Laserfiche WebLink
necessary until about 1980 when mining methodology (longwall) changed and wider cuts were <br />utilized. Based upon the above, no signiticant roof fall was suspected in 2005. <br />6. New subsidence of more than two feet is suspected in the permit area. Active mining ceased in <br />1995. Subsidence effects typically occur for a period of a few weeks after undermining widt total <br />subsidence often ending in less than a year. Subsidence reports for Empire were submitted through <br />1996. In 1997, based upon the lack of survey evidence of long term subsidence effects, Empire <br />made a request to Erica Crosby of DMG to suspend monitoring until mining resumed. The final <br />reports and letter to Erica were provided as an addendum to the 2004 AHR (see BTU Empire letter <br />dated June 1, 2005). In 2005 some subsidence effects were noted by DMG. An outline of these <br />effects is provided in the BTU Empire responses to Technical Adequacy Comments letter dated <br />12/07/05 (located at back of this AHR). <br />7. A Phase III bofu~ release application is to be filed in the subsequent two years. A bond release <br />application is being contemplated for the Utah Tract and Williams Fork Strip Pit portions of [he mine <br />property. BTU Empire is also examining their options for re-activating the mine site. In view of <br />these considerations, BTU Empire will revert to the active monitoring plan (pages 1 - 14 of Exhibit <br />29), beginning at the start of the second quarter of 2006. <br />C~ <br />L J <br />7 <br />I:\Env\Empi reV+H R\2005\Te#\Em pi re2005AH R.doc <br />