surface areas disturbed. by surface operation and facilities accord to 4.09. Each plan shall describe the
<br />geotechnical investi,yat.ion desi{an, construction operation maintenance and removal if ant�rooriate, of the
<br />• structure and be prepared in accordance with 2.05.3(6)(b), (c) and (d)
<br />RESPONSE
<br />There will be no excess spoil generated from surface areas disturbed by the surface operations and facilities of the
<br />Foidel Creek Mine operation.
<br />Area 1 Pit Coal Waste Disposal Operations
<br />Underground development waste generated from fault crossings, overcast development, and boring of ventilation
<br />shafts, and material from roof falls will generally be disposed of underground in mined -out areas. For a period of
<br />time, any excess development waste material and/or material high in carbonaceous material was placed in the Area
<br />1 Pit (a remnant surface mine pit adjacent to the Run -of -Mine Coal Stockpile), as shown on Map 24, Surface
<br />Facilities. The remnant pit area has an estimated capacity for storage of waste material of approximately 400,000
<br />cubic yards. The required fire -fighting plan for coal waste disposal operations in this area is provided in Exhibit
<br />25A.
<br />With construction of the Coal Refuse Pile (formerly designated as the Coal Waste Disposal Site), underground
<br />development waste materials are now routed to the refuse pile for permanent placement. With construction of the
<br />coal preparation plant, low quality coal stockpiled above grade adjacent to the Area 1 Pit and development waste
<br />from the Area 1 Pit were removed and processed to recover saleable coal. The western portion of the Area 1 Pit has
<br />been converted for interim use as a temporary water storage basin in conjunction with the mine dewatering and
<br />recycle system, and has been permitted as a mine impoundment. There is some potential that all or portions of the
<br />Area 1 Pit could again be utilized in the future for placement and disposal of underground development waste
<br />and/or coal refuse, therefore, TCC has retained the designation of the Area 1 Pit as a coal waste disposal area. On
<br />completion of operations, it is anticipated that the Area 1 Pit will be reclaimed as described under Rule 2.05.4(2)(c)
<br />. by backfilling with coal waste and/or spoils, placement of a minimum of 4 feet of suitable spoil (if used for coal
<br />waste only), topsoil replacement, and revegetation.
<br />If utilized for placement of coal waste materials, material will be placed in the Area 1 Pit by dumping from an open
<br />highwall with a wheel -loader, truck, or underground car, or will be dumped and pushed in by a tracked dozer or
<br />wheel -loader. Dumped materials will be spread and compacted in a manner similar to standard spoil handling
<br />practices. The option also exists for coal refuse to be discharged as a slurry, on an emergency basis, to temporary
<br />containment cells within the existing designated refuse disposal area. Decant from the temporary containment cells
<br />would discharge to the adjacent Area 1 Pit water Storage Basin, and be handled in the same way as mine discharge
<br />water. Because the Area 1 Pit is a totally incised excavation, the deposited waste materials will be confined on all
<br />sides by undisturbed natural ground or backfilled mine spoils, therefore no geotechnical investigation or analyses
<br />are necessary to verify operational or long-term stability for coal waste placement. Map 25, Surface Area Cross -
<br />Sections, shows a typical cross-section of the disposal area (Section Y -Y), including the approximate disposal depth
<br />and design postmining topography.
<br />In the Area 1 Pit, the Wadge Seam was extracted by surface mining methods. The Wadge Seam and overburden
<br />are part of the Williams Fork Formation of Cretaceous age. The lithology, structure and stratigraphy of the mine
<br />area are fully described in Rule 2.04.6. The lithology and stratigraphy of the Wadge Seam and overburden are
<br />considered to be very consistent over the mine area, as shown on Maps 7, 8, and 9, Geologic Cross -Sections A -A',
<br />B -B', and C -C', respectively, and as documented in Rule 2.04.6. Geochemical concentrations are largely uniform
<br />in the coal, roof and floor of the underground mine. A single drillhole was chosen for coring and testing the
<br />leaching potential of waste rock material, which is representative of the underground mine plan area. The location
<br />of the test Drillhole 006-83-66 is shown on Map 5, Surface Geology. A lithologic log of the hole is presented in
<br />Exhibit 12, Lithology Core Logs. The hole was drilled into the strata 12 feet below the Wadge Seam. Core
<br />samples were collected from the roof material 5 feet above the coal seam, from the coal seam itself, and from the
<br />floor material 5 feet below the coal seam. The core samples were delivered to the lab for leachate testing. In
<br />addition to the core samples, aggregate samples of actual waste rock material were collected from the underground
<br />mine. The aggregate samples came from roof material from roof falls, fault crossings, or overcast mining
<br />operations. The aggregate samples were also delivered to the lab for leachate testing.
<br />MR08-230 2.05-92 09/05/08
<br />
|