40 CFR §434.81

1. (a)This subpart applies to alkaline mine drainage at western coal mining operations from reclamation areas, brushing and grubbing areas, topsoil stockpiling areas, and regraded areas.
2. (b)This subpart applies to drainage at western coal mining operations from reclamation areas, brushing and grubbing areas, topsoil stockpiling areas, and regraded areas where the discharge, before any treatment, meets all the following requirements:
   1. (1)pH is equal to or greater than 6.0;
   2. (2)Dissolved iron concentration is less than 10 mg/L; and
   3. (3)Net alkalinity is greater than zero.
3. (c)The effluent limitations in this subpart apply until the appropriate SMCRA authority has authorized bond release.