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 23
6. WATER LEVELS AND WATER QUALITY IN THE FLOODED NEW ELK MINE
Previous production from the New Elk Mine occurred from the Allen coal seam between 1952 and 1988.
The mine was temporarily sealed in 1988 and allowed to flood. Monitoring data including the depth to
water and water quality were collected for the for the mine pool between February 2001 And November
2008. These data are presented in annual hydrologic monitoring reports (Picketwire Processing 2002 -2007;
New Elk Coal Company, 2008 and 2009) and are summarized in Figure 6 and Table 15. Active dewatering
of the mine resumed from the East Portal Air Shaft in December 2008 to facilitate entry and rehabilitation
of the mine.
NEW -2 (East portal Shaft)
IIn
Lmp ✓
# r nso
I . oo' le
(CFI underground datum corrected to confirm to t1SUS surface topography h, s.mael ng Im 73 feel)
Figure 6. Water Levels in Flooded New Elk Mine
Water level data indicate that by late 2004, the elevation of the mine pool near the East Portal Shaft (NEW -
2 and NEW -4) had stabilized to about 7,111 ft amsl. The water level at the Apache Canyon shaft continued
to rise until February 2007 when it reached a maximum elevation of 7,095 ft amsl. The gradient across the
mine pool at that time was 0.002 ft/ft to the southeast consistent With the regional water table shown in
Figure 2. Groundwater in the mine originates mainly from the Allen seam, and between 2001 and 2008, it
was a well- buffered, sodium - bicarbonate water with alkaline pH (7.5 to 8.8) and moderately elevated total
dissolved solids (average 771 to 1,340 mg/I).
4164A 110421 Whetstone Associates
Tv c4 WAN V.— 1,14 1/ 1l) 1 I
NEW- 31 (Apache Unyon Shaft)
NEW-4 (Well in Sealed Mine)
],ton
i,lIe
C 7 n
F
Iele
imo
role
].nle
"man
e
H
, 8 S" , .�R
q
I'll B e F C
(CFI underground datum corrected to confirm to t1SUS surface topography h, s.mael ng Im 73 feel)
Figure 6. Water Levels in Flooded New Elk Mine
Water level data indicate that by late 2004, the elevation of the mine pool near the East Portal Shaft (NEW -
2 and NEW -4) had stabilized to about 7,111 ft amsl. The water level at the Apache Canyon shaft continued
to rise until February 2007 when it reached a maximum elevation of 7,095 ft amsl. The gradient across the
mine pool at that time was 0.002 ft/ft to the southeast consistent With the regional water table shown in
Figure 2. Groundwater in the mine originates mainly from the Allen seam, and between 2001 and 2008, it
was a well- buffered, sodium - bicarbonate water with alkaline pH (7.5 to 8.8) and moderately elevated total
dissolved solids (average 771 to 1,340 mg/I).
4164A 110421 Whetstone Associates
Tv c4 WAN V.— 1,14 1/ 1l) 1 I