2010-11-16_PERMIT FILE - C1996083A (22)

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2.04.7 Hydrology Description • but the UDSA -FS does not want the Hubbard Creek road re- opened. Opening the Hubbard Creek road would be problematic because of public opposition, road slope instability and potential flooding. • • It is highly unlikely the public will use the deep bedrock groundwater located north of the proposed mine plan area. It is simply too expensive to install a domestic or livestock well at such extreme depths. The poor water quality would also discourage public use. The lack of deep bedrock groundwater monitoring data is somewhat mitigated by the highly unlikely public use of the water. Based on the above discussion, the Operator was granted relief from the installation of a down gradient monitoring well for the northeastern mining districts contemplated by PR -10, PR -11, and TR -65. The western mining district has a down gradient monitoring well located immediately west of Terror Creek (TC- 03- 01(13)) which monitors the B -Seam. For the period of record from September 2003 through June 2010, the average conductivity was 6,027 umhos /cm with a range of 4,580 to 7,400 umhos /cm, the average ph was 11.8 with a range of 9.2 to 13.1, average total iron was 2.1 mg /I with a range of 0.05 to 21.5 mg /I and average total manganese was 0.0593 mg /I with a range of below detectable limits to 0.403 mg /I. Monitoring of TC- 03- 01(R), which monitors the Rollins Sandstone has been discontinued based on the demonstration that the Rollins Sandstone will not be impacted by mining in the west expansion area (see pages 2.05- 115 and 116). This well will remain open for future sampling at the time of bond release if necessary. The western mining district has a down gradient monitoring well located immediately west of Terror Creek (TC- 03 -02) which monitors the sandstone above the B -Seam. Although this well is located up gradient of the Terror Creek Mains, it is primarily down gradient from the west mining expansion area. For the period of record from September 2003 through June 2010, the average conductivity was 1,678 umhos /cm with a range of 170 to 7,100 umhos /cm, the average ph was 9.7 with a range of 7.6 to 13.0, average total iron was 2.5 mg /I with a range of 0.35 to 10.7 mg /I and average total manganese was 0.127 mg /I with a range of below detectable limits to 0.37 mg /I. The western mining district has a down gradient monitoring well located immediately east of Terror Creek (TC- 03 -03) which monitored the sandstone above the B -Seam. Although this well is located up gradient of the Terror Creek Mains, it is primarily down gradient from the west mining expansion area. For the period of record from September 2003 through June 2006, the average conductivity was 2,559 umhos /cm with a range of 1,249 to 4,300 umhos /cm, the average ph was 9.9 with a range of 9.1 to 11.5, average total PR -12 2.04-32- 11/10/10 A PPRevcj 11116110