; and (II) as the Commission determines to be appropriate, promulgate comparable regulations pursuant to which the Commission may establish categorical exclusions for, and apply categorical exclusions to, qualifying projects. (ii) Transition period Until the date on which the regulations described in clause (i)(II) are promulgated by the Commission, the Commission may apply section 1021.410 of title 10, Code of Federal Regulations (or a successor regulation), to qualifying projects. (10) NEPA processes and compliance (A) Purpose The purpose of this paragraph is to ensure that there is no duplication of effort or processes with respect to environmental reviews relating to the siting, construction, or modification of national interest electric transmission facilities in national interest electric transmission corridors designated by the Secretary under paragraph (2) or (5) of subsection (b). (B) No environmental review required for NIETC designation Notwithstanding any other provision of law, the designation of a national interest electric transmission corridor under paragraph (2) or (5) of subsection (b) does not require the preparation of an environmental review document pursuant to the National Environmental Policy Act of 1969 ( 42 U.S.C. 4321 et seq. ) (including section 106 of that Act) or any other provision of Federal law. (C) Environmental review required for siting, construction, or modification of facilities With respect to any siting, construction, or modification of a national interest electric transmission facility in a national interest electric transmission corridor, the Commission, in accordance with this subsection— (i) shall be designated as the lead agency with respect to that siting, construction, or modification