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' 08 October 1999 • AGE-NC Project No. 95-0197 Page 3 of 5 elevations, as measured on 13 July 1999 are depicted in Figure 3. Ground water elevation at the site decreased an average 0.41 feet•between the April 1999 and the July 1999 ground water monitoring events. The general ground water gradient at the site was calculated to be approximately 0.002 ft/ft or approximately 11 feet per mile; the general ground water flow direction was calculated towards the north-northwest. ' In July 1999,the depths to first encountered ground water in wells MW-1, MW-2, MW-3 and MW-4 were approximately three to six feet below the tops of the well screens. Therefore, these wells are "properly screened", and yield samples representative of shallow ground water conditions. 1 3.2. ANALYTICAL RESULTS OF GROUND WATER SAMPLES Ground water samples were collected from wells MW-1,MW-2,MW-3 and MW-4 in July 1999 and ' submitted to a DHS-certified laboratory. TPH-g was not detected in any analyzed ground water samples; TPH-d was detected in ground water samples collected from MW-1, MW-2 and MW-3 at concentrations ranging between 51 micrograms per liter(gg/l) and 81 ug/l; the laboratory reported ' that the chromatograms for the samples did not have typical diesel characteristics: BTEX compounds were not detected in ground water samples collected from wells MW-1, MW-2, ' MW-3 and MW-4; however, MTBE was detected in ground water samples collected from wells MW-2 and MW-3 at concentrations ranging as high as 53 1.cg/1. MTBE was detected/confirmed utilizing EPA Method 8260 Modified in ground water samples collected from MW-2 and MW-3 -at concentrations ranging as high as 45 ,ug/l;- no other fuel- oxygenate analytes were detected above laboratory reporting limits. The analytical results of quarterly ground water samples are summarized in Table 3. The laboratory ' reports(Castle Analytical Laboratory Reference No. 2366 and McCampbell Analytical Inc. Lab I.D. No. 15373 through 15376) and chain-of-custody forms are included in Appendix B. 4.0. SUMMARY AND CONCLUSIONS The following is a summary based on the findings of the July 1999 investigation: Between April 1999 and July 1999, ground water elevation at the site decreased an average 0.41 feet. o In July .1999, the depths to first encountered ground water in MW-1, MW-2, MW-3 and Advanced GeoEnvironmental,Inc.