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-1'~- <br />"The person who conducts the surface coal mining operation must demonstrate <br />to the Board or Division, using standard geotechnical analysis, that <br />the minimum static factor of safety for the stability of all portions of <br />the reclaimed land is at least 1. 3." The required analytical demonstration <br />of slope stability must be made for the proposed reclaimed configuration <br />regardless of whether a variance is granted under Rule 2.06.5. On page <br />4.27-2 of the application, the applicant asserts that the stability analysis <br />completed for the Bear No. 2 Portals should be applicable to the <br />situation at the Bear No. 3. The applicant must provide documentation <br />of the geotechnical similarity, and, if a satisfactory comparison can be <br />made, the reclaimed configuration must reflect the results of that analysis. <br />Bear Coal Company should amend its application to include a thorough <br />geotechnical analysis of the proposed reclaimed configuration of the Bear <br />No. 3 mine. The static factor of safety of all cut and Fill slopes must <br />achieve static factors of safety of 1.3 or greater. In the event that an <br />adequate factor of safety cannot be achieved, it should be the applicant's <br />design objective to obtain the most stable configuration possible. This <br />objective applies whether or not a variance is granted under Rule 2.06.5. <br />The Division recommends that the applicant contact our senior engineering <br />geologist, Mr. Jim Pendleton for details on specific items which should be <br />included in the geotechnical investigation. No development shall occur <br />at the Bear No. 3 prior to review and approval of a geotechnical stability <br />analysis by the Division. <br />Topsoil Redistribution Plan - Rule 2. 05.9(2)(d) <br />The application should be amended to contain a plan for ripping the <br />regraded surface after final grading and before the replacement of <br />topsoil. This will ensure elimination of slippage surfaces, relieve <br />compaction, and provide for root penetration. <br />Revegetation Plan - Rule 2.05.4(2)(e) <br />The plan for revegetation contained within the application should be <br />revised to include a plan for periodic monitoring of the success of <br />revegetation, as required by Rule 4.15.1(4). This plan should provide <br />for periodic sampling of the revegetated areas to statistically compare <br />the revegetated community to the approved standard, conducted at appropriate <br />intervals and utilizing proper sampling methods and statistical tests. <br />Two recommended guidelines for selecting the proper methods and tests <br />are available from the OSM and are entitled "A Survey of Techniques for <br />Measurement of Herbaceous and Shrub Production Cover and Diversity on <br />Coal Lands in the West" and "A Statistical Evaluation of Revegetation <br />Success on Coal Lands in the West" (Larson 1980). Methods discussed in <br />the Di.vision's adequacy letter for the Dear 111 and Dear 112 rr_clamation <br />plan would be appropriate. <br />Bear Coal Company will be required to meet the revegetation success criteria <br />of Rule 4.15.10 for previously mined lands in the Dear N3 permit revision <br />area. Specifically, the ground cover of living plants shall not be Less <br />than can be supported by the best available topsoil and shall be sufficient <br />to control erosion. The sampling methods recommended for sampling <br />vegetation cover for the Bear N1 and k2 should be included in the Bear b3 <br />Revision. The success standard will be set by the Division. <br /> <br />