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The high incidence of partings and splits in the Deserado Mine area coal seams presented some <br />problems in delineating coal seam thickness. AS an example, a drill hole log showing an interval <br />' of seven (7) feet consisting of two (2) feet of coal, three (3) feet of parting, and two (2) feet of coal <br />can be interpreted as a seam of coal seven (7) feet thick with a three (3) foot parting or as two <br />' separate seams with three (3) feet of interburden. In the first case, the seven (7) feet would <br />over-state reserve estimates because it would include three (3) feet of non-coal material. The <br />second case would result in no coal reserve estimate because neither of the two coal seams could <br />' meet the 28 inch minimum thickness criteria to be included in the "coal reserve base° estimate. To <br />solve this problem and provide a consistent method by which the "coal reserve base" is estimated, <br />a ratio of 3:1 coal thickness to parting thickness was used. If the ratio of coal thickness to parting <br />thickness was equal to or greater than 3:1, the parting thickness was included. If this ratio was less <br />than 3:1 then individual coal splRS would have to meet the minimum thickness criteria of 28 inches <br />' to be included for the estimate. In fhe event that logs or cores showed there were multiple splits <br />to an individual seam (that qualified for the estimate) then the thickness of the qualifying splits would <br />be added together to provide a net coal thickness at that particular location. The net coal thickness <br />' value would therefore replace an individual seam thickness value. <br />Boundaries used for estimating the 'coal reserve base' included the Federal coal lease boundaries <br />and the individual seam outcrop. In addition, the lease stipulations for Federal coal lease <br />C-0126669 prohibit the mining of coal within 100 feet of the 100 year flood plain of the White River. <br />This area of C-0126669 was not included in the "coal reserve base'. Relative to the D Seam, the <br />area of the old abandoned Staley-Gordon coal mine was also excluded from the "coal reserve base" <br />estimate. <br />Table 4-4 is a summary by lease and by seam of the Deserado Mine Logical Mining Unit °coal <br />' reserve base". <br />4.3.2 Mineable Reserve Base Western Fuels has estimated the 'mineable reserve base' as <br />' defined in CFR Title 43-Subsection 3480.0-5 for coal contained in only the B and D Seams. Coal <br />in the other six seams is thin and limited in areal extent and therefore is not considered mineable. <br />' Mineable coal in the 8 and D Seams includes: <br />• Mineable seam thickness equal to or greater than four feet <br />' • Coal with more than 100 feet of overburden <br />' In addition, a 50 foot barrier pillar around the exterior boundary of the Deserado Mine Logical Mining <br />Unit was excluded as was the area within 100 feet of the 100-year flood plain of the White River. <br />The abandoned Staley-Gordon mine was also excluded from the mineable reserves for the D Seam. <br />'• 27 <br /> <br />