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August 1, 2008 <br />File No. 0&1-4 <br />Peters Residence <br />Page 5 <br />ordinance, the physical characteristics of this slope indicate a very high/severe erosion hazard <br />classification. While by definition, the slope is classified as a erosion hazard area, no <br />significant weather related erosion features are apparent on the slope surface or in the <br />vegetation cover. The lack of such features may be related to; 1) local topography, 2) road and <br />drainage infrastructure, 3) permeable site soils, and 4) a flat or slightly reversed surface grade <br />(away from the slope too). <br />At the time of my investigation work, numerous mountain beaver burrows were observed in the <br />bottom approximate 10 feet of the steep slope segment of the survey alignment. This type of <br />infestatior, has caused weakening and localized collapse of the slope surface in some cases on <br />other properties in the county. I would anticipate that, if such a collapse were to eventually <br />develop on this slope, it would have little effect on the Peters property or on the proposed <br />development. <br />Seismic Hazards <br />The subject property does not lie within a seismic hazard area, as shown on the City of Everett <br />Liquefaction (Seismic) Hazard mapping, (Critical Areas Map 4). Soil and ground water <br />conditions around this property and the adjacent slope are not conducive to liquefaction. <br />CONCLUDING OPINIONS <br />Based on my observations and understanding of the project concepts, I am of the opinion that <br />this property is compatible with the planed improvements. The dense native glacial advance <br />outwash soils are expected to provide a quality subgrade for support of the proposed addition, <br />and to maintain the current level of slope stability. The risk of slide related loss is expected to <br />be minimal for the new construction. <br />Development Considerations <br />Setbacks <br />The PCD currently requires that permanent structure setbacks in slide hazard areas be <br />determined by a qualified geologist based on slope dimension and geometry, geologic <br />conditions, site history, and other factors. As previously discussed, the slope on this property <br />appears to have a low wasting rate, and should not constitute an adverse impact to the planned <br />development. The planned remodel will utilize the existing building and garage foundations, <br />and basement level floor slabs. The mud room addition will be constructed on the south side o ; <br />��� Id <br />