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' 15 November 1995 �J AGE-NC Project No 95-0142 ' Page 4 of 19 ' feet and a second plug emplaced using,bentomte pellets to make a 3-foot plug to a depth of 5 feet The wells were then grouted to the surface with Portland cement ' _ 3 4 ANALYTICAL RESULTSF SOIL SAMPLES O ' A total of five soil samples were submitted to MAI for analysis, all samples analyzed were collected from depths of40 or 45 feet bsg TPH-g was detected in sample VE1-40 (near former UST TK1-9) at 2,900 mg/kg(parts per million ppm),BTE&X were detected in the same sample at concentrations ' up to 260 ppm Low concentrations of TPH-g and BTE&X were also detected in each of the other four samples submitted for analysts Arialytical results of the soil samples are summarized in Table ' 1 The laboratory report and chains-of-custody are included in Appendix B Samples VE1-15 and VE3-35 were submitted for physicochemical analysts and microbiological enumeration Analytical results of the samples indicated poor microbe viability and low ' concentrations of nitrogen and oxygen(required for microbe growth) Low microbe populations may in part be due to the presence of hydrogen sulfide gas in the soil, which could be smelled during drilling Hydrogen sulfide is the byproduct of anaerobic digestion, which indicates low oxygen concentrations in the environment The microbiological laboratory report and chain-of-custody form are included in Appendix C 4.0. QUARTERLY GROUND WATER MONITORING, SEPTEMBER 11995 t` 4 1 GROUND WATER MONITORING PROCEDURES On 29 September 1995, a Sohnst water level was used to measure the depth to ground water in each of the four ground water monitoring wells at the site The relative ground water elevation in each well and hydraulic gradient were determine from these data points(Table 2) Each monitoring well was then purged of 8 to 40 gallons of water(a minimum of 3 well volumes), using a PVC and stainless steel submersible pump The pump was washed in an Alconox solution and rinsed with water between each purging to avoid cross-contamination Temperature, pH, and conductivity were ' measure at ten-gallon intervals (two-gallon interval for MW-4) using an ICM water analyzer Monitoring well stabilization data and field data sheets are included in Appendix D Purged water was stored on-site in 55-gallon drums, pending laboratory analysis ' 4 2 COLLECTION OF GROUND WATER SAMPLES Water samples were collected from each purged well using new, clean disposable plastic bailers Immediately upon retrieval, the samples were transferred into 40-m1 VOA vials, preserved with