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1 I NOMA <br /> Working To Restore Nature <br /> the tank approximately 22.5 feet, 37 feet respectively, beneath the tank bottom, (Plate 3) One <br /> vertical soil boring (BJJS-SB3) was also advanced to investigate the extent of the contamination <br /> ' Monitoring well MW-1 was installed to the east of the tank to provide information on water <br /> quality at the site The location and orientations of the soil borings and monitoring well are <br /> depicted on Figure 5, RESNA's Problem Assessment Report, dated June 6, 1991 <br /> Gasoline hydrocarbon analytes were not present at or above method detection limits in the soil <br /> samples collected from well MW-1 In ASB-1 at 45 5 and 51 5 feet BTEX was present at levels <br /> ' generally below 1 ppm, and total petroleum hydrocarbons as gasoline (TPHg) was present at 6 8 <br /> and 4 2 ppm, respectively In ASB-2 at 26 feet below surface grade benzene, toluene, <br /> ethylbenzene, and xylenes (BTEX) was present at levels below 1 ppm and TPHg was not present <br /> ' at or above method detection limits In ASB-2 at 31 feet below surface grade toluene (390 <br /> ppm), ethylbenzene (110 ppm), and xylenes (570 ppm) and TPHG (3700 ppm) were present <br /> In vertical soil boring SB3 at 21 and 26 feet BTEX was present below l ppm and TPHg was <br /> ' present at 1 6 ppm in the 21 foot sample and was not present in the 26 foot sample Laboratory <br /> results are summarized in Table 1 <br /> ' Lab error resulted in analysis of the soil samples for total lead instead of soluble lead Results <br /> ranging from 81 ppm to 120 ppm total lead were observed All lead concentrations are <br /> comparable indicating ambient conditions Previous soluble threshold limit concentrations for <br /> lead were also low (Table 1), therefore, not considered to be an area of concern <br /> Groundwater was encountered during drilling at 715 feet below grade and the well was <br /> ' completed to 86 5 feet The well was monitored, purged and sampled on January 17, 1991 The <br /> water sample was submitted to Applied Analytical to be analyzed for BTEX and TPHg. <br /> Laboratory analyses of the groundwater samples indicated detectable levels of ethylbenzene and <br /> ' TPHG at 0 9 and 56 0 parts per billion (ppb), respectively Benzene, toluene, and xylenes were <br /> non-detectable Groundwater was resampled for confirmation purposes on January 24, 1991 <br /> Only 0 6 ppb xylenes and 63 ppb TPHg were detected in the sample A summary of <br /> groundwater laboratory results are presented in Table 2 <br /> ' Groundwater Monitoring and Sampling <br /> ' Well MW-1 has been monitored and sampled on five occasions since it was installed in January <br /> 1991 (January 1991, January 1993, and January, April and July 1994 Petroleum hydrocarbon <br /> analytes were present during the first two sampling episodes, January 1991 and January 1993 <br /> ' but were not present at or above method detection limits in January, April and July 1994 A <br /> summary of the groundwater analytical results are presented in Table 2 <br /> M 11500 NREP0RTSISR-N94 FNL 3 <br />