ARCHIVED REPORTS_XR0004962 - Laserfiche WebLink

Home Browse Search

1C a �r A S S D C I A T E S I N C ' layer was less pronounced and increased amounts of sand was encountered from approximately 54 to 63 feet bgs ' Soil in boring MW8 generally consisted of lean clay from the surface to depths between 6 5 to 10 feet bgs Soil consisted of poorly graded sand and silty sand from depths between 6 5 to 10 feet ' bgs and 16 5 to 20 feet bgs Soil consisted of lean clay and clayey sand from depths between 16 5 to 20 feet bgs and 26 5 to 30 feet bgs Soil consisted of elastic silt and silty sand from depths between 26 5 to 30 feet bgs and 36 5 to 40 feet bgs Soil consisted of lean clay from ' depths between 36 5 to 40 feet bgs and 46 5 to 50 feet bgs Soil consisted of silty sand and sandy silt from depths between 46 5 to 50 feet bgs and 61 5 to 65 feet bgs Soil consisted of lean clay from depths between 61 5 to 65 feet bgs and 71 to 75 feet bgs Soil consisted of elastic silt and silt from depths between 71 to 75 feet bgs and 86 5 to 95 feet bgs Soil consisted of silty sand from depths between 86 5 to 95 feet bgs and 101 feet bgs, the maximum depth explored Soil boring logs with a detailed description of soil types are contained in Appendix B 32 Hydromeology ' Water level measurements were collected from wells MW I through MW8 on December 14 2000 Water levels ranged from 6100 to 62 36 feet below the tops of the well casing elevations in wells MWl through MW7 The water level data were used to develop the groundwater elevation contour map (Figure 3) The water level data from well MW8 was not used in the gradient calculations because it might not be screened in the same aquifer as the shallow wells There appears to be a mounding effect in well MW2 Assuming that horizontal isotropic conditions prevail, groundwater in the uppermost aquifer beneath the site flowed towards the northwest The average hydraulic gradient on December 14, 2000 was calculated to be 0 002 Rift ' or approximately 11 ft/mile A summary of groundwater monitoring data is presented in Table 3 4.0 ANALYTICAL RESULTS 441 Soil Analytical Results Soil samples collected from borings MW4 and MW5 contained no detectable concentrations of TPHg, BTEX, MTBE, TAME, ETBE, TBA, or DIPE Soil samples collected from boring MW6 contained elevated concentrations of TPHg and moderate concentrations of BTEX constituents The soil samples collected from boring MW6 contained no detectable concentrations of MTBE, TAME, ETBE, TBA, or DIPE Sol] samples collected from borings MW7 and MW8 contained nondetectable to moderate concentrations of TPHg and BTEX constituents The soil samples collected from borings MW7 and MW8 contained no detectable concentrations of MTBE, TAME, ETBE, TBA, or DIPE Analytical results of soil samples are summarized in Table 1 1 w 1163931reportslsumn doe 5