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Ms. Kristin Shelton
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<br /> additives were detected. Results were reported in the Semi-Annual Groundwater Sampling and
<br /> Remediation Status Report, dated January 21, 2016.
<br /> Groundwater analytical results for the third quarter of 2014 are presented in Table 11 and
<br /> cumulative analytical results are summarized in Tables 13 and 14 (Attachment B).
<br /> Isoconcentration maps for TPHg, benzene and MTBE are presented on Figures 14, 15 and 16,
<br /> respectively (Attachment A).
<br /> ' Fourth Quarter 2015
<br /> ' On December 29, 2015, shallow groundwater was interpreted to flow generally in a southerly to
<br /> southeasterly direction, with a slight mound of high groundwater elevation around well MW8, at
<br /> ' a gradient ranging from approximately 0.008 ft/ft in the area to the south of the site to 0.02 ft/ft
<br /> in the central and southern portions of the site (Figure 17 in Attachment A).
<br /> On December 29, 30 and 31, 2015, samples were collected from wells MW2, MW3, MW4,
<br /> MW5, MW6R, MW8, MW10, MWI1, MW12, MW13, MW14and MW1D for analysis. MW7
<br /> was not sampled because the well was dry; well MW9R was not sampled due to the presence of
<br /> ' free product; and well VEWI-D was not sampled because it was actively being used for soil
<br /> vapor extraction.
<br /> No analytes were detected in the samples collected from wells MW2, MW4, MW5, MW10,
<br /> MWl 1, MWl2, MW14 and MW1D. TPHg and benzene were detected in the sample from well
<br /> MW3 at concentrations of 150 ppb and 5.0 ppb, respectively. TPHg and benzene were detected
<br /> in the sample from well MW6R at concentrations of 12,000 ppb and 1,100 ppb, respectively.
<br /> Moderate to high levels of toluene, ethylbenzene and xylenes were also detected. TPHd was not
<br /> detected in the sample collected from well MW6R. TPHg and benzene were detected in the
<br /> ' sample from well MW8 at concentrations of 21,000 ppb and 22,000 ppb, respectively. Moderate
<br /> to high levels of toluene, ethylbenzene and xylenes were also detected. TPHd was not detected
<br /> in the sample collected from well MW8. TPHg and benzene were detected in the sample from
<br /> ' well MW13 at concentrations of 190 ppb and 20 ppb, respectively. Low levels of toluene,
<br /> ethylbenzene and xylenes were also detected.
<br /> MTBE was detected in well MW3 at a concentration of 2.8 ppb, in well MW6R at a
<br /> concentration of 4,700 ppb, in well MW8 at a concentration of 43,000 ppb and in well MW 13 at
<br /> a concentration of 34 ppb. No other gasoline oxygenates or additives were detected in any site
<br /> well. Results were reported in the Semi-Annual Groundwater Sampling and Remediation Status
<br /> Report, dated January 21, 2016.
<br /> ' Groundwater analytical results for the fourth quarter of 2015 are presented in Table 12 and
<br /> cumulative analytical results are summarized in Tables 13 and 14 (Attachment B).
<br /> Isoconcentration maps for TPHg, benzene and MTBE are presented on Figures 18, 19 and 20,
<br /> respectively (Attachment A).
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