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In order to prevent water from seeping out of the ponds, they have been lined with bentonite. The bentonite was <br />• applied to the pond bottom and embankments and mixed in the surface soil layer. The heterogeneous mass of <br />bentonite and soil was wetted and then rolled to form a good seal. The embankments are sloped at 3H: I V and should <br />not present any operational problems. <br />Each of the ponds has a dewatering device located in its bottom. Once a pond is filled with settled solids, it will be <br />taken out of service and solids removed. The water that is drained from the pond will Flow into a sump and then <br />pumped from the sump into the first functioning pond of the system. This will prevent any discharge of water, high in <br />suspended solids, into [he Williams Fork River. <br />Two ramps as shown on Map 27, will be installed up the embankments of the ponds to provide access for sediment <br />cleaning equipment. A contractor will be utilized in the maintenance operation. The solids will be hauled to the <br />waste disposal site or placed into an approved landfill. However, the material may be subjected to soil and <br />overburden testing, and depending on the test results, the material may be used as a plant growth media. It is <br />understood by RAG EC that the DMG and OSM must approve this alternate use of material before the material is <br />used as a plant growth media. <br />A discharge ditch has been constructed to allow water discharged from the ponds to enter the Williams Fork River. <br />All discharge is in compliance with the terms of the NPDES Permit. <br />In order to supply additional water to the mine for dust suppression, longwall emulsion, and other mining related uses, <br />RAG EC proposed to use water from the #5 Mine Discharge Well. To accomplish this, approximately 400' of 4"pipe <br />was installed between pond SP-6 and the waterline that comes up from the Wise Hill #4 Well. The waterline was <br />buried 5' [0 6' deep, and extended south approximately 275' (from the west end of pond SP-6) and, from there, west <br />approximately 125'. A transformer will sit on the west bank of pond 5-P6 or on a pole adjacent to the pond. The <br />• pump will be put in a small pump house adjacent to the transformer to supply water. There is a small area exemption <br />for the pump house disturbance (see Exhibit 18, page 373). After the line was buried, the disturbed area (2' x 350' _ <br />700 ft2) was seeded with pastureland seed mix. The remaining 100' is part ofthe haul road and railroad so no seeding <br />was required. <br />7 North Anale DewaterinQ Borehole <br />An additional dewatering borehole was drilled into the 7 North Angle of the No. 5 Mine. The borehole was reamed <br />out to a nominal l5 inch diameter and 12 3/4 inch steel casing was placed in the hole. The annular space was grouted. <br />A pump was installed to pump water from the 7 North Angle sump. The capacity of the pump is approximately 400 <br />gpm. The dewatering borehole was located on a pad approximately 100' x 100'. Approximately 18 inches of topsoil <br />(550 cy) was salvaged from the pad. The well head was enclosed in a building along with the control panel and <br />chemical metering system. The building sits on a cement pad approximately 12' x 10' x 1' in size. An in-line static <br />mixer was placed in the discharge pipe to facilitate mixing of the coagulant and the mine discharge. The water was <br />then discharged into ditch 9-D 14. <br />A chemical metering pump will be used to inject the coagulant (Nalco 8852 or equivalent) into the discharge stream. <br />The system will be used only as needed, and it is anticipated that the system will have little if any usage. Past <br />experience with the No. 5 Mine sump indicates adequate settling access underground and coagulants are not needed <br />to meet discharge permit requirements. <br />As shown on Map 26, a sump will be excavated upstream of culvert 50. This will allow for settling of suspended <br />material prior to entering culvert. It is anticipated this will decrease maintenance work on this culvert. The pump will <br />. be approximately 5' wide x 25' long x 2' deep. Therefore, approximately IO cy of topsoil will be stockpiled adjacent <br />to the sump. Ttte stockpiled topsoil will be stabilized with the appropriate seed mixture. <br />..,. ,, t, ~~~w <br />tt , <br />Permit Renewal No. 3 2.05-12 ----~~'?j~ Revised 7/]0/00 <br />