2010-06-04_PERMIT FILE - C1982056A (9)

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In May 2003, a second borehole is' to be drilled in the same general area as the first boring, for a similar use. The location of the second boring is illustrated in Map 24. This boring will be 8 -inch diameter, cased with 6 -inch diameter steel piping. The piping will be grouted in place and connections made at the top and bottom for completing the airline. • When the line(s) are no longer needed, the airline tubing will be grouted in place and the remainder of the facility removed from the site. The usable equipment will be salvaged for later use. Site 109 Diversion The diversion will consist of a 6 inch PVC PIP irrigation pipe attached to the existing 109 riser. This line will be buried and will cross the existing berm immediately to the north of the 109 riser. From that point, the line will parallel the berm, crossing the roadway near the operations center at a depth of approximately 3 feet. Should ground conditions warrant it, an 8 -inch diameter steel pipe will be installed to act as a protective sleeve for the PIP pipe where it crosses the road. The line will then be buried along the berm until reaching the east end of the heavy- equipment pad, where the line will make a 45' turn to the north and pass under the PM Bay access road. Again, a protective steel pipe sleeve may be installed should conditions warrant it. From the PM Bay Road down to the existing Site 114 vertical culvert the line will be buried to a depth of 6 -8 feet. At Site 114, the existing culvert, which has been backfilled with washed rock, will be utilized as an infiltration point, with the line entering the culvert at a depth of not less than 6 feet. Water will then infiltrate into the spoils and replenish the aquifer prior to being pumped from Site 114 to the million - gallon tank and thence underground. Line location is shown on Map 24. In order to increase operational flexibility, the Site 109 Diversion may be plumbed directly into the line- feeding Site 114. Therefore, when this option is exercised all the water from site 109 will be diverted to site 114. An underground rock filter was installed along the six -inch water line at the location shown on map 24. The rock filter is needed to help filter the water discharged from the underground mine before it is placed into the million gallon tank. The • rock filter will be constructed by excavating the existing spoil material to a depth of approximately 15 - 20 feet and placing a gravel pack in the excavated area. Prior to excavating the spoil material, the topsoil will be stripped from the site and temporarily stockpiled adjacent to the area to be excavated. The disturbance associated with the construction of the filter is approximately 0.06 acres. After the gravel has been placed in the excavation, the gravel extends to within approximately 2 feet of the surface and encompasses an area of approximately 15 x 15 feet, the spoil material will be placed back into the remaining open excavation. The spoil will be graded to blend with the topography and the topsoil reapplied. The topsoil will be seeded with the pastureland seed mixture. It is anticipated that the topsoil will be redistributed during late March or early April, depending on field conditions. The disturbance lies upstream of a rock filter dam, which controls runoff from the area. The combination of the rock filter, vegetation filter and rapid reclamation of the site will provide secondary sediment control for the site. Stock Water Pond Line A stock water pond water -line was tied into TCC's existing No. 6 well and water can be pumped up to a pond located on the bond release area south of the portal area. The location of the buried line is shown on Map 24, Surface Facilities. The line will remain after reclamation, so no reclamation or bond information is included. Fueling Facility A new surface gas tank was installed on the northeastern corner of the equipment parking area, as shown on Map 24, Surface Facilities. The tank is of double -wall construction, and based on discussions with CDOH Staff, the double -wall tank satisfies the applicable secondary containment requirements. The tank was placed on a concrete pad, with metal posts strategically placed to prevent damage to the tank. In addition to the gas tank, two other • storage tanks, one containing magnesium chloride, a dust suppressant used on surface and underground roads, and a diesel tank, have been placed on the pad. Similar to the gasoline tank, the diesel tank is of double -wall construction. MR09 -238 2.05 -21 06/26/09