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3 J <br /> GeoTest Services,Inc. October 24,2014 <br /> Jacobson Deck and Garage Improvements,Everett,WA Job No. 14-0554 <br /> General Geologic Conditions <br /> General geologic conditions in the vicinity of the site are mapped as Transitional Beds <br /> overlying Whidbey Formation per the geologic map titled Distribution and Description of <br /> Geologic Units in the Mukilteo Quadrangle, Washington, prepared by the United Stated <br /> Geologic Survey(Minard, 1982). <br /> Transitional Beds consist of glacial and non-glacial deposits and consist of thick beds of <br /> gray clay, silt, and fine- to very-fine sand. Per the regional map, Transitional Beds can <br /> be as much as 80 to 90 meters thick and can extend into the upper beds of the <br /> underlying Whidbey Formation. Transitional Beds are firm-appearing on bluffs, but <br /> because of high water content, springs, and/or jointing of the soil unit, they can become <br /> unstable in steep slopes and are included in numerous landslides. <br /> The Whidbey Formation is an older unit that was deposited below Vashon-age glacial <br /> sediments. Whidbey Formation is described as a medium-bedded sand, silt, and clay <br /> with particle sizes from clay (very small) to coarse sand. Whidbey Formation is <br /> generally considered a glacially over-ridden deposit, but contains both granular and clay <br /> beds within the deposit. Where sand overlies clay, and in conjunction with steep slopes, <br /> failure is common and many landslides have occurred. <br /> Our on-site observations indicate the presence of steep, near vertical slopes on some <br /> portions of the exposed hill side that appear to be more indicative of Whidbey Formation <br /> than of Transitional Beds. GTS did not perform a subsurface soil exploration as part of <br /> our contracted services and our opinions are based on a review of the regional geologic <br /> map and our on-site observations. <br /> Site Conditions <br /> The location of the proposed deck and kitchen improvements are on the north side of the <br /> residence. It is expected that the footprint of the deck will be extended slightly to the <br /> north in some areas, but that no new significant foundation loads are expected as part of <br /> the planned improvements. <br /> The ground surface in proximity to the proposed deck and kitchen addition <br /> improvements are relatively flat with a gentle slope extending down toward the top-of- <br /> slope condition to the north. Below the top of slope condition is a steep slope estimated <br /> to be between 0.5H:1V and 0.75H:1 V, extending down to the BNSF railroad track at the <br /> toe of the slope. The vertical differential between the top-of-slope and toe-of-slope was <br /> estimate to be approximately 50 feet. GTS observed that the house currently has about <br /> 50 feet of horizontal separation between the above-grade portion of the house and the <br /> top-of-slope condition. This separation excludes the footprint of the existing deck. The <br /> horizontal separation between the top-of-slope condition and edge of the deck was <br /> estimated to be approximately 35 to 40 feet. <br /> Native vegetation on most of the immediate areas surrounding the existing residence <br /> has been removed and replaced with irrigated lawn and landscaping. _ The slope is <br /> moderately vegetated with deciduous trees and typical forest underbrush. During our <br /> site observations, GTS observed oversteepened and bare soil exposures on the slope <br /> that appeared indicative of shallow soil sloughing. GTS also observed "pistol-butting" of <br /> some of the trees on the slope which is indicative of past slope movement. <br /> Page 2 of 9, 7_ <br />