[Code of Federal Regulations]
[Title 40, Volume 31]
[Revised as of July 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR1502.22]

[Page 881]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
               CHAPTER V--COUNCIL ON ENVIRONMENTAL QUALITY
 
PART 1502_ENVIRONMENTAL IMPACT STATEMENT--Table of Contents
 
Sec.  1502.22  Incomplete or unavailable information.

    When an agency is evaluating reasonably foreseeable significant 
adverse effects on the human environment in an environmental impact 
statement and there is incomplete or unavailable information, the agency 
shall always make clear that such information is lacking.
    (a) If the incomplete information relevant to reasonably foreseeable 
significant adverse impacts is essential to a reasoned choice among 
alternatives and the overall costs of obtaining it are not exorbitant, 
the agency shall include the information in the environmental impact 
statement.
    (b) If the information relevant to reasonably foreseeable 
significant adverse impacts cannot be obtained because the overall costs 
of obtaining it are exorbitant or the means to obtain it are not known, 
the agency shall include within the environmental impact statement:
    (1) A statement that such information is incomplete or unavailable; 
(2) a statement of the relevance of the incomplete or unavailable 
information to evaluating reasonably foreseeable significant adverse 
impacts on the human environment; (3) a summary of existing credible 
scientific evidence which is relevant to evaluating the reasonably 
foreseeable significant adverse impacts on the human environment, and 
(4) the agency's evaluation of such impacts based upon theoretical 
approaches or research methods generally accepted in the scientific 
community. For the purposes of this section, ``reasonably foreseeable'' 
includes impacts which have catastrophic consequences, even if their 
probability of occurrence is low, provided that the analysis of the 
impacts is supported by credible scientific evidence, is not based on 
pure conjecture, and is within the rule of reason.
    (c) The amended regulation will be applicable to all environmental 
impact statements for which a Notice of Intent (40 CFR 1508.22) is 
published in the Federal Register on or after May 27, 1986. For 
environmental impact statements in progress, agencies may choose to 
comply with the requirements of either the original or amended 
regulation.

[51 FR 15625, Apr. 25, 1986]