17 E MARINE VIEW DR 2019 Geotech Report 2025-10-01

Shallow crustal faults with known or suspected Quaternary displacements within the project area include the Southern Whidbey Island fault,the Devils Mountain fault,the Utsalady Point fault,Strawberry Point fault and the Seattle Fault.The following is a summary of the distance from the site to the fault and a summary of each fault. ■ The Southern Whidbey Island fault zone is a northwest-southeast trending,north dipping reverse thrust fault zone ranging up to about 3 to 4 miles wide.The site is located approximately 7 miles northeast of the northern trace of the Southern Whidbey Island fault ■ The Devils Mountain fault is an east-west trending,north dipping reverse thrust fault.The site is located approximately 20 miles south of the Devils Mountain fault. ■ The Utsalady Point fault is a northwest-southeast trending,vertical dipping strike-slip fault. The site is located approximately 22 miles southeast of the Utsalady Point Fault. ■ The Strawberry Point Fault is an east-west trending,vertically dipping strike-slip fault.The site is located approximately 24 miles southeast of the Strawberry Point Fault. ■ The Seattle Fault zone is a 2-to 4-mile-wide, east-west trending zone of three or more splays of the south dipping reverse fault.The Seattle fault ruptured about 1,100 years ago and caused broad uplift and subsidence on either side of the fault.The rate of recurrence of large earthquakes on the Seattle Fault is thought to be on the order of thousands of years. The site is located approximately 32 miles north of the Seattle Fault zone. Surface Conditions The site is bounded to the south and east by railroad tracks with a bluff extending up to Marine Drive toward the south.The developable portion of the site is relatively level with elevations ranging between about 14 and 17 feet in the upland areas. The property located south of the proposed recycled asphalt building include warehouse buildings and industrial structures surrounded largely by paved and gravel parking and driveway areas.An existing timber bulkhead is present along the north perimeter of the site.The bulkhead is in need of repair in some areas. A large asphalt stockpile, roughly 250 feet long by 100 feet wide and 20 feet high is located in the southwest portion of the site. The balance of the site is primarily used for equipment storage, including a few small storage sheds,The surface conditions generally consist of crushed gravel and recycled asphalt. Subsurface Conditions Based on our review of the subsurface conditions encountered in the previous geotechnical explorations the subsurface profile generally consists of fill overlying recent alluvial deposits of a clean to silty sand with interbedded silt and estuarine deposits consisting of compressible fine-grained soils with some minor organic content. The recent alluvium and estuarine deposits appear to be underlain by an older alluvial deposit with higher density, and possibly some glacially consolidated soil. These units are discussed in more detail below and are illustrated on Cross Sections A-A'and B-B', Figures 3 and 4, respectively. Fill Soils Loose to medium dense sand with variable silt content, shell fragments and wood debris was observed in the upper 8 to 27.5 feet of all previously explored geotechnical soil borings. We interpret these soils to be fill soils associated with river dredging and site grading. Fill thicknesses encountered in the borings were GEOENGINEER� August3,2018 Page4 file No.0643.015 00