2014-05-13_PERMIT FILE - C1996083A ‎(3)‎

• Permit No: C1996083A
• IBM Index Class Name: Permit File
• Doc Date: 5/13/2014
• Doc Name: pages 2.05-84 to 2.05-165
• Section_Exhibit Name: Volume I 2.05 Operation and Reclamation Plans Part 2
• Media Type: D
• Archive: Yes

Flooded mine workings could also impact the water quality in the area. When the
mines are sealed they will slowly fill with water. Although no data for permeability or
transmissivity of the saturated portions of the coal bearing member of the Mesaverde
Formation are available within the permit area, the experience by others (Brooks,
1983) suggests the Mesaverde Formation transmits little water. Therefore, the
abandoned mine workings would not be expected to transmit water to the
surrounding strata. Based on the above discussion, if the mine workings fill with
water and discharge through the portals, the impact on the North Fork of the
Gunnison River would be less than or equal to the mine water discharge analysis
presented above.
The flooded mine workings could also affect the ground water quality and quantity in
the overlying Upper and Lower Perched Water Zones. However, as stated above,
the Mesaverde Formation transmits little water. Therefore, the impact the flooded
mine workings will have on the quantity and quality of the surrounding strata should
be minor.
The Rollins sandstone, as monitored in DH -34B, NM4X98 -29 and P- TC- 03 -01(R)
has pH in the range of 7.5 to 9.6, conductivity in the 1,200 to 7,900 umhos /cm range
and total recoverable iron in the 0.2 to 62.0 mg /I range. The Rollins sandstone is a
confined aquifer under piezometric head. The confining shale layers above the
Rollins sandstone and piezometric head should prevent any integration of waterfrom
either the D -Seam or B -Seam into the Rollins sandstone. There are two drill holes
(G -15) located near the mouth of Dove Gulch and DH 98 -57 located in the central
portion of the east mine workings that provide documentation of the hydraulic
isolation of the Rollins sandstone from the B -1 Seam, the lowest coal seam to be
mined. The following table shows the extent of the hydraulic isolation.
Hole (Interburden)
Mudstone
Sandy Mudstone
Sandstone
Coal
Lost Core
G -15 (89.8)
64.3
8.3
11.0
6.2
0.0
DH 98 -57 (94.9)
68.0
10.6
9.0
0.0
7.3
In the western mine plan area, west of Terror Creek, drill holeTC- 03 -03, CWI- DH -50,
51 and 62 document the hydraulic isolation between the Rollins sandstone and the
lowest coal seam to be mined. DH- CWI -51 is located in the northern portion of the
western mining district. The following table shows the extent of the hydraulic
isolation.
Hole (Interburden)
Mudstone
Sandy Mudstone
Sandstone
Coal
Lost Core
TC -03 -03 (74.5)
23.0
28.3
4.0
19.2
0.0
CWI -DH -50 (70.6)
31.7
17.7
10.0
8.0
3.2
CWI -DH -51 (70.0)
16.2
47.1
0.0
6.7
0.0
CWI -DH -62 (105)
9.0
60.0
15.5
20.5
0.0
PR -13 2.05-115 02/13