(a) If an action under consideration by the issuer may involve “major Federal action significantly affecting the quality of the human environment” (hereinafter called “Federal action”) under the National Environmental Policy Act of 1969 (hereinafter called “NEPA”) and where there has been duly prepared under NEPA both a draft environmental impact statement and a final environmental impact statement for said action, the issuer shall have no obligation with respect to this Part except that:

1. (1) compliance with the act shall be coordinated with and made in conjunction with Federal requirements in a single environmental reporting procedure and the issuer shall make and file, in accordance with section 4300.9 of this Part, the findings required by subdivision 8 of section 8-0109 of the act; or

2. (2) where the issuer did not participate in the preparation of the statements (or submit material relating thereto) prepared pursuant to the requirements of NEPA, such Federal statements shall be supplemented by a description of any growth-inducing aspects of the proposed action and a discussion of the effects of the proposed action on the use and conservation of energy; and

   Upon making the decision-making findings in accordance with section 4300.9 of this Part as provided in paragraph (1) above, or upon the supplementation of said statements as provided in paragraph (2) above, the issuer may undertake such action.