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_ 10 May 1999 AGE-NC Project No 96-0232 Page 3 of 5 3 1 RELATIVE GROUND WATER ELEVATION AND GRADIENT ' During the February 1999 monitoring event, depths to ground water in wells MW-1 MW-2 and MW-4 through MW-7 were measured to be between 6 34 and 7 80 feet below the top of well ' casings, ground water elevations were calculated to be between 1 76 and 194 feet above mean sea level Ground water elevation at the site increased an average 3 60 feet between the November 1998 ' and February 1999 ground water monitoring events The ground water elevation data for MW-1, MW-2 and MW-4 through MW-7 during the February 1999 ground water monitonng event is depicted in Figure 3 Due to the deep screened interval, data collected from MW-6B was not utilized Ito determine ground water elevations Ground water monitoring data collected in the area of wells MW-1, MW-2, MW-6A and MW-7 indicated a ground water flow direction generally toward the northeast at a gradient of 0 001 ft/ft, or approximately 5 feet per mile (Figure 3), ground water monitoring data collected in the area of wells MW-2, MW-4 and MW-5 suggested a ground water flow direction generally toward the southeast at a gradient of 0 001 ft/ft Ground water was approximately 35 feet above the screened intervals m monitoring wells MW6-B Therefore this well is "drowned", and yields a sample fully representative of deeper screened ground water that may be under confined or semi-confined conditions 3 2 LABORATORY RESULTS OF GROUND WATER SAMPLES TPH-g was detected in the water sample collected from MW-1 during the February 1999 sampling event at a concentration of 430 micrograms per liter (pg/1) TPH-d was detected in water samples collected from MW-1, MW-2, MW-4,MW-5,MW-6Atand MW-7 at concentrations ranging as high has 160,ug/l, TPH-d was detected in deeper screened water from MW-6B at a concentration of 1,500 µg/l The Iaboratory reported that the diesel chromatograms for all of the analyzed samples did not have typical diesel characteristics ' MTBE was detected in ground water samples' collected from all seven ground water samples utilizing EPA Method 8020 at concentrations as high as 1,000µg/l, MTBE was confirmed in MW-1, MW-2, MW-4, MW-6A, MW-6B and MW-7 samples utilizing EPA Method 8260, no other fuel oxygenates were detected above laboratory reporting limits MTBE was detected utilizing EPA Method 8020 and confirmed utilizing EPA Method 8260 in the drinking water well sample Analytical results of the ground water samples are summarized in Table 2 The laboratory reports (Castle Analytical Laboratory Reference No 2090 and McCampbeIl Analytical Inc I D No 04256 through 04262) and chain-of-custody forms are presented in Appendix B Advanced GeoEnvi ron mental,Inc r