18 CFR 1318.102: Determination of NEPA Adequacy.

TVA will determine whether a proposed action is already evaluated by an existing NEPA review, including a programmatic or generic review. In making a determination, TVA will evaluate and document whether the following conditions are met:

(a) The new proposed action is substantially similar to an action previously analyzed in an existing environmental document(s);

(b) The reasonably foreseeable environmental effects that would result from the new proposed action are similar to those analyzed in an existing environmental document(s); and

(c) Any new information or circumstances relevant to environmental concerns would not substantially change the analysis in an existing environmental document(s).