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the deeper boring need not be completed as a monitor well, as its purpose was to investigate soil contamination rather than groundwater contamination. Upgradient submitted the Work Plan to PHS/EHD on March 1 and it was approved on March 16 For corporate financial reasons, Gillies Trucking requested Upgradient to perform the ins estigation as soon as logistically possible Upgradient prepared a cost estimate and a Cost Pre Approval Request, which Mr Gillies submitted to the UST Cleanup Fund on March 12, but pr(-approval could not be obtained prior to the scheduled drilling date of March 19 Upgradient informed the Cleanup Fund by telephone on March 16 that in order to avoid additional delays in completing the investigation,drilling would begin on March 19 as scheduled. 13 Purpose of the Current Investigation In light of the regulatory concerns, the present investigation has two purposes The first purpose is to test the main interpretation that was presented in the Problem Assessment Report na-nely, that diesel fuel leached downward into a linear stream channel deposit below the UST caviti and was trapped within the channel by an aquitard that underlies it at a depth of 55 feet The second purpose is to re-establish the groundwater monitoring program with a more suitable well 1.4 Specific Objectives In planning the investigation to fulfill these purposes, Upgradient had six objectives for tt a shallow boring 1)to construct a well with a long screened interval in order to insure that a rise or i all in the static groundwater level would not prevent the well from being useful in future groundwater monitoring, 2)to obtain additional data about the magnitude of soil contamination along the axis of the "Modesto Channel", which previous investigations showed to be the principle con rol on the distribution of soil contamination beneath the site, 3)to install a well that would be suitable for testing the feasibility of potential remediation technologies, 4)to accurately determine the depth to the upper sand bed in the Modesto Formation, 5)to examine, in detail,hydrocarbon concentrations across the contact between thy: Modesto Channel and the underlying Modesto Aquitard; 6)to obtain additional data on the hydraulic conductivity and extent of the aquitarc The objectives of the deeper boring were different 2