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The Mark at Eugene January 6, 2026 Geotechnical Investigation and Seismic Hazard Study 4 Project No.: 2251077 Eugene, Oregon Landmark Construction, LLC SURFACE AND SUBSURFACE CONDITIONS Surface Conditions The building site is located in the southern half of the previous Peace Health Hospital campus between Hilyard Street and Alder Street and between E 11th Avenue and E 13th Avenue. An existing building presently occupies the western edge of the property and paved parking along the south and east side of the property. The center is presently covered in landscaped areas. A review of historic aerial imagery available through Google Earth Pro indicates previous structures previously occupied the landscaped area. The structures have since been demolished. Subsurface Conditions A discussion of the subsurface conditions is provided below. More detailed descriptions of the soil conditions are provided in the boring and test pit logs in Appendix B. A discussion of the local and regional geology is provided in the Seismic Hazard Study in Appendix D. The explorations encountered subsurface profiles that typically include the following strata: • Pavement Section. BH-1, BH-3, and BH-5 were drilled in the pavement at the southeast corner of the site and encountered a pavement section typically consisting of ±4 inches of asphalt concrete (AC) over medium dense crushed rock to crushed gravel extending to ±1.5 feet. • Topsoil/Fill. Soft to stiff silt with trace to some organics (topsoil/fill) was encountered in each of the explorations completed in the landscaped areas (i.e., TP-1, TP-2, TP-3, TP-4, and BH-2) extending to depths of ±12 to 16 inches and is typically underlain by a geotextile fabric. • Existing Granular Fill. Additional fill consisting of medium dense to very dense crushed gravel follows the topsoil/fill in TP-1, TP-2, TP-3, TP-4, and BH-2. Based on the location, depths, and observed condition of the fill, it appears the previous structures were demolished, and the excavations backfilled with imported crushed rock. The fill extends to depths ranging from ±3 to greater than 8 feet. • Fine-grained alluvium. Medium stiff, medium plasticity sandy silt with some clay typically extends below the pavement section and the fill to depths of ±20 to 35.4 feet. The fine-grained alluvium includes a zone of high plasticity clay at some locations. We noted the high plasticity clay at depths ranging from 7.5 feet (BH-4) 25 feet (BH-2). A lens of medium dense silty sand with some gravel was encountered in BH-3 and other locations included zones of sandy or gravelly silt.