Azusa Quarry & Reliance Landfill

For this six-year, environmentally sensitive mine reclamation project, Ames reclaimed one-half of a quarry while stripping and removing overburden for future mining on the other half.

Rock excavation on steep slopes required drilling and blasting when no other means to remove the material was possible. Excavated rock was then loaded into two jaw crushers for primary crushing, and a conveyor system transported the crushed material nearly three miles to a 99-acre landfill. The conveyor system traversed the San Gabriel River bed and a hiking trail that winds through the mine.

A 300-foot-long tunnel buried in the mountainside was fitted with large feeder pans, each capable of producing 1,500 tons per hour. The tunnel was also equipped with two hydraulic hammers that would break or size the rock. A belt in the tunnel ran at more than 650 feet per minute, moving up to 2,800 tons per hour.

At the landfill, the project operated three tunnels and 16 mobile “grasshopper” conveyors, which were moved throughout the project phases to place material.

A significant milestone was achieved when crews completed the first phase of reclamation by replacing the hillside’s 30- to 50-foot benches, known locally as the “Mayan steps,” with 1- to 2-foot micro-benches that will gradually contour to form a natural-looking hillside. Slope restoration included an application of topsoil, native seeding, and planting more than 38 acres to create a natural-looking hillside for local residents.