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1 09 May 2005 SAGE-NC Project No 97-0301 ' Page 4 of 6 32 LABORATORY RESULTS OF GROUND WATER SAMPLES i A total of twenty-six (26) ground water samples were submitted to CTEL for analysis ' TPH-g was detected from wells MW-1,MW-7 and MW-9A at concentrations of 1,600 micrograms per liter(µg/1), 31,000 µg/l, and 200 µg11, respectively The estimated extent of dissolved TPH-g ' in First Water Zone is depicted on Figure 5 For the sixth consecutive quarterly monitoring event, TPH-d,TPH-k,and TPH-mo were not detected from any of the twenty-six water samples analyzed Various BTEX constituents were detected in the same water samples(MW-1, MW-7 and MW-9A) 1 at concentrations as high as 11,000 µg/1 benzene, 380 µg/1 toluene, 2,100 }ig/l ethylbenzene, and 5,500 µg11 total xylenes J MTBE was detected from well MW-1 at a concentration of 36 µg/1, 1,2-DCA wa4,4 �00vwas ro�m3o �L wells MW-1 and MW-7, at concentrations of 3 2µg11, and 300 µg/1, respective detected in the water sample from well MW-7 at a concentration of 30 µg/1 No other fuel components were detected in the ground water samples Previous and current analytical p �' p Yt + results of ground water monitoring well samples are summarized in Tables 3 and 4 The laboratory i report(CTEL Laboratory I D 0412-077)and chain of custody forms are presented in Appendix B, GeoTracker confirmation pages ofthe submitted laboratory electronic deliverable format(EDF)files I are included in Appendix C r 4.0. SUMMARY AND CONCLUSIONS The implications from the 4th Quarter 2004 ground water monitoring event are as follows ' Generally, depth to ground water at the site varied between 34 75 feet and 36 85 feet bsg, ground water elevations ranged between 22 50 feet (MW-8A) and 23 62 feet (MW-8C) ' below MSL • Ground water flow direction for the area bound by First Water Zone wells MW-1 through 1 MW-12 was inferred to be east-northeast at an approximate gradient of 0 002 ft/ft or less (Figure 4) Due to the low gradient at the site, slight variations in ground water measurements or changes of recharge/discharge of the local ground water could greatly modify ground water flow direction • The average ground water elevation at the site on 09 December 2004 was 23 03 feet below MSL Generally, ground water elevation at the site increased an average 103 feet between ' the September 2004 and the December 2004 ground water monitoring events The increase in ground water elevation is probably due to seasonal fluctuation Advanced GeoEnvironmental,Inc