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�fl�lCi�+ifR�f� Mr. Charles Leubner 10 October 1991 Page 5 of the Soluble lead was eters preedsented in Table 1.using the Waste Extraction lLaboratory analytiical reports for the soil .�, ET). The resuItc Boll sample analyses are samples are included in Attachment B. In the soil samples submitted for analyses from the three borings, total petroleum hydrocarbons as gasoline (TPH-G), and benzene, toluene, ethylbenzene, and xylenes (BTEX) were detected only in samples from boring B-1. a The highest concentrations were detected in the sample collected at a depth of 10 feet below the ground surface (sample No. 132). Total petroleum hydrocarbons as gasoline were detected in this sample et an average concentration of 1,770 mg/Kg, and ethylbenzene and xylenes were detected at concentrations of 42,000 ug/Kg and 350,000 ug/Kg, respectively. This sample was submitted for analyses based on field screening results (i.e., degree of staining and OVA measurements greater than 1,000 ppm), which Indicated that it potentially contained the highest concentrations of petroleum hydrocarbons encountered while drilling at the site. Concentrations of petroleum hydrocarbon constituents, as indicated both by OVA measurements and analytical results, decreased rapidly downward from the ten-foot depth. Although it was not analyzed, the sample collected at a depth of 15 feet had an y OVA headspace reading of 80 ppm as methane indicating that petroleum hydrocarbons may,have migrated to that depth. Concentrations of total petroleum hydrocarbons as gasoline in the sample collected at a depth of 20 feet(sample No. 134) were below the. r laboratory's limits of detection. Because this sample was selected for analysis after we received the results of the analysis of samples collected at depths of 10, 30, 40 and 50 ;set; the sample was analyzed several days after the expiration of the holding time. ^' However, we feel that the data from the analysis of the 20-foot sample is a valid indication that the majority of the petroleum hydrocarbons are above the depth of 20 feet. CONCLUSIONS Petroleum hydrocarbons identified as gasoline, and the petroleum constituents toluene, ethylbenzene, and xylenes, are present in the soil beneath the former location of the .W gasoline tank. Based on the results of the soilto be lmi ed t the area immediately illed at the site, the areal extent of these petroleum hydrocarbons appears beneath the former tank,as no petroleum hydrocarbons were detected in the soil samples collected from efther Boring B-2 or B-3. Although the faun the soil boring was not observed ined the three boring that were drilled, it is planned, based on t g3'