2014-10-31_PERMIT FILE - C1981044A

Home Browse Search

the test results, the material may be used as a plant -growth media. It is understood that the DRMS and OSMRE must approve this alternate use of material before the material is used as plant - growth media. A discharge ditch has been constructed to allow water discharged from the ponds to enter the Williams Fork River. All discharges and related activities comply with applicable terms of MCM's CDPS Permit. In order to supply additional water to the mine for dust suppression, longwall emulsion make -up, and other mining related uses, it was proposed to use water from the No. 5 Mine Discharge Well. To accomplish this, approximately 400 feet of 4 -inch pipe was installed between Pond 5P -6 and the waterline that comes up from the Wise Hill No. 4 Well. The waterline was buried 5 to 6 feet deep, and extended south approximately 275 feet (from the west end of Pond 5P -6) and, from there, west approximately 125 feet. A pole - mounted transformer and pumphouse were installed adjacent to the pond to transfer the water. Runoff from the pumphouse disturbance is addressed by a Small Area Exemption (see Exhibit 18, page 373). After the line was buried, the disturbed area (2' x 350' = 700 fO was seeded with the pastureland seed mix. The remaining 100 feet is part of the haulroad and railroad disturbance, so no seeding was required. An additional dewatering borehole was drilled into the 7 North Angle of the No. 5 Mine. The dewatering borehole was drilled from a constructed pad approximately 100 x 100 feet. Approximately 18 inches of topsoil (550 cy) was salvaged from the pad. The borehole was reamed to a nominal 15 -inch diameter, 12.75 -inch steel casing was placed in the hole, and the annular space was grouted. A 400 gpm pump was installed to pump water from the 7 North Angle sump. The well-head was enclosed in a building along with the control panel and chemical metering system. The building sets on a 12 x 10 x 1 foot cement pad. In order to provide power for the dewatering system, a powerline was constructed between the existing YVEA line and the borehole, as shown on Map 26. The chemical metering pump is used to inject the coagulant (Nalco 8852 or equivalent) into the discharge stream. An in -line static mixer was placed in the discharge pipe to facilitate mixing of the coagulant and the mine discharge. The system will be used only as needed, and it is anticipated that the system will have little if any usage. Past experience with the No. 5 Mine Sump indicates adequate settling occurs underground, and coagulants are not needed to meet discharge permit requirements. When operating, mine discharge from the 7 North Angle Well flows to Ditch 9 -D14. As shown on Map 26, two new culverts (Culverts 50 and 51) were installed. Designs for these culverts are included in Exhibit 18, along with the designs for Ditch 9 -D14 and modified Ditch 9 -D7. A sump was excavated upstream of Culvert 50 to allow for settling of suspended material prior to entering culvert and reduce required culvert maintenance. The sump is approximately 5 x 25 feet x 2 ft deep, and approximately 10 cy of topsoil was recovered and stockpiled adjacent to the sump. The stockpiled topsoil was stabilized with the appropriate seed mixture. In order to facilitate handling of the mine discharge, the upper section of Ditch 9D -12 was removed, along with Culvert 20. The new or modified ditches have been designed to handle the additional runoff from this area. The mine discharge from the 7 North Angle Well flows through Ponds 9 -P2 and 9 -P3. These ponds provide approximately 12 hours of additional detention time beyond that provided by the sump. The ditch connecting Ponds 9 -P2 and 9 -P3 was reconstructed by excavating the ditch and lining it with conveyor belting laid in the bottom of the ditch. A buried 4 -inch poly -pipe waterline, pump, pumphouse, intake line, and powerline extension were installed at Pond P -2. Water can be pumped from Pond 9P -2 via the 4 -inch buried line to the existing water storage tank at the 5A Portal area. From this tank, the water can be transferred to the existing distribution system. Water is provided to Pond P -2 from the 7 North Angle mine dewatering pump. A skid- mounted pump was also installed along the south side of Pond P -2. This pump is protected by a metal or wooden shed approximately 10 x 10 x 8 feet, and is surrounded by a six -foot high chain -link fence. Power is supplied to the pump by means of a short distribution -line from the existing powerline adjacent to the 5A Access Road to the north of the pond. This powerline extension required the installation of 4 to 6 poles. An intake line was placed in the pond, and was fitted with a check valve and strainer head. Both the intake line and the 4 -inch receiving line are buried to a depth of approximately 6 feet. The line was buried using a trenching machine, and runs along the -toe of the access road outslope. A dozer was required for ripping of some short segments along the TR14 -36 2.05 -13 Revised 09/08/14