NAC445A.430. Stabilization of spent ore.

     1. Spent ore which has been left on pads or which will be removed from a pad must first demonstrate stability of the discharge effluent from the pads or from the spent ore such that:

     (a) WAD cyanide levels in the effluent are less than 0.2 mg/l;

     (b) The pH level of the effluent is between 6.0 and 9.0; and

     (c) Contaminants in any effluent from the processed ore which would result from meteoric waters would not degrade waters of the State.

     2. If the requirements established in subsection 1 cannot be achieved, the Department will grant a variance to those conditions if the holder of the permit can demonstrate that:

     (a) The remaining solid material, when representatively sampled, does not contain levels of contaminants that are likely to become mobile and degrade the waters of the State under the conditions that will exist at the site; or

     (b) The spent ore is stabilized in such a fashion as to inhibit meteoric waters from migrating through the material and transporting contaminants that have the potential to degrade the waters of the State.

     3. The Department may approve an alternate method for stabilizing ore that has been leached if the holder of the permit can clearly demonstrate that the condition in which the materials will be left will not create a potential for the waters of the State to be degraded.

     (Added to NAC by Environmental Comm’n, eff. 9-1-89; A by R141-06, 10-31-2007)