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Geotechnical Engineering Evaluation and Engineering Geologic Assessment - REVISED NGA File No. 1300621 Sharp Residential Remodel October 12, 2021 Everett, Washington Page 3 Subsurface Conditions Geology: The geologic units for this site are shown on the Distribution and Description of Geologic Units in the Everett 7.5-Minute Quadrangle, Washington by James P. Minard, (USGS, 1985). The site is mapped as Vashon Stade glacial advance outwash (Qva) with 'Transitional Beds' (Qtb) mapped nearby. Advance outwash is described as well -sorted sand and gravel; it was deposited by streams issuing from the advancing ice sheet. 'Transitional Beds' are an obsolete classification for a conglomeration of geologic units described as glacial and non -glacial deposits present beneath sand of the Vashon advance outwash. It customarily consists mostly of thick beds of gray clay, silt and fine to very fine sand. Our explorations generally encountered a thin, surficial layer of undocumented fill soils underlain by medium to coarse sand with varying amounts of gravel and silt, which are consistent with the description of glacial advance outwash at depth. Explorations: We visited the site on September 16, 2021 to explore the subsurface conditions within the site with three hand auger explorations. The approximate locations of our explorations are shown on the Schematic Site Plan in Figure 2. A geologist from Nelson Geotechnical Associates, Inc. (NGA) completed explorations, examined the soils and geologic conditions encountered, and maintained exploration logs. The soils were visually classified in general accordance with the Unified Soil Classification System, presented in Figure 3. The logs of our explorations are presented as Figure 4. The following paragraph contains a brief description of the subsurface conditions encountered in the explorations. For a detailed description of the subsurface conditions, the hand auger logs should be reviewed. At the surface of explorations in the front and backyards, we generally encountered between 1.3 and 1.4 feet of surficial silty sand with debris, which we interpreted to be undocumented fill. Underlying the fill in Hand Augers One and Three, we encountered tan to gray sand with varying amounts of silt and gravel in an increasingly dense condition to the depths explored. We interpreted these underlying soils to be the native advance outwash mapped on site. Hand Auger Two on the northern portion of the property encountered 2.5 feet of dark brown silty sand with gravel in a loose condition which we interpreted as undocumented fill, underlain by tan- to gray silty fine sand with organic particulate which we interpreted to also be undocumented fill. Hand Auger Two terminated within the undocumented fill, while other explorations terminated within the native soils, all at depths of 3.0 feet below the existing ground surface. NELSON GEOTECHNICAL ASSOCIATES, INC.