SITE INFORMATION AND CORRESPONDENCE

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and that the well was located nearly 50 feet upgradient of the former tank cavity. Diesel (69 parts per billion) had been reported in only one of the several water samples that had been collected from that well, and I suspected this to be a one-time laboratory error. Therefore, I argued that the most reasonable conclusion from the geological evidence was that no contamination is present in the vicinity of TT-3 and that it had.been adequately grouted on December 7. PHS/EHD also discussed the situation with V&'W Drilling, but subsequently informed us that the site would not be closed until the well had been drilled out. Therefore, on January' 19, 200X, V&W mobilized a larger drilling rig (BK-81) to the site and attempted to drill out the well with 15-inch augers. The driller encountered the same problem as the previous driller, and the augers began to drift off the original hole at a depth of approximately 6 feet. We continued drilling until we reached-the bottom of the December 7 boring (25 feet), and then removed the augers. Peering into the large borehole, it was possible to see the PVC casing from the original well and tilt it away from the sidewall of the boring. At this point, we requested permission from the PHS/EIHD inspector(Ms. Margaret Lagorio)to terminate further drilling and instead pump grout into the PVC casing to seal the well in place. With the inspector's concurrence,we then inserted a small-diameter PVC tremmie pipe into the PVC casing and attempted to pump cement into it, but only a small amount of grout could be pumped before it overflowed. This indicated that the casing had already been filled with grout during the December 7 work, as I had previously argued on December 8. After inserting a 10-foot length of 3/4-inch PVC pipe through the tremmie pipe to tag the top of the cement grout and make certain that it was hard,we.proceeded to fill the 15-inch diameter borehole with cement and resurface the asphalt. This should complete all site work, and you should contact Ms. Lagorio if you do not receive notification from PHS/EHD within two weeks. The final invoice will be sent shortly under separate cover. A copy of this letter report should be included with the invoice when you request reimbursement from the UST Cleanup Fund. Because we were required to re-mobilize the drilling rig on January 19, the total exceeds the pre-approved bid amount by$1,183.02. Thank you for the opportunity to be of service to Teresi Trucking. Q D G Sincergl"y, Victor B. Cherven, Ph. D. Principal Geologist Ne.3475 Cc: Margaret Lagorio, PHS/EHD