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ball or backhoe-mounted jackhammer. Any residual fuel present on the interior surfaces of the tanks will be removed by appropriate means (wiping or washing) within a contained area. Rinsate or hydrocarbon adsorbent pads contaminated during the cleaning process will be stored on site pending decontamination or disposal in accordance with City of Stockton and San Joaquin Local Health District requirements. A wipe test will be performed on the interiors of tanks so cleaned to confirm that they have been sufficiently decontaminated to permit disposal as scrap metal. As previously reported, samples acquired from soil borings advanced in the immediate area of the underground tanks revealed contamination by Total Petroleum Hydrocarbons as Gasoline (TPH-G) to 3, 140 parts per million (ppm) . While we believe it unlikely that groundwater has been impacted, we estimate that as much as 500 cubic yards of soil has been contaminated. Subsequent to the removal of the underground tanks, the extent of contamin- ation will be determined through exploratory excavation. The progress of this activity will be monitored utilizing both the GasTech Model 1314 Hydrocarbon Survey Instrument and field analysis of soil using a liquid to liquid extraction process. Soil samples will be acquired from the floor and walls of the excavation with the backhoe/excavator bucket. Upon removing the first three to four inches of soil from the top of the bucket, a clean brass tube ( 1 . 92 inches in diameter by 6.0 inches in length) will be driven into the remaining soil until such time as the tube is completely filled with a discrete sample. The brass tube will then be withdrawn and its ends promptly covered with aluminum foil, fitted with plastic caps, and sealed with black electrical tape. The tube will then be marked and placed on dry ice for on site, uncertified analysis or delivery to a certified hazardous waste analytical laboratory under chain of custody for final, certified analyses. As has been specified by the San Joaquin Local Health District, laboratory analyses will be for TPH-G, benzene, toluene, total xylenes, and ethyl- benzene (BTX&E) using EPA Methods 5030/8015-8020, ethylene dibromide (EDB) using EPA Method 8010, and Total Lead. At such time as the boundaries of contamination have been determined and contaminated soil has been removed, the excavation will be backfilled with clean, imported material. Contaminated soil will be stockpiled on the paved parking area North of the tank site. While the San Joaquin County Air Pollution Control Board (APCB) has approved passive aeration of the excavated soils in accordance with Bay Area Air Quality Management District (BAAQMD) Regulation 8 protocol, we expect that the clay content of the soils will inhibit the aeration process- perhaps significantly so. Should this prove to be the case, the soils may be detoxified through aerobic bio- degradation. Here, the contamination soils would be amended