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- 999 <br />STATE OF COLORADO <br />DIVISION Of MINERALS AND GEOLOGY <br />Department of Natural Resources ~,~pP~oOro~ <br />ti_ <br />Ne'/ <br />1313 Sherman St., Room 215 <br />Denver, CO 80203 • • feve • <br />Phone: 1303) 866-3567 <br />FAX: 13031832.8106 <br />Ray Romer <br />Governor <br />December 10, 1992 Michael g. Long <br />Division Direcror <br />Richard Atkinson <br />Director of Lands and Enduonmental Affairs <br />Colowyo Coal Company <br />5731 State Highway 13 <br />Meeker, CO 81641 <br />RE: Colowyo Coal Mine (C-81-019) <br />MR-22: Revision of blasting sketches; TDN X-92-02-0244-2 TV-2 <br />Dear Mr. Atkinson: <br />The Division has had the opportunity to review the three blasting reports submitted by Colowyo <br />on November 25, 1992. Thank you for submitting those reports. Based upon our review there <br />appears to be several discrepancies between the information found in the text and that found <br />in the sketch portions of the blasting reports. The Division has the following adequary concerns <br />that need to be addressed: <br />Overburden Blast -November 24, 1992: <br />1. The number of holes per delay given in the text (6) does not agree with the maximum <br />number of holes per delay shown in the sketch (7) nor does it agree with the maximum <br />number of holes per delay that could be present if there were eight rows in the blast <br />pattern, as is indicated by the eight found on the left margin of the sketch (8). Please <br />explain. <br />2. The value given in the text for pounds of explosives per delay (5,724) does not agree <br />with the amounts calculated by the Division given the number of holes per delay <br />indicated by the sketch (7 x 954 = 6,678) or indicated by margins of the sketch (8 x 954 <br />= 7,632). Please verify the number of holes per delay. <br />3. The maximum weight of explosives that was fired during any 8 ms period on November <br />24, 1992 does not appear to be in compliance with Rule 4.08,4 of the regulations if the <br />there were, indeed, eight holes in some delays. The Division's calculations far <br />determining this are as follows: <br />