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LJ-Haul#709-50 Additional Site Characterization Blaes Enviromnemal ' summ of anal �'Y yttcal results are presented in Table 1 23 1 Tyke egu e u tan e Relead Based on the detection of hydrocarbons to soil samples collected during removal of the USTs (ETS, 1990), ' the apparent substances released included unleaded and/or regular� (leade d )gasoline ' 232 Quantgyt e le The quantity of petroleum hydrocarbons released from the former gasoline UST area is unknown Based on results of soil samples collected during removal of the USTs (ETS, 1990), the release areas included the UST area and the product piping areas (Figure 4) 2 4 PREM01 JR 'qT-rP PUAATI A TI [JIBS Following the detection of petroleum hydrocarbons in soil at the site ETS completed Investigation and Evaluation Report''in October 1991 This report included results odril ling and rslam sampling ' three soil borings (B-1, B-2, and B-3) to approximately 100 feet bgs, and the installation of thep g monitoringwells three (MW-1, MW-2, MW-3) within the borings Results of this investigation indicated that petroleum hydrocarbons were present in soil at depths of approximately 60 to 75 feet bgs Subsequent groundwater monitoring performed by ETS in May 1992 (Table 2) indicated concentrations of hydrocarbons ' above the California action levels in groundwater samples from the three wells ' Applied Consultants of San Diego, California, began managing the site for U-Haul in 1992 Quarterly groundwater monitoring conducted in September 1992 indicated that the depth to groundwater across the ' site ranged from 85 5 to 86 74 feet bgs and the groundwater flow direction was to the north at a gradient less than 0 001 feet/foot Analytical results of groundwater samples indicated that groundwater at two of the three wells (Mw-1 and MW-3) contained benzene at concentrations greater than the California action level ' (Table 2) Applied Consultants completed further assessment of hydrocarbons in soil andoun gr dwater in 1993 This work involved drilling and sampling five additional soil borings and the installation of three additional on-site monitoring wells Applied Consultants report concluded that the source of hydrocarbons in soil was located near boring B7 Analytical results of soil samples from B7 indicated that hydrocarbons were present from 10 feet bgs to approximately 70 and 75 feet bgs (the depth to groundwater at that time) Thelaboratory analytical results are presented in Table 2 Analytical results of groundwater samples indicated that the 4