7815 E GLEN DR 2016-01-01 MF Import

Topsoil Soil encountered at the surface at the location of EP-2, and below the fill at the location oi EP- 1, generally consisted of very loose to loose, wet to saturated, brown, silty sand with some gravel and substantial quantides of organic matter. This material was interpreted to be an organic topsoil or topsoil fiil. The tlrickness of the topsoil or topsoil fill at the locations of EP- 1 and EP-2 ranged from approximacely 2'fz to 4�k feet, respectively. Lodgement Till Sediments encountered below the fill and organic topsoil or topsoil fill, at depths ranging from approximately 4'k t� 6 feet, geneially consisted of inedium dense to very dense, gray to brownish gray, silry sand with gravel and scattercd cobbles. These sediments are interpreted to be lodgement ull. The dense to very dense condition characteristic of lodgement till is due to its compaction by the several thousand feet glacial ice that once overlaid these sedimenu. Where the till has been exposed at the surface, the density of the upper several feet of the dll is �ften reduced due to the effects of weathering. At the locations of EP-1 and EP-2, the upper 1 to 1'k feet of the lodgement till had been �veathered to a medium dense condition. Review of the geologic map endded "Distri6urion and Description of the Ceologic Units in the Everett Quadrangle, Washirtgton" by Jame.; Minard (1981), indicates tUa: the area of the subject site is underlain by Vashon lodgeme.nt till. The Vashon dll was deposited during the Vashon Stade of the Fraser Glaciation approximately 12,500 to 15,000 years ago. Our _ ___--_---------- interpretation of the sedimenfs encountered in the explo�afion�pi�a-af the site arc�"in general agreement with this map. _ 4 � Hvdroloev Minor amounts of ground water seepage were encountered at We locadons of both o1' tlie exploradon pits. Slow ground water seepage was observed to emanzte from the medium dense, W�eadiered lodgement till sediments at the locadon of exploration pit EP-1 at a depth of approximately 6 to 7 feet. At the location of exploration pit EP-2, located downslope of EP-1, itioderate ground water seepage was observed to emanate from both the organic topsoil or topsoil fill and weathered lodgement till at depths ranging from approximately 3 to 6 feet. The seepage at the location of EP-2 was accompanied by internutter�t caving. At both exploration pit locations, the ground water appeared to be perched atop the underlying unweathered, dense to very demse. lodgement till sediments. � ��s.��l a.� �,��1�.�. 4