5034 OCEAN AVE Geotech Report 2022-10-25

51xx Ocean Avenue (Parcel#00571700100100) November 1, 2017 Everett, Washington Project#17110 Stratigraphy Fill Soils We encountered fill soils of significant thickness in all the explorations performed for this study. We presume that these fill soils are associated with previous grading of the subject property. Based on the location and foundation elevations of the proposed home, the fill soils will require mitigation to provide adequate support for the new home. We presume that the fill soils will be over-excavated and replaced with structural fill or the foundation of the new home will be supported by steel pipe piles. Transition Beds The native soils encountered underlying the fill soils consisted of medium dense to dense, fine to medium sand with varying amounts of silt and gravel, as described in the attached exploration pit logs. We interpret these sediments to be transition beds,which is in agreement with the referenced geologic map (Minard, 1982). These sediments consist of glacial and non- glacial sediments of pre-Fraser to Fraser-age. These fine-grained sediments were deposited in pro-glacial lakes and fluvial environments prior to the Vashon glacial advance. These sediments were over-consolidated by the Vashon glacial ice. In some localities,where exposed in steep slopes and adverse groundwater conditions are present,these sediments are prone to landsliding. For the slopes and conditions observed on site, it is our opinion that the site conditions do not present a significant risk for landslide. Hydrology There was minor to moderate ground water seepage in EP-2 at depth of 6 feet. It is likely that there will be groundwater seepage from the temporary cut slopes required for the foundation excavation. These temporary cut slopes may need to be field fit and made less steep during construction, but it appears that there is enough room to do so. Though groundwater conditions may change due to seasonal weather conditions, it is our opinion that any groundwater encountered during construction can be mitigated by following the recommendations set forth in the section titled "Drainage Considerations". Geologic Hazards The following discussion of potential geologic hazards is based on the visual reconnaissance of the site, the subsurface explorations, review of aerial photographs and regional topographic and geologic maps of the area, review of applicable maps available online,and review of the City of Everett Municipal Code. Though there are some moderate to steep slopes on the subject property, it is our opinion that there are no geologic hazards associated with this lot. As such, the following sections of this report will discuss the existing slopes with respect to the proposed development, provide some basic erosion control best management practices for use during construction, and will address general seismic risks and design parameters associated with a seismic event. SOUTH FORK GEOSCIENCES, PLLC Page 2 PO Box 1275 NORTH BEND,WA 98045 425-831-2023 I ANDREW@SFGEO.COM