Laserfiche WebLink
1 <br /> tSoil samples collected from borings SB-1 through SB-5 and CPT-1 and CPT-2/Contained <br /> detectable concentrations of TPHg, total BTEX, and the fuel oxygenate MTBE��ii Maximum <br />' detectable concentrations are noted as follows TPHg (330 mg/kg in SB-4 at 5 5 to 6 0 feet <br /> bgs), benzene (4 3 mg/kg in SB-4 at 7 5 to 8 0 feet bgs), and MTBE (4 0 mg/kg in CPT-2 at <br /> 7 0 feet bgs Analytical results of soil samples are summarized in Table 1 Laboratory data <br />' sheets and chain-of-custody documentation for soil samples are presented in Appendix C <br /> 4.2 Groundwater Analytical Results <br /> Groundwater samples collected from borings SB-2 through SB-4 and CPT-1 and CPT-2 <br /> contained detectable concentrations of TPHg, total BTEX, and the fuel oxygenate MTBE�T�m <br />' TPHg concentrations ranged from c 50 ug/l (SB-1 and SB-5) to 8,700 ug/l (SB-4), benzene <br /> concentrations ranged from c 0 50 ug/l (SB-1 and SB-5) to 83 ug/l (SB-4), and MTBE <br /> concentrations ranged from c 0 50 ug/l (SB-1 and SB-5) to 8,100 ug/1 (SB-3) ' Groundwater <br />' samples were collected from CPT-2 at a depth of 41 and 67 feet bgs, respectively " From each <br /> interval, TPHg was detected at 7,600 ug/l and 300 ug/l, respectively Benzene was detected at <br />' 22 ug/l and 2 7 ug/l, respectively MTBE was detected at 2,100 ug/l and 120 ug/l, <br /> respectively <br /> Analytical results of groundwater samples are summarized in Table 2 Laboratory data sheets <br /> and chain-of-custody documentation for groundwater samples are contained in Appendix JC <br />' 5.0 DISCUSSION <br /> Based on the results of this subsurface investigation and the historic subsurface investigation <br /> and monitoring activity, groundwater in the central and western portion of site and offsite area <br /> adjacent to Holly Street are impacted with dissolved and adsorbed MtBE, BTEX, and TPHg <br /> Groundwater collected from the two deeper groundwater horizons (41 feet bgs and 67 feet bgs) <br />' as observed in CPT-2 are also impacted MtBE, BTEX and TPHg Additionally, soils in the <br /> vicinity of the former UST basin and extending west to SB-4 indicate elevated levels of MtBE <br /> and TPHg <br />' 6.0 RECOMMENDATIONS <br />' ATC recommends additional offsite subsurface investigation to define the horizontal extent of <br /> the dissolved and adsorbed hydrocarbon plume Additionally, further subsurface evaluation is <br />' necessary in the deeper (>20 feet bgs) water bearing zones beneath the site <br /> 1 <br /> 1 <br /> S\Enviromenta11258471Reports\SUM doe 5 <br /> 1 <br />