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Mountain Coal Company west FJk Mine Post Oflke Box 597 Sarnerset, Colorado 91434 Tekplwne 970 924 5 0 7 5 Fau 970 9?BS595 September 12, 1996 Mr. Michael Boulay Colorado Division of Mmerals and Geology 1313 Sherman Street, Room 215 Denver, CO 80203 III IIIIIIIIIIIIIIII /\ ~. ~r-r~ 16 19yfi ~~r,:u A uooW9Y RE: Minor Revision No. 196; West Elk Mine; Permit No. C-80-007 Deaz Mr. Boulay: Mountain Coal Company (MCC) requests a minor revision to revise the West Elk M'me's B seam mine plan. MCC proposes to mine two short panels in Section 21, as opposed to three as shown in the current permit document, and also proposes to rotate the east longwall panels 10 degrees to ~~ the south. Please find enclosed revised Map 52,'B-Seam Mme Plan" and a Subsidence - Evaluation of the revised panel layouts prepared by Wright, Water Engineers: , .~ ;.. ~ , ~ : .. ;~;. r ~:. MCC originally planned to mine three panels in Section 21 in the years 2021 to 2025. However, MCC now plans to mine these panels in the years 1996 to 2000 as a result of mine development shortfalls that occurred in 1995. It has been decided that these panels will be mined following completion of the panels in Jumbo Mountain. The panel geometry is also revised to allow a lazger bamer pillar under Sylvester Gulch to reduce the risk of roof damage in the adjacent long tent main entries. Tlris revision also reduces the number of panels in section 21 to two, rather than three. This change is slightly offset by increased panel width. Panel reorientation for the longwall panels to the east will improve roof and rib conditions by mining farther off parallel to the coal cleat and the major roof joint orientation in the mine. This change was proposed after observing ground conditions in other areas of the acne, where several roof falls occurred as block type failures when the major rock joint orientation occurred at low angles to entry headings. Rib sloughage has also been observed to increase due to mining at a low angle to the coal cleat. The panel rotation 10 degrees south will significantly reduce MCC's miners' exposure to roof and rib hazards without reducing coal recovery. Wright Water Engineers (W WE) has prepared for MCC a Subsidence Evaluation of the above described revised panel layout. The evaluation concluded that the revised panel layout will not change the effects of subsidence from those projected in Exhibit 60 contained in the currently approved permit document. This evaluation should be added to Exhibit 60 of MCC's permit document.