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21 December 2040. - - AGE-NC Project No. 99-0657 "Page 3 of 4 detected in. samples from all. the monitoring wells at concentrations ranging from .1.2 µg11 of ethylbenzeile in MW-3 to 380 �cgll.of:ethylben- e in MW-2. MTBE was not detected above laboratory reporting limits in any of the ground.water-samples collected and analyzed.- Current and previous analytical results.are summarized ori Table 2. The laboratory report (MAI Lab ID No. 55108 through�55113), QA/QC report'and chain-of-custody form are included in Appendix B. 4.0. SUMMARY AND CONCLUSIONS : Based on the data collected during this monitoring period, AGE concludes: - • Depth to ground water at the site as of 05 December 2000 was approximately.12 feet below surface grade with a north-northwesterly flow-direction, . + . The highest concentration of dissolved hydrocarbons quantified as'TPH-g, TPH-d; and generally BTEX compounds . extends northeast. from the 'former UST9._ Dissolved' ' hydrocarbons were encountered in the down-gradient.directiori from the former USTs.in: = MW-5-and MW-6. - samples from monitoring wells MW-2 The lateral extent of petroleum hydrocarbon impacted ground.water has not been-defined toward the northeast beyond MW-5 and MW-6.-The 'hydrocarbon.plume is fairly well. defined to the south, east and-west and northwest. 5.0. RECOMMENDATIONS Based on the findings'ofthis,investigation, AGE recommends: Continued.quarterIy monitoring of the ground water monitoring wells. The next monitoring . event should be performed in March 2000. • If concentrations do .not decline significantly during. the next monitoring event, AGE recommends additional monitorin .wells be installed to the north and-east of monitoring well. r g . ' . MW-5 to further assess the lateral extent ofpetroleum hydrocarbon impacted ground water. _ Advanced GeoFnvironmental,Inc.