2111 ROSS AVE 2018-01-02 MF Import

content and occasional shell fragments and silt. Each of these units is discussed in more detail below. Topsoil/Fill Topsoil containing roots from surface vegetation was observed in the upper foot of the soil profile in each of the explorations. A layer of fill approximately '/-foot thick was observed in test pit TP-1 below the topsoil layer. The fill observed in test pit P-1 consists of medium dense sand with silt. Fill was also encountered, in borings C-1 and C-2, completed for a previous project. The fill in boring C-2 was approximately 1!/2 feet thick and consisted of loose silty sand with organic matter. The fill in boring C-1, located to the west of the Wilder site, ranged up to ' 13-%: feet thick and consisted of very loose to loose sand with variable silt and organic matter content. ' Recent Alluvium Organic Silt/Peat. The topsoil/fill is underlain by 10 to 17 feet of very soil to medium stiff 1 organic silt and silt with occasional interbedded sand layers. The silt contains variable amounts of fibrous organic material. A deposit of peat approximately 4 feet thick was observed in test pit TP-7 located near the middle of the site. It is probable that other peat deposits exist in the project vicinity. Test pits TP-1, TP-7 and TP-8 were terminated in the upper organic silt layer. The remainder of the explorations penetrated through the organic silt and peat deposits. ' Sands. The organic silt/peat soils are generally underlain by loose to medium dense fine sand with variable silt content. With the exception of boring B-1(02), all of the explorations that ' encountered this sand unit were terminated within this unit. Boring B-1(02) penetrated through the sand deposit at a depth of 73 feet. Based on shell fragments observed in the soil samples below a depth of about 43 feet, it appears the upper portion of the sand (to a depth of about 48 feet) was deposited in an alluvial environment, and the lower portion of the sand unit (48 to 73 feet) may have been deposited in an estuary -type environment. fEstuarine Deposits The estuary deposits include the lower 25 feet of the sand deposit described above. The sand p is underlain by very soft to stiff silt to a depth of approximately 99 feet in boring B-1(02). Boring 11 B-1(02) was terminated in a layer of medium dense silty fine sand at a depth of l01'/ feet. Groundwater Conditions Groundwater seepage was observed in the majority of the explorations at a depth of I approximately 5 feet below the ground surface at the time of the explorations. Evaluations of the representative soil samples obtained during the explorations indicate that the elevation of the groundwater is variable and has risen to near the existing ground surface. It is anticipated that the Igroundwater elevation will fluctuate as a function of precipitation, time of year, surrounding 6File 3101-020-00\072502 I t t G e 0 E n g i n c e r s