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Kate Pickford -2- May 1, 2008 <br />7. The following language was added to amended page D-3, Mining experience <br />has shown that any perennial ground water encountered lies on a clay layer, which <br />apparently underlies the entire pit. Agravel/clay mix that cannot be piacessed by the <br />Operator lies approximately 24"above this solid clay layer. When this gravel/clay mix <br />is encountered, mining ceases at that level. This senses as a self limiting factor that <br />has remained constant since mining began, and leaves at least 2'of undisturbed <br />material above the perennial water table. Test holes are periodically excavated to <br />confirm the lateral continuity of the clay layerand the gravel/clay layermix. <br />8. The Marilyn Allen and San Miguel Power damage waiver agreement are part <br />of the approved mining permit. Copies are enclosed. <br />9. The stability analysis I provided for the Bray and Ruhsing headgate <br />demonstrates a worst case pit slope of 4.2H:1V. My understanding from <br />working with Steve Shuey on a similar issue is that the DRMS generally <br />considers a 3H:1 V slope to be stable and thus a geotechnical evaluation <br />should not be required. <br />Two copies of amended pages D-1, D-2, D-3, E-2 & G-1 are enclosed along with the <br />items referenced in numbers 1, 2, 3 & 8. Please call if you have any questions. <br />Sincerely, <br />~f <br />J. E. Stover, P.E. <br />Consulting Engineer <br />