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-5- The entire outcrop and sub-crop of the Sudduth Coal seam in the mine plan and adjacent areas comprises the recharge area for the coal seam. Snow melt provides the majority of the recharge to the coai seam. The estimated recharge over the entire coal seam was calculated to be 4.75 acre ft/y r. No wells are located in the Sudduth Coal seam, and there is only one discharge point in the area, a spring at the 01d Sudduth Mine iocated in Section 15, T9N, R781i. 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 Sudduth Coal seam does not appear to discharge to or be recharged by the alluvium of kf111ams and Bush Draws. Th15 15 evident from water table elevations (Map 15a and Table 8a of the original permit application) which are lower in the coal seam than in adjacent alluvial wells. Hoffstra, who conducted aquifer tests in the overburden, reported permeability values of 0.37 gpd/ft2 in unfaulted overburden, and 7.5 gpd/ft2 near faulted areas. These values indicate that the overburden is essentially a confining unit, but approaches a semi-confining state in areas of secondary permeability. The Upper Coalmont Formation, which is located near the axis of the Johnny Moore Syncline, contains limited perched aquifers. These perched systems typically consist of lenticular channel sands, usually less than thirty feet thick. Kerr Coal Company conducted an aquifer test on 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 In addition. a Sudduth Coal seam observation tell located 20 feet arty from the test hole showed no drawdown during pugging of the test hole. This data indicates that the Pierre Shale is a confining unit that transaits little rater. The test also deapnstrates that the Sudduth Coal is not hydraulically connected to the underlying Pierre Shale. The Sudduth Coal seas. underburden and overburden units of the open Pit No. 3 are in hydrologic caomunicatlon rlth the alluvlu~ of Sudduth Draw. The bottae of open Pit No. 3 will be 120 feet below the level of Sudduth Drar. The pit rill be dewatered during mining. These factors rill produce an increased ground water gradient for flor frog Sudduth Drar towards the pit. rewlting in a depletion of flow to Sudduth Draw. This depletion can be ~1ni~ized Dy decreasing the infiltration over the sub-crop in Sudduth Draw. Two stock ponds, one upstream and one over the sub-crop. exist on Sudduth Drar. These ponds increase the amount and the length of time that surface waters can infiltrate the alluvium, as 1s evident from the sub-irrigated area helot the ponds. (later, which is allowed to infiltrate through the ponds upstreao and over the sub-crop area, rill be lost to beneficial use 1n the immediate area and downstream during-and after wining the northern section of Pit No. 3. To resolve this concern, the folloring stipulation ras necessary: