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Project No. 034-98081 Page No. 5 the contaminants, with highest concentrations of TPH-G and BTEX being present in soils from a depth of 10 to 20 feet in Boring P2. Because very low concentrations of ethyl benzene and total xylenes were detected in the Boring P2 soil sample from a depth of 40 feet, and since the actual groundwater depth at the site had not been determined at the time of the assessment, it was unknown whether groundwater had been impacted by PHCs associated with the former UST. Based on the information gathered during the soil assessment, it was Krazan's opinion°that the former l gasoline UST had not created a significant soil contamination condition (due to low concentrations and limited extent). Furthermore, it was unlikely that a significant groundwater contamination condition was related to the former gasoline UST. However, groundwater conditions beneath the sitejl'were unknown, k andsam sampling and analysis would be required to provide definitive groundwater g P g . Y ' information. � 5.2 March 1998 Groundwater Assessment Based on the conclusions of:,.Krazan's February 1998 soil assessment report for the subject site, H&H Engineering authorized Krazan to collect a grab groundwater sample near the location of soil boring P2. '1 -} The results of that investigation are summarized below and were documented in Krazan's March 13, 1998 report Groundwater Sampling, Farmer Underground Storage Tank Area, H&H Engineering Property, 212 Industrial Drive, Stockton, California. On March 6, 1998, one exploratory boring (P5-W) r was advanced to a depth of 46 feet bgs using direct push; (Geoprobe®) equipment. One grab groundwater sample was collected and submitted to a State-certified analytical laboratory to.determine the presence and concentration of BTEX/TPH-G by EPA Method 8015M/8020M and other volatile organics by EPA Method 8260 included the common fuel oxygenates (methyl tertiary butyl ether ; [MTBE], etc.) and common chlorinated compounds such as tetrachloroethene (PCE),1 trichloroethene (TCF), and 1,2-dichloroethene (1,2-DCF). Table II presents:, the results of the chemical analyses performed on the submitted groundwater sample. ;; r The collected groundwater sample contained elevated concentrations of petroleum hydrocarbons rE (including benzene and toluene above their respective State Maximum Contaminant Levels [MCL]), but no concentrations of fuel oxygenates or chlorinated hydrocarbons. Based on the results of the ti groundwater investigation, it was Krazan's opinion that further soil and groundwater l assessment was o KRAZAN&.ASSOCIATES, INC. Offices Serving tie Western United States 1 3498081.WP