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23 May 1996 <br /> AGE-NC Project No 95-0139 <br />' Page 3 of 4 <br />' from probe borings B5 and B6 at concentrations up to 37 mg/kg (milligrams per kilogram or parts <br /> 3 per million, ppm,B5-13) TPH-d was detected in soil samples from probe borings B5, B6 and B7 at <br /> w concentration up to 25 ppm No petroleum hydrocarbons were detected in samples from probe <br />' borings B8 and B9 nor in the grab ground water sample collected from probe boring B9 <br /> A <br />' 3.0. PROCEDURES <br /> 3 1 MONITORING WELL PURGE PROCEDURES <br /> 1 <br /> On 12 April 1996, a Solinst water level meter was used to measure the depth to water in each well <br /> relative to the top of the casing The relative ground water elevations and hydraulic gradient were <br />' determined from these data (Table 1) <br /> After depth to ground water measurements, a submersible pump was used to remove standing water <br /> from each well Approximately 5 to 6 gallons (minimum of three well volumes) of water were <br /> removed from each well to stabilize temperature, pH and conductivity Ground water parameters <br /> were measured at one-gallon intervals using an ICM water analyzer <br /> All purging equipment was decontaminated by being washed in an Alconox solution and rinsed in <br /> water after each well was purged Purged water was stored in 55-gallon drums on-site Stabilization <br /> data and field logs are included in Appendix A <br /> 32 COLLECTION OF GROUND WATER SAMPLES <br /> Water samples were collected from each well using disposable plastic bailers The samples were <br /> transferred into 40-m1 EPA vials containing hydrochloric acid as a preservative and 1-liter amber <br /> bottles The sample containers were Iabeled with the date, monitoring well identification and time of <br />' collection After collection, the samples were placed in a chilled container and transported under <br /> chain-of-custody to Western Environmental Science & Technology (WEST) in Davis, California <br /> Each water sample was analyzed for TPH-g and TPH-d and volatile organics (benzene, toluene, ethyl <br /> benzene and total xylenes,BTE&X)in accordance with EPA methods 8015m and 602, respectively <br /> t <br /> 4.0. FINDINGS _ <br /> 4 <br /> 41 GROUND WATER GRADIENT AND DIRECTION <br /> ' The relative elevation of ground water in each well was calculated by subtracting the ground water <br /> depth from the surveyed casing elevation (Table 1) Depth to ground water at the site ranges from <br /> F Y <br />