One of Almaden’s top priorities at Ixtaca is water quality and a mine plan that provides a permanent and consistent long-term supply of water for residents. The plan outlined in the Feasibility Study has evolved through the open dialogue between the Company and residents over the past number of years and as part of the Social Investment Plan consultation (see section below on “Community”).
Rainfall in the Ixtaca vicinity falls primarily during a relatively short rainy season. With no local water storage facilities, the flash flows of water are currently lost to the communities. Under the Feasibility Study, rainwater will be captured during the rainy season in the water storage reservoir and slowly released during the dry season, for use by both the mining operation and local residents.
Extensive geochemical studies have evaluated the potential for acid rock drainage and metal leaching from the waste rock and tailings using globally accepted standardised methods of laboratory testing and in compliance with Mexican regulations. Most of the waste rock at Ixtaca is limestone, and the studies of both waste rock and tailings have consistently shown that there is more than enough neutralising potential present in the waste rock to neutralise any acid generated.
Testing to date also indicates low potential for metal leaching. These results along with the excellent access to potential markets in the growing industrial state of Puebla, indicate the potential for rock waste and tailings from the Ixtaca deposit to be secondary resources such as aggregate and cement feedstock. These opportunities will be fully examined in 2019 as part of the Company’s commitment to best sustainable practices.
In consideration of these findings and the hydrologic conditions at Ixtaca, Almaden and its consultants reviewed Best Available Technology and Best Applicable Practice in the design and planning of tailings management at Ixtaca, which resulted in selecting a dry-stack tailings facility which would include co-disposal of waste with filtered tailings, use much less water than traditional slurry facilities, reduce the mine footprint, allow for better dust control, and enable earlier rehabilitation of the tailings and waste disposal areas.