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.) <br />exhibits some fines, even after screening. Therefore, we also need to modify the grain-size <br />distribution to the following: <br />PROPOSED SPECIFICATION <br />7. Select Drain Cover Fill -processed, free draining, poorly graded Cresson Ore, Pad N2 <br />Material, or Granitic Material (Granodiorite) from the Valley Leach Area placed around <br />the vertical riser pipes conforming to the following SPECIFICATIONS: <br />U.S. Standard <br />Sieve Size <br />Percent Passing <br />by Dry Weight <br />1-inch <br />3/4-inch <br />1/2-inch <br />No. 40 <br />No. 200 <br />Plasticity Index: <br />100 <br />30 - 85 <br />0-12 <br />0-5 <br />0-2 <br />0 <br />I emphasize that this granitic material has been crushed and screened for this particular use at <br />the Project. It is not run-of-pile or reject material. We are proposing to add the two additional <br />screen limitations along with the modification of the 3/4 inch and 1/2 inch allowances to assist <br />in maintaining high permeability and controlling migration of fines into the pumps. As is <br />explicit in both the existing and the proposed specification, this material is used solely around <br />the vertical riser pipes that hold the turbine pumps. <br />I apologize for adding this request to your list at this time, but your approval is necessary to <br />ensure CC&V remains within the Technical Specifications and that we produce a reliable system. <br />I suspect that re-handling of the granitic material necessitated by the limited storage area plus <br />dampness which allowed a small amount of fines to pass through the screens caused the slight <br />increase in fines compared to the original specification. <br />Thank you for your consideration and patience. <br />environmental Affairs <br />FILE: CC&VSTIP.003 <br />2 <br />