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(SolutionsEarth <br /> Lk <br /> NWLLC <br /> April 1, 2019 Earth Solutions NW LLC <br /> ES-6516 Geotechnical Engineering, Construction <br /> Observation/Testing and Environmental Services <br /> DevCo, Inc. <br /> 10900 Northeast 8t" Street, Suite 1200 <br /> Bellevue, Washington 98004 <br /> Attention: Mr. David Ratliff <br /> Dear Mr. Ratliff: <br /> Earth Solutions NW, LLC (ESNW) is pleased to present this report titled "Geotechnical <br /> Engineering Study, Four Corners, 8102 Evergreen Way, Everett, Washington". Based on the <br /> results of our investigation, the proposal is feasible from a geotechnical standpoint. Our study <br /> indicates the site is underlain primarily by glacial till, with minor areas of fill. Perched groundwater <br /> seepage was encountered at the boring locations between depths of about 3 to 15 feet below the <br /> existing ground surface elevation. In our opinion, the contractor should be prepared to manage <br /> discrete zones of groundwater seepage during construction. <br /> Based on our findings, it is our opinion the proposed multi-family structures may be constructed <br /> on conventional continuous and spread footing foundations bearing upon dense to very dense <br /> native soil. In general, dense native soil suitable for support of foundations will likely be <br /> encountered beginning at depths of about two-and-one-half to eight feet below existing grades. <br /> Where loose or unsuitable soil conditions are exposed at foundation subgrade elevations, <br /> overexcavation to a depth that exposes dense native soils and replacement with crushed rock or <br /> lean mix will be necessary. <br /> Given the presence of dense to very dense native glacial till at relatively shallow depths, it is our <br /> opinion infiltration is not feasible from a geotechnical standpoint. The appreciable fines contents <br /> and high in-situ density of the deposit will likely inhibit the function of any full-scale infiltration <br /> system. From a geotechnical standpoint, the native glacial till should be considered impervious <br /> for purposes of large scale infiltration design. <br /> Pertinent geotechnical recommendations are provided in this study. We appreciate the <br /> opportunity to be of service to you on this project. If you have questions regarding the content of <br /> this geotechnical engineering study, please call. <br /> Sincerely, <br /> EARTH SOLUTIO S NW, LLC <br /> 1 /1 4 <br /> Chase G. Halsen <br /> Senior Staff Geologist <br /> 1805 - 136th Place N.E., Suite 201 • Bellevue, WA 98005 0 (425)449-4704 0 FAX(425)449-4711 <br />