Laserfiche WebLink
excellent quality. Sunshine Mining Company had an NPDES permit for the mine water discharging <br />from the Revenue Portal in 2001. WET tests were conducted and the company was allowed by the <br />CDPHE to abandon this permit with no further action. <br />Since ground water flows come from surface snow melt passing through fractures and old mining <br />excavation above Revenue, it can be assumed that the miscellaneous unknown mine workings <br />below the Revenue level will not contribute ground water to the Revenue discharge. The primary <br />drivers of the ground water behavior at the Revenue Mine will consist of: <br />a) the old Virginius vein development above the Revenue Tunnel in the Monogahela workings, <br />b) the Revenue's own historic ground water interceptions, and <br />c) any ground water produced by new mine development intercepting area fracture zones <br />above the new workings. <br />Historically the mine water has been high in zinc and, at times, slightly high in lead. This is due to <br />the presence of these metal sulfides in the host rock and ore that oxidize and produce acid water. <br />This acid water then leaches more metals from the area rock. The historic water data attached as <br />Appendix 3 shows some higher lead and zinc levels. However, water at all areas measured inside <br />and outside the Revenue Mine have always had neutral a pH. Also, the pH of the Revenue mine <br />water discharging from the portal is neutral and has been that way since the first measurements <br />were taken many years ago. This is the reason that the water quality is generally good, except for <br />the noted zinc levels, which are well known to remain in solution at undesired levels, even when the <br />pH is neutral. <br />Table G -1 shows a summary of the water analysis data collected over the years at the Revenue <br />Mine portal. <br />Revenue Mine August 2012 G -5 <br />