4800 DOGWOOD DR Geotech Report 2022-10-25

Subsurface Exploration, Geologic Hazards, View Ridge Community Church Addition and Geotechnical Engineering Report Everett, Washington Geologic Hazards and Mitigations hazard by the City of Everett and is mapped as a very low liquefaction susceptibility by Snohomish County. No detailed liquefaction analysis was completed as part of this study, and none is warranted, in our opinion. 6.3 Ground Motion It is our opinion that earthquake damage to the proposed addition, when founded on suitable bearing strata in accordance with the recommendations contained herein, will likely be caused by the intensity and acceleration associated with the event. Design of the addition should follow 2015 IBC standards using Site Class "D" as defined in Table 20.3-1 of American Society of Civil Engineers (ASCE) 7 — Minimum Design Loads for Buildings and Other Structures. 7.0 EROSION HAZARDS AND MITIGATIONS EMC defines a high erosion hazard area to include slopes of 25 to 40 percent in advance outwash and alluvial geologic units, and slopes of greater than 40 percent in other geologic units. The existing slope and soils on the site are considered highly prone to erosion when exposed to surface water. The surrounding area, steep slope and Dogwood -Elm Creek should be protected from the effects of construction traffic and prevent the off -site transport of sediment -laden water. To mitigate the erosion hazards and potential for off -site sediment transport, we recommend the following: 1. Construction activity should be scheduled or phased as much as possible to reduce the amount of earthwork activity that is performed during the winter months. 2. The winter performance of a site is dependent on a well -conceived plan for control of site erosion and storm water runoff. The project temporary erosion and sediment control (TESC) should include ground -cover measures, access road, and staging areas. The contractor must implement and maintain the required measures. A site maintenance plan should be in place in the event storm water turbidity measurements are greater than the Washington State Department of Ecology (Ecology) standards. 3. TESC measures for a given area to be graded or otherwise worked should be installed soon after ground clearing. The recommended sequence of construction within a given area would be to install sediment traps or sumps, and establish perimeter flow control prior to starting construction. August 29, 2016 ASSOCIATED EARTH SCIENCES, INC. SKL11d - KE160351A2 -Projects �20160351 JKEJ WP Page 8