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• 2.05.6(6) <br />(f)(ii) A narrative of the detailed description of the mining method and other <br />measures to be taken which may affect subsidence follows: <br />(f)(ii)(A) <br />Room and pillar and longwall mining will be used for coal removal. The size <br />sequence and timing for development is presented on Map 14, Mine Plan. <br />(f)(ii)(B) <br />Nearly all of the areas to be mined are areas in which planned-subsidence <br />mining methods will be used. There are a few exceptions to this statement <br />as outlined below. <br />In orderto protect againstchimney subsidence, only development mining will <br />be performed in areas with less than 110 feet of overburden. <br />The subsidence implications dealing with mining in low overburden areas <br />adjacent to the fault trace are a concern. The First North Mains mined into <br />• the fault in late 1997 or early 1998. Additionally, the Operator has probe <br />drilled the fault on numerous occasions. The fault is characterized as a <br />shear fault as opposed to a roll fault and little fracturing was noted. The <br />probe drilling has not encountered any appreciable waterwhich indicates the <br />fault trace is virtually dry. <br />The subsidence implications of mining through the fault are summarized in <br />Exhibit 15. Inadequate roof support could result in a conical chimney <br />collapse which could breach 285 feet of overburden. Additionally, regardless <br />of the depth, when a fault is encountered and coal is mined beneath the fault <br />plane on the upthrow side of the fault, a step on the surtace could result. As <br />explained in section 2.05.3(1), the Operator is committed to adequately <br />support the openings developed through the fault trace to avoid the <br />subsidence implications explained above. <br />Also when, during development of the panels near the outcrop, low quality <br />coal is encountered, one row of development pillars will be left in place to <br />prevent the potential crushing, sliding, or other failure near the outcrop. See <br />• Exhibit 15, Section 1.7. Zones Along Outcrop Barrier Pillar. <br />PR-04 2.05 - 106 - 01/01 <br />