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and VW-14 appeared anomalous and these wells were not used in contour construction Groundwater
<br /> flow was generally to the south at an average gradient of 0 087 ft/ft Groundwater flow in the upper water
<br /> bearing zone has been to the south, south-southeast, and toward the southwest during previous quarters
<br /> GRO, benzene, and MTBE were reported in well VW-3 GRO and benzene were also reported in wells
<br /> MW-4, MW-8, VW-2, and VW-14, benzene and MTBE were also reported in well VW-6, and benzene was
<br /> also reported in well VW-5 The highest concentrations of GRO (140,000 µg/L) and benzene (11,000
<br /> ug/L) were reported in welt MW-4, and the highest concentration of MTBE (170 µg/L) was reported in well
<br /> VW-6 1,2-DCA was reported in wells MW-8 (36 µg/L) and VW-14 (77 µg/L) TAME was reported in well
<br /> MW-8 (29 pg/L) TBA, EDB, DIPE, ETBE, or ethanol were not reported in any of the upper zone wells
<br /> Analytical results for the third quarter 2005 are generally consistent with previous quarters GRO,
<br /> benzene, and MTBE analytical data for the samples collected on September 19, 2005, are presented in
<br /> Figure 5 Analytical data were submitted to the State Water Resources Control Board as required by
<br /> AB2886 The electronic delivery receipt is attached in Appendix C
<br /> Lower Water Bearing Zone (Sand Zone 2)
<br /> During the site visits conducted during the third quarter 2005, free product was measured in well MW-1 at
<br /> a thickness of 0 03 feet Free product was also measured in well MW-15 at thicknesses ranging from
<br /> 0 18 and 0 33 feet Approximately 10 gallons of product/water mixture were manually bailed during the
<br /> third quarter 2005 from wells MW-1 and MW-15, and stored in a properly labeled DOT approved drum
<br /> pending disposal Approximately 203 gallons (MW-1) and 27 gallons (MW-15) of product/water mixture
<br /> have been manually bailed to date Product thickness measurements and volumes of liquid balled are
<br /> summarized in Table 1
<br /> At the time of the third quarter 2005 monitoring event, groundwater levels had increased between 0 11
<br /> and 6 60 feet in wells MW-9, MW-10, and MW-12 since the previous monitoring event (June 21, 2005)
<br /> Depth-to-water measurements were normalized to mean sea level (MSL) and used to construct a
<br /> groundwater elevation contour map (Figure 4) Wells that contained less than 1 foot of water are
<br /> interpreted to be dry and are indicated as "dry" on Figure 4 Groundwater flow was generally to the
<br /> southeast at an average gradient of 0 195 ft/ft Groundwater flow has been to the east-southeast and east
<br /> during previous quarters
<br /> GRO and benzene were reported in wells MW-9, MW-10, and MW-12 The highest concentrations of
<br /> GRO (69,000 µg/L) and benzene (12,000 pg/L) were reported in well MW-12 1,2-DCA was reported in
<br /> wells MW-9 (59 µg/L) and MW-10 (62 µg/L) TBA (200 pg/L) and EDB (5 1 pg/L) were reported in well
<br /> MW-9 TAME (50 pg/L) was reported in well MW-10 MTBE, DIPE, ETBE, or ethanol were not reported
<br /> in any of the lower zone wells Analytical results for the third quarter 2005 are generally consistent with
<br /> previous quarters GRO, benzene, and MTBE analytical data for the samples collected on September 19,
<br /> 2005, are presented in Figure 5 Analytical data were submitted to the State Water Resources Control
<br /> Board as required by AB2886 The electronic delivery receipt is attached in Appendix C
<br /> I
<br /> Domestic Well
<br /> GRO, STEX, MTBE, TBA, TAME, DIPE, ETBE, EDB, 1,2-DCA, or ethanol were not reported in the
<br /> domestic well GRO, benzene, and MTBE analytical data are presented in Figure 5 These analytical
<br /> results for the third quarter 2005 are consistent with historical data
<br /> K\Bp-Arco for URS\6100\Quarterly\2005\Arco_6100}Q05 doe 5TRATUS
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