2010-05-07_PERMIT FILE - C2006085 ‎(2)‎

• Permit No: C2006085
• IBM Index Class Name: Permit File
• Doc Date: 5/7/2010
• Section_Exhibit Name: 2.05 Operation and Reclamation Plans
• Media Type: D
• Archive: No

Mine Portals
Northfield will construct a single slope from the surface through
overburden strata to intercept the coal seam which lies approximately
300 feet vertically below the surface. The slope is shown in cross -
sectional format on Figure 2.05.3 -3. This opening will be mined
downward at approximately a 15 percent grade. At this gradient, the
total length of the slope will be approximately 2,000 feet from ground
level to the Ocean Wave seam. Portal development will begin by
excavating alluvial material /weathered rock to expose competent rock
to begin mining the slope. The excavated materials will be temporarily
stockpiled and subsequently used as backfill around the concrete portal
structure and as fill material on the mine facility bench area. The
excavated materials from the slope development will be temporarily
stockpiled during development of the slope. This material will
subsequently be moved and placed to form portions of the facilities
bench area. Material volumes and placement details regarding the use
of the excavated alluvial and development materials are described in
later in this section under "Coal Mine Waste and Non -Coal Processing
Waste ".
The portal structure will include concrete foundations and slabs with
steel support members to provide ground control at the mouth of the
opening for the long -term protection for personnel and equipment.
Concrete retaining walls will adjoin the portal within the open ramp
area at the mouth of the opening. These retaining walls will angle
away slightly from the alignment of the slope for structural stability.
The area behind the wing walls will be backfilled with the
aforementioned excavation materials. General construction and
dimensional information for the portal area is provided on Table
2.05.3 -2.
The slope and portal area will be designed, constructed, and
maintained to provide stable long -term access for the life of the
Northfield mining operations. Portal maintenance will involve periodic
inspections, adjustment or replacement of roof control devices,
drainage of any water inflows, and belt maintenance to ensure safe
and dependable transportation and coal haulage.
Upon completion of mining activities, Northfield will seal the mine
portal to prevent access. Sealing will require either fabrication of a
block or concrete wall, or filling of the opening with compacted
incombustible material for distance of at least 25 feet, in accordance
with 30 CFR 75.1711. The void between the portal seal and the surface
2.05.3 -10 Revised 12/04/09, TR -01