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Schwartzwalder Mine -Hydrologic Evaluation of !~1ine ('losure and Reclamation `q <br />SW <br />~ooo <br />esoo <br />eooo <br />ssoo <br />soon I <br />X500 <br />woo <br />Figure 17. Conceptual Model of Groundwater Flow-Post-Mining <br />~.2 Mine Inllu~~ <br />The first occurrence of groundwater in the Schwartzwalder Mine was recorded in 199 when an inflow of <br />17 gpm was encountered in the No. 1 Shaft. After 199, water was pumped from the mine as required to <br />nlalntaln dry working conditions, but because the treatment of discharged water was not required, no record <br />of mine pumping was kept until 19T. Mine pumping records are available, however, from 1973 to 2000. <br />Pumping from the lowest level of the mine was discontinued on May 19, 1998 and the spiral decline <br />(heriveen 2,200 and 1,900 feet) was allowed to flood. Pumping from the 19 Level was discontinued on <br />May 24, 2000 and the mine has been tilling with water since that time. <br />~.?.1 h1.11)l~)lll~r Rc~c~orclc <br />Groundwater intlo~~ to the mine between 1973 and 2000 varied from about 7~ gpm to over 600 gpm <br />depending on mine development and construction activities (Figure 18). Mine operations that affected the <br />rate of groundwater inflow and pumpage included: <br />1. Ueepcning of shafts and mine expansion. Typically, higher inflows occurred during the initial <br />shaft sinking and mine expansion, and decreased with time as water drained from storage in the <br />bedrock. For example, mine inflow increased from about 200 gpm in 197> to more than 600 gpm <br />in 1976 during sinking of the #3 shaft. In the 2 years after the completion of the #3 shaft, pumping <br />from the mine declined to a low of about 300 gpm. <br />t ~ Q`)I~.rr7 ~ ~ ~ ~' Whetstone Associates <br />- ~ - <br />D <br />r ~ <br />~ ~ <br />~ ~ <br />~ O <br />Z Z <br />~ ~ NE <br />m <br />m <br />~c m <br />