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n . Mr Michael Infurna Page 6 of 7 Soil and Groundwater Analytical Results The soil samples collected from borings MW 1 and MW2 did not contain any detectable amounts of TPHd, TPHg, BTEX, MTBE or gasoline oxygenate additives No MTBE or gasoline oxygenate additives were detected in the soil samples from boring MW3 "TPHg", ethylbenzene, and xylenes were reported at concentrations of 48 ppm, 0 28 ppm, and 0 42 ppm at 25 feet bgs, and at 110 ppm, 1 1 ppm, and 0 80 ppm at 30 feet bgs, in boring MW3 The laboratory reported that the "TPHg" chromatographic signature did not match typical gasoline chromatograms The levels of TPHd in soil samples from boring MW3 were 1,600 ppm and 3,500 ppm, at 25 and 30 feet, respectively Soil analytical results are summarized is Table 1 Laboratory reports and chain of custody documentation are included it Attachment B The groundwater analytical results in wells MW 1 and MW2 were reported as being non-detectable for TPHd, TPHg, BTEX, MTBE and gasoline oxygenate additives In well MW3, TPHd was detected at a level of 3,000 parts per billion (ppb), "TPHg" (did not match typical gasoline chromatogram) was detected at a level of 700 ppb, MTBE was detected at a concentration of 1,000 ppb and Cert-butanol was detected at a concentration of 180 ppb Benzene was reported at a concentration of 4 7 ppb, along with low levels of toluene, ethylbenzene and xylenes Groundwater analytical results are summarized in Table 2 Laboratory reports and chain of custody documentation are included in Attachment B CONCLUSIONS • Contrary to reported regional flow, groundwater at the site flowed to the northwest in November, 1999 • Some contaminated soul in the saturated zone is still present in the immediate vicinity of MW3 This is likely a very small residual volume • Groundwater contamination is present in MW3 Concentrations of dissolved hydrocarbon contaminants in the sample collected from the well are lower than those previously detected in samples from soil boring SB4 and from the excavation RECOMMENDATIONS Pnor to proposing any additional subsurface investigation, Ground Zero recommends that at least two rounds of groundwater monitoring and sampling be conducted to confirm contaminant concentrations, groundwater flow, gradient, and variations in water levels Subsequently it may be necessary to install additional monitoring well(s)to provide downgradnent control woolseycnV \s„nu,azy ac