Between August and September of 2016, EnerTek carried out a life expectancy study for three dams in the Yanacocha mine in Cajamarca, Peru. The study included topbathymetric surveys, core samples from sediment deposits, total suspended sediment (TSS) sampling and data analysis and modeling.
The topobathymetry study, which covered an area of approximately 140 ha (in the dams and their surroundings), was completed using an acoustic doppler echo sounder (ADCP) and a total station. An ROV-type remote navigation system was implemented as a safety measure to avoid wading beyond the shallow area of the dams. A historical survey of the topobathymetric data was carried out to evaluate the dams’ discharge and determine the annual sedimentation rate.
For the water and soil sampling, several sediment samples were collected at the bottom and on the edges of the dam using Ekman dredging equipment. Laboratory results of the samples were analyzed to determine characteristics such as granulometry, density and contamination by organic matter and heavy metals of the sediments.
At the end of the study, a model was built based on the topobathymetric and climate data to estimate the useful life of the dams, and allow the mine to plan for the safe elimination of the sediments.