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Appendix A Site Closure Request July 2,2010 Speedy Foods-Stockton Page 6 of 13 • Figure 7B: Cross-Section B-B': Shows lateral and vertical extent of MTBE soil and groundwater contamination • Figure 8: TPHg Groundwater Isoconcentration Map • Figure 9: MTBE Groundwater Isoconcentration Map • Figure 10: Groundwater Gradient—A Zone Aquifer • Figure 1 l: Groundwater Gradient—B Zone Aquifer 6.0 Boring Logs and Cross-Sections Monitoring and extraction well boring logs are included in Attachment A. A site map showing the locations of the monitoring/extraction wells is included as Figure 4. Soil boring logs and CPT logs are included in Attachment B. A site map showing the soil boring, CPT, and confirmation boring locations is included as Figure 5. 7.0 Disposition of Excavated Soil On September 23, 1998, Hunter & Associates supervised as Thorpe excavated approximately 166 yd of impacted soil. The excavation was covered in plastic and the soil put back into the UST pit. On September 23, 1998, the previously excavated soil was removed from the plastic lined UST pit and transported directly to Forward Landfill for disposal using analytical results from soil samples collected during the January 1998 UST removal activities. A strong petroleum odor and some visible discoloration were noted in the upper portion of the removed soil. As soil removal continued, the bottom of the excavation began to clean up, and the west and south walls appeared to have only occasional areas of minor contamination. However, the north and east walls still showed evidence of discoloration. On September 23 &24, 1998, approximately 369 yd of clean fill dirt and 54 yd of gravel base were brought in to fill the excavation. The soil was compacted as required by San Joaquin County. Currently there is no stockpiled soil at the Site. 8.0 Well Fate Information There are currently twenty-two monitoring and extraction wells located on-site. • Eleven A Zone groundwater monitoring wells ranging in total depth of 72 to 80 feet bgs • Three B Zone groundwater monitoring wells ranging in total depth of 124 to 130 feet bgs • Two C Zone groundwater monitoring wells ranging in total depth of 222 to 237 feet bgs • One D Zone groundwater monitoring well with a total depth of 301 feet bgs • Three groundwater extraction wells ranging in total depth of 80 to 95 feet bgs • Two soil vapor extraction wells with total depths of 47 and 73 feet bgs