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4.8.2.2a. GROUND WATER INFLOW, 2013-2017. <br />DERRINGER PIT <br />The QR seams were mined out in Derringer pit during the 1998-2002 permit term. Average mine <br />inflows to Derringer pit, including the D pit well dewatering which continued into early 1998, varied <br />from just over 1 to approximately 50 gpm during the period from 1997 through 2001. Additional <br />dewatering needs in this pit are not anticipated during the 2013 — 2017 term. <br />ASHMORE AND HAWKEN PITS <br />Average mine drainage from the Ashmore pit varied from 0 to approximately 20 gpm from 1997-2001. <br />Similar discharge rates are anticipated for the current permit term (2013 — 2017). Hawken pit <br />dewatering effectively ceased in 1997 with backfilling in this pit completed during the 1998 — 2002 <br />permit term. <br />FLINTLOCK PIT <br />Groundwater inflows to Flintlock pit including dewatering well volumes as well as pit pumping volumes <br />varied from 10 to approximately 30 gpm on average from 1997 to 2001. Dewatering well operations in <br />F pit were discontinued in 1998. Flintlock Pit was completed and backfilled by the fall of 2012. <br />Additional dewatering well installations are not anticipated in the future for this pit area. <br />KIMBER AND LANCASTER PIT <br />Mining of the H, I, K, L, M, Q and R seams is planned for K pit during the 2013 — 2017 permit term. <br />Aquifer dewatering wells utilized in the backfilled G pit area have produced from 2 to 29 GPM during <br />the period from 2002 to present. Inflows attributable to groundwater are expected to continue at a <br />similar rate during the 2013 — 2017 permit term. The contour orientation of K pit may result in <br />additional surface runoff flows being retained in the pit. To the extent possible, diversion ditches will <br />be utilized to route water around open pit areas. Lancaster pit will be of the down dip orientation and <br />is not expected to produce or retain any more water than prior pits of this design. <br />4-226c <br />M-07� <br />MAY 21 2013 <br />