PERMFILE103730

• Permit No: C1980007
• IBM Index Class Name: Revision
• Doc Date: 12/2/2004
• Doc Name: 2.05.5 Post-Mining Land Uses
• Type & Sequence: PR10
• Media Type: D
• Archive: No

West Elk Mine
• sufficient size, the roof strata will cave. As a result, the overlying strata continue to bend and break
until the piles of the fallen rock fragments aze sufficiently high to support the overhanging strata. At
this time, the overlying strata no longer cave, but bend and rest on the underlying strata. Strata
bending in subsidence develop upwazd until reaching the surface and fomilng a subsidence basin.
The whole overburden strata and the surface subsidence basin will further go through a period of
compaction and gradually become stabilized."
The purpose of this section is to describe on asite-specific basis, and to quantify to the extent
feasible, the various phenomena that are embodied in this definition. This section provides an
inventory of structures and renewable resource lands in the current permit azea, which includes the
South of Divide permit revision area, as well as a subsidence survey analysis, potential subsidence
consequences, and the subsidence monitoring and control plan. Table 42 of this section provides a
list of symbols and defuutions for commonly used terms associated with subsidence and used
frequently in this section.
It is essential to present the meanings of the following terminology relative to
understanding this portion of the permit revision text. To further facilitate an
understanding of the areas associated with each geographic expression, see Map lA (and
Figure 1 of Exhibit 60B).
Apache Rocks Mining Area -The Apache Rocks mining area encompasses all of the longwall
mining panels in Sections 26, 27, 28, 29, and 30, T13S, R90W, 6th P.M. See also Map 52.
• Apache Rocks Mining Area. East and West Panels -The Apache Rocks west panels refer to the
three western panels in the Apache Rocks mining area which aze located in Sections 28, 29, and 30,
T13S, R90W, 6th P.M. Both B and E Seam longwall mining are planned in this area The Apache
Rocks east panels refer to the four eastern panels in the Apache Rocks mining area (longwall panels
14SE through 17SE) which are located in Sections 26 and 27, and a portion of Section 35 T13S,
R90W, 6th P.M. Only B Seam mining is planned in this area.
Box Canyon Mining Area -This area is designated on Map lA and includes longwall panels 18NE
through 23A1E located in portions of Sections 10, 11, 13, 14, 15, 22, 23, and 24 T13S, R90W, 6"'
P.M. The Box Canyon permit revision azea encompasses the remainder of the Box Canyon lease
tract. Only B Seam mining is planned in this azea.
South of Divide Mining Area -The mining area encompasses the E Seam longwall panels
located primarily in Sections 32, 33, and 34 of Township 13 South, Range 90 West of the 6th
Principal Meridian, and Sections 3, 4, and 5 of Township 14 South, Range 90 West of the
6t° Principal Meridian. The panels are identified as El through E9.
South of Divide Permit Revision Area -The permit revision area is indicated by the
regulatory boundary added to the mine permit, as shown on Map lA.
Critical Mining Width -The width of a mining panel necessary for maximum subsidence to
occur; the length of the panel must also be greater than, or equal to, critical panel width for
. maximum subsidence to occur. Critical width (Wer) commonly ranges from 1.0 to 1.4 times
the overburden depth (d}.
1.05-93 Revised November 2004 PR10