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i1vvz <br /> A S S O C I A T E S I N C <br /> Groundwater samples were placed on ice and delivered under chain-of-custody documentation to <br /> Argon Laboratories for chemical analysis. The groundwater sample was analyzed by Argon for <br /> TPHg, TPHd, TPHss, BTEX, and oxygenate fuel additives. The analytical results for the <br /> groundwater sample are summarized in Table 2. Laboratory data sheets and chain-of-custody <br /> documentation'are included in Appendix E. <br /> 3.0 SUBSURFACE CONDITIONS <br /> ' 1 Geology <br /> ogy <br /> Soil in angle boring S132A from the surface to approximately 3.5 feet consists of fill material. <br /> Soil in angle boring S132A from 3.5 feet bgs and 11 to 15 feet bgs consists of lean clay and lean <br /> clay with sand. Soil in angle boring SB2A from between 11 to 15 feet bgs and 25 feet bgs <br /> consists of elastic silt. Soil in angle boring S132A from between 25 feet bgs and 32 feet bgs, the <br /> maximum depth explored, primarily consists of lean clay and sandy silt. Groundwater was <br /> ' encountered at approximately 32 feet bgs during drilling activities. Taking into account the <br /> thirty degree angle of the soil boring, groundwater was encountered at 27.7 feet bgs. <br /> Soil in boring MW4 from the surface to approximately 21.5 to 25 feet bgs consists of elastic silt <br /> and elastic silt with sand. Soil in boring MW4 from between 21.5 to 25 feet bgs and 26.5 to 30 <br /> feet bgs consists of poorly graded sand with silt. Soil in boring MW4 from between 26.5 to 30 <br /> ' feet bgs and 39 feet bgs, the maximum depth explored, primarily consisted of lean clay. <br /> Groundwater was encountered at approximately 25 feet bgs during drilling activities. <br /> ' 332 Hydrogeology <br /> t Water level measurements were collected from wells MW1 through MW4 on April 11, 2000. <br /> Water levels ranged from 22.58 to 23.47 feet below the tops of the well casing elevations. The <br /> water level data were used to develop the groundwater elevation contour map (Figure 3). <br /> Assuming that horizontal isotropic conditions prevail, groundwater in the uppermost aquifer <br /> beneath the site flowed towards the northeast. The average hydraulic gradient on April 11, 2000 <br /> was calculated to be 0.001 ft/ft or approximately 5 ft/mile. A summary of groundwater <br /> ' monitoring data is presented in Table 3. <br /> 4.0 ANALYTICAL RESULTS <br /> ' 4.1 Petroleum Hydrocarbons in Soil <br /> ' The soil samples collected from angle soil boring S132A and boring MW4 contained no <br /> detectable concentrations of TPHg, TPHd, TPHss, BTEX, or oxygenate fuel additives. <br /> Analytical results of soil samples are summarized in Table 1. Laboratory data sheets and chain- <br /> of-custody documentation for soil samples are presented in Appendix B. <br /> w:1172951reporlslsumiii.doc 5 <br />