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r <br /> Union Ice Company- 61Veber Street <br /> Report of Findings <br /> Page: 5 <br /> 4.0 SITE CCNDnms <br /> 4.1 Soils <br /> The soils underlying this site have been investigated to a depth of 61.5 feet. <br /> These soils are composed of interbedded clays, silty clays and sands. They are <br /> part of a group of Quaternary Age sediments which belong to recent basin <br /> deposits in the Great Valley of California. These sediments were deposited <br /> during flood stages of major streams in areas between natural streant levees and <br /> alluvial fans. They include San Joaquin-Sacramecto River deposits in the <br /> Stockton area. <br /> The soils beneath the site are predominantly composed of moderately plastic to <br /> highly plastic clays and silty clays. They are dark brown to blue-grey in color, <br /> and contain localized thin lenses of sand and pea gravel_ Penetration resistance <br /> of the clays and silty clays ranges from 6 to 32 blows p;.:foot, which classifies <br /> them as being medium stiff to hard. The lower silty clay unit is approximately <br /> 16-20 feet thick and has the features consistent with being an excellent aquitard. <br /> It is a vett' fight clay and locaily is hard and difficult to penetrate with the <br /> auger. In MW-41), at the 50 foot sample, the blow count was 32 blows per <br /> foot. <br /> The sand units present at this site are wet and generally form the aquifers. The <br /> sands are fine to medium grained, tan to grey in color, micaceous, and contain <br /> localized thin pea gravel lenses. Upper sand units frequently contain varying <br /> amounts of clay. The lower sand unit, which is also the second aquifer, is a <br /> clean sand with less than five percent non-plastic fines. These sands are <br /> classified as loose to medium dense(Plate 2). <br /> 4.2 Ground Water <br /> Ground water was encountered between 15 and 17 feet in all monitoring wells <br /> as they were being drilled. After the wells were developed, the levels rose to <br /> between 12 and 13 feet. This shows that the upper clays have confined the first <br /> aquifer somewhat. A gradient contour map (Plate 3)was prepared and shows a <br /> gradient of approximately <br /> �e 0.4-fe-et/100 feet with—a-gradient direction-of-__ <br /> aPProcmatey Sde$rees E. The upper aquifer <br /> zone, between 15 and 33 <br /> feet, is composed of sands and pea gravel.lenses interbedded with thin silty clay <br /> horizons. All these units are saturated, however, the sands and gravels make <br />