Mining Leach Pads

Silver Basin Dam and Reservoir

 1

Silver Basin Dam and Reservoir

Ames crews constructed the first asphalt core dam to be completed in the U.S. along with a leach pad with supporting collection ponds for a major mining company in Arizona. Replacing an existing reservoir, the new Silver Basin Reservoir dam and leach pad were constructed concurrently, with Ames managing the internal sharing of personnel and equipment resources between the two projects.

Crews established a quarry site to load, haul, and place material for the dam embankment. Crushing and processing operations were run on a double shift, six- or seven-day workweek to maintain daily project demands as the dam was raised from the foundation to the ultimate crest height elevation. Multiple crushing spreads were utilized, and more than 1 million cubic yards of material were crushed and placed in the dam.

During placement, crews were prohibited from crossing the core. To manage this challenge efficiently, placing operations were hopscotched upstream and downstream every two to three days to allow concurrent asphalt and embankment placements while maintaining an approximately level surface.

Additional project features included an intake tower, steel conduit feed line, reservoir inlet structure, overflow spillway, bifurcation structures, and main pump station, along with placing 4.6 million square feet of liner. The project also involved constructing a new bypass pipeline to allow the existing reservoir to continue to operate during construction, providing the town with an ongoing water supply. During decommissioning of the existing reservoir, Ames installed a temporary pipeline to transfer water upstream to the new reservoir and collaborated with a fish recovery specialist to relocate the fish with care and caution.

When the project scope expanded with no adjustments to the schedule, Ames adapted by adding more personnel and equipment and resequencing work fronts. The stockpile work was delivered five months early, opening up the mining area, and leaching began three months ahead of schedule. Completion of this new facility allows the client to expand operations while maintaining a consistent water supply for its industrial needs and for the community.

OTHER MINING LEACH PAD PROJECTS