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' 11 November 2002 • AGE-NC Project No. 98-0468 ' Page 3 of 4 3.1. GROUND WATER ELEVATION AND FLOW DIRECTION During the September 2002 monitoring event, the depth to ground water at the site ranged from 11.63 to 14.90 feet below the tops of well casings (btoc) in wells MW-1 through MW-5 and wells . ' MW-7 and MW-8.During the same monitoring event,the depth to ground water in wells MW-9 and MW-l0 were 19.50 feet and 19.55 feet btoc. Ground water wells MW-6 through MW-10 have not ' been surveyed and were not utilized to determine the ground water flow direction or gradient (Table 1). Groundwater elevation at the site ranged from 4.74 to 5.73 feet below mean sea level (MSL). Ground water elevation in the monitoring wells decreased an average of 1.3 feet since the ' previous monitoring event. A summary of depth to ground water and ground water elevation measurements is presented in Table 1. ' A ground water elevation contour map for September is illustrated on Figure 3. Based on ground water elevation data, ground water flow direction is inferred to be toward the northeast. Ground water gradient for the latest sampling event was calculated to be 0.019.In general,groundwater flow ' direction and gradient for this monitoring event appear to be consistent with previous monitoring events results. ' 3.2. LABORATORY RESULTS OF GROUND WATER SAMPLES ' Ground water samples were collected from MW-3 through MW-10 for laboratory analysis. A summary of ground water analytical results are presented in Table-2.The laboratory analytical report is included in Appendix C. Toluene was detected in well MW-3 at a concentration of 0.78 micrograms per liter (µgll). Other ' BTEX compounds or TPH-g in the ground water samples analyzed. MTBE was reported in the ground water samples collected from monitoring wells MW-3, MW-4, ' MW76, MW-7, MW-9 and MW-10 at concentrations of 0.78 µg/1, 290 gg/l,'120 pg/l, 0.84 gg/l, 58 µg11 and 1.9 µg11, respectively, by EPA Method 8260. ' The MTBE concentration in these samples exceed the DHS - established maximum contaminant level(MCL)of 5 µg/l for MTBE in ground water.'The DHS action level for MTBE is 13 µg/l. There were no reported detections of any other fuel oxygenating compounds. ' Laboratory results of ground water samples analyzed for petroleum hydrocarbons,fuel additives and . VOCs are summarized in Table 2. The laboratory reports (MAI Laboratory ID: 0209390), quality ' assurance and quality control (QA/QC)reports and chains-of-custody are included in Appendix C. ' Advanced GeoEnvironmental,Inc.