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MW-2 contained no detectable concentrations of TPHg or BTEX Well locations are shown on Figure 2 Groundwater samples were collected and analyzed quarterly for TPHg, TPHd, and BTEX through March 1992 The purpose of groundwater monitoring was to verify the extent of hydrocarbons in groundwater, monitor the fluctuations in concentrations of dissolved hydrocarbons in groundwater, and monitor the depth to groundwater MW-3 contained no petroleum hydrocarbons for six consecutive quarters and MW-2 contained only toluene once during those six quarters MW-1 Icontained petroleum hydrocarbons at low concentrations during this period Groundwater analytical results are summarized in Table 2 In March 1992, RESNA supervised the installation of groundwater monitoring well MW4 to a depth of 32 feet using a hollow stem auger drill rig The well was constructed with 2-inch diameter PVC casing and completed as shown on the well log contained in Appendix C The well was monitored, developed, and samples collected The samples were placed on ice, secured, transported under chain-of-custody protocol to Argon Laboratories, and analyzed for TPHg, TPHd, and BTEX MW- 4 contained no detectable concentrations of TPHg, TPHd, or BTEX The well location is shown on Figure 2 In January 1995, Smith Environmental supervised the installation of groundwater morutonng well MW-1R to a depth of 29 feet using a hollow stem auger drill rig The well was a replacement for MW-1 which was destroyed during excavation activities conducted during November 1993 The well was constructed with 2-inch diameter PVC casing and completed as shown on the well log contained in Appendix C The well was monitored, developed, and samples collected The samples were placed on ice, secured, transported under chatn-of-custody protocol to Argon Laboratories, and analyzed for TPH& TPHd, and BTEX MW-1R contained ethylbenzene at concentrations of 8 6 parts per bdhon (ppb), xylenes at concentrations of 16 ppb, and TPHg at concentrations of 620 ppb The sample contained no detectable concentrations of benzene, toluene, or TPHd Groundwater analytical results are summarized in Table 2 and well location is shown on Figure 2 The monitoring wells have been monitored intermittently since their installations The downgradient well, MW4, has never contained detectable concentrations of petroleum hydrocarbons during its seven quarters of monitoring MW-3 has contained a petroleum hydrocarbon constituents once (xylenes at 19 ppb, March 1993) in nine sampling events since its initial sampling in August 1990 MW-2 has contained a petroleum hydrocarbon once (toluene at 0 8 ppb, November 1991) in ten sampling events MW-I and MW-1R have contained low levels of petroleum hydrocarbons since their installations 4.44 Remedial Actions 4.4.1 Soil Excavation In November 1993, approximately 1,500 cubic yards of soil were excavated from the vicinity of the former underground fuel storage tanks The limits of the excavation are shown on Figure 5 w 19433 ftiosure doc 4 1 r SKYN