(a) When available, the Responsible Official should use existing NEPA analyses for assessing the impacts of a proposed action and any alternatives. Procedures for adoption or incorporation by reference of such analyses must be followed where applicable.
(b) If existing NEPA analyses include data and assumptions appropriate for the analysis at hand, the Responsible Official should use these existing NEPA analyses and/or their underlying data and assumptions where feasible.
(c) An existing environmental analysis prepared pursuant to NEPA and the Council on Environmental Quality regulations may be used in its entirety if the Responsible Official determines, with appropriate supporting documentation, that it adequately assesses the environmental effects of the proposed action and reasonable alternatives. The supporting record must include an evaluation of whether new circumstances, new information or changes in the action or its impacts not previously analyzed may result in significantly different environmental effects.
(d) Responsible Officials should make the best use of existing NEPA documents by supplementing, tiering to, incorporating by reference, or adopting previous NEPA environmental analyses to avoid redundancy and unnecessary paperwork.