What stationary combustion turbines are not subject to this subpart?

(a) An integrated gasification combined cycle electric utility steam generating unit subject to subpart Da of this part is not subject to this subpart. (b) A stationary combustion turbine used in a combustion turbine test cell/stand, as defined in § 60.4420a, is not subject to this subpart. (c) If any solid fuel is combusted in the HRSG, the HRSG is not subject to this subpart. (d) Combustion turbines subject to title II of the Clean Air Act are not subject to this subpart. [91 FR 1985, Jan. 15, 2026, as amended at 91 FR 43566, July 16, 2026]