Laserfiche WebLink
existing condition, and Sunnyside Gold will then be relieved of the <br /> burden, under clean water statutes, to treat the continued <br /> discharge. Be advised that, although the Division and Board would <br /> certainly take any such determination by CDOH into consideration, <br /> a separate determination could be made that continued treatment at <br /> the portal is necessary to minimize disturbance to the hydrologic <br /> balance. Such a determination is likely to be based on the fact <br /> that Sunnyside Gold has utilized the American Tunnel for access to <br /> mine workings for many years, that Sunnyside Gold has undoubtedly <br /> maintained and upgraded the American Tunnel during the period <br /> (figure 10 of the Feb. 11, 1992 Simon Hydro Search report indicates <br /> that the 0700 runaround will be outbye of the proposed bulkhead, <br /> and that a significant inflow occurs at the runaround) , that the <br /> facilities at the American Tunnel portal are included within <br /> affected lands defined in the Sunnyside Mine reclamation permit, <br /> and that by allowing approximately 75 percent of the current flow <br /> from the American Tunnel to be discharged without treatment would <br /> represent an increase, rather than a minimization, of disturbance <br /> to the hydrologic balance. <br /> Based on the foregoing discussion, Sunnyside Gold must commit to <br /> treatment of tunnel effluent that continues after bulkhead <br /> placement, such that discharge meets applicable standards. For <br /> Sunnyside Gold to be L•elea5ed from the responsiuility to treat this <br /> water, a finding by the Board would be necessary. Sunnyside Gold <br /> should also develop options, such as additional bulkheads, passive <br /> treatment, as well as infiltration controls, to handle any <br /> continued discharge in such a way that perpetual treatment is not <br /> necessary, and disturbance to the hydrologic balance is minimized. <br /> It should be noted that if technical revision TR-14 is approved, <br /> such approval would not extend to installation of the second, <br /> outbye American Tunnel bulkhead discussed in a conceptual fashion <br /> in the report prepared by John Abel submitted with the revision. <br /> 2 . Potential for Emergence of Contaminated Mine Water After <br /> Bulkhead Installation <br /> The bulkhead designs submitted attempt to maximize the length of <br /> natural hydraulic flow paths from the mine water pool to the ground <br /> surface. Table 8 in the March 12 , 1993 Simon Hydro-Search report <br /> indicates that in the "Most Likely Case" , it will be 160 years <br /> before the first emergence of mine pool water in seeps along Cement <br /> Creek. If this anticipated scenario develops as predicted in the <br /> Simon Hydro-Search reports, the Division would concur that flooding <br /> of the Sunnyside Mine workings has effectively minimized the <br /> disturbance to the hydrologic balance. However, the Simon Hydro- <br /> Search report also recognizes that water from the impounded mine <br /> pool may move along the Brenneman vein and intersect the idle <br /> workings of the Mogul Mine, creating a surface discharge. It is <br /> the Division' s viewpoint that any significant, near-term discharge <br /> created by installation of bulkhead seals in the Sunnyside <br /> workings, whether the discharge is from the Mogul Mine, one of the <br /> other mine openings in the vicinity, Lake Emma, or in the form of <br /> 2 <br />