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• -63- <br />into the west pit. A slurry wall is typically constructed; one of this depth <br />is typically constructed using an extended boom back hoe that can reach depths <br />of 40 or 50 feet. You keep the trench open using a bentonite slurry, and as <br />the trench is developed along the axis of the trench, you back fill it with a <br />mixture typically of the native soils and the bentonite slurry mixed together <br />until you've got an appropriate mix to achieve a very low permeability. Our <br />intent with this slurry wall, should it turn out to be necessary, is to <br />achieve a permeability in that wall which would be about 3 feet thick of a <br />permeability very similar to that of the underlying Sante Fe which we would be <br />keying the slurry wall into. The slurry wall will be keyed -- as designed <br />right now, will be keyed into the Sante Fe on the bottom as well as on both <br />ends to eliminate all those potential seepage pads. <br />MR. JOUFLAS: Questions? <br />• MR. BARRY: That's to prevent seepage both directions? Which way is <br />downhill? <br />MR. JOHNSON: Well, it would. I think really the only direction that's <br />likely is from the Rito Seco towards the pit wall. The Rito Seca being the <br />source of the water. <br />UNKNOWN SPEAKER: It serves to minimize any reduction in they alluvial <br />flow into the pit, as well as minimize arty potential for pit water to develop. <br />MR. DANIELSON: Is this the right witness to ask questions about pit <br />water? <br />MR. MASSE Y: Probably not. <br />MR. DANIEL SON: Okay. <br />• MR. HOLDER: Do you have a pit water expert? <br />