2202 100TH ST SW Geotech Report 2022-10-25

Subsurface Exploration, Geologic Hazard,and Stephens Everett Property Preliminary Geotechnical Engineering Report Everett, Washington Project and Site Conditions the project site. Due to the irregular surface of the lodgement till, groundwater contained within the lower portion of the recessional outwash can thicken in low areas on the underlying till surface, and can be thin or go dry on underlying higher till surfaces. Recharge to the local recessional outwash sediments occurs from precipitation, surface flow, or shallow interflow. • Perched water in the lodgement till: Groundwater was also observed emanating from a sandier lens within the Vashon lodgement till sediments in exploration pit EP-4. Where present, these sandy lenses provide a more-permeable pathway for water to flow when compared to the general composition of the lodgement till. These lenses are typically limited in extent and are not a significant source of groundwater. Wetlands Two wetland areas have been identified on the east and east-central portions of the project site.The upper boundary of the two wetlands has an elevation of approximately 551.5 feet and appears to naturally drain offsite to the southeast. No standing water was observed in the wetlands at the time of our explorations. Portions of the interflow and perched water in the recessional outwash is interpreted to discharge to the wetlands. March 29,2019 ASSOCIATED EARTH SCIENCES,INC. TG/ms-180567E001-2-Projects\201805671 KEI WP Page 6