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Groundwater Groundwater near the Canadian Strip Mine occurs in both consolidated and unconsolidated aquifers. The Sudduth Coal seam is the most significant source of groundwater in the area. Aquifer tests, in the azea of the mine site, have been conducted in the overburden, the coal seam and in the underburden. Flow within these units is locally controlled by faulting and fractures. Alluvial groundwater flow occurs in the alluvial material associated with both Bolton Draw and the Canadian River. Flow in the alluvial material generally pazallels the drainage pattern of the stream channel. Two springs have been identified near the permit area. The first spring issues from the contact between unconsolidated upland terrace deposits and the underlying Coalmont Formation. This spring is in an area next to the Canadian Strip Mine on a small tributary of the North Fork of Bolton Draw. This spring feeds a small pond used for stock and wildlife watering. This spring will not be effected by mining or reclamation activities since it is outside the permit boundary upslope of the operation. The second spring, at the Old Sudduth Mine located in Section I5, T9N, R78W discharges from the Sudduth Coal. This spring does not provide sufficient discharge to be considered a significant water source. There have been no other observed springs or seeps from the Sudduth Coal seam in the adjacent area. The entire outcrop and sub-crop of the Sudduth Coal seam near the mine and adjacent area comprises the recharge area for the coal seam. Snowmelt provides most of the recharge to the coal seam. The estimated recharge over the entire coal seam was calculated to be 4.75 acre ft./yr. A U.S.G.S. study conducted aquifer tests and reported permeability values of 0.37 gpd/ft~ in unfaulted overburden, and 7.5 gpd/ft2 near faulted overburden. These values suggest that the overburden is essentially a confining unit, but approaches asemi-confining state in areas of secondary permeability. The upper Coalmont Formation contains limited perched aquifers. These perched systems typically consist of lenticular channel sands, usually less than thirty feet thick. An adjacent operation conducted an aquifer test of the underburden (upper Pierre Shale) near the mine site. From this test, the permeability of the underburden was calculated to be 0.15 gpd/ft'. A Sudduth Coal seam observation well located 20 feet away from the test hole showed no drawdown during pumping. Data show that the Pierre Shale is a confining unit that transmits little water. The test also shows that the Sudduth Coal is not hydraulically connected to the underlying Pierre Shale. Information concerning groundwater may be found in Appendix C, Volumes I and II of the permit application. Canadian Strip Mine, C-81-026 g December 5, 1996