From waste rock to tailings, we are committed to managing all the waste we generate at Terronera in safe and environmentally responsible ways, and being transparent about how we do that. A waste management system is in place to guide our workforce and contractors in the proper handling and disposal of different forms of waste.

Waste Rock

• A temporary waste rock storage facility will be constructed southeast and uphill from Portal 2 and will vary in size throughout the LOM, reaching a maximum capacity of approximately 1.2 million tonnes. The overall slope ratio will be 2.7H:1V to ensure physical stability during the operation of the temporary facility.

Wastes

• Sewage pump stations pump domestic waste to the sanitary sewage treatment plants located within the project.
• Hazardous waste generated onsite is loaded into containers that clearly identify the type of waste and handle in an appropriate way according to the environmental legislation.

Tailings Management

• The Terronera mine, once in production, will use the “dry stacking” method to store filtered tailings. Dry stacking is the most sustainable system for the management of such tailings, and will minimize downstream contamination risk and maximize geotechnical stability in western Mexico’s seismically active coastal area.
• Tailings will be piped from the process plant to a filter plant, where a dry tailings material will be produced and trucked to a TSF located northwest of the process plant.
• The TSF will be located in a valley approximately 1 km northwest of the process plant. The current footprint of the TSF occupies an area of approximately 89,760 m² and will accommodate approximately 4.4 million m³ (8.3 million tonnes) of compacted filtered tailings
• The TSF has been designed with an overall downstream slope of 2.8 Height (H) to 1 Vertical (V) with interim benches of 6 m width and slopes 10 m in height at 2.2H:1V slope.
• Below the TSF to the northwest will be a seepage water collection pond to collect, monitor, treat and release stormwater from the TSF surface area and any subgrade water that is not qualified to be released downstream. Upstream drainage will be captured in cut-off ditches constructed immediately above the TSF upstream perimeter and routed to the natural drainage course below the TSF.

Dry Stacking: A More Sustainable Option

Dry stack tailings are often considered better than wet tailings for several environmental and safety reasons: 

• Reduced water consumption: Dry stack tailings require significantly less water compared to wet tailings systems. In a dry stack system, the majority of the moisture is removed from the tailings before they are stored, reducing the demand for water resources.
• Enhanced safety: Dry stack tailings are generally more stable and less prone to catastrophic failures compared to wet tailings dams. This enhances the safety of nearby communities and ecosystems, reducing the potential for disasters like dam breaches.
• Faster rehabilitation: Dry stack tailings can be reclaimed more quickly and easily than wet tailings impoundments. Once the moisture has been removed, the dry tailings can be reshaped and revegetated more effectively, facilitating land reclamation efforts.
• Dust control: Dry stack tailings are typically compacted and covered to control dust emissions, minimizing the potential for air quality issues in surrounding areas. Wet tailings can generate dust when they dry out