Endeavour takes a comprehensive approach to waste management, so that we identify and mitigate any environmental or community impacts. Our operations generate mineral and non-mineral waste:
- Mineral waste takes the form of waste rock storage piles and plant tailings. Almost all mines produce tailings – the leftover waste materials after mineral is extracted from ore. All our mines have surface tailings storage facilities.
- Non-mineral waste includes hazardous waste (e.g., used oils, batteries), non-hazardous waste (e.g., plastic, cardboard, solid urban waste) and special management waste (e.g., tires, toners).
At each mining site, we have waste management systems in place that specify how the different types of waste produced by our activities will be handled. These systems are evaluated on an ongoing basis with the objective of increasing recycling rates and coprocessing where possible and reducing both waste to landfill and waste-rock volumes stockpiled over time. No waste of any kind is shipped internationally; everything is managed onsite or locally.
Our efforts to reduce and responsibly handle waste includes employee and contractor education, awareness campaigns around waste minimization and recycling, and safe handling of hazardous waste. We continuously promote worker safety and have emergency readiness plans for handling spills of hazardous substances and for protecting anyone who has been exposed to these substances. We use qualified contractors to manage offsite treatment and disposal of materials not suitable for onsite storage.
Endeavour manages three tailings facilities across our active and legacy mine sites in Mexico:
- Two active tailings facilities, in Guanaceví and Bolañitos
- One facility in El Compas, that is in care and maintenance is no longer receiving material.
Bolañitos and El Compas are unlined wet tailings facilities with internal drains to recover +80% of the process water (loss due to evaporation) and external diversion ditches to keep rain and stream water away from contacting tailings. Embankments are constructed with properly compacted rock and soil that is structurally competent. Bolañitos is upstream construction and El Compas is downstream construction.
Guanaceví is a lined compacted filtered tailings facility that recovers +85% of the process water. We ensure tailing proper moisture content and then compact the tailing to ensure design criteria are met. Our new site in development at Terronera, once operational, will also use a filtered tailing or dry-stack facility. The benefits to filtered tailings are more efficient water recycling back to the plant prior to placement and compaction, as well as the smaller footprint.
All of our facilities meet at least 1.5 when static and 1.0 in dynamic conditions.
In keeping with industry best practice, we have a stringent Tailings Management Facility Protocol. We continuously monitor and evaluate the stability and conditions of our current and out-of-use tailings storage facilities, using aerial mapping, satellite imagery and water wells and drill holes to evaluate the compaction of the tailings. Each year, we engage an external engineering company to audit our tailings storage facilities for safety measures and to identify opportunities for improvement.
Our ongoing monitoring of tailings conditions and stability includes all active and inactive tailings storage facilities. Our teams conduct regular onsite inspections and use technology such as satellite and drone aerial mapping. We actively monitor water levels in both the tailing and embankments to ensure dewatering efficiency and stable conditions.
Each year, our engineer of record conducts reviews and audits our tailings storage facilities for safety and to ensure we’re following best practices and to help identify opportunities for improvement. We keep all records of the engineering design, construction and operation of each facility and maintain closure plans for each.
In September 2020, the International Council on Mining and Metals launched the Global Industry Standards for Tailings Management (GISTM). It establishes the first international standard on tailings management and strives to achieve the ultimate goal of zero harm to people and the environment. Endeavour supports this important new initiative to drive best practices. Our management team is using the GISTM to align our tailings management practices with the standard.
Endeavour’s Regional Environmental Manager oversees environmental matters at our company, including tailings and waste management (along with the plant manager and projects manager). Each mine has an environmental coordinator who monitors day-to-day operations, facilitates permitting and reports any matters to management. Our environmental group monitors suppliers to ensure their procedures and standards comply with government regulations.
We work cooperatively with local governments to ensure that we understand and fulfill all environmental requirements and meet expectations. We also collaborate with local communities to help improve municipal waste management systems.