Laserfiche WebLink
2.0 EXECUTIVE SUMMARY <br /> • One soil boring (SB-2) and two groundwater monitoring wells (MW-9 and MW-10) <br /> were drilled to further assess gasoline constituent. concentrations in soil and <br /> oundwater east(cross-gradient) and north (down-gradient) of the site. I' <br /> • No TPHg or;..BTEX:was detected in any soil samples collected from the borings, <br /> • MTBE was only detected in soil'samples- collected from well boring MW-10 at <br /> concentrations ranging from 0.0069 to 0.020 mg/Kg. <br /> • No constituents of concern were detected in the grab groundwater sample collected <br /> from boring 5B-2,.delineating the horizontal extent of.petroleurn hydrocarbons and <br /> fuel oxygenates in groundwater east of the site. <br /> No constituents.of concern were detected in the groundwater samples.collected from <br /> off-site well MW-9, delineating the horizontal extent of petroleum.hydrocarbons and <br /> fuel oxygenates in groundwater northeast of the site. <br /> • Off-site well MW-10 has contained up to 990 µg/L TPHg and 760 gg/L MTBE. CRA <br /> notes that the TPHg detected in this well is likely due to the presence of fuel <br /> oxygenates. <br /> • During the fourth quarter 2008, up to 140 µg/L TPHg, 85 gg/L MTBE, and 37 gg/L <br /> TBA were detected in groundwater samples from on-site wells. No benzene was, <br /> detected in any groundwater samples this quarter. <br /> • The fuel oxygenate plume is not defined to the northwest as indicated by the MTBE <br /> detection in MW-10. <br /> • CRA recommends further:assessment of fuel oxygenate impact to groundwater <br /> down gradient of MW-10 and discontinuing monthly vacuum truck purging of <br /> on=site wells MW-2 and MW-6 due to the low mass removal rate. <br /> i <br /> 241661(l) 2 CONESTOGA-ROVERS&ASSOCIATES <br /> t . <br />