2008-05-28_REVISION - C1981008 - Laserfiche WebLink

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ensure that tables, text, and maps are consistent. Please describe how the bottom of each lift will. be identified for salvage in the field. Section 2.05.4(2)(d Topsoil Redistribution 14. Narrative on page 2.05.4(2)(d)-6 describes overburden/interburden handling operations. The third paragraph describes the typical sequence, in which upper unconsolidated overburden is removed by shovel and trucks and placed into the adjacent mined out pit. The narrative actually references removal of the upper consolidated overburden, but we assume this is an error, since the upper overburden zone at New Horizon typically is unconsolidated; if the material were consolidated strata, it presumably would be initially drilled and blasted. Please clarify, and amend the wording as appropriate. 15. The narrative on page (d)-6 continues on to describe cast-blasting of consolidated strata beneath the upper zone, and removal of the lower-most overburden down to the coal seam by heavy equipment. Finally, the section includes discussion of special handling of Bench 1 overburden material, which would be undertaken as a mitigative measure to replace a suitable root zone, if problems are identified by the spoil monitoring plan. There is contradictory language regarding whether a four foot or 2-4 foot thickness would be replaced (four foot should be specified). A larger issue is that the discussion in this section is inconsistent with the description of typical overburden handling operations included in the Walsh Environmental letter in Attachment 2.05.4(2)(d)-1. In the attachment, it is stated that the upper unconsolidated "Bench 1" overburden material "is mechanically removed as a separate unit and is the last overburden unit to be placed over the reclaimed mine. As such there are generally several or more feet of the bench 1 material underlying replaced topsoil in the reclaimed areas." It is further stated that it was this Bench 1 material that was placed as the upper layer of overburden in the areas that were backfilled prior to February 2008, west of 2700 Road. So, the cited Attachment (d)-1 discussion indicates that stripping and replacement of Bench 1 overburden material would be (and has been) a standard operating practice, whereas the permit narrative on page (d)-6 indicates that Bench 1 overburden is typically hauled or blasted into the adjacent pit void, and that stripping and surface replacement of the Bench 1 overburden (prior to soil replacement), is done only where "special handling" is necessitated based on identification of unsuitable material on the surface of the replaced spoils. Please address this discrepancy, and amend the permit text or Attachment (d)-1 description as warranted to be consistent and to accurately describe the overburden handling operation as practiced in the past and proposed for current and future operations. 6