A numerical model was developed in order to estimate the residence time of a sediment plume generated by potential deep-sea mining activities with special attention to discharges in the bottom boundary layer. The site of the Disturbance and Recolonization Experiment (DISCOL) in the Peru Basin in the southeast Pacific Ocean was chosen as a case study. The model includes the actual bathymetry, as well as the characteristic flow patterns in this region. Various aspects affecting the transport and sedimentation of the plume, such as stratification, flocculation in a sediment-laden water column, and the hydrodynamics are discussed in conjunction with field data and studied with the overall aim of providing a reliable risk assessment of deep-sea mining environmental impacts. ¿ American Geophysical Union 1996