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REMEDIATION COMPLETION REPORT-LATHROP DEHYDRATOR STATION 3.0 FIELD ACTIVITIES 3.4 Pre-Disposal Soil Characterization and Demolition Sampling On February 3,2004,a pre-disposal soil sample (sample 90Lathropdis-5)was collected using an excavator to dig a 5-foot-deep test pit near the former sump area (see Table 3 and Figure 2).Soil was collected from the excavator bucket and placed into the sample container. The sample was analyzed for petroleum hydrocarbons and benzene,toluene,ethylbenzene, and total xylenes (BTEX)compounds using EPA Methods 8015 Modified and 8020,and for California Administrative Manual metals (CAM 17) (EPA Method 7000/6010B/7471)for the purposes of pre-acceptance landfill waste profiling. Results from CAM 17 metals analysis detected trace metals,with lead at a concentration of 11 mg/kg.A subsequent waste extraction test conducted for the sample detected a soluble threshold limit concentration for lead at 6.7 mg/L,which exceeds the California hazardous waste criterion of 5 mg/L. On February 13,2004, three additional pre-disposal characterization soil samples were collected and analyzed for TPH in the gasoline range(TPH-g)/BTEX,TPH in the diesel range (TPH-d),TPH in the motor oil range (TPH-mo),and soluble lead and mercury. The three samples (905A60N40W-5,905B82N57W-5,and 905C94N35W-5)were believed to be more representative of the majority of the excavation and were therefore composited and analyzed as a single sample (Sample 905A,B,C). TPH-d was detected in the composite sample at a concentration of 14 mg/kg,while TPH-g,BTEX,soluble mercury and soluble lead were not detected above reporting limits.The analytical results for pre-disposal sampling are presented in Table 3.The approximate location of each sampling location is illustrated on Figure 2.The analytical data reports for these samples are included in Appendix D. Based on the results, the soil within the area of sample 90lathropdis-5 (near the former sump) was designated for disposal to a Class I waste facility (Chemical Waste Management, Inc.in Kettleman City,California). Approximately 220 tons (approximately 350 cubic yards) of soil from this area was sent to Chemical Waste Management,Inc. as a Class 11 waste. A total of eleven soil samples were collected from February 5, 2004 to April 19,2004.These samples were collected beneath potential sources located outside of the proposed excavation area.The samples were collected during demolition activities in the areas of the former odorant tank and production fluids tank, the active odorizer unit,and beneath the two equipment pads formerly located near the northwest boundary of the Site. The samples were analyzed for petroleum hydrocarbons,BTEX,and ethylene glycol(sample 907-5N4W- 2) to determine if excavation was warranted in the demolition areas.TPH-g,BTEX,and ethylene glycol were not detected above reporting limits in any of the samples.TPH-d was detected in three samples,with the highest concentration at 80 mg/kg,which is below the cleanup goal of 100 mg/kg.TPH-mo was detected in seven samples,with the highest concentration at 300 mg/kg,which is below the cleanup goal of 1,000 mg/kg.Based on these results and their locations within the PG&E station,no excavation was performed in these areas. However,for"good housekeeping' purposes,two truck loads (or approximately 25 cubic yards) of soil from the former odorant storage tank and production fluids tank area were scraped and sent to Forward Landfill in Manteca,California for disposal.The analytical results for these samples are presented in Table 4. SFO\LATHROPCOMPLETIONREPORT_12-1-04.DOC 6