; and (2) by inserting after paragraph (8) the following: (9) No duplication of environmental reviews (A) Purpose The purpose of this paragraph is to ensure that there is no duplication of effort or process with respect to preparing environmental documents relating to the designation of national interest electric transmission corridors under subsection (a) and the issuance of permits under subsection (b). (B) Review relating to designation Unless the Secretary determines that the preparation of an environmental document with respect to the designation of a national interest electric transmission corridor under subsection (a) is necessary under the circumstances, the Secretary shall not be required to prepare an environmental document in connection with the designation of such a national interest electric transmission corridor. (C) Effect on applications to construct or modify certain transmission facilities (i) No review relating to designation of corridor If the Secretary has not prepared an environmental document with respect to the designation of a national interest electric transmission corridor under subsection (a), the Commission shall prepare an environmental document for any construction or modification proposed in an application made under subsection (c) before issuing a permit for such application under subsection (b). (ii) Review relating to designation of corridor If the Secretary has prepared an environmental document with respect to the designation of a national interest electric transmission corridor under subsection (a)— (I) the Commission and any other Federal agency preparing an environmental document for any construction or modification proposed in an application made under subsection (c) within such national interest electric transmission corridor— (aa) shall rely on any findings of the environmental document prepared by the Secretary; and (bb) shall not duplicate any work of the Secretary relating to the preparation of such environmental document