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A pumphouse will he constructed a[ Pond A to supply water to the coal preparation plant. The pumphouse will be an approximately IS" x15" metal building built on a concrete slab. The building will contain [he pumps and the associated controls. The water will be pumped through a new 8 inch waterline to be buried along the shoulder of the existing access road from the Tipple to Pond A. The waterline will run from Pond A to a new valve box at Location A. The buried waterline will continue [o a new vah~e box at Location B. The new line will [hen continue adjacent to Haul Road B to existing Location 8 and will continue on to new Location C. New waterlines will be laid from Location C into the preparation plant and to existing Location 6. The location of [he new waterlines and valve boxes are shown on Map 24, Surface Facilities. All new waterlines will be located within existing disturbed areas. Rockdust Distribution A rockdust tank located north of [he portal area as shown on Map 24, Surface Facilities, will supply rockdust to the underground mine (see Figure 16, Rock Dust Bin Operations Design). The tank's pad and truck accesslunloading area will be filled with pit run gravel. A borehole measuring 12'/a inches in diameter will be drilled to the underground workings to supply rock dust and power for the Tank Feeder Drive and Top Blower. The pipes inserted in the borehole for these purposes will be a 6 5/8 inch O.D. pipe and a 2 3/8 inch O.D. pipe, respectively. The remaining open volume around the pipes will be filled with grout. The pad for the bin will consist of a solid one foot thick footer and four concrete pillars. The total volume of concrete will be about I I cubic yards. Surface Facilities The Foidel Creek Mine portal area is located in a partially backtilled final cut. This excavation was tilled [o an elevation of 6,860 feet and leveled. Before fill materials were placed in the pit, a low permeable barrier was constructed against the highwall. Approximately 20,000 BCY of surticial materials high in clay and silt +vere required [o install a barrier berm about IS fee[ in thickness. An average depth of I.5 feet of soil materials were • removed from an area north of the portal pit to construct the barrier. The suitability of the materials selected for the barrier is illustrated by dte following textural analysis of soil samples collected from the designated salvage site: DESCRIPTION %CLAY %SILT %SAND Loam-Clav Loam 27 47 26 Clay Loam-Silty/Clay Loam 37 43 20 The purpose of the barrier is to isolate the spoils aquifer from the underground mine workings. Pit walls have been pre-split or trim blasted to an angle of 65 degrees ro [he horizontal. Blasting was conducted in accordance with all regulations and procedures presented in the Minor Revision of Technical Revision to Permit No. 79-177 Area I, Final Pit. The 68,000 BCY of blasted rock was utilized to partially backfill the old Area I dragline pit, presently serving as [he portal area to the 6,860 foot eleva[iat as described above. Highwall modification and partial backfilling were designed to provide greater safety and enhance stability for the entrances by initiating the rock tunnels used for pennanen[ entries in competent sandstone. rDetailed cross-sections of the final cut that is being utilized as the staging area for the Foidel Creek Underground Mine are shown on Map 25, Surface Area Cross-Sections. GEC The spoils to the south of the portal area were dozed down to a 2 to I slope to comply +vith stability requirements. Three slope stability monuments have been installed as shown on Map 24, Surface Facilities. Past monitoring results indicate the slopes to be stable. Monuments will continue to be monitored and the results submitted ut • CMLRD annually. MR 97-I ~4 2.115.53 Revised 9/9/97