Waste Management //
Each of our operations has developed waste management systems which specify how the different types of waste produced by our activities will be managed. These systems are evaluated on an ongoing basis with the objective of reducing waste to landfill and reducing volumes of waste stockpiled over time.
The non-mineral waste at all of our operations is classified as hazardous, non-hazardous, or special management waste. Hazardous waste disposal follows Mexican environmental regulations and is taken to a landfill, sent to final disposition with authorized suppliers, or sold for off-site energy recovery. All sites have a storage place for hazardous materials and hazardous waste. Non-hazardous waste such as plastic and cardboard is recycled, and urban waste is taken to the municipal landfill. Special management waste is recycled or reused on-site or in the community. No waste of any kind is shipped internationally.
Since 2015, a major effort has been undertaken to recycle as much material as possible and reduce the amount of waste generated. All of our operations now recycle plastic bottles, cardboard, ink cartridges, and toners. Tires are reused at Bolañitos and El Cubo and to some extent at Guanaceví – where its remote location makes final off-site tire disposal an ongoing challenge.
The non-hazardous waste intensity in 2016 dropped from 0.49 kg per tonne of processed material to 0.40 per tonne. One area of major reduction was in the management of urban waste, mainly at El Cubo, where an intense effort has been undertaken to classify and separate materials and recycle where possible. This has been accompanied by employee and community education and awareness campaigns.
Hazardous waste intensity increased from 0.045 kg per tonne of processed material in 2015 to 0.08 kg in 2016. This is mostly due to the expanded development activities in Guanaceví (almost double last year) and the arrival of a new contractor, whose waste is now included in these statistics (the previous contractor took responsibility for their own waste).
One of the main challenges for all three sites is the management of oil waste in the heavy equipment garages. Endeavour is researching a new technology to freeze oil when cleaning equipment, which would considerably reduce the amount of waste (water and dust mixed with the oil) collected.
Endeavour’s operations all generate mineral waste in the form of waste rock, sludges, and tailings.
The amount of waste rock almost doubled at Guanaceví in 2016 due to increased development from Santa Cruz and North Porvenir. Bolañitos reduced its waste rock in 2016 over 2015 by close to half due to significantly less development, and El Cubo remained relatively static. Our total tonnes of tailings and minimal amount of sludge at each operation also remain similar to the previous year at all three mines.
Tailings Storage Facilities
Mine tailings — and the integrity of tailings storage facilities — is an issue of global environmental concern. Surface tailings can represent one of the most significant environmental risks of mining operations, and in keeping with best industry practice, Endeavour has a stringent Tailings Management Facility (TMF) Protocol. The Mexican environmental regulatory authority PROFEPA has also reflected the importance of the issue with increased monitoring visits and more rigorous reviews.
All three of our mines have surface tailings storage facilities. We meet local laws and regulations related to tailings management, and we aim to exceed them where possible, focusing on the adoption of best environmental practices. We continuously monitor and evaluate the stability and conditions of our current and out-of-use tailings storage facilities, using water wells, drill holes to evaluate the compaction of the tailings, aerial mapping and satellite imagery.
In recent years, we have implemented several company-wide initiatives to improve tailing storage stability so that our facilities meet or are better than Canadian tailings facility standards. Every year, an external engineering company conducts an independent evaluation to audit for safety measures and make recommendations for any improvements. In 2016, El Cubo identified a potential risk in the stability of one of its tailings ponds, and suspended the use of this tailings area until the necessary upgrades were completed to ensure that the right safety factors were in place. An older tailings pond was rehabilitated to provide room for continued tailings storage while a new tailings facility was evaluated and permitted.
Stability metrics are monitored regularly using CPT drill holes, which take measurements in the tailings and provide stability factors for the facilities. This additional work on the tailings facility explains the higher environmental protection expenses at El Cubo in 2016. At Bolañitos, the tailings pond limits were expanded to handle the continued production from the mine and maintain the safety of the pond.