For purposes of sections
7413 and
7420 of this title a prohibition under subsection (b) of this section, and a corresponding rule or order under subsection (c) of this section, shall be treated as a requirement of section
7413 of this title. For purposes of any plan (or portion thereof) promulgated under section
7410
(c) of this title, any rule or order under subsection (c) of this section corresponding to a prohibition under subsection (b) of this section, shall be treated as a part of such plan. For purposes of section
7413 of this title, a prohibition under subsection (b) of this section, applicable to any source, and a corresponding rule or order under subsection (c) of this section, shall be treated as part of the applicable implementation plan for the State in which subject source is located.