other industrial operating conditions. Ability to wear required personal protective equipment (PPE) and work safely in active mining and industrial environments. All candidates will be required to complete a pre-employment medical exam, drug and alcohol test, and background check. All positions require a pre-placement physical examination to ensure candidates are 'fit for duty'. Additional training and/or testing may be required. Capstone maintains a drug and alcohol-free workplace.

CAPSTONE COPPER IS AN EQUAL OPPORTUNITY

EMPLOYER.