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q f Tank Closure Report Quik Stop No. 121 Page 3 three fuel tanks appeared to be in reasonably good condition. The tanks were transported by Ecology Central Industries and Trident Truck Lines under Uniform Hazardous Waste Manifest (Permit Nos . 95788033, 95788034 and 96844278) to Erickson, Inc. in Richmond, California for proper processing and final destruction. The Hazardous Waste Manifests are included in Appendix B. Under the direction of the County, soil samples S-1, S-2, S-3, S-4, S-5 and S-6 were collected from areas under each end of the fuel tanks (Figure 2) . The soil samples were collected from native soil, which was composed of a fine-to-medium grained sand, approximately 14 to 15 feet below the surface. A backhoe bucket was used to collect soil from the bottom of the excavation and raise it to the surface. The soil samples were collected in 2 x 6 inch brass liners, labeled, logged on a chain-of-custody form and placed into a cooler containing ice for transport to a state- certified laboratory. The soil samples were analyzed for total petroleum hydrocarbons as gasoline (TPHG) , benzene, toluene, ethyl benzene and total xylenes (BTEX) and oxygenates using EPA Test Method 8260 . Groundwater was encountered at the bottom of the excavation. Two grab water samples (W-1 and W-2) were collected from the south end of the excavation using a disposable bailer and nylon string. Approximately 200 cubic yards of pea-gravel were excavated from the tank area prior to the removal of the three underground fuel tanks on March 26, 1998 and stockpiled on the southwest and west sides of the site. The County requested this material be sampled for contamination. Seven discrete samples (SP-1 through SP-7) were collected from the stockpile for analysis of TPHG/BTEX and oxygenates. At this point, the open excavation at the subject site measured approximately 35 ' x 44 ' x 33 ' x 39 ' and ranged in depth from approximately 12 to 15 feet. The existing canopy and the western footing of the canopy structure were exposed and being undermined by the collapsing, into the open pit, of the unexcavated pea-gravel that was beneath the concrete slab and canopy footings . In addition, the native soil (sand) on the north and northwest sides of the excavation was, at times, collapsing into the open excavation (after the removal of the tanks and while excavating to collect samples of the native soil) . Based on this, Quik Stop intended to place the stockpiled material back into the open excavation to shore-up the exposed canopy footings and to prevent further soil collapse as quickly as possible. All of the soil and grab water samples were submitted to North State Environmental (North State) on a 24-hour turn around time frame.