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Soil samples were collected from two depths in each of the monitor well bonngs based on the results of volatile organic compound screening of all samples collected These samples were ' submitted to the California certified WESTON Analytics' laboratory in Stockton, California, for analysis of TPH-G by Method 8015M and for BTEX by EPA Method 8020 The analytical results for these samples indicate that there were no detectable TPH-G or BTEX compounds in ' any of the six soil samples The complete analytical reports for these samples are also presented in Appendix D ' A 750-gallon plastic tank was placed on the site for temporary storage of monitor well development water and equipment decontamination nnsate The tank is located in the northwestern part of the site behind the former gas station office building and will also be used ' to accumulate purge waters from future quarterly sampling events Water stored in this tank will be characterized and disposed through proper channels at the completion of this project or when ' the tank is full. 3.1.3 Conclusions from the Results of the Third Quarter Activities ' From the combination of the results of the well installation program, the soil remediation preparatory work and the third quarter monitoring event, the following conclusions can be ' derived for the site o Hydrocarbon presence in the in-place soils at the site appear to be confined to the southwest corner of the bottom of the tank excavation area No hydrocarbon presence was found in the excavation sidewalls nor was it found in any of the pipeline trenches 0 I Hydrocarbon presence in the previously stockpiled soils is not detectable in at least the first 1'/a feet of the outside surface of the irregular-shaped pile Conditions deeper within the core of the pile are still unknown I0 The only hydrocarbon compound presence currently found in groundwater is TPH-G at very low concentrations in MW-3 and benzene in MW-2 and MW-5 The relationship between the two wells is consistent chemically and hydrogeologically as MW-5 is downgradient of MW-2 The concentration of benzene at the downgradient property line is 6 5 µg/L This data suggests that the remedial plan previously submitted for the site be revised to reflect the implications of the current data 3.2 Revised Remedial Plan The original soil remedial plan for the site consisted primarily of placing the previously stockpiled soils from the tank excavation area back in the excavation and installing a SVE system to treat the stockpiled soils as well as remaining in-place soils showing elevated hydrocarbon concentrations Because of the current data developed by the September and October 1992 soil and groundwater evaluation work, this plan now appears not to be the most efficient course of I action As discussed previously, hydrocarbon compounds are currently present only in one corner of the bottom of the excavation and are not present at all in the exterior portion of the ti ' nXC\Rp{SSAREG3QTR WA 10 11713M