4927 23RD AVE W 2016-01-01 MF Import

UAVID L. NELSON AND ASSOCIATES. INC. Consulting Fneineering Geology � September 19, 1989 Project No. 12489 "� Page 2 , � LOCATION & SITE DESCRIPTION � The investigated site area consists of a residential lot area, located , immediately east of the existing Koch residence lot, located at 4925 - 23rd I Avenue West, in Everett, Washington. � Presently, the subject lot area is undeveloped, but has apparently been the � scene of some past grading and filling activity. Topographically, the lot � area slopes gently down toward the northeast, but breaks sharply over a distinct top-of-slope along the easterly portion of the lot. Belooi the too- I of-slope, the area slopes v?ry steeply down toward Narbeck Creek to the east. Vegetation within the area upslope of the top-of-slope consists of a few rnedium to large sized evergreen and deciduous trees, and scattered grass. At � the top-of-slope and downslope to the east, the vegetation consists of a mixture of various sized evergreen and deciduous trees, and thick underbrush. JSOILS CONDITIONS � The subsurface soils stratigraphy can best be seen on the enclosed test pit logs. Geologically, the site is underlain by cortipact fine grained deposits, � considered the Whidbey Formation interglacial deposits, common to the area. The basal native soils encountered within the site area consist of grey-brown � to grey, medium dense to dense, silty very fine sand and fine sandy silt. These materials were encountered throughout the site area, generally below Jabout 5.5 to 10.5 feet below grade. An overlying strata of brown to �rey, medium dense to dense, silty very fine sand and sandy silt in a fractured j state was generally encountered, and was found to vary from about 1.5 to 4.5 i feet thick. This material is considered the same as the underlying strata, � expect for a decrease in density due to the observed fracturing. Overlying these basal compact fine grained deposits across the site are weathered zone � materials, consisting of about 1.0 to 3.5 feet of brown and grey, loose to medium dense, silty fine sand. The native surficial soils were generally found to consist of about 2 feet of brown loose silty sand with rcots. + �