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December 13,2006 <br /> Project No.T-6001 <br /> Figures A-2 through A-8 present more detailed descriptions of the subsurface conditions encountered in the test <br /> pits. The approximate test pit locations are shown on Figure 2. <br /> 3.3 Mapped Geology <br /> The soils in the vicinity of the site are mapped on Geologic Map of the Everett 7.5-Minute Quadrangle, <br /> Snohomish County, Washington (1985)as Vashon Till (Qvt). As described on the map,Vashon Till "...is a non- <br /> sorted mixture of mud, sand, pebbles, cobbles, and boulders..." The till-like soils observed in our test pits <br /> generally correlate with the published description of Vashon Till. <br /> 3.4 Groundwater <br /> Light to moderate groundwater seepage was observed in each of the test pits at depths ranging from 1.5 feet to 3 <br /> feet below current site grades. The groundwater generally occurred as seepage perched within the upper zone of <br /> loose to medium dense soils lying immediately above the till-like soils. The dense to very dense till-like soils <br /> have a relatively low permeability that impedes the downward migration of the infiltrated surface water. As a <br /> result, groundwater seepage will develop and tend to flow laterally along the till contact. Locally, such seepage <br /> is referred to as interflow. <br /> The depth to groundwater and seepage volumes in excavations will vary both seasonally and annually. In a given <br /> year,we expect the highest groundwater levels and seepage volumes will occur between November and March. <br /> 4.0 GEOLOGIC HAZARDS <br /> E <br /> 4.1 Erosion <br /> As outlined in City of Everett Ordinance No. 2909-06,Section 8,erosion hazard areas are classified as: <br /> • Hig1; and very high-severe risk of erosion <br /> e Medium risk of erosion <br /> Each classification is based on slope inclinations of 25 percent, 25-40 percent, and >40 percent, in combination <br /> with specific geologic units. Due to the absence of slopes at the site, the site does not meet City of Everett's <br /> criteria for high, very high/severe, or medium risk erosion hazard areas. Regardless,erosion protection measures, <br /> as required by City of Everett, will need to be in place prior to and during grading activity on the site. <br /> 4.2 Landslide and Steep Slopes <br /> Review of the City of Everett Ordinance No. 2909-06 indicates that, according to Section 8, no portion of the site <br /> lies within a landslide hazard area. This is due to the absence of slopes at the site, the site's geology, and <br /> observed site conditions. <br /> Page No. 3 <br />