Laserfiche WebLink
-51- <br /> XVI. Backfillinq and Gradin - Rules 2.05.3(9) , 2.05.4(2) (c) , 4.09 <br /> any <br /> The backfilling and grading plan in Section 5-E of Volume 7 of the <br /> application has been reviewed by the Division for compliance. <br /> The applicant proposes to backfill the mine benches by breaking the <br /> concrete foundations of the surface facilities, placing this material <br /> against the face-ups, then subsequently covering the broken concrete. <br /> Insufficient information is contained within the application to judge <br /> stability of the proposed final reclamation backfilling and grading plan <br /> for the five mine portal benches. In accordance with Rules 4. 14 and <br /> 4.27, the applicant is required to demonstrate that the proposed regraded <br /> configuration will achieve a minimum static slope safety factor of 1 .3. <br /> Because the five mine portal benches now exist in their proposed maximum <br /> state of disturbance and reclamation will not occur until cessation of <br /> mining (approximately 40 years in the future) , this topic is amenable to <br /> Stipulation. The Division finds that the following stipulation is <br /> necessary for a finding of compliance with the backfill and grading <br /> requirements of Rules 2.05.3(3) , 2.U5.4(2)(c) and 4.14. <br /> Stipulation No. 7 ' <br /> THE DIVISION DIRECTS THE PERMITTEE TO COMPLETE A THOROUGH <br /> GEOTECHNICAL INVESTIGATION AND STABILITY ANALYSIS OF THE PROPOSED <br /> BACKFILLED CONFIGURATIONS FOR THE FIVE PORTAL BENCHES AT THE COAL <br /> BASIN MINES. THE PURPOSE OF THIS PROJECT SHALL BE TO DEVELOP <br /> SPECIFIC BACKFILLING, GRADING, DRAINAGE, AND RECLAMATION PROCEDURES <br /> TO ASSURE OPTIMUM STABILITY OF THE FINAL RECLAIMED PORTAL BENCHES. <br /> FURTHER, THE PERMITTEE SHALL PREPARE A DETAILED MATERIAL BALANCE, <br /> DESIGNATING THE PROPOSED SOURCE OF MATERIALS TO BE UTILIZED IN 50 <br /> COMPLETING THE BACKFILLING AND GRADING OF THE MINE PORTAL AREAS. v v <br /> THE PERMITTEE SHALL SUBMIT THE REPORT OF THE GEOTECHNICAL V" J <br /> INVESTIGATIO14 AND STABILITY ANALYSIS, THE DETAILED MATER <br /> BALANCE, AND A DETAILED PORTAL BENCH RECLAh1ATION P 0 THE � 7 <br /> DIVISION FOR REVIEW PRIOR TO DECEMBER 31 198 L�'Q <br /> The application includes the construction of a rock tunnel to be uis <br /> haul coal from the No. 1 and No. 2 mines to the base of the steep sTopeyo <br /> portion of the Basin' s road system. This tunnel will allow discontinued <br /> hauling of coal py truck along the upper road system, which will greatly <br /> decrease impacts upon the Coal Basin environment and significantly reduce <br /> hazard exposure for the truck drivers and other mine Dersonnei . The rock <br /> tunnel and its associated 320,000 cubic yard waste pile was reviewed and <br /> approved as a technical revision during 1979 and 1980. The approval of <br /> the tunnel and its associated undergrouna development waste pile <br />