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Lateral drains were constructed as discussed under the Stability Analysis <br />Section in Lambert and Associates report dated November 10, 2003. Lateral <br />drains consist of a toe drain and bench drains as show on Figure 4 of Lambert's <br />report. Bench drains will be constructed on 50-foot vertical centers or at any <br />damp spots encountered in the coal mine waste disposal area founding. See <br />Figure 2 for the layout of the lateral drains. No damp spots were encountered. <br />The lateral drains are not be in hydraulic communication with the rock under- <br />drains, since they might inadvertently permit the infiltration [Rule 4.09.1(13)] of <br />water. See the detail on Figure 1 which shows how the lateral drains will be <br />isolated from the rock under-drains. <br />The run-off and collection ditches are shown on Figure 2. Run-off from the <br />benches will be directed to the east and west to collection ditches. The east and <br />west collection ditches D-F4 and D-F11 are; 1) lined with riprap to ensure they <br />are stable; 2) constructed off the fill and; 3) designed to safely pass the run-off <br />from the 100-year, 24-hour precipitation event. Ditches D-F4 and D-F11 are also <br />designed to safely pass the run-off from the 100-year, 24-hour precipitation <br />event from the upper diversion ditches. <br />Temporary upper diversion ditches and the east and west collection ditches were <br />constructed prior to placement of coal mine waste. During construction of the <br />pile, a bench configuration will be maintained at the contact point between the <br />coal mine waste and the natural ground surtace. Thus, run-off from above the <br />pile and below the upper diversion ditches will be directed to the east and west <br />collection ditches by the temporary benches. The temporary benches will be <br />configured the same as the permanent benches. <br />See Appendix B for detailed design information of the run-off and collection <br />ditches. <br />TR-43 <br />6- <br />05/06 <br />iq ppRovED <br />9~n~o6 <br />