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28 January 1993 (GeoAudit CV43F1-1. 35) Page 4 of 5 FINDINGS The generalized stratigraphic sequence in the boring consisted of alternating layers of sandy silt, silty sand and silt/clay mixtures. The depth to groundwater in the well, as measured on 8 January 1993 , was 91. 90 feet. Organic vapors were detected only in soil sample B3-90, at 13 parts per million (see attached boring logs) . No hydrocarbon odor was noticed in the water sample. Four soil samples from MW-2 were analyzed. No hydrocarbon contamination was detected in any of the four soil samples. Total lead was detected in three of the four soil samples at levels ranging from 5. 5 ppm to 8 . 5 ppm. Table 2 summarizes the laboratory results. The laboratory report and chain of custody for the soil samples are included in appendix A. The water sample from MW-2 was analyzed according to EPA method 8015, and total petroleum hydrocarbons in the gasoline range (TPH- g) were detected at a concentration of 83 Ag/L (ppb) . Analysis according to method 8020 detected benzene at a concentration of 1. 0 ppb, but no toluene, ethylbenzene or xylenes were detected. However, an unknown hydrocarbon with a boiling point intermediate between that of benzene and toluene was detected in the sample (see chromatogram of the 8020 analysis) . The hydrocarbon was suspected to be a halogenated solvent. Therefore, the sample was analyzed for halogenated volatile organic compounds (HVOC' s) by EPA 601. Eight of the 28 target analytes were detected in the water sample. These individual constituents included 1, 1-Dichloroethene (120 ppb) , 1, 1, 1-Trichloroethane (16 ppb) and Trichloroethene (36 ppb) . The sum of these concentrations exceeds the 83 ppb TPH-g that were detected in method 8015, which indicates that all of the TPH-g can be accounted for by the concentrations of HVOC's. As reported by WEST laboratories in the accompanying letter, the TPH is not typical gasoline, and is probably the halogenated hydrocarbons. The I laboratory reports and chains of custody are included in Appendix B. ICONCLUSION AND RECOMMENDATIONS No contamination was detected in soil samples collected from the monitoring well drilled during this phase of investigation. There is no evidence of vadose zone contamination in the vicinity of the boring, indicating that MW-2 is located beyond the margin of the soil contamination plume.