Laserfiche WebLink
10 December embe 2001 <br /> I AGE-NC Project No 95-0141 <br /> Page 4 of 5 <br /> IConcentrations of TPH-g, benzene and 1,2-DCA in ground water are illustrated on Figures 4, 5 <br /> and 6, respectively <br /> 4.0 SUMMARY AND CONCLUSIONS <br /> IThe findings of the 12 November 2001 site investigation events include the following <br /> • Contamination by TPH-g was encountered in ground water samples collected from five of <br /> the eight on site monitoring wells at the site (MW-1, MW-2, MW-3, MW-6 and MW-7) <br /> Concentrations as high as 140,000 µg11 were detected <br /> • BTEX constituents were detected in four of the eight ground water monitoring wells with <br /> concentrations as high as 10,000 µg/l benzene, 25,000 µg/l toluene, 3,700 µg/1 ethylbenzene <br /> and 16,000 µg/l total xylenes <br /> • TBA was detected in MW-3 at a concentration of 29 gg/l Fuel oxygenates had not been <br /> detected prior to the May 2001 monitoring event DIPS,MTBE, ETBE and TAME were not <br /> detected in any of the ground water samples collected <br /> • 1,2-DCA was detected In ground water samples collected from seven of the eight monitoring <br /> wells at the site at concentrations as high as 280 µg/1 (MW-1) EDB was detected in the <br /> ground water sample collected from MW-1 at a concentration of 5 1 ug/l <br /> • The horizontal and vertical extent of contamination related to the former UST has not yet <br /> been defined in soil or ground water <br /> Measured ground water elevation is approximately 13 3 feet below ms], and was within the <br /> screened interval of the two shallow monitoring wells (MW-7 and MW-8) Ground water <br /> was approximately 8 to 9 feet above the screened intervals of MW-i through MW-5 and was <br /> approximately 39 feet above the screened interval of the deep well MW-6 <br /> S.U. RECOMMENDATIONS <br /> Based on the results of this and previous investigations, AGE recommends <br /> • Continued quarterly monitoring of the ground water monitoring network <br /> • Preparation of a work plan addendum to define the vertical and horizontal extent of <br /> hydrocarbon impacted soil and ground water at the site <br /> • <br /> Advanced GeoEnvironmental,Inc <br /> I <br />