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<br />Preliminary Adequacy Comments <br />Rule 2.05,3(6): Overburden <br /> <br />The operator is required to present sufficient information within the application <br />to demonstrate conformance with the performance standards of Rule 4 for any <br />temporary overburden or underground development waste storage structures. This <br />information should include, at a minimum, location, geometry and method of <br />placement of the material. The application is inadequate in these regards. <br />(Further reference to this topic occurs under comments below regarding Rules 2.06,7(3) <br />and 4,22.) <br />Rules 2.05.3(6)(a) and 4.OB: Blasting Plans <br />Staff inspections have determined that blasting techniques, such as stemming and <br />sequencing of detonation, have been modified at the operations currently <br />permitted under Permit No. 79-277, which is referenced as proof of conformance <br />within this application. The appropriate amendments to the existing Permit No. <br />79-177 must be accomplished prior to approval of this application. <br />Rules 2.05.3(9) and 4,09: Underground l~ ve2opment f~as to <br />The applicant proposes to place underground development waste in the existing pit <br />remaining from the final cut of the Energy No. 1 surface mine, immediately to the <br />west of the portal development area. The applicant observes that stability of <br />these materials is not a concern because they will eventually be covered with <br />backfilled spoil and will exist below final grade. However, the applicant must <br />demonstrate that no hazard will exist in regard to the adjoining portals and that <br />the water quality of the affected area will not be jeopardized. <br />Rule 2.05,6(3)(b): Protection of the Hydrologic Balance - Subsidence Related <br />Aspects <br />On pages 2.05-50 and 2.05-51 of the application document, the applicant presents <br />a discussion of the subsidence-related aspects of protection of the hydrologic <br />balance. This presentation is inadequate as it exists, requiring more detail and <br />justification for the conclusions presented. The applicant projects limits for <br />overburden caving and fracturing above the extracted coal seam which are signifi- <br />cantly less than observations contained in the current technical literature. <br />Further, the applicant concludes that no adverse impacts of subsidence upon the <br />hydrologic balance or water rights are anticipated from the planned underground <br />mining activities, <br />The applicant will have to further justify the assumptions concerning extent of <br />caving, fracturing and hydrologic impacts. In addition, the applicant should <br />develop a means of verifying projected effects upon the hydrologic balance, in <br />specific, potential hydrologic effects upon the "overburden aquifer" and the <br />Twentymile Sandstone aquifer should be monitored. <br />