2008-08-29_APPLICATION CORRESPONDENCE - C2008086

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Gary Isaac CAM-Colorado, LLC August 29, 2008 Page 21 would be salvaged from the waste pile founding in advance of waste placement, and replaced contemporaneously as waste pile construction proceeds, on completed bench outslopes. The 129.4 acres of non-waste pile disturbance would be topsoiled using the soil in Topsoil Stockpile #2, which would provide an average 4.7 inch replacement thickness over the final regraded facility area surface. The Division has the following questions and comments: 53. The total disturbance area given in the above referenced section for the waste pile footprint and additional facility areas combined is 194.6 acres. Total surface disturbance listed on Map-26 Affected and Disturbed Areas is 227 acres. Please address the reason for this apparent discrepancy, and include clarification as warranted in appropriate section(s) of the application. 54. The soil salvage plan in the Volume 1 narrative indicates that topsoil and subsoil lifts would be separately salvaged and stockpiled from the map units within the coal waste pile footprint area, in general conformance with consultant recommendations in Table 1 of the Exhibit 7 baseline soil survey. However, for disturbances other than the coal waste pile area, it appears that the consultant recommendation to salvage subsoil in a separate lift was not followed. Volume 1 table and narrative on page 2.05-37 indicate that topsoil thickness within the various map units would be salvaged in general conformance with Exhibit 7 recommendations, but that no subsoil would be salvaged. Given the fact that salvage of topsoil lifts only, with no subsoil salvage, would result in an average replacement thickness of only 4.7", and that, in many areas, it is likely that the final graded surface would be dominated by heavy textured, saline Mancos shale, the Division believes separate salvage, stockpiling, and replacement of subsoil materials, in accordance with Exhibit 7 recommendations, is warranted on all disturbance areas, not just within the coal waste disposal area footprint. Please revise the soil handling plan narrative and tables in Sections 2.05.3 and 2.05.4 of the application accordingly. 55. Due to the comparatively high quality subsoil available from the Mesa Loam (Map Unit A), the Division concurs that it is appropriate that the Mesa Loam subsoil be separately handled and segregated from remaining coal waste pile subsoils. This may allow for the establishment of a relatively productive shrub/grass community on the top of the pile. However, we are concerned that the proposed plan, to store the Map Unit A subsoils on a particular portion of the single coverfill stockpile, would not ensure proper isolation. Please revise the plan to separate stockpiling of the Map Unit A subsoil, to ensure the material will remain properly segregated throughout the soil storage and handling process.