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I The following sections present a summary of the analytical data for each sample area along with conclusions relating to the need for E.y further investigation or remediation. i 4.1 Tank Bottom (Pit A) Pit A is the excavation area from which the three tanks were pox removed. It is located adjacent to the east side of the building. 4 A review of Table 1 indicates that only one compound analyzed for was detected. This was total lead at a concentration of 7.9 mg/Kg T in the soil sample designated SA. This concentration is well below the Title 22, Total Threshold Limit Concentration (TTLC) of 1,000 mg/Kg and the DL concentration of 500 mg/Kg. Therefore, no additional investigation/remediation is required within this area. 4.2 Tank Bottom (Pit B) F Pit B is a small excavation area from which piping was removed adjacent to the northeast corner of the building. This was the area in which previou=!y mentioned pipeline failure had occurred. A review of the data contained in Table 1 indicates a number of hydrocarbon related compounds were present in the soil samples. r Total lead was detected in samples EB and SB at concentrations of 5.3 mg/Kg and 5.4 mg/Kg respectively. These values are well below the applicable regulatory standards noted in Section 4.1. .s For samples NB and WB, EDS was detected at concentrations of 0.018 k" mg/Kg and 0.0011 mg/Kg respectively. These values are below.the DL of 0.05 mg/Kg. I k, Also detected in sample NB were three of the BTX&E compounds. These compounds and their detected concentrations are as follows: o Toluene - 7.6 mg/Kg ' o Xylene - 32 mg/Kg o Ethylbenzene - 6.1 mg/Kg These concentrations are below the DL's of 100 mg/Kg, 620 mg/Kg and 1400 mg/Kg for Toluene, Xylene and Ethylbenzene respectively. I : r, Total Petroleum Hydrocarbons (TPH) were also detected in sample NB at . a concentration of 105 mgr/Kg. Since no established criteria exists for the allowable concentrations of TPH, WESTON utilized Table 2.1A i� { ppendix C) .of- the LYTFT Manual for the evaluation of an allowable concentration. While WESTON realizes that the San Joaquin County Office of Environmental services does not utilize leaching potential analysis for the determination of allowable TPH concentrations due to a --- ---- - ,T - --"generically"-established-area-wzde-shallow-depth to groundwater, WESTON believes that, due to the extremely varied geological conditions within the County, leaching potential analysis is the is only substantiative means for establishing cleanup goals. a. 6