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1 r19 February 1997 • AGE-NC Project No 95-0104 Page 3 of b r the to the nearest 0 01 foot to determine the elevation relative to existing wells The results of the monitoring well survey are contained in Table 1 - Relative Ground Water Elevations r2 1 6 WELL DEVELOPMENT rOn 11 December 1996, wells MW-5 and MW-6 were developed utilizing a Grundfos Rediflo TI submersible pump Ground water was purged from each well until each well was essentially sediment free Approximately 25 gallons of ground water were purged from each monitoring well Purged rground water was containerized in properly labeled D O T model 17H 55-gallon drums and stored on-site in an area inaccessible to the general public r 2 1 7 SOIL PROFILE Generally, a brown to gray sandy silt and silty sand were encountered from surface grade to depths of approximately 87 feet in each boring However, small lenses of fine-grained sand and silt were encountered throughout the soil profile Groundwater was encountered during drilling activities at a depth of approximately 72 feet General r soil conditions are summarized in boring logs contained in Appendix A Cross sections depicting soil lithology and the approximate extent of hydrocarbon-impacted soil on the site are depicted in Figure 5 - Cross Section A -A ' and Figure 6 - Cross Section B -B' r 2 1 8 FIELD EVIDENCE OF HYDROCARBON-IMPACTED SOIL r During drilling activities organic vapors (OVs) were detected at concentrations as high as 1 2 PPm in MW-5 at 75 feet( hydrocarbon odors were not detected in 1\4W-5) Hydrocarbon odors and OVs rwere detected in MW-6 at depths between 40 and 65 feet bsg r2 2 GROUND WATER MONITORING AND SAMPLING 2 2 1 GROUND WATER DEPTH MEASUREMENTS On 11 December 1996, the depth to ground water in each monitoring well was measured to the nearest 0 01 foot utilizing a Sohnst water level meter The relative ground water elevations were calculated by subtracting the depth to ground water from the relative casing elevations surveyed from a temporary benchmark assigned an arbitrary elevation (Table 1) Relative ground water elevations were plotted and contoured on a scaled site map (Figure 7 -Relative Elevation Ground Water Map)