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ponds. Spring snowmelt will cause the ponds to discharge, although the levels of <br />total suspended solids in snowmelt runoff will be substantially below pre-mine <br />levels in most cases due to settling in the sediment ponds. Pit pumping will also <br />cause some drainage systems to discharge on a regular basis but this water is of <br />generally acceptable quality for stock watering and other agricultural purposes <br />and no problems are projected due to this discharge. Once vegetation is re- <br />established throughout a drainage, runoff in the drainage may decrease below pre- <br />mining levels as surface water infiltrates more easily into the subsurface which <br />has been disaggregated by mining. <br /> <br />The most noticeable change in surface water quality will likely be an increase in <br />the levels of total dissolved solids (mainly calcium sulfate) contributed by springs <br />that discharge from the mined-out pits that have been back-filled with spoil and <br />from the Horse Gulch Fill structure. Following reclamation, each spoil-filled pit <br />and fill structure will likely develop a flowing spring on the ground surface at the <br />down-slope end of the pit or fill. The pit or fill effluent that discharges from a <br />spring will be composed of water that is rich in the minerals that are dissolved <br />from the spoil which fill the mined-out pit or that was used to construct the fill. <br />The effluent discharging from a spoil spring or fill spring will flow downslope to <br />the nearest drainage channel. <br /> <br />As of 2008, Trapper considers only Johnson Gulch Spring and Spring 99-1 to be <br />spoil springs. All other springs on Trapper are believed to be natural springs. <br /> <br />Water from Johnson Gulch Spring has a TDS level of around 4000 mg/l and an <br />average iron content of 0.42 mg/l as found in samples taken in 1995 and 1996 <br />(Appendix W of permit application). This spring supplies around 10% of the <br />annual flow of Johnson Gulch within the permit area. The Johnson Gulch Spring <br />water exceeds secondary drinking water standards although it is not currently <br />used as drinking water downstream of the mine area. Cottonwood and Wapiti <br />Springs are natural springs and have total dissolved solids concentrations usually <br />around 1200 mg/l, similar to pre-mining levels. <br /> <br />Trapper considers that Colt Seep, a seep that was mined through and reclaimed in <br />1988, discharged from a spoil aquifer. Trapper believes that during the last few <br />years of the Colt Seep's existence, the seep's water quality was improving after <br />having been degraded by mining. <br /> <br />The spoil leachate that discharges from spoil springs and fill springs would be <br />diluted during springtime runoff. The leachate from spoil springs has exceeded <br />irrigation quality limits, but is not used for that purpose. Leachate should be <br />acceptable for stock water and wildlife usage. <br /> <br />Suspended solids may be elevated in surface waters in a drainage in the permit area early <br />in the mining cycle or fill construction, until reclaimed vegetation is established to <br />control erosion. Sediment control measures described in the permit application will <br />reduce the sediment load added to surface waters. <br /> <br /> <br />33 <br /> <br />Trapper MineJuly 9, 2013 <br /> <br />