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31 October 2003 <br /> • AGE-NC Project No 95-0137 <br /> Page 5 of 6 <br /> 3 4 GROUND WATER GRADIENT AND FLOW DIRECTION <br /> Depths to ground water on 14/16 May 2003 ranged from 23 88 to 25 00 feet below the well casing <br /> ' tops, the depth to ground water has increased an average of 14 feet from the January 2003 <br /> monitoring event The calculated ground water elevations ranged from 32 89 feet (MW-2) to <br /> 36 62 feet (MW-5), and ground water flow was inferred to be northwest at a hydraulic gradient of <br /> ' 0 027 foot/foot (Figure 3) <br /> ' 3 5 ANALYTICAL RESULTS OF GROUND WATER SAMPLES <br /> TPH-g was detected in the ground water sample from well MW-4 at a concentration of 630 gg/l, and <br /> ' the lead scavenger 1,2-DCA was detected in samples MW-1, MW-2 and MW-4 at concentrations <br /> of 15 µg/1, 30gg/l and 110 gg/l, respectively <br /> No additional contaminants of concern were detected in the analyzed samples The analytical results <br /> are summarized in Tables 5 and 6 A copy of the laboratory report (CTEL Lab ID Numbers <br /> ' 0305085), quality assurance and quality control (QA/QC) report and chain-of-custody form are <br /> included in Appendix V . <br /> t <br /> 4.0. SUMMARY AND CONCLUSIONS <br /> Based on the data collected from the site, AGE finds <br /> • Approximately 97 7 kg (215 3 lbs), or 34 45 gallons of hydrocarbons as gasoline were <br /> ' extracted and destroyed by the SVE network at the site between May and September 2003 <br /> (second and third quarters), a total of 2095 5 kg, (4,169 7 lbs), or a volume of 739 gallons <br /> hydrocarbons as gasoline was removed between December 2000 and September 2003 <br /> ' • Extracted organic vapor concentrations measured with the OVM were low compared to the <br /> analytical results from the soil-vapor samples, the highest concentration of organic vapor <br /> measured with the OVM was 40 ppmv <br /> ' • The ground water depth increased an average of 14 feet between the first and second quarter <br /> monitoring events, the decreased depth of the water table has exposed additional petroleum <br /> ' hydrocarbon-impacted soil to the SVE system <br /> • Dissolved hydrocarbon concentrations decrease overthe previous quarter,and remained well <br /> below the highest concentrations detected at the site t Uyv 41 W q 114 S t 0 S 66)A4 rr],) <br /> • Dissolved 1,2 DCA concentrations have remained stable, however, the concentrations are <br /> above the MCL of 0 5 gg/1 in drinking water <br /> ' Advanced GeoEavtronmental,inc <br />