2011-05-18_PERMIT FILE - C1981012 ‎(2)‎

• Permit No: C1981012
• IBM Index Class Name: Permit File
• Doc Date: 5/18/2011
• Doc Name: PROBABLE HYDROLOGIC CONSEQUENCES OF MINING
• Section_Exhibit Name: Exhibit 08.4 Probable Hydrologic Consequences of Mining on the Allen & Apache Coal Seams
• Media Type: D
• Archive: No

Probable Hydrologic Consequences New Elk Mine ii
LIST OF TABLES
Table 1.
Average Analyses for Coal from Commercial Testing and Engineering 1981 ... ..............................5
Table 2.
Average Sulfur Analyses for Coal from the 2010 Exploration Drilling Program (1.4 float fraction,
arb) .................................................................................................................. ............................... 5
Table 3.
Average Sulfur Analyses for Roof and Floor Rocks from the 2010 Exploration Drilling Program
(1.4 float fraction, arb) ..................................................................................... ..............................5
Table 4.
Colorado Division of Water Resources Well Records for Alluvial Wells within a One -Mile
Radius of the Permit Boundary ....................................................................... ...............................
8
Table 5.
Water Quality Summary Table for Alluvial Wells ............................................ .............................10
Table 6.
Colorado Division of Water Resources Well Records for Raton Formation Wells within a One -
Mile Radius of the Permit Boundary .............................................................. .............................12
Table 7.
Average Monthly Discharges at USGS Gauging Stations on the Purgatoire River Near the New
ElkMine ......................................................................................................... .............................14
Table 8.
Water Quality Summary Table for Stations PRS -1 and PRS -4 on Purgatoire River ......................15
Table 9.
Summary of Springs within a One -Mile Radius of the Permit Area ................. .............................16
Table 10.
Construction Details for Raton Formation Monitoring Wells ......................... .............................17
Table 11.
Development Parameters for 2010 Monitoring Wells ..................................... .............................17
Table 12.
Packer Test Summary by Lithology ................................................................. .............................20
Table 13.
Packer Test Summary By Borehole ................................................................. .............................21
Table 14.
Shut In Water Levels for Packer Test Sections ................................................ .............................22
Table 15.
Water Quality Data Summary Table For Flooded New Elk Mine ................... .............................24
Table 16.
Predicted Subsidence for Mining in the Allen and Apache Coal Seams ......... .............................26
Table 17.
Hydrologic Effects of Subsidence above Mining Panels ................................. .............................26
LIST OF FIGURES
Figure 1. Areal Extent of Existing Underground Workings ............................................. ..............................2
Figure 2. Geologic Map for the New Elk Mine Area ....................................................... ..............................4
Figure 3. Generalized Configuration of the Long -Term Water Table in the Northern Portion of the Raton
Basin(Watts, 2006a) ....................................................................................... ..............................7
Figure 4. Depth to Water in Purgatoire Valley Alluvium near East Portal Shaft ............. ..............................9
Figure 5. Location of Boreholes used for Packer Permeability Tests .............................. .............................19
Figure 6. Water Levels in Flooded New Elk Mine .......................................................... .............................23
Figure 7. Overburden Thickness above Apache Coal Seam ............................................ .............................25
LIST OF PLATES
Plate 1. Existing Surface Facilities
Plate 2. Cross Section - Coal Seams
Plate 3. Locations of Wells, Surface Water, and other Hydrologic Features
Plate 4. Location of CBM Production Wells
4164A.110421 Whetstone Associates •
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