2011-09-26_PERMIT FILE - C1981012 ‎(24)‎

• Permit No: C1981012
• IBM Index Class Name: Permit File
• Doc Date: 9/26/2011
• Section_Exhibit Name: EXHIBIT 08 HYDROLOGY AND GEOLOGY INFORMATION
• Media Type: D
• Archive: No

Probable Hydrologic Consequences New Elk Mine
24
Table 15
Water Quality Data Summary Table For Flooded New Elk Mine
Parameters
Units
NEW -2
NEW -4
# of Samples
Min
Max
Mean
# of Samples
Min
Max
Mean
Solution Parameters and Major Ions
pH (Lab)
S.U.
1
8.2
8.2
8.2
0
- --
- --
- --
Dissolved Oxygen
ppm
1
5.25
5.25
5.25
0
- --
- --
- --
Hardness
CaCO3 mg/1
6
16
73
26
6
34
63
41
SAR
S.U.
6
8.35
32.8
26.96
6
24.8
51.5
7
TDSgl80C
mg /1
7
460
11380
771
7
200
1,650
340
TDS (calculated)
mg/l
4
674
767
724
4
1,580
1,680
1,628
TSS
mg/1
3
< 5
14
8
3
< 5
26
13
Hydroxide
CaCO3 mg/l
2
< 2
< 2
- --
3
< 2
< 2
- --
Carbonate
CaCO3 mg/l
6
< 2
77
38
6
< 2
85
32
Bicarbonate
CaCO3 mg /1
6
342
601
516
6
929
1520
1385
Calcium, dissolved
mg/I
5
4
22.6
8.0
6
7.2
17.9
9.6
Chloride
mg/1
5
5
8
7
6
4
9
8
Magnesium
mg /I
1
2
2
2.0
1
4.2
4.2
4.2
Magnesium, dissolved
mg/l
6
1.4
4
1.9
4
3.8
4.5
4.1
Potassium, dissolved
mg/1
6
4.4
8
7.0
6
4.7
7.1
6.5
Sodium
mg/1
0
- --
- --
- --
1
692
692
692
Sodium, dissolved
mg/1
6
162
300
264.5
5
448
702
628.8
Sulfate
mg/I
1 5
35
60
46
6
10
56
26
Metals �
Iron, total
mg/I
6
0.14
2.15
0.93
5
0.16
0.51
0.34
Iron, total rec.
mg/l
4
0.14
3.12
1.50
4
0.3
0.72
0.49
Iron, dissolved
mg/1
5
0.0007
0.38
0.14
6
< 0.01
0.79
0.15
Manganese, total
mg/1
4
0.013
0.025
0.018
6
< 0.005
4.1
0.698
Manganese, dissolved
mg/1
6
< 0.005
0.024
0.010
6
< 0.005
3.8
0.642
Lead, dissolved
Selenium, dissolved
mg/I
mg/I
1
1
0.0007
0.005
0.0007
0.005
0.0007
0.005
1
1
< 0.0002
< 0.001
< 0.0002
<0.001
<0.0002
<0.0001
Field Parameters
pH
S.U.
17
7.5
8.8
8.2
16
7.6
8.4
8.1
Specific Conductance
µS /cm
18
918
11555
1,074
17
893
2,840
1,848
Temperature
°C
18
11.7
16.9
13.9
17
11.9
17.5
14.5
6. SUBSIDENCE PREDICTIONS FOR MINING OF THE ALLEN AND APACHE COAL
SEAMS
A subsidence analysis for retreat room and pillar mining at the New Elk Mine was prepared by Agapito
Associates to support the evaluation of surface and hydrologic impacts from the mining operation ( Agapito,
2011). Under the current plan, coal would be produced from the Allen and Apache seams in different areas
of the mine. Nine entry production panels would be used to access the coal. Each entry would have a
width of 20 feet (ft). The pillar and panel dimensions would vary according to cover depth. The panel
lengths would be variable, with inter -panel barrier widths equal to widths of panel pillars. Barriers and
panel pillars would be mined during retreat. Ideally, the plan would result in full extraction of the
production and barrier pillars. The planned extraction thickness of the Allen seam varies from 5 to 6.5 feet;
the planned extraction thickness of the Apache seam varies from 4 to 5 feet. Multi -seam retreat mining of
the Allen and Apache seams is not currently planned.
Two subsidence scenarios were evaluated for the mine. The first scenario was for the minimum
overburden depth of 450 feet above the coal seams. The second scenario considered the maximum
overburden depth of 1,200 feet. Projected depths to the top of the Apache seam are shown on Figure 7.
The evaluations assumed sequential extraction of adjacent panels with the maximum planned mining height
of 6.5 feet. The analysis is conservative in the case of the Apache seam where the maximum planned
mining thickness is 5 feet. The results of the calculations are summarized in Table 16.
0 - -
4164A.110130 Whetstone Associates
PR 02 Exhibit 8(4) Page 145 Revised 1/31/11