Your Questions, Our Answers

Answer: The integrity of plant tailings storage facilities are issues of heightened global environmental concern, following recent tailings dam failures in Brazil, Mexico, Peru and Canada. Surface tailings can represent one of the most significant environmental risks of mining operations, leading to potential injury or loss of life and serious water and soil pollution if not properly managed.

All four of our mines have surface tailings storage facilities for the finely ground rock that remains after the ore minerals are removed. Responsible management of tailings is a key priority for Endeavour. In keeping with industry best practice, we have a stringent Tailings Management Facility Protocol that allows us to meet or exceed Canadian and Mexican standards for minimizing tailings risks.

We continuously monitor and evaluate the stability and conditions of our current and out-of-use tailings storage facilities, conducting regular onsite inspections and using satellite and drone aerial mapping, water wells and drill holes to evaluate the compaction and stability of dam and tailings material and recovery and management of water in the tailings facilities.

Each year, we engage independent engineering companies to audit our tailings storage facilities for safety, to advise us on management practices and to 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 2018, we had no reportable incidents or spills at any of our tailings facilities.

Each year, we report on the performance of our tailings facilities in our annual sustainability report, view 2018 report here https://csr.edrsilver.com/English/sustainability-programs/environment/default.aspx. Because of heightened concerns worldwide, we plan to significantly increase the details of our tailings disclosure in our 2019 and future sustainability reports.

Here is a summary of Endeavour’s tailings facilities:

• Currently manage four active tailings facilities in Mexico
• Own three of them and lease the fourth (El Compas)
• All four contain tailings behind earthen dams
• Guanacevi is a lined dry stack filtered tailings facility that recovers 95+% of the process water
• Bolanitos, El Cubo and El Compas are unlined wet tailings facilities with internal drains to recover 80+% of the process water (loss due to evaporation) and external drains to keep rain and stream water away from the tailings
• Bolanitos and El Cubo are upstream construction and El Compas is downstream construction
• El Cubo also has several small historic tailings facilities that are stable and dry