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<br />III IIIIIIIIIIIIIIII~ <br />999 <br />STATE OF CO~UKADO <br />DIVISION OF MINERALS AND GEOLOGY <br />Department of Natural Resources <br />1313 Sherman 5t., Room ? 1 5 <br />Denver, Colorado 80203 <br />Phone: (303)8663567 <br />F.~,X: 13031 832-8106 <br />L I \' I) 1 O N O r <br />MINERALS <br />-~ <br />GEOLOGY <br />4E.L AIn ATION <br />n IN~NG•SAFETT <br />B~II Owel\s <br />DATE: March 12, 1999 Govzrnor <br />-- Gre; E. watcher <br />.~ <br />TO: Dan Mathews ~ `~` F\ecuuve Dlreuor <br />7 ; n~irhael B long <br />i ~~C (,~C- Dkrnnr <br />FROM: Jim Pendleton ~.,-- t-=~~-\'`" <br />RE: Powderhorn Coal,•G~ompany 1998 Annual Subsidence Report <br />r_ ;.-(Permit No: C-81-041) <br />I have reviewed the 1998 annual subsidence report submitted by Powderhorn Coal <br />Company for its Roadside/Cameo mining complex. The approved permit requires the <br />conduct of twice yearly visual inspections of the potentially effected area above both the <br />Roadside South and Roadside North mines. The unidentified author of this report candidly <br />observes that, because of staffing turnover in the engineering department, only one <br />inspection was conducted above the North Portal workings during December of 1998. Thin <br />and sparse snow cover appear to have allowed this inspection to be definitive. No <br />subsidence impacts were discerned by the inspection. Fortunately, little secondary recovery <br />(pillaring) was conducted during 1998, so I would anticipate minimal subsidence to be <br />manifested at the ground surtace above the North Portal workings. Two inspections were <br />conducted above the South Portal workings. No mining has been conducted within the <br />South Portal workings since 1996, although these workings are being ventilated and <br />maintained for possible future extraction. No phenomena were observed during these <br />inspections which did not comply with projections included within the permit subsidence <br />predictions. <br />The regulatory decision concerning possible enforcement action is yours. In my opinion <br />there appears to have been no loss of data or damage to the environment as a result of the <br />missed inspection. It is important, however, that the operator conduct the two required <br />inspections, particularly as the mains are extended beneath the north flank of Jerry Creek. <br />During previous inspections, conducted and documented by Mr. Larry M. Reschke, P.E. <br />(previously in the employ of Powderhorn Coal Co.), several subsidence-related cracks were <br />observed. During the 1996 and 1997 inspections, these cracks were observed to be filling in <br />with sediment and detritis, or "healing". During the 1998 inspection no observations of these <br />previous sites were conducted. It would be informative for these cracks to be reinspected <br />during future inspections if there location can be established from Mr. Reschke's previous <br />inspection reports and included photographic record. I recommend that the company be <br />