2014-05-20_REVISION - C1982056 - Laserfiche WebLink

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TWENTYMILE COAL, LLC - FOIDEL CREEK MINE RESPONSES TO TECHNICAL ADEQUACY REVIEW TR13 -83, WOLF CREEK RESERVE INITIAL DEVELOPMENT 1. Based on the proposed revised pages 2.04 -16, 16.1 and 162, proposed Exhibit 53 provides information of the Wolf Creek Reserve Geologic and Mine Plan information. The information provided in Exhibit 53 is inadequate to address Rule 2.04.6 Per Rule 2.04.6(3)(a) the geology description for underground mining shall include a separate description of the coal to be mined including a map and cross- sections prepared to the standards of 2.10. Please provide the following: Rule 2.04.6(3) (a) (i) — A description including an appropriate map and cross- sections prepared to the standards of 2.10 which shows the nature, depth, and thickness of the Wolf Creek Coal Seam and any rider seams above the Wolf Creek Seam to be mined. Please note that drawing #1 of Exhibit 53 identifies the Wolf Creek Seam Typical Geologic Column; however, this column differs from the approved Figure 2 stratigraphic column. In addition the proposed Map 23 identifies the overburden thickness of the Wadge Coal Seam, and not the Wolf Creek Coal Seam. Rule 2.04.6(3) (a) (ii) — A geologic map with geologic cross- sections of the Wolf Creek Coal crop lines and the strike and dip of the Wolf Creek Coal. Rule 2.04.6(3) (a) (iii) —A description including an appropriate map and cross- sections prepared to the standards of 2.10 which shows the geology of the Wolf Creek Coal Seam including: (A) - The logs of drill holes, test borings or other samples showing the lithologic characteristics, physical properties and thickness of the interburden of the Wadge Coal Seam and the Wolf Creek Coal Seam and the Wolf Creek Coal Seam itself. (B) - The location of subsurface water not previously identified (C) - Chemical analysis of the Wolf Creek Coal Seam for acid-forming or toxic forming materials. (D) - The chemical analysis of the stratum immediately above and below the Wolf Creek Seam for acid- .forming. Toxic forming or alkalinity producing materials and their content. (E) — The thickness and engineering properties of clays or clay shale, if any, in the stratum immediately above and below the Wolf Creek Coal Seam. Response: At the time the revision application was prepared and submitted, the available information on site geology was somewhat limited, as reflected in the baseline information submitted. Ongoing drilling and material analysis have provided significant additional information, as reflected in the revised and expanded baseline text descriptions and associated maps and supporting materials which accompany these responses for replacement or insertion in the PAP. This revised and expanded information addresses the noted requirements of Rules 2.04.6(3)(a)(i — iii). The following are additional comments or clarifications relative to the specific geologic information requirements: The referenced Drawing 1 of Exhibit 5' ) shows only the Wadge /Wolf Creek lithologic sequence, which is only a small segment of the overall lithologic column shown by the approved Figure 2 in the PAP. It is, however, labeled as "Wolf Creek Seam — Typical Geologic Column ", to reflect this distinction.