Home Depot constructed a 134,000 sq ft retail building supply store at SW Washington Street and Cascade Highway (Hwy 213) in Oregon City, Oregon. The site encompasses about 16 acres and is part of the former Rossman’s Landfill. As part of the preliminary geotechnical investigation of the site, GRI evaluated the thickness of the existing landfill cap and refuse. GRI conducted a site-specific seismic hazard study for the project, which included review of seismic literature, seismic cone penetration tests (SCPT) to measure in situ shear wave velocities of the subsurface materials, drilled borings to collect undisturbed samples of the refuse and underlying soils to determine bulk unit weights, identification of potential seismic activity that might affect the site, and characterization of that activity by a series of generalized design events. Acceleration-depth profiles were also produced for each event. Close coordination with DEQ was required to safely allow drilling through landfill refuse. As a condition of developing the property, a portion of Hwy 213 was widened, turning lanes were added, and the intersection was improved with new signals. GRI provided recommendations for roadway embankment widening including settlement estimates and requirements for settlement monitoring, fill materials and compaction methods, lateral earth pressures for retaining wall design, review of existing pavement conditions, design of new pavements, and design of foundations for support of new signal and sign poles. GRI personnel provided on-site observation services and consultation during earthwork and foundation construction.