6307 36TH AVE W Geotech Report 2025-07-29

I I August 13, 2008 Project No.T-6241 • Slab-on-grade floors • Stormwater facilities I • Subsurface drainage • Utilities I • Pavements should be noted that the recommendations outlined in this report regarding drainage are associated with soil IlL strength, design earth pressures,erosion, and stability. Design and performance issues with respect to moisture as it relates to the structure environment (i.e., humidity, mildew, mold) is beyond Terra Associates' purview. A ' building envelope specialist or contractor should be consulted to address these issues,as needed. 3.0 SITE CONDITIONS I 3.1 Surface The project site is an irregular shaped 35.74-acre parcel located east of and adjacent 36th Avenue West and northeast of the intersection of 36th Avenue West and Seaway Boulevard in Everett, Washington. TheII approximate location of the site is shown on the Vicinity Map,Figure 1. The site is bordered to the north by the existing Intermec development as well as undeveloped forested land, to Ithe east and south by undeveloped forested land,and to the west by 36th Avenue West. The currently undeveloped site is heavily forested with both young and mature coniferous and deciduous trees I and thick undergrowth consisting of blackberries, ferns,and brush. Site topography is undulating with the overall gradient falling from west to east-northeast. A generally moderately inclined slope exists in the eastern portion of the site,outside of the proposed development area. 3.2 Soils ISoils we observed in the test pits generally consisted of three to six inches of forest duff overlaying loose to medium dense, reddish-brown silty sand followed by medium dense to dense variations of brown and gray silty I sand to sand with silt. Soils underlying the surficial organic and weathered soils varied from east to west. In general, with exception to Test Pit TP-5, soils in the eastern majority of the site consisted of medium dense to dense outwash deposits composed of silty sand to sand with varying silt.content. Soils in the western portion of I the site consisted of medium dense to very dense, weakly to moderately cemented glacial till composed of silty sand with gravel. I Test Pit TP-5, in the eastern portion of the site found glacial till soils to its termination depth. Test Pits TP-11 through TP-14 encountered medium dense to dense sand with varying amounts of silty sand to sand with silt underlying the glacial till horizon at depths of 9 and 12 feet below existing surface grade. I Page No.2 1