Section 440.140 - Applicability; description of the gold placer mine subcategory(a) The provisions of this subpart M are applicable to discharges from-(1) Mines and dredges that produce gold or gold bearing ores from placer deposits; and(2) The beneficiation processes which use gravity separation methods for recovering gold from placer deposits.(b) The provisions of this subpart M are not applicable to any mines or beneficiation processes which process less than 1500 cubic yards (cu yd) of ore per year, or to dredges which process less than 50,000 cu yd of ore per year, or to dredges located in open waters ( i.e. , open bays, marine waters, or major rivers).