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e� n A S S O C I A T E S I N C monitonng data (March 1992) determined groundwater flow direction to the south A detailed discussion of the initial subsurface investigation can be found in RESNA's "Interim Problem Assessment Report, Soil and Groundwater Contamination,"dated June 8, 1992 In July 1994, a RESNA field geologist observed the drilling of four additional groundwater ' monitoring wells (MW4, MWS, MW6, and MW7) at the site to further characterize subsurface conditions Groundwater samples collected from these additional wells contained no detectable ' petroleum hydrocarbons A detailed discussion of the Phase II Subsurface Investigation can be found in RESNA's "Summary Report, July 1994 Investigation,"dated August 26, 1994 In PHS/EHD correspondence dated March 1995, regulatory approval was given to sample wells MW3 and MW5 and wells MW4, MW6 and MW7 on an alternating semi-annual basis MW and MW2 were to be sampled every quarter, conditions permitting To further evaluate the extent of residual soil contamination in the vicinity of the former underground fuel storage tank (UST), Smith Technology supervised the advancement of four soil borings (SB-1, SB-2, SB-3, and SB-4) on February 29, 1996 to depths of approximately 16 to 26 feet bgs Total petroleum hydrocarbons as gasoline (TPHg), benzene, toluene, ethylbenzene, and xylenes (BTEX) were detected above method detection limits at low to moderate concentrations in samples collected at depths between 10 and 15 feet bgs in borings SB-1, SB-2, and SB-3 A detailed discussion of this subsurface investigation can be found in Smith Technology's "Subsurface Investigation Report, " dated April 30, 1996 ' 2.0 METHODS AND PROCEDURES 2.1 Soil Boring Advancement and Sampling To evaluate the extent of impacted soil and groundwater at the site, five soil borings (SB-11 ' through SB-15) were advanced at the site Three soil borings, SB-11, SB-12, and SB-15 were advanced to first encountered water, which ranged from 5 to 19 feet below ground surface (bgs) ' Soil borings SB-13 and SB-14 were be advanced to depths of approximately 26 to 27 feet bgs Boring locations are shown on Figure 2 ' The five borings were advanced using truck mounted Geoprobe® narrow diameter, direct push technology Drilling was conducted by Fisch Environmental (C57 License No 683865) An ATC field geologist was present to log all soil samples Descriptions of soil types encountered ' and sample collection intervals were recorded on boring logs contained in Appendix A Soil samples were collected at five-foot intervals, except at SB-14 where soil samples were collected continuously, and were field screened with a Flame Ionization Detection (FID) meter One soil sample each from borings SB-11, SB-12, SB-13, and SB-15 were submitted for laboratory analysis and two soil samples from boring SB-14 were submitted for laboratory analysis Sample selection was based on FID measurements and field observations (i a odor and soil discoloration) ' w 4ordproW803LSuh_mv doe 2