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Memorandum to City of Everett <br /> February 28, 2022 <br /> Page 2 <br /> Original site grading occurred during the early 1990s when the roadways and development were constructed. <br /> Based on review of historic photos, it appears the area south of the fence within the center of the landslide <br /> mass was recently cleared(2018).We observed significant debris(cut wood rounds,stumps,concrete,downed <br /> trees, yard debris) throughout the eastern portion of the slope within the slide mass and within the recently <br /> cleared area. This area has a gentler slope than the adjacent native slopes and may contain more fill placed <br /> during original development. The slope was saturated with standing water during our site visit, and contained <br /> small pools within the heavy debris area south of the fence line. ras <br /> igfft <br /> ,1 � <br /> �• 3 iq,�6 � <br /> ij 6• rt a i'it � <br /> � � t / <br /> .. y k ,.� u" f �. 3a •a,rr� '�r y " cf.,,• <br /> , b ry � ,,a. <br /> 1 <br /> ` n fir. .;h»,�:. - �� ix !Lr�'x,ww".�t 4 ,! '�"� <br /> • <br /> !' -?i�p ` �R t fib.1 .i fr.. yf <br /> - G.a -? - '"t t <br /> • <br /> Photo 3. Looking East from Central Area of Landslide Photo 4.Looking South at Debris on Slope(Discarded <br /> Wood,Downed Trees,Yard Debris, <br /> Vegetation within the landslide area includes a few standing large deciduous trees and brush (primarily <br /> blackberry) and an occasional conifer. We observed numerous large deciduous trees had fallen on the slope <br /> exposing the root ball and underlying soils. Exposed soils within the depressions appeared to consist of old <br /> landslide debris and transitional deposits(loose,saturated silt with sand/sand with silt). <br /> GEOLOGY <br /> Soils in the immediate vicinity of 59th Street SW and the closest cross street 25th Avenue West,are mapped as <br /> glacial till (Vashon Till) within the upland area overlying advance outwash (Fraser Glaciation) on the upper <br /> slopes.Transitional beds(Fraser Glaciation to pre-Fraser)are mapped on the lower slope of Powder Mill Gulch <br /> (Minard 19821). <br /> In the Everett area, advance outwash is exposed where the overlying glacial till cap has been eroded away, <br /> typically within the upper portions of ravines and bluff margins.The outwash deposits typically consist of clean <br /> fine to medium sand that has been overridden by thousands of feet of ice. They are typically dense to very <br /> dense and moderately to highly permeable. <br /> Transitional beds underlying the advance outwash in the site vicinity consist primarily of clayey silt with lenses <br /> of sand and silty sand in the upper portion of the deposit. The transitional beds and advance outwash layers <br /> 1 Distribution and Description of Geologic Units in The Mukilteo Quadrangle,Washington,dated 1982 by James P.Minard. <br /> GeoEngineers,Inc. <br /> File No.0661-133-00 <br />