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faye 5 <br />Colorado Westmoreland, Inc. <br />MLR D/OSM ,l oint Review <br />December 2, l9&0 <br />Backfillinq and Cradi <br />The two studies by Mr. 7.caf and Mr. Medearis included in the permit <br />application have provided some justification for lcaviny the steep slopes <br />in the disturber) area. In order to assess the reports, however, additional <br />information is needed. The assumptions and calculations •csed to develop the <br />erosion rates in thc• heaf report should be pro viderl and documented. For <br />the Fiedearis report, the assumptions and input information should be provided. <br />The slopes or areas which were used for calculation purposes in these reports <br />need to be clearly delineated on a plan view of the disturbed area and <br />cross-referenced. <br />Additional information on the waste pile is also needed. A plan view of <br />the pile at maximum volume needs to be provided, prefcrabZy on a 5 foot <br />contour interval map and on the final reclaimed contours map. Cross-sections <br />of the pile should also be provided with the cross-section Iocations noted <br />on the plan view. Stability calculations and a foundation analysis For the <br />pile also needs to he provided. In addition, the samples which were taken to <br />represent material which is or will be placed in the pile need to be located <br />on a map and described. <br />Geology <br />Much of the geology information, such as drill logs, drill hole locations <br />and cross-sections, needs to be provided for the groundwater baseline data. <br />Zn addition, regional and site-spn_cific geologic maps need to be provided. <br />Samples of the coal should be analyzed; the sample locations need to be stows. <br />Au heiAence <br />The application, in its amended form, appears to conform with regulatory <br />reguirements except that subsidence monitoring be conducted on a semi-annual <br />basis. <br />The projected effects of subsidence on tl~e proposed mining area are based <br />largely on observation of the offects in previously mined area. A more <br />detailed comparison of the proposed area with the previously mined area <br />(i.e., depth of cover, type of cover, structure and faulting, etc.) and <br />a comparison of mining mechanics (i.e. pillar removal plans, etc.) must be <br />provided. <br />Waste Disposal Area <br />The entire subject of waste disposal needs to be addressed in considerable <br /> <br />