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VII. Depth of Ground water: { Depth of Ground water is apr: oximately 15 feet. This was established at the time of th:a tank removal when ground water entered the excavation. This in fact probably fluctuates, with tidal movement and river levels in the nearby Stockton Channel. VITT. Proposed Remedial Steps: Step 1: The soils adjacent to the tank locations will be excavated by means of a backhoe/ excavator to a depth, not to exceed 25 feet, so we can remove the contaminated soil for treatment. The anticipated perimeter should not exceed 60 feet by 80 feet in size. Soil samples from the bottom ' and side -galls of the excavation will be analyzed in accordance with sampling procedures as described in San Joaquin Local Health District, Option #1, Re-excavation guidelines. The excavation will be subject to approved engineering practice relative to cave in protection. The excavation walls may be sloped 1:1 if needed. Step 2: Because of the shallow depth to ground water, we r,ould install one or more, "up gradient" ground water extraction wells. These wells would be used to prevent ground water form re-charging the excavation area. Once the contaminated soil has been removed from the excavation ` we would allow some water to enter the excavation. This water would be pumped into 4 or 5 - 10,000 gallon tanks. we would analyze the water, and if we found it free of contamination we would discharge it to the local sanitary sewer, or storm drain, or onto the vacant land at the west end of Union Ice property. Any water found to be contaminated would be treated with carbon until it becomes clean enough for the above disposal options. The ground water clean-up would continue until we achieve an acceptable level of clean-up. IX. Proposed Disposition of Soils We do not anticipate reaching contaminated soil until we reach a 6apth of 8-9 Beet. We propose excavating and testing each load of soil with a portable P.I.D. gas chromatograph. If we find none detected, we propose to put that soil in an area segregated from any contaminated soil. € All contaminated soils will be stored on asphalt or 6 mil visqueen. All contaminated :oils will be covered with 6 t..: mil visqueen, to prevent uncontrolled emission of hydrocarbons. Based on the lab analysis of the contaminated soil, the appropriate remedial methods will be employed to reduce hydrocarbon levels to meet the San Joaquin Local Health District standards. We anticipate and hope to use either aeration on site, or biodegradation on b_ `�• site. all proposed remediation activity, will be in