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ieoTest Services, Inc.—Revision 1 April 10,2020 <br /> Kikuchi Retaining Wall, Everett,Washington Project No. 20-0344 <br /> ummommi <br /> slopes. Yard waste can retain water and cause slope instability. <br /> • Proper drainage controls have a significant effect on erosion. Surface and collected <br /> drainage water should not be allowed to be concentrated and discharged down the face <br /> of an existing steep slope. All collected stormwater should be directed to an appropriate <br /> collection system. <br /> • All areas disturbed by construction practices should be vegetated or otherwise protected <br /> to limit the potential for erosion as soon as practical during and after construction.Areas <br /> requiring immediate protection from the effects of erosion should be covered with either <br /> plastic, mulch or erosion control netting/blankets. Areas requiring permanent <br /> stabilization should be seeded with an approved grass seed mixture, hydroseeded with <br /> an approved seed-mulch-fertilizer mixture or landscaped with a suitable planting design. <br /> In addition to the preceding recommendations, typical erosion control measures during <br /> construction will be required.These measures can include a rock-surfaced construction entrance <br /> or downslope silt fencing, depending on the regulations of the City of Everett. No other <br /> mitigations are required to address erosion hazards on the property. <br /> Seismic Hazard Areas <br /> Seismic Hazard Areas are defined by EMC as "areas mapped as high and moderate to high <br /> liquefaction susceptibility on the Liquefaction Susceptibility Map of Snohomish County, <br /> Washington, Washington State Department of Natural Resources, Palmer, Stephen, et al., <br /> September 2004." <br /> Based on a review of information obtained from the Washington State Department of Natural <br /> Resources (DNR) Geologic Information Portal, the subject property is mapped as having a very <br /> low to low liquefaction susceptibility. However, this map only provides an estimate of the <br /> likelihood that soils will liquefy as a result of an earthquake and is meant as a general guide to <br /> indicate areas potentially susceptible to liquefaction. It is GeoTest's opinion that the subject <br /> property is in general accordance with the mapped very low to low liquefaction susceptibility and <br /> therefore is not located in a Seismic Hazard Area. Thus, no mitigation for seismic hazards are <br /> needed for site development. <br /> 12 <br />