Laserfiche WebLink
i <br /> ' 29 October 2002 <br /> S AGE-NC Project No 98-0465 <br /> Page 3 of 4 <br /> ' 32 ANALYTICAL RESULTS OF GROUND WATER SAMPLES <br /> TPH-g and BTEX were not detected at concentrations at or above the laboratory reporting limits in <br /> any of the ground water samples TPH-d was detected at the reporting limit (50 µg/1) in the sample <br /> collected from monitoring well MW-4 <br /> MTBE was detected in samples collected from MW 1, MW3 and MW4 by EPA Method 8260B at <br /> concentrations of 480 µg/l, 12 µg/1 and 1 1 µg11,respectively No other fuel oxygenated compounds <br /> were detected in the ground water analyses Figure 4 illustrates the approximate extent of MTBE- <br /> impacted ground water <br /> Analytical results of water samples collected during August 2002 are summarized on Table 2, the <br /> ' laboratory report(MAI Lab IDs 0208188-001 through 0208188-004), QA/QC report and chain-of- <br /> custody form are included in Appendix B <br /> ' 4.0. SUMMARY AND CONCLUSIONS <br /> The following conclusions were drawn from the results of this investigation <br /> ' a The ground water elevations ranged from 8 62 to 8 75 feet below MSL Ground water was <br /> inferred to flow radially toward the northeast,varying from northwest to northeast, under an <br /> average gradient of 0 001 feet/feet The ground water elevation at the site decreased an <br /> average 0 9 feet between the June 2002 and August 2002 monitoring events <br /> a TPH-d was detected at 50µg/1 in the sample collected from well MW-4 TPH-d had not been <br /> detected in at the site since October 2000 <br /> ' a MTBE was detected in samples collected from MW-1, MW-3 and MW-4 at concentrations <br /> of 480 µg11, 12 µg/1 and 1 1 µg11,respectively,by EPA Method 8260B The sample collected <br /> ' from MW-1 during the August 2002 monitoring event contained the highest detected <br /> concentration of dissolved MTBE since monitoring began in July 2000 However, the <br /> detected concentrations of MTBE in MW-3 and MW-4 have remained relatively stable <br /> during the same period <br /> a The lateral extent of MTBE-impacted ground water has been defined to the northeast of the <br /> ' former UST area, but not toward the west to northwest, east or south <br /> Advanced GeoEnvironmentai,Inc <br />