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12 August 2003 AGE-NC Project No. 03-1035 Page 6 of 7 be prior to the use of MTBE in fuel. Consequently, AGE had the two impacted soil samples re- analyzed,B 1-14 once and B 1-24 twice.None of the target analytes were detected in the subsequent analyses. The samples from boring B-3 were submitted to CTEL for analysis on 20 June 2003. The soil and ground water samples did not detect any of the contaminants of concern in soil or ground water. The analytical results are summarized in Tables 1 and 2. A copy.of the laboratory report (CTEL Laboratory ID Nos. 0305-179-1 to -5, 0305-179-3a; 0305-179-5b, 0306-011-1 to -5, 0306-139-2 to -4, 0306-139-7, and 0306-139-9 to -10) is included in Appendix B. 6.0. SUMMARY AND CONCLUSIONS Based upon data collected and analyzed in May and June 2003, AGE concludes: • In general, subsurface soil consisted of reddish-to yellowish-brown silty fine sand and fine sand from the surface to 25 feet bsg and silt from 25 feet bsg to total depth. The clay content is generally low. Ground water was encountered in boring B-3 at an approximate depth of 42 feet bsg. • Low concentrations of MTBE were detected in samples B1-14 and B1-24, and low concentrations of BTEX compounds were detected in sample B1-24. Since the former gasoline UST reportedly was out of service since the middle to late 1960s,prior to the advent of MTBE in gasoline, it appears unlikely that it was the source of MTBE. Subsequent reanalysis of these two samples did not detect any BTEX compounds or MTBE in the samples. • After consultation with the SJCEHD, an additional soil boring (B-3) was advanced immediately adjacent to the suspect boring B-1 to verify if contamination was present. Soil samples were collected at the same depth as samples B 1-14 and B 1-24. In addition, deeper soil samples down to ground water,and a ground water sample,were collected for analysis. No contaminants of concern were detected in the analyzed samples. • AGE concludes that the initial detection of contaminants was possibly due to sampling problems (e.g., surface side-wall soil-"sluff'-incorporated into the sample) or laboratory error. —• Advanced GeoEnvironmental,Inc.