Laserfiche WebLink
16 April 2002 <br /> AGE-NC Project No 95-0167 <br /> Page 3 of 4 <br /> BTEX compounds were detected in the water samples collected from monitoring wells MW-1 and <br /> MW-2, the highest concentrations were detected in the sample from MW-1 at 1,500 µg/1 benzene, <br /> 1,300 µg/l toluene, 340 µg/1 ethylbenzene and 2,600 µg/1 xylenes MTBE was detected in MW-1 at <br /> a concentration of 16 µg/l by EPA Method 8020 MTBE was detected by EPA Method 8260B in <br /> sample MW-1 at a concentration of 20 µg/1 No other oxygenates were detected in the ground water <br /> samples <br /> Analytical results of water samples collected in March 2002 are summarized on Tables 2 and 3 The <br /> laboratory report(CTEL Laboratory IDs 0203-085-1 through 0203-085-6),QA/QC report and chain- <br /> of-custody form are included in Appendix B Figure 4 depicts the estimated areal distributions of <br /> impacted ground water containing TPH-g and benzene for 14 March 2002 <br /> 4.4. SUMMARY AND CONCLUSIONS <br /> Data collected at the site indicates that <br /> • The ground water flow direction during this monitoring event was toward the north- <br /> northwest at an average gradient of 0 030 ftJft Ground water flow at the site has historically <br /> been towards the northwest Ground water flow direction is not well defined near the former <br />' UST pit <br /> • Relatively high concentrations of TPH-g and BTEX occur in ground water in the area of <br /> monitoring wells MW-1 and MW-2 <br /> • <br /> MTBE was present in monitoring well MW-1 at a concentration of 20 µg/1 <br /> • The contaminant plume appeared to be confined to the general area of the former UST <br /> location and MW-1 and MW-2 Petroleum hydrocarbons were not detected in perimeter <br /> wells MW-3, MW-4, MW-5 and MW-6 <br /> 1 <br /> 5.0. RECOMMENDATIONS <br /> Based on present site conditions, AGE recommends <br />' Continued quarterly ground water monitoring at the site The next monitoring event should <br /> be scheduled for June 2002 <br /> • Preparation of a work plan for installation of additional ground water monitoring wells south <br /> and northwest (down-gradient) of the site to further delineate the dissolved-hydrocarbon <br /> plume <br />' advanced GeoEnviron mental,Inc <br />