DESCRIPTION: The Dillard Landfill is located on the west flank of a hillslope immediately north of the Roseburg Forest Products (RFP) mill. For several decades, the landfill has accepted wood waste and ash from the adjacent mill. RFP is proposing to close the original landfill cell and expand the landfill facility onto a ±45-acre parcel to the north. The landfill expansion will be completed in phases.
SERVICE: Foundation Engineering completed geotechnical investigations to provide site characterization for the expansion of the landfill and the closure of the original landfill. The work for the expansion involved evaluating the site geology, subsurface conditions, typical soil properties, seismic characterization, potential settlements and slope stability considerations associated with the proposed landfill configuration. The evaluation for the closure involved monitoring of inclinometers to study long-term creep of existing, steep landfill slopes. Slope stability analysis was completed to evaluate suitable landfill height and slope configurations for the final closure.