CFR > Title 40 - Protection of Environment > CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY > SUBCHAPTER N—EFFLUENT GUIDELINES AND STANDARDS (Parts 400–471) > PART 421—NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY > SUBPART F—Secondary Copper Subcategory (§421.60 to §421.67) > 421.64—Standards of performance for new sources.