2009-10-20_PERMIT FILE - C1980004A (2)

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2-27i Coal Mine Waste and Non-Coal Processing Waste A plan view with of the coal mine waste pile is show on Figure 2.2-3. A description of the hydrologic and geologic setting of the disposal area is presented in Buckhorn Geotech's stability evaluation located in Volume II, Appendix R. Buckhom drilled five boreholes in the footprint of the pile to characterize the foundation conditions. A sixth borehole was drilled southwest of the gob pile footprint and a monitoring well was installed. A discussion of the hydrologic impact of the waste disposal area is presented in Volume II, Appendix N. There will be no subsidence from the subsurface strata resulting from past underground mining activities since the footprint of the pile has not been undermined. The stability analysis presented in Appendix R uses coal mine waste strength parameters used by Snowcap Cal Company in its analysis and design of its two Cameo refuse disposal areas. The strength parameters are contained in Snowcap's permit, Volume 4, Appendices 13-4 and 13-5. Since the Operator will mine the same seam as Snowcap, the characteristics of the coal mine waste should be similar. The Operator will perform another stability analysis of the coal mine waste pile with site specific strength parameters for the coal mine waste after five feet of fill have been placed in the over-excavated founding of the pile. The stability analysis, located in Appendix R; shows the coal processing waste bank to have factors of safety that range from 1.7 to 2.1. The impoundment associated with the coal processing waste bank is Class A, because failure may cause minor damage to farm buildings, agricultural land, or township and county roads. A failure of the impoundment would not damage SH-139 since the deeply incised East Salt Creek drainage would intercept the flow. The impoundment does not TR-16 Mc-Volume I 10/08