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Subsurface Exploration, Geologic Hazard, and <br /> 2721 Wetmore Preliminary Geotechnical Engineering Report <br /> Everett, Washington Project and Site Conditions <br /> The advance outwash is suitable for support of building foundations but may not be <br /> encountered in the base of the excavation for the proposed structure. These sediments can be <br /> used in structural fills, and the ability to achieve suitable compaction and performance of the fill <br /> will depend mostly on the moisture content at the time of placement. At the time of our <br /> subsurface investigation program, the observed moisture content of the advance outwash was <br /> at or above that necessary to achieve the required level of compaction needed for use as <br /> structural fill. Some moisture-conditioning (wetting or drying) may be required depending on <br /> the time of year construction occurs. <br /> 4.2 Geologic Literature <br /> Review of the Geologic Map of the Everett 7.5-Minute Quadrangle, Snohomish County, <br /> Washington (United States Geological Survey [USGS] Map MF-1748) by James P. Minard (1985) <br /> indicates that the area of the subject site is mapped as Vashon till. Vashon advance outwash is <br /> mapped within a few blocks topographically downslope to the east and west of the site. Our <br /> interpretation of these sediments encountered in our explorations is in general agreement with <br /> the referenced regional geologic map. <br /> 4.3 Hydrology <br /> Minor groundwater seepage was encountered in one exploration boring completed by <br /> Associated Earth Sciences, Inc. (AESI) on the property. A limited zone of groundwater seepage <br /> was encountered in boring EB-1 while drilling from 35 to 40 feet. We interpret the observed <br /> groundwater to represent a locally perched condition that can occur above more silty interbeds <br /> within the advance outwash as was observed in other borings on the site. This localized <br /> groundwater seepage is located below the maximum depth of the excavation for the planned <br /> structure. Though not observed in the lodgement till onsite at the time of drilling, limited zones <br /> of groundwater seepage such as this should be anticipated in other areas during excavation for <br /> the structure. <br /> It should be noted that the depth and occurrence of groundwater seepage may vary in <br /> response to such factors as changes in season, precipitation, and site use. <br /> May 28,2019 ASSOCIATED EARTH SCIENCES, INC. <br /> FSM/Id-190168E001-2-Projects\20190168\KE\WP Page 5 <br />