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k" KLEINFELDER <br /> The six piezometers will be tremmie grouted to the surface using a progressive cavity pump. <br /> Tremmie grouting will be achieved by pumping a bentonite slurry into each well until filled. The <br /> six piezometers will then be sealed using a plastic gasket and the hydraulic pressure from the <br /> drilling rig. Additional bentonite slurry will then be pumped into each of these six piezometers <br /> under pressure. The pressure will be maintained for approximately five minutes to better <br /> increase infiltration of the grout into the filter pack and immediately adjacent formation voids. <br /> The following is a summary of the well construction details and estimated volume of bentonite <br /> slurry to be used. <br /> Piezometer Total Depth Screened Depth Boring Estimated Use of <br /> (Feet) Interval (feet) Diameter Grout/Bentonite Slurry <br /> PZ-1 47.92 28-48 8-inches 33 gallons <br /> PZ-2 40.70 20-40 32 gallons <br /> PZ-3 50.58 30-50 33 gallons <br /> PZ-4 44.80 20-45 39 gallons <br /> PZ-5 61.37 32-62 35 gallons <br /> PZ-6 70.70 40-70 50 gallons <br /> The upper three feet of material will be drilled out for each piezometer and backfilled with soil. <br /> Task 3—Domestic Well Abandonment <br /> A domestic/irrigation well is located in the northern gravel pit in the vicinity of piezometer PZ-4. <br /> This well was uncovered during mining of the gravel pit and the former use is unknown. The <br /> total depth of the well was measured at about 55 feet below ground surface (bgs). The 12-inch <br /> diameter metal casing will be perforated from this depth and at 2-foot intervals up to the surface. <br /> Other well construction details are unknown. The casing will be tremmie grouted from the <br /> bottom of the well using a 9 sack sand and cement slurry. <br /> The following is a summary of known well construction details and the calculated casing <br /> volume. Because of the unknown variables such as the type of gravel pack used, formation soil <br /> type, etc., an estimate for the grout to be used in addition to the calculated casing volume has not <br /> been included. <br /> Casing Total Depth Screened Boring Casing <br /> Size (Feet) Interval Diameter Volume <br /> 12-inch Diameter <br /> Metal Casing 55 unknown unknown 325 gallons <br /> 20-YPO-357/2000429/2000W047 Page A-2 <br /> Copyright 2000, Kleinfelder, Inc. November 27,2000 <br />