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iiiiiiiiiiiiiiiiiii <br />STATE OF COLORADO <br />DIVISION OF MINERALS AND GEOLOGY <br />D~•parlmenl ui Natural Resources <br />I f I { Shorman SI .Roam 21 5 <br />Drover. Colorado ril P_Ol <br />I'huno' 15011 lSL6- {56- <br />FAX I SII Il 7f 13-7f I111~ <br />DATE: October 26, 1998 <br />TO: Dan Mathews <br />L(~.'cG, <br />FROM: Jim Pendleton <br />RE: Roadside orth -Minor Revision Application <br />Cameo "C' eam Exploration Mine & <br />Realignment of Mains in Cameo "B" Seam <br />(Permit No: C-81-lldl) <br />~I~ <br />DEPARTMENT OF <br />NATURAL <br />RESOURCES <br />Roy Ramer <br />Governor <br />lames 5 Luc hhead <br />Ececwi.~e D~rraor <br />Michael B loop <br />Davison Director <br />I have reviewed the recent Minor Revision application submitted by Powderhorn Coal Cornpany <br />(PCC) for its Roadside North mine. PCC proposes to ramp up 17' into the Cameo "C" Seam to <br />explore the possibility of mining in the upper seam. Because the main workings involved are to <br />be mined i.n development only, I anticipate there will be no subsidence manifest above these <br />limited workings. PCC commits to the submittal of a subsequent revision application if any <br />additional mining is proposed. <br />PCC also proposes the realignment of the previously approved Cameo "B" Seam workings. This <br />realignment is being proposed to reflect roof conditions and to align pti~els perpendicular to the <br />overlying escarpment face, in order ro limit roof and ground control challenges. The <br />configuration of panels and the barrier pillar designs are consistent with the original plan. <br />I recommend approval of the requested minor revision as proposed by PCC. The potential <br />implications of subsidence control plan modifications necessitated by retreat mining within the <br />Cameo "C" Seam workings will have to be addressed when approval is requested for additional <br />mining within the Cameo "C" Seam. At that time geotechnical observations completed during <br />the development mining should support a precise projection of subsidence impacts due to the <br />superposition of the Cameo "B" Seam and "C" Seam workings. <br />cc: David Berry <br />doe: M:\COAL\J.P.\CAMCSEAM.WPD <br />JP/JP <br />