Sec. 251.2. Applicability

(a) New sources and modified existing sources.

The provisions of section 251.3(a) of this Part apply to owners or operators of:

(1) new major electric generating facilities that commence construction after July 12, 2012; and

(2) existing major electric generating facilities that commence construction for an increase in capacity of at least 25 MW at the facility after July 12, 2012. Only those emission source(s) involved in the increase in capacity at the electric generating facility shall be subject to the emission limits established in section 251.3(a) of this Part.

(b) Non-modified existing sources.

The provisions of section 251.3(b) of this Part apply to owners or operators of fossil fuel-fired existing major electric generating facilities that provide more than 10 percent of their annual electric output to the electric grid and that are not subject to section 251.3(a) of this Part.

(c) All other provisions of this Part apply to owners or operators of major electric generating facilities.