406 PECKS DR Geotech Report 2025-07-14

• December 30th, 2021 G-5593 4730— Seahurst Ave,Washington 98203 Page 4 footprints to steep slope hazard areas is 25 feet, allowing for the development of the proposed project. Erosion Hazard—Medium We understand that the City of Everett has designated the western margin of the project site as a medium erosion hazard. The designation also includes the immediate west-adjacent property to the site. The area is illustrated on Geologically Hazardous Areas Map, attached as Plate 4 to this report. Per Everett Municipal Code (EMC) 19.37.080, these areas are described slopes between twenty-five (25)percent and forty (40)percent in Qvt(Glacial Till) geologic units. According to the USDA NRCS Soil Map, attached as Appendix B to this report,the site is underlain with Alderwood gravelly sandy loam (3) on slopes between 15 to 30 percent, Alderwood-Everett gravelly sandy loam(4) on slopes between 25 to 70 percent, and Alderwood- Urban land complex (6) on slopes between 8 to 15 percent. These soils have moderate to severe erosion susceptibility ratings according to USDA classification. We observed that the soils at the project site are mostly covered with native vegetation which include trees, shrubs, grass and other groundcover. In our opinion, the existing vegetation is a mitigating factor in regards to downslope soil erosion at the site. No additional mitigation other than the practices described in the grading and earthwork section of this report are necessary for the project, in our opinion. CONCLUSIONS AND RECOMMENDATIONS Seismicity Evaluation In accordance with the 2018 International Building Code,the site classification is Site Class C (very dense soil). Glacially consolidated soils have a high shear strength and the potential for landslides, liquefaction and/or lateral spreading is negligible during a strong motion earthquake. The site is stable and the risk of a surface rupture,resulting from a large magnitude seismic event, is very low. No seismic mitigation measures are recommended, with the exception of the addition of design criteria for seismically induced soil loads on permanent below-grade basement and retaining walls. GEO Group Northwest,Inc.