40 CFR § 62.14805
What must I do if I close my air curtain incinerator and then restart it?
June 9, 2020
(a) If you close your incinerator but will reopen it prior to the final compliance date in this subpart, you must achieve final compliance by October 4, 2004.
(b) If you close your incinerator but will restart it after October 4, 2004, you must have completed any needed emission control retrofits and meet the opacity limits of §62.14815 on the date your incinerator restarts operation.
(c) You are subject to the operating permit requirements of title V of the CAA and 40 CFR part 70 or 71 until you close your air curtain incinerator and at the time you restart it.