Laserfiche WebLink
1 v <br /> 0 <br /> A S S O C I A T E S I N C <br /> The groundwater samples from wells MW4 and MW5 were analyzed by Sequoia Analytical for <br /> TPHg, TPHd, BTEX, and oxygenate fuel additives Groundwater analytical results are <br /> summarized in Table 3, and laboratory data sheets are presented in Appendix D <br /> 3.0 SUBSURFACE CONDITIONS <br /> 3.1 Geology <br /> Soil in borings MW4 and MW5 consisted of poorly graded sand with silt from the surface to 6 5 <br /> to 10 feet bgs Soil from depths between 6 5 to 10 feet bgs and 31 5 to 3 5 feet bgs consisted of <br /> well graded sand with poorly graded sand in boring MW4 between 26 5 and 30 feet bgs to 30 5 <br /> feet bgs Soil from depths between 31 5 and 35 feet bgs to approximately 36 5 feet bgs, the <br /> maximum depth explored, consisted of lean clay <br /> 3.2 Hydrogeology_ <br /> Water level measurements were collected from wells MW1 through MW5 on July 16, 1999 <br /> Water levels ranged from 19 82 to 20 66 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 south-southwest The average hydraulic gradient on July 16, <br /> 1999 was calculated to be 0 001 ft/ft or approximately 5 ft/mile A summary of groundwater <br /> monitoring data is presented in Table 2 <br /> 4 0 ANALYTICAL RESULTS <br /> 41 Soil Analytical Results <br /> Soil samples collected from borings MW4 and MWS contained no detectable concentrations of <br /> TPHg, TPHd, BTEX, or oxygenate fuel additives Analytical results of soil samples are <br /> summarized in Table 1 <br /> 442 Groundwater Analytical Results <br /> The groundwater samples from wells MW4 and MW5 did not contain detectable concentrations <br /> of TPHg, BTEX, or oxygenate fuel additives The groundwater samples from wells MW4 and <br /> MW5 did contain concentrations of TPHd at 1,190 parts per billion (ppb) and 395 ppb, <br /> respectively Analytical results of groundwater samples are summarized in Table 3 <br /> Isoconcentration maps of TPHd, TPHg, and benzene in groundwater are shown on Figures 4, 5, <br /> and 6, respectively <br /> w 1130991reportslsumwe11 doc 4 <br />