3620 BROADWAY VERIZON 2019-01-11

r Geotechnical Engineering Evaluation NGA File No.983917 Stadium Flowers Addition March 10,2017 Everett,Washington Page 2 SITE CONDITIONS Surface Conditions The site is situated on a 0.27-acre split rectangular lot. The site is situated on a gentle, east-facing slope that descends from the western property line to the eastern property line along Broadway. The site is composed of an existing parking area located within the eastern portion of the property, and a proposed building addition excavation on the western portion of the property. The excavation covers an area of approximately 150 square yards, with a maximum depth of 4.8 feet below the adjacent concrete and asphalt-paved surfaces. Soils on the site are mostly covered with impermeable surface, with sparse landscaping areas around the perimeter. At the time of our visit, we did not observe surface water flowing on site. Subsurface Conditions Geology: The Geologic Map of the Everett Quadrangle, Washington, by James P. Minard(USGS, 1985) was reviewed for this site. The site is mapped as advance outwash deposits(Qva), with nearby areas of Vashon Till (Qvt). The advanced outwash is described as gray, unconsolidated sand, and was deposited approximately 17,000 years ago, by meltwater streams flowing from the continental glacier. The Vashon Till is described as a nonsorted mixture of clay, silt, sand, pebbles, cobbles, and boulders in variable amounts. Our explorations generally encountered undocumented fill underlain by `clean' sand soils consistent with the description of advance outwash at depth. Explorations: The subsurface conditions within the vicinity of the proposed development area and the site slope were explored with four 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) was present during the explorations, examined the soils and geologic conditions encountered, obtained samples of the different soil types, and maintained logs of the explorations. The soils were visually classified in general accordance with the Unified Soil Classification System presented in Figure 3. The logs of our explorations are attached to this report and presented as Figure 4 and 5. We present a brief summary of the subsurface conditions in the following paragraphs. For a detailed description of the subsurface conditions,the logs should be reviewed. At the surface of Hand Augers I and 4, we encountered approximately 0.6 and 2.4 feet of loose, red- brown surficial topsoil,respectively. Underlying the topsoil in Hand Auger 1,we encountered 1.3 feet of loose-medium dense silty fine to medium sand. NELSON GEOTECHNICAL ASSOCIATES,INC.