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~i of the observed features. MCC will attempt to revisit previously identified subsidence features <br />to note any changes that have occurred since the previous visit. MCC will also attempt to <br />replicate the aspect of the photographs taken previously to document the progression of <br />subsidence and subsequent healing. The discussion of the field observations will in particular <br />address the development and healing of the subsidence features, utilizing the photographic <br />documentation. In addition, MCC will discuss baseline conditions observed in areas prior to <br />undermining. The report will document how the inspection was conducted, and include such <br />observations as weather and ground conditions. <br />• <br />In addition to performing the visual surveys, aerial or other type photos will be taken prior to <br />beginning mining in an azea, periodically during mining, and after mining when subsidence is <br />complete to document landslides, rockfalls, vegetation, etc. over the azeas being mined. This <br />documentation will provide a broader, more extensive view from which to associate or assess <br />landslide and other surface activity due to mining. <br />For the original F-Seam and B-Seam monitoring program, <br />techniques were applied for surveying the former monument ?p <br />surveys were designed to achieve horizontal accuracies complyi: <br />Commerce's "Second order, Class II" surveying standazds, and ve <br />feet. Grids were surveyed twice prior to the initiation of sl <br />triangulation bench mark monuments outside the area of antic <br />selected and established. Monitoring of the grid was discontinued <br />reports aze submitted on an annual basis, due by September 30 0 <br />will be maintained at the West Elk Mine. <br />Monitoring Frequency - 2.05.6 (6)(b) p) (D,E&F) <br />Monitoring frequency is conducted and reported on an annual basis. <br />onventional ground surveying <br />d, as shown on Map 29. The <br />g with the U.S. Department of <br />:ical accuracies no less than0.2 <br />~sidence. A minimum of six <br />gated subsidence effects were <br />n 1999. Subsidence monitoring <br />each yeaz. Aerial photos taken <br />Subsidence Control Plan - 2.05.6 (6)(b)(iii)(B), (6)(d)(i&ii), i(6)(e)(iv) & (6)(f)(i-vii) <br />Description of Mining Methods - 2.05.6 (6)(fl(ii)(A&B) <br />C~ <br />As discussed in the previous section (2.05.6(6)(e)(i)(A), Brief Description of Mining Method, the <br />longwall mining method is planned for the Apache Rocks and Boz Canyon mining areas. An east- <br />west panel layout, is planned except for the two northeast panels (LONE and 11NE) which are <br />orientated in a north-south direction. Development mining will employ room-and-pillaz methods. <br />Specific panel geometry and pillaz design aze discussed in the above referenced section. <br />Longwall mining is currently planned for extraction of the B-Seam and E-Seam (in Sections 29 and <br />30) in the Apache Rocks and the Box Canyon mining areas. Although longwall mining may <br />initially induce more caving and fracturing of the roof rocks as (compared to the room-and-pillar <br />method due to the complete removal of coal in the panel, it offers the advantages of maximizing <br />resource recovery. The longwall method also causes more complete subsidence (full extraction of <br />panel) and causes equilibrium conditions to be reached in a shorter period of time (i.e., there is no <br />additional, lingering pillar crushing in panels). As such, to the extent possible, the longwall panels <br />2.05-]35 Minch 2005PRL <br />i <br />~4a`~ <br />~' <br />