9606 19TH AVE SE PREMIER STORAGE Geotech Report 2022-10-25

Premier Storage Everett, LLC ES-2432 June 26, 2012 Page 6 Revised June 28, 2012 Site Preparation and Earthwork Site preparation activities will likely include removing existing structures and installing temporary erosion control measures. Site Stripping Recommendations Where asphalt pavement and gravel surfacing is not present, stripping will likely be limited to about three to four inches and will be required primarily along the western site margins. Topsoil and organic-rich soil is not suitable for foundation support, nor is it suitable for use as structural fill. Topsoil or organic-rich soil can be used in non-structural areas if desired. Temporary Erosion Control Temporary construction entrances and drive lanes, consisting of at least 12 inches of quarry spalls can be considered in order to minimize off-site soil tracking and to provide a stable access entrance surface. Erosion control measures should consist of silt fencing placed along the down gradient side of the site. Soil stockpiles should be covered or otherwise protected to reduce soil erosion. Temporary sedimentation ponds or other approaches for controlling surface water runoff should be in place prior to beginning significant earthwork activities. In-situ Soils The soils encountered throughout the majority of the test sites have a high sensitivity to moisture and were generally in a moist to wet condition at the time of the exploration (June 2012). In this respect, the in-situ soils may not be suitable for use as structural fill if the soil moisture content is above the optimum level at the time of construction. In general, soils encountered during site excavations that are excessively over the optimum moisture content will require aeration or treatment prior to placement and compaction. Conversely, soils that are substantially below the optimum moisture content may require moisture conditioning through the addition of water prior to use as structural fill. If the in-situ soils are determined to not be suitable for use as structural fill, then use of a suitable imported soil may be necessary. In our opinion, a contingency should be included in the project budget for exporting unsuitable soil and importing structural fill. Wet Season Grading If significant grading takes place during the wetter winter or spring months, a contingency in the project budget should be included to allow for export of native soil and/or existing fill and import of structural fill as described below. Earth Solutions NW, LLC