Dorey & Associates
HOME
Profile
Capacity
Development
Auditing & Due Diligence
Contact
C O N S U L T I N G, L.L.C.
Relevant Experience
Next
Guatemala (continued from previous page)
The project site is situated in a region capable of
producing large magnitude earthquakes. Preliminary assessments indicate a peak ground acceleration for the design earthquake for the facility could range from 0.35 to 0.4g.Climate data indicate the site receives about 1,000mm of rainfall per year. The preliminary tailings storage facility water balance indicates the impoundment will remain saturated throughout the mine life and a free water pool may cover the entire impoundment surface for much of the year. The impounded tailings and water may also contain residual levels of contaminants high enough to be of some concern.
Challenging design considerations coupled with severe failure consequences classify the proposed facility as high risk. To this end, it is considered necessary to design the dam using the conservative approach that would be adopted for a primary water retention structure. The design selected is a zoned earth structure with an inclined low-permeability core. The dam will employ a "downstream" construction process using conventional earth fill methods.
The design included facility layout, dam design, water balance (including an assessment of discharge water quality, and review of discharge and water treatment options), seepage analysis, embankment stability analysis, seepage containment design incorporating a grout curtain, tailings delivery and recycle water return, and reclamation and closure design. Capital, operating and closure costs were estimated, and a feasibility stage work program developed, including geotechnical investigations, laboratory testing program and facility design.
DAA team members were retained to provide technical and environmental support for the environmental and socioeconomic baseline studies and environmental/social impact assessments for the project. Montana also retained DAA team members to present a seminar on Mining and the Environment to the Mining and Environmental Ministries in Guatemala in March, 2003. Currently the project is under construction and is scheduled for operation in 2005.
Previous