(1) Prior to the preparation of an EIS, the agency shall initiate a process to determine the scope of the EIS.

(2) To identify the scope of an EIS, the agency shall:

(a) invite the participation of affected federal, state, and local government agencies, Indian tribes, the applicant, if any, and interested persons or groups;

(b) identify the issues related to the proposed action that are likely to involve significant impacts and that will be analyzed in depth in the EIS;

(c) identify the issues that are not likely to involve significant impacts, thereby indicating that unless unanticipated effects are discovered during the preparation of the EIS, the discussion of these issues in the EIS will be limited to a brief presentation of the reasons they will not significantly affect the quality of the human environment; and

(d) identify those issues that have been adequately addressed by prior environmental review, thereby indicating that the discussion of these issues in the EIS will be limited to a summary and reference to their coverage elsewhere; and

(e) identify possible alternatives to be considered.