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1 06 June 2003 AGE-NC Project No. 98-0468 ' Page 3 of 4 ' through MW-5 ranged from 3.05 feet below mean sea level(MSL)in MW-3 to 3.82 feet below MSL in MW-4; ground water elevation decreased in five wells(MW-1 to MW-5)an average of 0.76 feet. Based on ground water elevations from wells MW-1 through MW-5, ground water flow direction ' is inferred to be'toward the northeast at a'gradient of 0.02 (Figure 3). 3.2. ANALYTICAL RESULTS OF GROUND WATER SAMPLES Laboratory analytical results of groundwater samples from monitoring wells MW-3 through MW-1.0 are provided for the second quarter 2003 monitoring events. TPH'g was detected in groundwater samples MW-6 and MW-8 at concentrations of 290 micrograms ' per liter(µg/1)and 140.µg/l,respectively. The BTEX compounds were not detected in ground water samples analyzed. ' MTBE was detected in water-table-well samples MW-4 and MW-6 at concentrations 16 µg1! and '120µg/1,respectively. MTBE was also detected in deep-screened-well samples MW-9 and MW-1.0 concentrations of 80 µg/1 and 28 µg/1, respectively. No additional analytes were detected in the analyzed samples. Laboratory results of ground water samples analyzed for petroleum hydrocarbons and fuel additives are summarized in Table 2. The laboratory reports (CTL Laboratory ID: 0304-116), quality assurance and quality control(QA/QC) reports and chains-of-custody are included in Appendix B. 4.0. SUMMARY/CONCLUSIONS w ' The following summary points and conclusions were drawn from the results-of the site investigation: ` Ground water elevations in the five surveyed wells(MW-1 through MW-5)ranged between 1 w water elevation decreased in all the wells b 3.05 and 3.$2 feet be MSL.o S Ground y 0.76 feet since the previous monitoring event. ; ' Ground water flow was inferred to be toward the northeast at a gradient of 0.02; in general,' the ground water flow direction and gradient for this monitoring event appear to be ' consistent with results of previous monitoring events. • MTBE was detected in the ground water samples collected from wells MW-4,MW-6,MW-9 and MW-10 by EPA Method 8260. The down-gradient extent of MTBE-impacted ground water has been'delineated in the first water table;however,the MTBE impact to deep ground '' Advanced GeaEnvironmental Inc.