Section NR 256.20 - Applicability; description of the copper casting subcategory(1) This subchapter applies to discharges to waters of the state and to introductions of pollutants into publicly owned treatment works from copper casting operations. It applies to a production process if the molten metal contains, on average, greater than 50% by weight of copper or if copper comprises the greatest percentage of the metal, measured by weight.(2) This subchapter does not apply to the casting of ingots, pigs or other cast shapes following primary metal smelting, which is regulated by the nonferrous metals manufacturing point source category under 40 CFR Part 421 . This subchapter does not apply to the casting of copper alloys containing either beryllium at 0.1 % or greater by weight or precious metal at 30% or greater by weight.(3) Processing operations following the cooling of castings, except for grinding scrubber operations, may be regulated by the electroplating point source category under ch. NR 260 or metal finishing point source category under ch. NR 261.Wis. Admin. Code Department of Natural Resources NR 256.20
Cr. Register, June, 1989, No. 402, eff. 7-1-89.