Laserfiche WebLink
the new table, and include discussion of ditch changes that will occur in <br />association with sediment pond removal, within the relevant diversion <br />channel text on page 2-12. <br />10. Please provide a "master" permanent channel summary table that would <br />provide summary design information for all permanent ditches and channels <br />(including upper road and portal area channels, waste disposal area <br />channels, lower road "dry fords", and any other permanent channels in a <br />single location. Having a single design schedule that includes specifications for <br />flow, slope, bottom width, side slope, depth of flow, total depth with freeboard, <br />and liner material type vegetation/riprap, for each design segment of each <br />permanent ditch/channel is very useful for confirming compliance following <br />completion of reclamation and for bond release. <br />11. Please include the sediment pond peak stage water elevation for the 10-year, <br />24-hour precipitation event and the 25-year, 24-hour event on Figure 2.2-7. <br />12. Based on review of postmine topography depicted on Map Figures 3.1-5, 3.1-6, <br />and 3.1-7, and stability cross-sections 18+00, 42+00, and 47+00 depicted on Map <br />Figure 3.1-8, we have several observations and questions regazding final grading <br />of the portal access road, and we believe clarification is warranted. <br />(a) Our understanding based on review of applicable permit text and figures, is <br />that reclamation of most of the length of the road, with the exception of the upper- <br />most segment, would entail grading to a more or less uniform slope that will <br />eliminate the existing cut slope and tie into the undisturbed hillslope, as depicted <br />on the cross-section at Station 18+00. <br />(b) Along the upper-most segment of the road, beginning in the approximate <br />vicinity of the cross-section at Station 42+00 and continuing up to the tie-in with <br />the portal bench reclamation, the original road disturbance would be only partially <br />backfilled (due to stability considerations), and along this upper segment, sections <br />of the existing road cut would remain exposed, as appears to be depicted on the <br />cross-sections for Station 42+00 and 47+00. <br />(c) The topography between the disturbed azea upper and lower boundaries <br />depicted of Figure 3.1-7, appears to reflect a more or less uniform slope in the <br />vicinity of Station 42+00 and Station 47+00, which does not appear to correspond <br />to the final topography of the disturbed area as indicated on the relevant cross- <br />sections on Figure 31-8. <br />(d) The cross-section for Station 47+00 appears to show the upper boundary of <br />disturbance (crest of cut slope) at approximate elevation 5778', whereas Map <br />Figure 3.1-7 indicates upper boundary of disturbance at approximate elevation <br />5750'. It would appear that the upper boundary of the existing disturbance for the <br />road segment depicted on Figure 3.1-7 may not be correct. <br />