; or (ii) for which the significance of the effect on the quality of the human environment is unknown. (B) Requirement An environmental assessment prepared under subparagraph (A) shall be a concise public document prepared by a Federal agency that briefly provides evidence and analysis for determining whether to prepare an environmental impact statement or a finding of no significant impact. (3) Sources of information In making a determination under this subsection, an agency— (A) may make use of any reliable data source; and (B) shall not be required to carry out new scientific or technical research. . (d) Environmental impact statement requirements (1) In general Title I of the National Environmental Policy Act of 1969 ( 42 U.S.C. 4331 et seq. ) (as amended by subsection (c)) is amended by adding at the end the following: 107. Environmental impact statement requirements (a) Statement of purpose and need (1) In general Subject to paragraph (2), an environmental impact statement shall briefly specify— (A) the underlying purpose and need to which a Federal agency is responding