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• -12- <br />The buttress itself will be constructed of durable rock materials which <br />is the waste material from the pit area. It is designed as a free draining <br />structure and, to facilitate that, a filter fabric will be placed between the <br />buttress materials and the highwall to ensure that there would not be buildup <br />of head on the highwall side which would compromise the integrity of the <br />buttress. The overall factor of safety for the south wall with ttre buttress <br />in place is increased to about 1.8. That's over the long term. <br />Regarding the slurry wall, I need to make a correction into the record as <br />to what we were referring to this as last month. We referred to it the record <br />as a grout curtain and there's a difference between a grout curtain and a <br />slurry wall. The proposal, well, the Company commitment at this point, would <br />be to install a slurry wall at the site adjacent to the Rito Seco alluvium in <br />the vacinity of the south wall of the West pit. The actual purpose of the -- <br />the actual proposal is to build a south wall or the slurry wall so as to <br />inhibit any inflows of alluvial waters from the Rito Seco alluvium into the <br />South Pit or the West Pit, I'm sorry. <br />• Data submitted to the Division indicates that inflows could be expected <br />up to 125 gallons per minute. However, this is data from one hole and it's <br />not, cannot be precisely determined. I think this is an estimate that we are <br />using to go with. Based on this information, the Division does Feel that the <br />slurry wall would be necessary to ensure that, first off, the hydrologic <br />balance of the alluvium material would not be materially disrupted at post <br />mining and that during mining, the operation would remain essentially dry. <br />Battle Mountain Resources has submitted a typical slurry wall design, the <br />exact specifications of the design have not been submitted and w•fll not be <br />submitted until the actual need for the trench is determined or the slurry <br />wall is determined. <br />We will determine the necessity for this slurry wall about two years <br />after an excavation is completed. This excavation would essentially be a <br />trench in the alluvial materials in the vicinity of the south wall of the West <br />Pit. It's felt by the Staff, that this would be the best method to determine <br />the necessity and to determine the actual inflow rate and volume,, if any, <br />into the pit area. With that in mind, the Company has committed to <br />