40 CFR § 60.2886
What is a new incineration unit?
June 9, 2020
(a) A new incineration unit is an incineration unit subject to this subpart that meets either of the two criteria specified in paragraphs (a)(1) or (2) of this section.
(1) Commenced construction after December 9, 2004.
(2) Commenced reconstruction or modification on or after June 16, 2006.
(b) This subpart does not affect your incineration unit if you make physical or operational changes to your incineration unit primarily to comply with the emission guidelines in subpart FFFF of this part. Such changes do not qualify as reconstruction or modification under this subpart.