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�� <br /> . ' , Mr. Charles Thompson <br /> Project BL-04-05907 <br /> ` October 27, 2004 <br /> Page 3 <br /> � ', <br /> � <br /> � <br /> B.3. Soil <br /> � Twelve standard penetration test borings were completed as part of the geotechnical evaluation. The <br /> � standard penetration test borings were completed with an off road floatation tire and truck-mounted core <br /> and auger drill rig. Split-barrel soil samples were collected at 2 1/2-foot vertical intervals to the 10-or <br /> � 15-foot�depths,then at 5-foot intervals to the termination depths of the standard penetration test borings. <br /> � . <br /> ,■ The general soil profile on the site consists of approximately 1/2 to 2 feet of topsoil underlain by various <br /> thicknesses of previously-placed fill soils at most locations. The fill soils were then underlain by mixed <br /> '� layers of alluvial-deposited silty sand, sandy silt and silt soils, and glacially-deposited sandy lean clay or <br /> � poorly graded sand with silt soils. <br /> , <br /> '� The notable exceptions to the above profile occurred on the eastern portion of the site nearest <br /> � Highway 12. The borings in this area(ST-4, ST-10,ST-11 and ST-12 had substantial thicknesses of fill <br /> soils (up to 6 1/2 feet)underlain by thick deposits of soils with various amounts of organics. At the <br /> � northernmost boring(ST-10), the fill was underlain by organic silty sand down to about the 13-foot <br /> ' , depth. At Borings ST-4, ST-11 and ST-12, the fill soils were underlain by organic clay, organic sandy <br /> silt, and peat deposits to depths on the order of 13 to 23 feet below the current grades. <br /> � <br /> � Penetration resistances within the alluvial-deposited soils ranged from 3 to 19 blows per foot,indicating <br /> very loose to medium dense conditions. The penetration resistances in the organic deposits on the <br /> � eastern portion of the site ranged from 1 to 5 BPF,indicating generally very soft to rather soft conditions. <br /> � ' <br /> B.4. Groundwater <br /> � Groundwater was observed in Borings ST-2, ST-3, ST-5, ST-6, ST-8, ST-10, ST-11 and ST-12 at the <br /> � time of our site exploration. We estimate the groundwater level to vary from 6 1/2 to greater than 22 1/2 <br /> � feet below the surface of our borings. Based on the site elevations,it is likely that many of these water <br /> levels are perched wherein groundwater is trapped in permeable soil layers above less pern`►eable soils. It <br /> � is likely that the long-term groundwater levels would stabilize at elevations more on the order of the large <br /> ■ wetland to the southwest portion of the site, and at elevation on the order of 955. <br /> � Groundwater elevations should be expected to fluctuate both seasonally and annually. <br /> i <br /> � <br /> � <br /> ■ <br /> � - <br />