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i . FOURTH QUARTER,2002 GROUNDWATER MONITORING REPORT AND ADDITIONAL ASSESSMENT REPORT JAMAR OIL DISTRIBUTION MARCH 2003 Groundwater analytical data are summarized in Table 2 and shown on Figure 6 Copies of the laboratory reports with COC documentation are included m Appendix B Fourth Quarter 2002 Groundwater Monitoring Conclusions The majority of constituent concentrations in the groundwater declined this quarter TPH D was non-detect in all samples and TPH G was only reported in the samples from MW-1 and MW-4 Benzene levels were also dramatically lower in all samples except the one from MW-1 As previously noted, this was the first time the analysis for this site was conducted by the new laboratory Generally, the petroleum hydrocarbon concentrations and MTBE have remained relatively consistent over the last two years Geoprobe Soil Analytical Results Results of analysis of soil samples collected from the geoprobe borings are presented in Table 3 and shown on Figure 7 Petroleum hydrocarbon constituents and/or fuel oxygenates were detected in samples collected from HP-1 and HP-3 The highest concentrations of all constituents were reported in the soil samples collected from depths of 28 feet bgs and 44-feet bgs in HP-1, located on the subject site MTBE was reported at 170 micrograms per kilogram (pg/kg) in the sample from 28-feet bgs and at 2,100 gg/kg in the sample from 44-feet bgs TBA was reported at 110 µg/kg and 190 pg/kg in the same two samples Benzene, toluene, total xylenes, and 1,2-DCA were reported at lower concentrations in the soil samples from HP-1 i I The soil samples from HP-2 were all non-detect (ND) for all constituents analyzed The soil samples from HP-3 only reported MTBE MTBE was reported at 6 4 ug/kg in the sample from 25-feet bgs, at 7 2 ug/kg in the sample from 42-feet bgs, and at 6 6 ug/kg in the sample from 52 5-feet bgs in HP-3 Laboratory reports with COC documentation are included in Appendix B Geoprobe Groundwater Analytical Results Results of analysis of groundwater samples collected from the geoprobe borings are presented in Table 4 and shown on Figure 8 Groundwater samples were taken from two locations in each boring, approximately 65-feet bgs and approximately 96-feet bgs Because of the proximity of monitoring well MW-4 to geoprobe boring HP-1, the 65-foot sample was taken from the monitoring well • 9