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SECOND QUARTER 2005 ANALYTICAL RESULTS
<br /> ' None of the analytes of interest were detected in the groundwater samples collected from MW 10 and
<br /> MW 11 R. BTEX constituents were detected in the groundwater samples col lected from MW 1, MW2,
<br /> MW3, MW5, MW6, and MW8. The highest concentrations of benzene, 5,900 gg/L and 4,900 gg/L,
<br /> ' were detected in the groundwater samples collected from MW8 and MWI, respectively. TPHg was
<br /> detected in the groundwater samples collected from MWI, MW2, MW3, MW5, MW6, MW8, and
<br /> MW9. The highest concentrations of TPHg, 180,000 gg/L and 130,000 gg/L, were detected in the
<br /> ' groundwater samples collected from MWI and MW8, respectively. MTBE was detected in the
<br /> groundwater samples collected from MW2, MW3, MW4, MW7, MW9, and MW12 at concentrations
<br /> ranging from 1.1 gg/L to 29 gg/L, respectively. The highest concentration of MTBE was detected in
<br /> ' the groundwater sample collected from MW2. 1,2-DCA was detected in the groundwater samples
<br /> collected from MWI through MW9 and MW12 at concentrations ranging from 1.2 gg/L to 730 µg/L.
<br /> The highest concentration of 1,2-DCA was detected in the groundwater sample collected from MW8.
<br /> ' TBA was detected in the groundwater samples collected from MW2 and MW3 at concentrations of
<br /> 43 gg/L and 22 gg/L, respectively. Analytical results of groundwater samples are summarized in
<br /> Table 2. Laboratory data sheets and chain-of-custody documentation are contained in Attachment 2.
<br /> ' lsoconcentration maps depicting benzene, MTBE, and I,2-DCA concentrations in the groundwater
<br /> samples collected from the shallow zone during the second quarter of 2005 are shown on Figures 15,
<br /> 16, and 17, respectively. Isoconcentration maps depicting benzene, MTBE, and 1,2-DCA
<br /> concentrations in the groundwater samples collected from the intermediate zone during the second
<br /> quarter of 2005 are shown on Figures 18, 19, and 20, respectively.
<br /> 1 GEOTRACKER DATA UPLOAD
<br /> The depth to water and laboratory data associated with the first quarter 2005 sampling event were
<br /> submitted electronically to the State Water Resources Control Board (SWRCB) Geotracker database
<br /> (confirmation numbers 7878880143 and 7412053465, respectively)_ Laboratory analytical data
<br /> associated with the groundwater sample collected from MW11R on April 18, 2005, were also
<br /> submitted to the SWRCB Geotracker database (confirmation number 6174878656). Depth to water
<br /> and laboratory data associated with the second quarter 2005 sampling event (confirmation numbers
<br /> 7367721378 and 2289769172, respectively); depth to water and laboratory data associated with the
<br /> fourth quarter 2004 sampling event (confirmation numbers 1158308267 and 2682675778,
<br /> respectively); laboratory data associated with soil samples collected during the installation of MW5
<br /> through MW12 (confirmation number 1858622312); and boring logs for MW5 through MW11,
<br /> '
<br /> MWI IR, and MW12 (confirmation numbers 9920728385, 1028669059, 9448943912, 2650525748,
<br /> 6072354972, 5084684073, 2957181632, 2375730216, and 3273038566, respectively) were also
<br /> submitted to the SWRCB Geotracker database. Documentation of the data submittal is contained in
<br /> Attachment 4.
<br /> CONCLUSIONS
<br /> ' The laboratory analytical results of the groundwater samples collected from MWI through MW 10,
<br /> MW 11 R, and MW12 in March and June 2005 are generally consistent with recent historical
<br /> analytical results of groundwater samples collected from these wells. MWI and MW8 located in the
<br /> s:lenviromental1283491reports12005 1 &2 QMR.doc 5 ATC Associates Inc.
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