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Ireriffiar.c. SACRAMENTO Peripheral borehole samples B3-15 and B4-15 were found to contain low levels of BTEX while B5-15 was below the reporting limit (BRL) . The analyses for TPH detected levels of 110 mg/kg in sample B4-15 and 150 mg/kg in B5-15 while B3-15 was BRL. Hydrocarbon contamination in the soil samples from borehole BHI was found to be significantly higher. Sample Bl -20 contained 2,600 mg/kg of TPH, identified as diesel fuel , which increased to 7,100 mg/kg in sample B1-30. Sample B1-40 was found to be BRL for TPH. Each of the three soil samples from borehole BH1, including sample BI-40, were found to contain low levels of BTEX. Figures 4-2 and 4-3 show the horizontal and vertical extent of the diesel fuel contamination. 5.0 REMEDIATION WORK PLAN 5.1 Contaminated Soil The Pacific Bell Ashley Road facility has significant soil contamination. Data obtained from borehole and laboratory analysis indicate that a vertical plume of diesel fuel contamination is present beneath the former location of a UST. The highest level of contamination encountered is 7,100 ppm TPH at 30 feet below the surface near the plume head. There appears to have been lateral migration of contaminants at 15 feet below the surface. This migration is probably related to the high clay content found in the soil at that level . 5.2 Initial Preparation Prior to excavating the contaminated soil , two operations must be completed. First the septic tank, located approximately 30 feet west of the former UST site, will be pumped out and closed off for the duration of the excavation. The second operation will be the installation of a temporary six foot fence around the excavation site. This is required by Cal OSHA and will reduce the potential liability to Pacific Bell during the period when the pit is open. 10