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• highwall face due to the geology of the anticline. The strata <br />overlying the Sudduth seam will become drained up gradient in <br />advance of the excavation. This should be a local effect, probably <br />extending not more than 500 feet in advance of the excavation. <br />Some water may also enter the pit from the underlying sandy unit of <br />the Pierre Formation if fractures or faults are encountered which <br />penetrate the strata underlying the Sudduth Seam. Experience with <br />the existing pit, and permeability tests conducted on rock samples <br />indicate total groundwater seepage into the pit will be very <br />minimal, if any. <br />Only one other ground water appropriation exists in Bolton <br />Draw, that of the Kerr Mine approximately 2 miles north. Neither <br />drainage of the pit, nor use of water from a well penetrating the <br />Pierre should affect this well. Furthermore, groundwaters being <br />utilized are not in direct connection with the weathered surficial <br />aquifer and use of these waters should not impact surface water <br />• rights. <br />Of the total acreage within the Bolton Draw watershed, only a <br />minor percentage of the area will be affected by mining. Drainage <br />from Area III will not be affected by mining (see Plate 4, Willard <br />Owens report). Runoff from Area Iv upstream from the disturbed <br />area will be channeled around Pit 2 by a diversion ditch back into <br />Bolton Draw. Runoff from Area IV downstream from Pit 2 will not be <br />affected, but will flow as it presently does. <br />Mining in Zone IV should not greatly impact the quality of <br />either surface or groundwaters. A discussion of the impact on <br />surface and groundwater quality is discussed in Section 2.05.6(3) <br />(b) (iv) . <br />As described previously, nine monitor wells will be maintained <br />in the Pit 2 area, in addition to the existing wells in the Pit 1 <br />vicinity. Also surface water monitoring will be maintained at <br />• <br />-73- <br />