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AUG 09 '96 12~24PM PEABODY WSTN SENECA MINE P.5 drainage bleaker and toe drain be rnoctruaed. The plans call for a 6-inch diameter pipe be placed in rho too drain. We recommend that the pipe consist of perforated PVC pipo meeting the roquiremeats for Schedule 30:14 is accordance with ASfM. The free draining gravels [o be used in the tce drain should meet the aper~5catioas outlinod on page 13.3-1i of the apecificatioas for the toe drain materials. We would also recommend that the same free draining materials be used for the drainage blanket, It u our understanding Wet Cornell Resources, in Milner, Colorado, is presently producing a washed aggregare material which would meet this specifieatioa. The pleas call for We drainage blanket to be a minimum of 1 loot thick; however, we would reeoatmmd that the drainage blanket be a minimum of 2 feet in thiciotess. In addition, we recommend that We toe drain sad drainage blanket be wrapped, 'sop and bottom, wiW Mvafi 140N or as equivelmt product. The base of the embaakmeol, below We drainage zystem should be underlain wiW Mvafi 140N and not We 50f1)i. a} A stability analysis of the embankment s[ruaure has ao[ been completed For this project. Therefore, basod on our eoaversation wiW you, ow fum will complete a stability analysis for this atruaurc using SB-Slope sad the slope ronfgurations shown on the project pleas. It is our understandutg the[ the fill materials to be placed in the embankment will come from the cv[ slopes being consvuc[ed for Haul Roads Y-B and Y-A. We will use the [rialdal shear strength information obtained earlier oa these materials for the embankment fill materials. The results o[ rho stability analysis will be forwarded to your office as soon as they are wmpleted. I.f you haw any quosti~its rCgBTdlag this letter, our observations or recommmdatioas or if we may be of further service, pie contact this office. Sincerely, 1NC., Brian L. )oe No. 45.73&1 Norihvcs[ talorado Conaulunts, Inc. Page 2