ARCHIVED REPORTS_XR0010269 - Laserfiche WebLink

Home Browse Search

I06 February 2003 AGE-NC Protect No 01-0827 IPage 3 of 4 3 2 ANALYTICAL RESULTS OF GROUND WATER SAMPLES TPH-g was detected only in the ground water sample from well VW-2d at a concentration of 4,500 gg/l, TPH-d was not detected in the analyzed ground water samples BTEX compounds were detected only in sample VW-2d at concentrations of 710gg/1 benzene, 24 ' gg/l toluene,35 µg/l ethylbenzene and 60 gg/l xylenes,respectively No other ground water samples contained detectable concentrations of BTEX MTBE was detected in ground water samples MW-1, VW-2d and VW-5d at concentrations of 2 3 gg/l, 120 gg/l and 7 26 gg/l,respectively TBA was detected in sample VW-2d at a concentration of 57 gg/l The chlorinated solvent 1,2-DCA was detected in one ground water sample at a Iconcentration of 4 2 gg/l The analytical results are summarized in Tables 2 and 3 A copy of the laboratory report(PET Lab ' ID 19523-01 to 07) and chain-of-custody form are included in Appendix B 4.0. SUMMARY AND CONCLUSIONS I Based on the data collected from the site, AGE finds • On 13 January 2003,ground water was encountered at a depth of approximately 23 feet btoc, ground water flow was inferred to be towards the northeast under a gradient of 0 006 ft/ft IExcept for wells VW-1 and VW-3, all site wells are "drowned" and analytical data from these wells may not be representative of shallow-water conditions • The maximum concentrations of petroleum hydrocarbon and BTEX compounds in ground water were detected in the ground water sample collected from on-site vapor well VW-2d • The concentrations of MTBE in sample VW-2d and 1,2-DCA in sample MW-1 were above the DHS's Primary Maximum Contaminant Levels (MCL) of 13 gg/l and 0 5 gg/l, respectively,for these chemicals in drinking water,the TBA concentration in sample VW-2d was above the DHS's Action Level of 12 µg/1 for TBA in drinking water 50. RECOMMENDATIONS Based on the findings of the remediation activities recounted in this report, AGE recommends • Continued quarterly ground water monitoring, the next monitoring event is scheduled for iMarch 2003 Advanced GeoEnviron mental,Inc