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Pacific Ridge — DRH, LLC ES-7852.01 <br /> March 15, 2022 Page 4 <br /> Geologic Hazard Areas Assessment <br /> As part of this geotechnical engineering study, the geologically hazardous areas section of the <br /> Everett Municipal Code (EMC) chapter 19 and the referenced hazard maps were reviewed. <br /> Based on the results of our study, the site is not within, or immediately adjacent to, geologic <br /> hazard areas. <br /> DISCUSSION AND RECOMMENDATIONS <br /> General <br /> In our opinion, construction of the proposed residential development is feasible from a <br /> geotechnical standpoint. The primary geotechnical considerations associated with the proposed <br /> project include earthwork, temporary excavations, structural fill requirements, subgrade <br /> preparation, foundations and soil bearing capacity, utility support and trench backfill, and <br /> drainage. <br /> The existing fill encountered within the western/southwestern portion of the site is not suitable for <br /> structural support in its current condition. We recommend overexcavating and replacing the <br /> existing fill or supporting structures on pipe piles. Recommendations for overexcavating and <br /> replacing the existing fill are provided in this report; ESNW can provide recommendations for pipe <br /> piles, or other deep foundation options, upon request. <br /> As part of mass grading activities, we recommend overexcavating and replacing the existing fill <br /> with suitable structural fill; ESNW can further evaluate the suitability of the existing fill during <br /> construction. We anticipate existing fill to extend to depths of about four to six feet. Based on <br /> moderate to heavy groundwater seepage encountered at the test pit locations, an approximate <br /> two-foot layer of quarry spalls will likely be necessary where existing fill is overexcavated. Filter <br /> fabric should be placed over the quarry spalls prior to placing general fill soil. <br /> After completing earthwork activities in accordance with recommendations in this report, the <br /> proposed structures can be supported on conventional spread and continuous foundations <br /> bearing on undisturbed, competent native soil, recompacted native soil, or new structural fill. <br /> Where loose or unsuitable soil conditions are encountered at foundation subgrade elevations, <br /> compaction of the soils to the specifications of structural fill, or overexcavation and replacement <br /> with suitable structural fill will likely be necessary. A representative of ESNW should confirm <br /> suitability of foundation subgrades at the time of construction. <br /> Due to the high moisture sensitivity of the site soils, foundation subgrade areas should be <br /> protected from wet weather or areas of remediation should be anticipated; a layer of crushed rock <br /> can be considered to protect foundation subgrade areas. If structural building pads are disturbed <br /> during wet weather, remediation measures such as cement treatment or overexcavation and <br /> replacement with rock may be necessary in some areas. Additionally, perched groundwater <br /> seepage may create unsuitable soil conditions above the hardpan which would require aeration, <br /> cement treatment, or replacement with crushed rock. <br /> Earth Solutions NW, LLC <br />