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Gary Isaac <br />CAM-Colorado, LLC <br />August 29, 2008 <br />Page 16 <br />Please provide appropriate request for road retention from BLM, or revise the <br />reclamation plan to conform to 4.03.1(7). <br />41. The haul road reclamation plan does not appear to be a realistic, achievable plan. <br />Narrative indicates that "reclamation of remaining haul roads will involve returning the <br />road to its pre-mining contours". This is indeed depicted on the Map 17 series <br />topographic maps and Map 19 series cross-sections, which show postmining contours <br />exactly matching premining contours. In a number of locations, particularly along the <br />steep rock outcrop and canyon segments of Haul Road #1, very steep backfill slopes are <br />depicted, which would not be stable at the gradients depicted. For example, along the <br />segment of Haul Road #1 depicted on operational Map 15-2 and Premine/Postmine <br />Topographic Map 17-2, backfilling of several of the steeper road cuts depicted would <br />appear to result in numerous backfill slopes with segments steeper than 2:1 (50%), <br />apparently ranging up to 100% or more in certain locations. The extent of reclamation <br />backfill versus original canyon slope is difficult to discern in some areas, but presumably <br />disturbance limit, and thus reclamation backfill, would extend up to the upper disturbed <br />area boundary, if the exact original topography is being restored, as indicated. <br />A realistic haul road reclamation plan, with revised postmining contours and cross- <br />sections, and demonstration that "worst case" backfill slopes will achieve a minimum <br />static safety factor of 1.3, pursuant to Rule 4.14.2(1)(b), will need to be provided. <br />Narrative will need to be revised to address requirements of 4.03.1(7), and to correspond <br />to amended postmining maps and cross-sections. Additional cross-sections are <br />warranted, particularly in the steep road cut sections, to more clearly define the proposed <br />plan. The cross-sections should be oriented perpendicular to backfill slope orientation. <br />Upper and lower perimeters of proposed reclamation backfill, as well as upper and lower <br />limits of disturbance associated with operational cut and fill should be delineated on the <br />topographic maps and cross-sections. <br />Rule 2.05.3 (4) Operation Plan-Ponds, impoundments other treatment facilities and diversions <br />42. Based on field observations at the McClane Mine and at the Munger Mine over the years, <br />the Division has concerns about normal hydrologic modeling procedures accounting for <br />the intensity of the precipitation events in this area. The Book Cliffs are steep cliffs with <br />little vegetative cover. This area gets hit with very intense localized summer storms. <br />Large amounts of sediment and other debris (tree stumps, rocks, etc.) have come down <br />with the runoff from these intense storms. Relying on the design storm event and <br />SEDCAD modeling to size sediment control structures doesn't work well in this <br />environment. The Division highly recommends that CAM consider oversizing the <br />structures, or consider other measures, to account for the intensity of the storms in the <br />Book Cliffs.