2012-05-11_PERMIT FILE - C1981033 ‎(3)‎

• Permit No: C1981033
• IBM Index Class Name: Permit File
• Doc Date: 5/11/2012
• Section_Exhibit Name: Rule 2.05 Operation and Reclamation Plans
• Media Type: D
• Archive: No

2.05.6(3) Protection of the Hydrologic Balance
• an average conductivity of 4535 uhmos /cm and an average TDS of 3,168 mg/I. In order to
account for additional flow from the spring, it will be assumed that the spring flow equals 30
gpm. The maximum measured TDS value for the mine water is 4090 mg/I. The total worst
case mine seepage through the coal seam outcrop is calculated above and totals 17.0 gpm.
The range in estimated outcrop seepage from the B -Seam and C -Seam is 1.4 to 17 gpm.
According to data supplied by the USGS, the annual seven day minimum flow for the North
Fork of the Gunnison River is 25 cfs. This low flow value occurred February 17, 1978, is for
the period of record from 1934 through 1995 and is measured upstream of the Town of
Somerset, CO.
The maximum TDS measurement at the upstream North Fork of the Gunnison River
monitoring station during 2001 was 140 mg/I. The following table presents the estimated
affect the slide spring, mine outcrop seepage and alluvial flow will have on the quality of
water in the North Fork of the Gunnison River:
PHC North Fork of the Gunnsion River
Flow qpm
Flow cfs
TDS
North Fork
11,220
25.0
140
Slide Spring
30
0.07
3168
Mine Seepage
17
0.04
4090
Combined Flow
112671
25.1
154
Based upon the above calculation, the slide spring, and mine seepage will not have a
measurable impact on the quality of water in the North Fork of the Gunnison River.
The First North Mains were developed near Lone Pine Gulch and springs G -26A, G -26B &
C, and CR -12. Mining ceased in this area at the end of 1994. Spring G -26B and G -26C are
south of the proposed mining area and well outside of the potential angle of draw of the
mine workings. Springs G -26A and CR -12 and Lone Pine Gulch are relatively close to the
mined area. Seven years of monitoring data collected for the annual hydrologic reports has
shown the mine has not had a noticeable affect on the above mentioned gulch or springs.
(b)(iv) The hydrological monitoring plan is presented in Section 2.04.7(1)(v) and 4.05.13.
Monitoring and reporting water data is discussed under Section 4.05.13. Additional infor-
mation concerning hydrologic impacts and mitigation measures are set forth in Section
2.04.7.
0 n,P_- as
(9/V -0 9)
A l`PRoveD 0114103
2.05 -55c
Rev. 1/03