5109 SOUND AVE 2017-08-02 - Laserfiche WebLink

July 21, 2014 Two Single-Family residences L&A Job No. 14-065 Page 3 TIIc project site is currently occupied in its west half by an existing house, with a swiinming pool in its northeastern quadrant. Above the site is a steep northwesterly- trending hillside with its toe extending into the southeast quadrant of the project site. The rest of the project site slopes down very gently northwesterly towards the northwest corner of the site. The toe of the steep hillsidc in the southeast quadrant of the site is dotted by young deciduous trees and shrubs and is covered by thick underbrush. The open space of the site is mostly covered by lawn grass. GEOLOGIC SETTING The Preliminarv Surficial Geolo�v Map of the Mukilteo and Everett Quadran�les, Snohomish County, Washington, by Mackey Smith, published in 1976 by U. S. Geological Survey, was referenced for the geologic and soil conditions of the site. According to this publication, the surficial soil unit sat and in the vicinity of the site are mapped as Vashon Till (Q�) underlain by Whidbey formation (Q�,�,). The geology of the Puget Sound Lowland has been modified by the advance and retreat of sevcral glaciers in the pasi and subsequent deposits and erosion. The latest glacier advanced to the Puget Sound Lov��land is referred to as the Vashon Stade of the Fraser Glaciation, which has occurred during ihe later stages of the Pleistocene Epoch and retreated from the region sorne 12,500 years ago. The deposits of the Vashon till soil unit were plowed directly under glacial ice during the most recent glacial period as the glacier advanced over an eroded, irregular surface of older fonnations and sediments. This soil unit is composed of a mixture of unsorted clay, LIU & ASSOCIATES, INC.