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-4- <br />(Visual-Manual Procedure)". The final exploration logs represent our <br />interpretation of the contents of the field logs and the results of laboratory <br />observation. . - — <br />SITE AND SUBSURFACE CONDITIONS <br />The existing substation is located on a relatively flat reclaimed tidal area <br />less than one-half mile from Possession Sound in Everett, Washington. <br />Approximately 150 feet east of the site there is a steep bluff which most <br />probably at one time was the border between Possession Sound and land. Tfiis <br />tidal flat area probably was then filledtin for usable land. The station <br />subgrade is covered with crushed gravel sfialier than about 2 irches in size. <br />Beneath the surficial crushed gravel, our explorations encountered <br />approximately 27 feet of very loase to medium dense fill which consisted of <br />material ranging from charcoal, arganic material, waod chips, saw dust, and <br />pieces of brick. The matrix of the fill ranged from a sandy silt to a silty <br />sand and gravel which became more organic;below the water table. Water was <br />encountered in bath borings at about 12 feet below the ground surface. The <br />groundwater down to 27 feet was black and had a high organic content. At 27 <br />feet below the ground surface, a dense to very dense sand was encountered in <br />' both borings. The sand contained scattered pieces of wood which may indicate <br />that it was deposited in a water environment and possibly a beach environment. <br />The sand layer continued to the end of each boring at 52 feet below the ground <br />• surface. <br />DISCUSSION AND RECOMMENDATIONS <br />The upper fill layer,'27 feet thick at our boring locations, is unsuitable for <br />shallow or medium depth foundations such'as spread footings, slabs, or shallow <br />drilled piers. The loads imposed by the circuit switcher will need to be <br />supported by a deep foundation which will transfer the load to the dense to <br />very dense sand layer. We anticipate that there will be minimal grading <br />involved with the replacement of the circuit switcher; however, the near <br />surface soils have a high silt content and, may degrade to a slurry-like <br />comerse conaiMar�h r11v <br />