[Code of Federal Regulations] [Title 40, Volume 13] [Revised as of January 1, 2003] From the U.S. Government Printing Office via GPO Access [CITE: 40CFR65.65] [Page 60] TITLE 40 - PROTECTION OF ENVIRONMENT CHAPTER I - ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PART 65 - CONSOLIDATED FEDERAL AIR RULE--Table of Contents Subpart D - Process Vents Sec. 65.65 Monitoring. (a) An owner or operator of a Group 2A process vent maintaining a TRE index value greater than 1.0 without a recovery device shall monitor based on the approved plan as specified in Sec. 65.63(d). (b) As required in Sec. 65.63(a) and (c), an owner or operator of a Group 2A process vent maintaining a TRE index value greater than 1.0 with a recovery device or a Group 1 process vent shall comply with Sec. 65.142(b).