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GEOMATRIX hydrocarbon constituents were not detected in the other soil samples collected during this investigation. 5.3 GROUNDWATER Groundwater samples were to be collected from on-site wells MW-2 and MW-3 and from the uppermost groundwater encountered in off-site boring locations GMX-10, GMX-11, and GMX-12. Depth to water measured in the two monitoring wells in August 2003 ranged from about 32 to 33 feet below TOC (Table 4), which is consistent with previous data. A sheen of immeasurable thickness was noted in MW-2; as such, a groundwater sample was not collected from this well. No separate-phase petroleum was observed in MW-3 or in the off-site boring locations GMX-10, GMX-11, and GMX-12. Groundwater analytical results are summarized in Table 2 and shown on Figure 5. TPHd(analyzed without a silica-gel preparation procedure)was detected in on-site well MW-3 at 86 micrograms per liter(µg/1) and from the grab groundwater samples collected from GMX-10, GMX-11, and GMX-12, at 210µg/1, 3600µg/1, and 110 pg/1, respectively. Follow- ing the silica gel preparation procedure, TPHd was detected at 73 µg/l in MW-3, 110µg/l in GMX-11, and was not detected above the quantitation limit(50µg/1) in the grab groundwater samples collected from GMX-10 and GMX-12. This result indicates that the material quanti- fied as "TPHd"without the silica-gel preparation procedure may be partially polar components that may be due to intrinsic bioremediation of petroleum near these locations. TPHg, BTEX, and PAHs were not detected in the groundwater samples collected from monitoring well MW-3 or from the grab groundwater sample locations,with the exception of acenaphthene (0.2µg/1) and phenanthrene (0.1 pg/1), which were detected at or slightly above the detection limit(0.1 µg/1) in the grab groundwater samples collected from GMX-11 and GMX-12, respectively. 6.0 SUMMARY AND CONCLUSIONS The results of this and previous investigations are summarized below. • Soil beneath the site consists primarily of fine-grained deposits (i.e., silts)with interbedded coarse-grained deposits (i.e., sands and gravel) that are underlain by a sandy lean clay at a depth of approximately 80 feet bgs. • The depth to groundwater measured in the existing monitoring wells at the site has ranged from about 30 to 35 feet bgs. Historical horizontal groundwater flow direc- tions at the site have been to the northeast or southeast. I:\Doc_Safe\6000s\6447.001\OffSite Rpt\US Can SoilGW Rpt 2003.doc 9