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' 07 October 2003 �. AGE-NC Project No 95-0121 ' Page 4 of 7 3 2 LABORATORY RESULTS OF GROUND WATER SAMPLES 1 TPH-g was detected in water samples collected from wells VW-4 and VW-6 at concentrations of ' 1,500 micrograms per,hter(,ugll) and 150 pg11, respectively (Figure 4) TPH-d was not detected in any of the analyzed samples ' Benzene, toluene, ethylbenzene and xylene constituents(BTEX)were detected in the ground water sample collected from well VW-4 at concentrations of 270 µg11, 6 ug1l, 83 ,ug/1 and 68 pg/l, respectively ' Utilizing EPA Method 826013, MTBE was detected In the water sample collected from well VW-4 at a concentration of 14µg/l 1,2-DCA was detected in water samples collected from wells VW-4 ' and VW-6 concentrations of 17 ,ug/l and 9 2 ,ug1l, respectively No other fuel components were detected during the laboratory analysis ' Previous and current analytical results of ground water monitoring well samples are summarized in Tables 3 and 4 The laboratory reports(Cal Tech Environmental Laboratories Sample I D 0306-076- 1 through 5) and chain-of-custody forms are presented in Appendix B ' e ' 4.0 SUMMARY AND CONCLUSIONS The Implications from the June 2003 ground water monitoring event are as follows • Ground water flow direction for the area bound by wells MW-1 through MW-9 was Inferred to be towards the northeast at a gradient'of 0 001 fl/ft or less (Figure 3) The flow direction likely represents the lower sand level or semi-confined aquifer at the site and may not represent the upper most water table flow direction • 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 I • Between February 1991 and May 1998, ground water elevations at the site significantly increased from 26 'feet to 7 feet below mean sea level (msl), however, ground water measurements collected between May 1998 and present have generally fluctuated very little between 7 feet and 1 I feet below msl (Table 2) • Ground water data collected from VW-I through VW-7 are representative of shallow ground I water conditions, however, ground water data collected from wells MW-1 through MW-9 were generally between 6 and 16 feet below the ground water table, and probably yields samples more representative of deeper ground water conditions (Table 2) s Advanced GeoEnvironmental,Inc I