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' 29 April 2005 • AGE-NC Project No 98-0497 ' Page 3 of 4 ' 3 2 ANALYTICAL RESULTS OF GROUND WATER SAMPLES The analytical results from the March 2005 ground water monitoring event are as follows ' • TPH-g was detected in well MW-1 at a concentration of 3,000 micrograms per liter(µg/1) The laboratory report noted that the detected concentration was mostly in the diesel range ' • TPH-d was detected in well MWA at a concentration of 84,000 µg/1 • BTEX compounds and MTBE were not detected in the five ground water samples analyzed Laboratory results of the submitted water samples are summarized in Table 2 The inferred areal extent of hydrocarbon-impacted ground water is illustrated on Figure 4 Copies of the laboratory report(CTEL Project No CT214-0503149),quality assurance/quality control(QA/QC)reports,and chain of custody form are provided in Appendix B i 4.0. SUMMARY AND CONCLUSIONS i • The findings of the March 2005 ground water monitoring event include the following ' • Ground water elevations at the site averaged approximately 40 58 feet below MSL, indicating an average increase of 2 46 feet since the last monitoring event in November 2004 • Ground water was inferred to be flowing in a southeast-trending trough across the former UST area,under hydraulic gradients ranging from approximately 0 0006 ft/ft to 0 0013 ft/ft • TPH-g and TPH-d were detected in well MW-1 at concentrations of 3,000µg/l and ' 84,000 µg/l, respectively, however, the reported TPH-g concentrations were mostly in the TPH-d range i • Comparing the ground water sample results from this quarter and the previous quarter, the TPH-d concentrations detected in November 2004 (450,000 µg/l in MW-1 and 17,000 µg/1 in MW-4)were exceptionally high,possibly due to ground water having been at or near the ' lowest ever recorded at the site for two quarters(third and fourth) The results for the fourth quarter of 2004 appear to have been an anomaly • The hydrocarbon-impacted ground water plume appears to be limited to the former UST area immediately surrounding well MW-1- • Advanced GeoEnvironmental,Inc 1