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Peabody <br />BTU Empire Corporation <br />June 1.2005 <br />RECEIVED <br />Mr. Kent Gorham JUN p,~ 2005 <br />29515 Routt County Road #27 <br />Oak Creek, CO 80467 <br />970.879.3800 <br />Division of Mi e rals and~Geologyst II Division of Minerals S Geology <br />1313 Sherman Street, Room 215 <br />Denver, Colorado 80203 <br />(303) 866-4931 <br />RE: Response to DMG Comments on BTU Empire 2004 Annual Hydrology Report (AHR). <br />Dear Mr. Gorham <br />The following is in response to your AHR comment letter dated Apri] 28, 2005. <br />General Comments: <br />1. Two updated ~~opies of Figure 2 are attached. <br />• 2. Explicit verification for seven events that trigger reversion to active mining plan: <br />a. See table 9 A <br />b. The No. _i Mine well pump has a maximum capacity of 600 gpm. The 7NA pump has a <br />maximum capacity of 500 gpm (see attached pump specifications for both). Therefore, the <br />2000 gpm limit cannot be exceeded. <br />a See table 9 <br />d. Flow for i1SGS site 09251000 was estimated at 27 cfs on August 1, 2002, at 215 cfs August <br />1, 2003, and at 165 cfs on August 1, 2004 (See attached USGS data sheets). Therefore the <br />minimum limit of 100 cfs was met during two of three consecutive years. See attached USGS <br />data sheets. USGS data for this site will be attached as a table in future AHR's. <br />e. MSHA inspected the mine quarterly from the time the mine closed in 1995 until the Portals <br />were sealed in 2002 (see attached MSHA records. Note that records listing Eagle # 5 mine <br />actually includes both No. 5 and No. 6 mines). The last MSHA documented roof fall (216 sq <br />feet) was in 1997. Historically, roof conditions were excellent to the point where roof <br />bolting was not deemed necessary until about 1980 when mining methodology (longwall) <br />changed and wider cuts were utilized. Based upon the above, no significant roof fall was <br />suspected in 2004. <br />f. Active mining ceased in 1995. As you are aware, subsidence effects typically occur for a <br />period of a few weeks after undermining with total subsidence usually ending within a year. <br />Subsidence reports for Empire were submitted through 1996. In 1997, based upon the lack <br />of survey evidence of long term subsidence effects, Empire made a request to Erica Crosby <br />. of DMG to suspend monitoring until mining resumed. The final reports and letter to Erica are <br />attached. No significant subsidence effects (i.e. greater than 2 feet) were noted during 2004 <br />