|
S E C O R
<br /> Number Number Wells With Number
<br /> Wells Wells of Wells With
<br /> of Wells of Wells Stable or Non-
<br /> Constituent Concentrations Concentrations Stable or Non-
<br /> Concentrations Concentrations Detectable
<br /> Increased Decreased. s Detectable
<br /> - Increased Decreased Concentrations Concentrations
<br /> MW-41,MW-53, MW-16,MW-24, MW-26,MW-27,
<br /> TPHg MW-54 3(5) MW-55 3(3) MW-29,MW-32, 6(5)
<br /> MW-35,MW-44
<br /> MW-26,MW-27,
<br /> TPHd MW-29,MW-35, 7(5) MW-16,MW-24, 3(4) MW-32, MW-53 2(4)
<br /> MW-41,MW-44, MW-54
<br /> MW-55
<br /> MW-16,MW-24,
<br /> MW-53,MW-54, MW-29,MW-32,TPHo MW-26,MW-27 2(3) MW-55 3(1) MW-35,MW-41, 7(9)
<br /> MW-44
<br /> MW-16,MW-24, MW-26, MW-27,
<br /> Benzene - 0(6) MW-53,MW-54, 5(0) MW-29, MW-32, 7(7)
<br /> MW-55 MW-35, MW-41,
<br /> MW-44
<br /> MW-16,MW-24,
<br /> MtBE MW-04,MW-54 2(3) MW-32,MW-53, 3(2) MW-26,MW-27, 7(8)
<br /> • MW-55 MW-29,MW-35,
<br /> MW-41
<br /> MW-16,MW-24,
<br /> TBA MW-41 1 (4) MW-53,MW-54, 3(1) MW-26, W
<br /> MW-27, 8(8)
<br /> MW-55 MW-29,M -32,
<br /> MW-35,MW-44
<br /> In general, reported TPHg, TPHo, benzene, MtBE and TBA concentrations in samples from the
<br /> deep zone wells were within historical ranges during first quarter 2008. Following second
<br /> quarter 2007 construction activities, TPHg concentrations sampled during 3Q07 in wells MW-42
<br /> (20 mg/L) and MW-51 (61 mg/L) were atypical due to the potential presence of tetrahydrafuran
<br /> in the sample matrix. Tetrahydrafuran is typically associated with PVC glue, which was used
<br /> during construction activities conducted on the Site. These wells were not able to be sampled
<br /> again until the current quarter due to renegotiations of the off site access agreements with the
<br /> property owners. TPHg concentrations recorded in both wells during 1 Q08 were consistent with
<br /> to historical data.
<br /> Dissolved TPHg, TPHd, and MtBE in B-Zone groundwater are generally delineated to the west
<br /> in the L&M OU. Benzene is delineated, except to east. TBA is delineated to the
<br /> west/southwest, and TPHo is delineated, except to the east(Figures 11 through 16). The extent
<br /> of petroleum-affected groundwater in deeper C- and D-zones is not defined. The extent of
<br /> petroleum-affected deeper(B-, C-, D-Zones)groundwater has not been investigated at the UOU
<br /> and MOU.
<br /> •
<br /> 1 Q08QSSRQRSRQMR.Final.doc 25 April 30,2008
<br /> 77TW.26397.42.1307
<br />
|