Reducing total suspended solids

Hardfill Dam Engineering and Construction

Since 1993, we have provided a Peruvian gold mine with permitting, engineering, and environmental services in support of development, operation, and/or closure of various sites at the mine. Located in the Peruvian Andes, specific projects include environmental impact studies, waste rock reclamation design, reclamation plans, staff training, sediment control studies, and design/construction management of sediment control structures.

Mine activities had resulted in elevated levels of total suspended solids (TSS) in surface water drainage. Our team was contracted to design three dams to provide detention of surface water leaving the mine site to reduce TSS levels to meet regulatory requirements. We also provided construction management support and quality assurance, and worked closely with the mining company to provide detailed and effective dam designs using construction materials that are available at or near the mine site.

The dam locations are in a narrow valley near Cajamarca, Peru. The valley floor provides a weak foundation because it is comprised primarily of andesitic volcanic rock and is affected by varying degrees of weathering. Borrowing from our experiences throughout the world, we recommended the construction of Latin America’s first-ever Faced Symmetrical Hardfill Dams. These dams feature a symmetrical design to improve seismic strength, as well as improve stability and lower stresses within the dam and foundation.