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OVEREXCAVATION On April 21, 1995 Ground Zero observed additional overexcavation of less than twenty cubic yards of soil from the eastern end of the southern dispenser/product line area (Figure 2). Four additional soil samples were collected from native soil at depths of approximately 3 to 6 feet bgs from the.limits of the overexcavation. The soil samples were sent to Argon. At the direction of SJCPHS-EHD, two of the samples were analyzed for TPI-Ig and TPHd using EPA Method 8015, and for BTEX using EPA Method 8020 (Table 4). Petroleum hydrocarbons were not detected in the soil sample (LS313-6) collected from the bottom of the excavation nor in the sample collected from the northwest sidewall (LS3B-NW5). Laboratory reports and chain of custody records are included in Attachment B. SOIL STOCKPILES SSSS removed approximately 450 cubic yards (cu yds) of overburden and backfill from above and between the former USTs. The overburden was stockpiled onsite, and sampled for disposal. Approximately 150 cu yds of soil generated during lateral overexcavation of the tank cavity was stockpiled onsite, and sampled for disposal. Stockpile soil samples were sent to Argon and analyzed for TPHg and TPHd using EPA Method 8015; and BTEX using EPA Method 8020, and for total lead using EPA Method 7421 (Table.5). Laboratory reports and chain of custody records are included in Attachment B. Approximately 350 to 400 cubic yards of soil generated during the deepening of the UST cavity was also stockpiled onsite and profiled for disposal. The stockpiles were transported to Forward Inc. (Forward), of Stockton, California by by Paul E. Vaz Trucking of Acampo, California. Bills of lading are included in Attachment C. The additional 250 to 300 cubic yards of soil generated during dispenser removal and overexcavation was stockpiled onsite, profiled for disposal, and transported to Forward by Paul E. Vaz Trucking of Acampo, California. Disposal certificates are included in Attachment C. SUMMARY Following overexcavation, petroleum hydrocarbons were not detected in soil samples collected from the sidewalls or the bottom of the tank cavity. Petroleum hydrocarbons were not detected in soil samples collected from beneath the dispensers, and product lines, except for gasoline hydrocarbons which were detected beneath the eastern end of the southern dispenser. The impacted soil was overexcavated and confirmatory samples were non detect for petroleum hydrocarbons. A sheen was initially observed on the surface of groundwater encountered in the tank cavity. This apparently was a result of soil disturbance during overexcavation. Petroleum hydrocarbons were detected in two sets of groundwater samples collected from the tank cavity, but were not detected during the subsequent sampling event. 3