1136 GRAND AVE A&B 2016-01-01 MF Import

' � April 23, 2007 Mc Scott Anderson L&A.lob No. 6A 12( Page 2 The site is currently occupicd in its middle by an existing house. The unpaved open ama of thc site is covered �vith lawn grass and with widely scattcred, tall, maturc, evcrgreen trces dotting the front yard and the crest of the steep slopa 'fhe trunks uf thesc trees are straight, indicating they have not expericnccd soil movemcnt on thc site. l�hc steep slope is covcrcd by dense brush and shrubs. Geologic Settin�and Soil Conditions Geoloeic Map of the Hverctt 7.5-Minute Ouadrangle, Snohomish County, Washington, by James P. Minard, published by U. S. Gcological Survey in 1985, was refemnced for the geologic and soil conditions at thc sitc. According to this publication, thc su�cial soil units at and in thc viciniry of the subjcct site is mapped as Vashon Till (Q,�) underlain Advance Ourivash (Q�.�). 'I'hc geology of thc Pugct Sound Lowland has been modified by the advance and retreat of several glaciers in the past and subsequent deposits and erosion. The latest glacier advanced to the Pugct 3ound Lowland is referred to as the Vashon Stade of the rraser Glaciation, which has occurtcd during the later slages of thc Pleistocene Gpoch and retreated from the region some �a,soo ,��:,�s .��,. "I'hc Vashon till soil unil is depositcd dircctlp by glaci.il icc Juring the most recent glacial period �s it advanced ovcr an crodcd, irregular surFace of older formations and sediments. It is a very dense mi�ture of unsorlcd clay, silt, sand, gravel, and scattered cobbles and boulders, often referreJ to as "hard pan". The Vashon till over the top t�vo to four feet is normally wealhered to a mediunrdense state, and is moderately pernicable and compressible. The underlying fresh till is very dense:tnd is practically impervious to stormwater infiltration. The fresh till has the strength of low-grade concrete and can stand in a sleep natural or cut slope for a long period. If rcmains LIU & ASSOCIATES, INC.