|
i
<br /> . 31 August 2005
<br /> AGE-NC Project No 96-0232
<br /> Page 7 of 30
<br /> between 64 and 67 feet and from P 13 at depths between 73 and 76 feet at concentrations of
<br /> 85 µg11 and 170 µg/1, respectively Dissolved ethanol was detected from P16 at depths
<br /> between 37 and 40 feet and 70 and 73 feet at concentrations of 8 5 µg11 and 8 6 µg11,
<br /> respectively,dissolved ethanol was detected from P-17 at depths between 37 and 40 foot, 55
<br /> and 58 feet, 80 and 83feet and 111 and 114 feet at concentrations of 13 gg/l,20 µg11,27 µg/1
<br /> and 20 pg/l, respectively Analytical results of grab ground water samples are summarized
<br /> in Table 3
<br /> Interim ground water remediation measures were enacted at the site by continuously pumping
<br /> ground water from EW-1 at a rate of 2 gallons per minute into a 5,900-gallon above ground
<br /> storage poly tank Four grab water samples were initially collected from the EW-1 discharge
<br /> line in April 2000 Dissolved MTBE was detected in the samples at concentrations of 1,800
<br /> µg/1, 1,800 µg/l, 1,600 µg/1 and 1,000 µg11 Analytical results of EW-1 grab samples are
<br /> summarized in Table 7
<br /> Eighteen soil borings (P18 through P35) were advanced on-site to depths of 20 feet bsg
<br /> utilizing push point technology to better assess MTBE-impact to soil and ground water in
<br /> and near the fuel dispenser area,the storm drain area and the existing UST system at the site
<br /> •� Soil boring locations are depicted in Figures 2 and 3, boring logs are in Appendix F Soil
<br /> data collected from borings P 18 through P35 were incorporated into cross sections A-A',B-
<br /> B', C-C, D-D'and E-E'(Figures 5 through 9, respectively) Laboratory analysis of the 10-
<br /> foot soil samples collected from P31, P32 and P34 (fuel dispenser area) detected MTBE at
<br /> concentrations as high as 0 72 mg/kg, the 15-foot soil samples from P19, P20 and P22
<br /> (south-southwest UST pit area) contained MTBE at concentrations as high as 0 63 mg/kg,
<br /> the 20-foot soil samples from P23 (south fuel dispenser area), P24 (east UST pit area), P25
<br /> and P26 (west UST pit area)contained MTBE at concentrations as high as 0 35 mg/kg The
<br /> 10-foot soil samples collected from P31 and P34 (northeast and southeast fuel dispenser
<br /> area)contained TBA at concentrations of 0 071 mg/kg and 0 12 mg/kg,respectively,the 10-
<br /> foot soil sample from P31 (southeast fuel dispenser area) contained TPH-g, TPH-d and
<br /> BTEX compounds at concentrations as high as 3 2 mg/kg The most significant MTBE-
<br /> impact to soil was encountered in the southern fuel dispenser area,the southwestern storm-
<br /> drain area and around the UST pit Analytical results of soil samples are summarized in
<br /> Table 2 and plotted in plan view and cross sectional views in Figures 10 through 13
<br /> Grab water samples collected from P22, P24 (south and east UST pit area), P30 (west fuel
<br /> dispenser area), P31 (southeast fuel dispenser area}and P34 (northeast fuel dispenser area)
<br /> detected TPH-g at concentrations as high as 11,000 µg/1, dissolved TPH-d was detected in
<br /> samples from P18, P19, P20, P23, P24, P25, P27, P28, P30, P31, P32, P34 and P35 (UST
<br /> pit area, fuel dispenser area and east of the fuel dispenser area) at concentrations as high as
<br /> 1,900 gg/l, dissolved BTEX compounds were detected in P30, P31, P34 and P35 samples
<br /> • at concentrations as high as 2,900 4g/1,dissolved MTBE was detected in P 18,P19,P20,P23,
<br /> a
<br /> Advanced GcoE'nvironmental,Inc
<br />
|