3003 COLBY AVE COURTYARD BY MARRIOTT 2021-03-09

1 Proposed Everett Hotel Property Environmental Site Characterization and Everett, Washington Remediation Recommendations IFill Fill soils (those not naturally placed) were encountered at the locations of borings EB-1, EB-2, EB-4, EB-7, EB-8, and EB-12. Borings EB-1 and EB-2 were located in the area where two underground storage tanks (USTs)were ,reported to have been located. These tanks were associated with the former en Buick car dealership)Boring EB-7 is located in the reported former area of a fuel dispenser also associated with the former car dealership. The fill generally consisted of loose to medium dense sand with variable silt and gravel content, and stiff, non-plastic silt. Trace to moderate quantities of organic debris, roots, and small pieces of asphalt were encountered in the fill at some locations. The approximate thickness of the fill encountered at each of these locations is shown in Table 1. Table 1 Summary of Fill Thicknesses Approximate Fill Thickness 1 Boring No. (feet) EB-1 13 EB-2 6.5 EB-4 8.5 EB-7 3.5 EB-8 3 EB-12 8 I 1 Lodgement Till With the exception of boring EB-1, sediments encountered below the fill, or directly below the ground surface where no fill was encountered, generally consisted of very dense, grayish tan to gray, silty sand with gravel. Scattered, thin lenses of sand were encountered within this unit at some locations. We interpret these sediments to be representative of Vashon lodgement till. ' The Vashon lodgement till was deposited directly from basal, debris-laden glacial ice during the Vashon Stade of the Fraser Glaciation approximately 12,500 to 15,000 years ago. The high relative density of the lodgement till is due to its consolidation by the massive weight of the glacial ice from which it was deposited. Where lodgement till is or has been exposed at the ground surface, the upper several feet of the till typically becomes weathered. At the locations of exploration borings EB-2 through EB-4, EB-7, EB-8, EB-11, and EB-12, the upper portion of the till was weathered to a reddish brown to tan color and loose to medium dense condition. The thickness of the weathered till horizon at these locations ranged from approximately 1.5 feet at the locations of borings EB-2 and EB-8, to 7 feet at the location of boring EB-3. The thickness of the weathered till at the location of boring EB-3 seemed unusually high. For this reason, it is possible that this may be due to the presence of a fill layer between the ground t August 24, 2009 ASSOCIATED EARTH SCIENCES, INC. TJP/tb-KV090168A5-Projects120090168IKVIWP Page 3