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XIII <br />XIV <br />C. Seed mixes and distribution rates For the Red Canyon site can be <br />found on pages 132 and 132a. <br />Protection of Underground Mining <br />A. There are no current or proposed surface mining operations within or <br />next to the Red Canyon Mine. <br />Subsidence Control <br />A. The applicant proposes a subsidence control plan in accordance with <br />Rule 2.05.6(6) to prevent material damage due to subsidence of the <br />undermined area. Extraction is to be limited to a maximum of <br />55 percent of the in-place coal. Further, within "safety zones," <br />beneath the structures delineated within the area of potential <br />influence, extraction is to be limited to 50 percent of the in-place <br />coal. Two meChods of pillar stability analysis are presented to <br />demonstrate the adequacy of the designed pillar sizes to bear <br />existing overburden loads. Safety factors are demonstrated to be <br />sufficient in all cases. "Safety zones" are delineated on Map <br />2.05.6(6)(f)(ii)(c)-1 for workings within both the D and E seams. In <br />addition, a South African analytical technique is utilized to <br />demonstrate that the mine design should preclude interaction between <br />extraction within the E and D seams. The plan adopts all measures in <br />order to reduce the likelihood of subsidence, prevent material <br />damage, or mitigate the effects. The Division proposes to approve <br />the plan (4.20.1(2) and 4.20.3(1)). <br />The application includes the proposal of a monitoring program in <br />accordance with Rule 2.05.6(6)(c) to verify both mechanical and <br />geohydrologic projections. Monitoring wells are in place to observe <br />variations in both alluvial and bedrock aquifer water tables. Map <br />2.05.6 (6)(f)(ii)(c)-1, Sheet 1 of 2, delineates subsidence monuments <br />installed in the field above the underground workings. A typical <br />monument installation is depicted on Map 2.05.6(6)(f)(ii)(c)-1, Sheet <br />2 of 2 of the application; the surveyed locations, orientations, and <br />elevations of the 11 delineated structures are also provided. In <br />addition to the required monitoring structures, survey monuments and <br />water table elevations, the operator has provided a photographic <br />record of all potentially affected structures. Finally, the <br />applicant commits to the rehabilitation or reconstruction of any <br />affected structure. <br />Subsidence monitoring is currently in cessation, following approval <br />of Technical Revision 2 on January 13, 1987. The applicant has <br />committed to initiating monitoring six months prior to mining. This <br />monitoring will continue quarterly for at least two years after <br />mining into the projected area of influence. The results of the <br />subsidence monument monitoring program will be submitted to the <br />Division semi-annually. The results of the geohydrological <br />monitoring will be submitted annually following the end of the water <br />year. <br />XV <br />XVI <br />Concurrent Surface and Underground Mining <br />A. This section does not apply to the Red Canyon Mine. <br />ions on Alluvial Valley Floors <br />The applicant has identified several areas of unconsolidated <br />streamlaid deposits. The majority of this material occurs as mudflow <br />27 <br />