2015-01-27_PERMIT FILE - C1996083A

Home Browse Search

2.04.7 Hydrology Description During 2014, the Operator through its contractor HydroGeo, did an extensive monitoring well rehabilitation project. HydroGeo's November 2014 report detailing the rehabilitation project is located in Volume III Exhibit 3. The western mining district, west of Terror Creek 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, west of Terror Creek, had 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 iron was 6.4 mg /I with a range of 0.05 to 17.2 mg /I and average manganese was 0.184 mg /I with a range of below detectable limits to 0.507 mg /I. Well TC -03 -03 has had a pinched casing since 2006 and the well has been sealed. Monitoring wells TC -03 -01 and TC -03 -02 could not be rehabilitated during 2014. The wells can be used as water level piezometers but the wells are not functional for water quality data. During July and August 2010 exploration hole DH- 2010 -2 was drilled in the west mining district. The hole was located on private land owned by the Turkey Track Ranch. This private landowner consented to the Applicant drilling the exploration hole but would not consent to the hole being converted into a monitoring well. The Applicant closely monitored this hole for groundwater inflows. At a depth of 1,400 feet there was indication of groundwater inflow. The Applicant set a packer below the water bearing zone and collected a sample. Total dissolved solids were 980 mg /I, ph was 9.1, total iron was 184.0 mg /I and manganese was 2.42 mg /I. The coal seam was at a depth of 2,054 feet. The coal seam was dry. A monitoring well was not established because the Applicant did not have long term access. Additionally, monitoring a well that is 2,054 feet deep is not technically or economically feasible. MR -172 2.04-34- 01/15