[Code of Federal Regulations] [Title 40, Volume 5] [Revised as of July 1, 2003] From the U.S. Government Printing Office via GPO Access [CITE: 40CFR57.109] [Page 135] TITLE 40--PROTECTION OF ENVIRONMENT CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PART 57--PRIMARY NONFERROUS SMELTER ORDERS--Table of Contents Subpart A--General Sec. 57.109 Maintenance of pay. The Administrator will not approve or issue an NSO for any smelter unless he has approved or promulgated SIP provisions which are applicable to the smelter and which satisfy the requirements of section 110(a)(6) of the Clean Air Act.