Laserfiche WebLink
17 November 1999 <br /> AGE-NC Project No 95-0128 <br />' Page 5 of 7 <br /> • MTBE was detected in ground water samples collected from monitoring wells MW 1 through <br /> MW7 and from vapor well VW1 Detected concentrations of MTBE ranged from 2 7 µg/l <br /> (MW 1) to 230 4gll (MW5 and VW 1) <br /> • TBA was detected in samples from MW3, MW4, MW5, and VWl at concentrations of 6 6 <br /> µg/l, 39µg11, 9 3 ,,zg/l, and 72 �,g/l, respectively <br /> • DIPE, TAME, and ETBE were not detected in the ground water samples collected during <br /> the 27 October 1999 ground water monitoring event <br /> Laboratory results of water samples analyzed for petroleum hydrocarbons are summarized in Tables <br /> 2 and 3 The laboratory reports for the quarterly monitoring event (MAI Laboratory ID No 15251 <br /> to 15258) QA/QC reports and chain-of-custody form are included in Appendix B <br /> 4.0. SUMMARY AND CONCLUSIONS <br /> Based on results of the 08 July 1999 investigation AGE concludes <br /> • All properly screened wells on site yield ground water samples that have been impacted by <br /> detectable concentrations of various BTEX compounds and petroleum hydrocarbons with <br /> the exception of MW7 <br /> • The three monitoring wells with deeper-screened intervals yielded samples with no <br /> I detectable levels of various BTEX compounds and petroleum hydrocarbons The deeper- <br /> screened monitoring wells do yield samples with low concentrations of MTBE The samples <br /> from monitoring wells MW2 and MW3 were also impacted by low concentrations of TBA <br /> The data suggests that vertically downward migration of petroleum hydrocarbons is minor <br /> to insignificant, and also indicates that deeper hydrocarbon-impacted soil horizons are not <br /> significantly impacting the ground water with petroleum hydrocarbons This also suggests <br /> that the more significantly impacted ground water is confined to the upper twenty feet of the <br /> ground water column <br /> • The oxygenating fuel additive MTBE was detected in ground water samples collected from <br /> all thV VVVila YV it11 laic exception Wf V TV 1 T1LV lowL.st voliVeiltraL1W110 of;V,;Tr, J" (� 7 1w6/I acid <br /> 12 4g11) were detected in the deeper-screened MW1 and MW3, respectively Compared to <br /> I the 59µg11 to 300 F.cg/l MTBE detected in the properly screened wells in the core area and in <br /> the down-gradient area, the deeper concentrations are suggestive of minor vertical migration <br /> of MTBE <br /> Advanced GeoEnvxronmental Inc <br />