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L <br /> direction and magnitude of the groundwater gradient beneath the site. -On July 21, 1995 the new <br /> j <br /> wells were developed using pumping and surge and bail techniques until.the produced water was <br /> -�}ft relatively free of sediment. At least three well volumes (casing..and sandpack) were purged from <br /> each well prior to collecting groundwater samples. Temperature, pH, water elevation, and <br /> electric conductivity were monitored and allowed to stabilize. Groundwater samples were <br /> collected using disposable bailers, one dedicated to.each well. Groundwater samples collected <br /> from all monitoring wells were submitted using chain-of-custody record to Argon Mobile Labs for <br /> analysis of TPHg and BTEX using EPA methods'80.15 (modified),and 8020;respectively. Purged <br /> water was stored on-site in 55-gallon drums approved for hazardous liquid storage pending <br /> laboratory analyses. <br /> i Analytical results for groundwater samples are contained in Table 2. Groundwater monitoring <br /> data are contained in Table 3. Copies of chain-of-custody records and laboratory results are <br /> contained in Appendix II, and copies of monitoring data sheets are contained in Appendix III. <br /> r <br /> RESULTS OF INVESTIGATION <br /> ti <br /> ra Site Geolou <br /> Site boring logs and sediments encountered while drilling suggest that the site is underlain by <br /> t <br /> three lithologic units. The upper unit, located from below the asphalt pavement to depths <br /> between 12 and 13 feet bgs, is dominantly sandy silty clay with some silty clays and sandy clays.` <br /> The middle unit, beginning at 12 to 13 feet bgs and ending at 19.5 to 25 feet bgs, is a layer <br /> consisting of well graded sand. The bottom unit is dominantly sandy silty clay with some silty <br /> clay. <br /> .:V . ... <br /> NA95122TAR:doc <br /> __ SNRH <br />