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Grassy Creek Permit Application <br />Geotechnical Inadequacy Comments <br />e 2.05.3(61 - Overburden <br />The amended application briefly states that it has been the operator's <br />experience during the mining of pits 1 through 3, under the interim <br />program permit, that overburden swell has regularly equalled the amount <br />of material removed as coal. The operator projects a swell factor of <br />approximately 15%, balanced by coal extraction, resulting in an overall <br />bulking factor of 1.0. The applicant should verify this conclusion <br />regarding projected bulking. This demonstration could take the form of <br />comparison of pre-mining and post-mining surveyed topography of the <br />completed pits at the Grassy Greek mine. The applicant should include <br />material movement and balance discussion, in order to confirm that this <br />comparison considers the final disposition of all materials originally <br />extracted from the pits. <br />The application mentions that temporary overburden stockpiles are <br />developed to store overburden from the pits during extraction. In <br />accordance with Rule 2.05.3(6), the applicant must describe, at a <br />minimum, the location, geometry and method of placement of these <br />overburden stockpiles. Considering the steep slopes encountered <br />throughout the Grassy Greek mine site, the operator should describe the <br />selection of sites and the preparation of the foundation of the various <br />piles in order to demonstrate that they will be stable during their <br />temporary life span. Appropriate discussion of the reclamation of the <br />stockpile sites should also be included within the appropriate <br />reclamation plan sections of the amended application. <br />Rule 2.05.3(5)(a) requires that a detailed blasting plan be included <br />within the mine application. The amended application fails to present an <br />acceptable blasting plan. The operator indicates that some portions of <br />the overburden do require blasting, which is commonly conducted by a <br />local blasting contractor. The applicant should present, at a minimum, a <br />discussion of neighboring structures and a typical blasting configuration <br />utilized by the contractor. In addition, the application should include <br />a demonstration of conformance with the vibrational limitation equation <br />included in Rule 4.08.4(10). Further, approprate blasting record forms <br />and publication verification must be included within the amended <br />application document. The applicant is referred to Rules 2.05.3(6)(a) <br />and 4.06 for detailed presentations of the required blasting plan details. <br />