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throughout the existing permit area. Monitoring stations No. 201 through No. 224 had <br /> been installed above projected fault traces in an attempt to discern the effects of differential <br /> subsidence between alternating fault blocks. Stations No. 42 through No. 51 had been <br /> located in areas of thick overburden. Stations No. 28 through 41, in contrast, had been <br /> installed above overburden thicknesses considered typical throughout the permit area. The <br /> high-resolution subsidence data had been used to evaluate and further define the projected <br /> angle of draw. Data collected from these monument grids allowed verification in some <br /> cases, and supported redesign in other cases, of the subsidence control plans proposed by <br /> the operator for implementation in the future. <br /> On May 10, 1996, the West Mine experienced a large bounce in Panel 2 Right. The <br /> pillaring plan at that time was subsequently revoked by the Mine Safety and Health <br /> Administration (MSHA). A modified plan, allowing only the mining of bottom coal in <br /> certain areas, was approved by MSHA. <br /> BRL submitted Technical Revision No. 16 to the Division in October 1991. The revision <br /> allowed BRL to temporarily discontinue subsidence monitoring over inactive portions of <br /> the original mine,which have been sealed since 1986. Annually submitted subsidence data <br /> has indicated that the area has stabilized. The Division approved the revision February 11, <br /> 1992. <br /> With the approval of Technical Revision No. 45 in January of 2005, Division approval was <br /> given to suspend subsidence monitoring of the wide-spaced subsidence monument stations <br /> 14, 15, 16, 6, 81, 82, 83, 95, 99, DH-55, DH-65, and DH-68. <br /> Technical Revision No. 57 (approved in 2013) suspended the requirement to utilize <br /> monuments PL-1 through PL-7 along the Pitkin Mesa Pipeline. <br /> The subsidence portion of the application is in compliance with the Regulations. <br /> XVI. Concurrent Surface and Underground Mining - Rule 4.22 <br /> This section is not applicable to the Bowie No. 1 Mine. <br /> XVII. Operations on Alluvial Valley Floors - Rule 4.24 <br /> The discussion of Alluvial Valley Floors (AVF) can be found in Section 2.06 of Volume I <br /> and in the AVF Appendix, Volume 4 of the PAP. <br /> Identification of Alluvial Valley Floors <br /> The general area in which the Bowie No. 1 Mine is situated contains several deposits of <br /> alluvium. These alluvial deposits are derived from three sources: 1) Floodplain alluvium <br /> (Qal) along the North Fork of the Gunnison River; 2) Valley fill deposits (Qvf) along a <br /> 40 <br />