917 112TH ST SE Geotech Report 2022-10-25

Habitat for Humanity of Snoiomish County ES-5168 April 26, 2017 Page 2 Project Description We understand the site will be redeveloped with six multi-family units, an addition to the residence at 917 — 112th Street Southeast, and related infrastructure improvements. Existing structural improvements (several residences and associated outbuildings) will be removed in accordance with the proposed redevelopment. A stormwater detention vault (vault) is proposed within the northern portion of the site. At the time of report submission, specific building load and grading plans were not available for review; however, based on our experience with similar developments, the proposed residential structures will likely be two to three stories in height and constructed using relatively lightly loaded wood framing supported on conventional foundations. Perimeter footing loads will likely be about 1 to 2 kips per lineal foot (klf). Slab-on-grade loading is anticipated to be approximately 150 pounds per square foot (psf). Cuts and fills of about five feet may be necessary to establish finish grade elevations for the new residential lots. We expect cuts to achieve the vault subgrade elevation will be roughly 10 to 15 feet. Retaining walls and/or rockeries may be incorporated into final designs to accommodate grade transitions, where necessary., If the above design assumptions are incorrect or change, ESNW should be contacted to review the recommendations provided in this report. ESNW should review final designs to confirm that appropriate geotechnical recommendations have been incorporated into the plans. SITE CONDITIONS Surface The subject site is located north of the intersection between 112th Street Southeast and. Windsong Lane in Everett, Washington. The approximate location of the subject site is depicted on Plate 1'(Vicinity Map). The subject site is comprised of three adjoining tax parcels (Snohomish County parcel numbers 2805190030-0300, -1200, and -2600) totaling approximately 1.42 acres of land area. The site is bordered to the east, north, and west by residential developments, and to the south by 112th Street Southeast. Several single-family residences and associated improvements currently occupy the site. Site topography is generally flat with five feet or less of elevation change across to subject site. Vegetation is comprised primarily of grass and shrub landscaping with areas of dense brush and bramble. Earth Solutions NW,LLC