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October 11, 2011 Page 3 <br />A comprehensive study of subsidence related to longwall mining in the Allen Mine was <br />initiated in 1981. The final report for this study is dated September 19, 1982. This study <br />obtained subsidence data (vertical and horizontal) over longwall and room - and - pillar mining <br />areas. According to New Elk Coal Company, LLC, the data obtained during this study indicated <br />that subsidence in this area typically occurs as vertical displacement of the total overburden unit <br />(i.e., very little differential settlement) with dampened horizontal status. Partial subsidence data <br />indicate maximum vertical displacement of about 3 ft over a 6 -ft -high longwall panel and <br />maximum horizontal displacement of less than 1 ft. This displacement occurred within 6 months <br />of longwall undermining. Subsidence under room - and - pillar areas was considerably less <br />(maximum vertical 0.3 and 1.4 ft), with most displacement occurring within 3 months. Based on <br />the data obtained, it can be inferred that subsidence over the New Elk Mine occurs quickly and in <br />mass, with very little visible surface expression. Therefore, it is reasonable to conclude that any <br />subsidence that may have resulted from undermining (more than 20 years ago) has already <br />occurred and that additional subsidence resulting from placement of the refuse pile would be <br />minimal. The stability of the refuse pile as designed (SF 1.5) should not be affected by <br />subsidence. <br />The post- mining and pre - mining land uses of the permit area are identical and are <br />described in detail in Section 2.04.3 of the current permit. The land use is shown on Map 4, Pre - <br />Mine Land Use; Map 15, Surface Disturbance and Post - Mining Land Use —East Portal; and <br />Map 16, Surface Disturbance and Post - Mining Land Use —West Portal. New Elk does plan to <br />monitor subsidence at the New Elk Mine. Mining during the permit term will be in the non- <br />renewable resource areas as shown on Map 20, Sheets 1-3—Structure Inventory. Renewable <br />resources will not be undermined with retreat - mining methods. <br />Agapito Associates, Inc. <br />