(b) The department will tentatively indicate which alternatives require the preparation of an environmental impact report (EIR) by the applicant or an environmental impact statement (EIS) by the department. If an EIS is required, formal adoption of a proposed plan by district resolution cannot take place until a preliminary environmental impact report (PER) has been completed, circulated, and the period for comment ended. Note: The authority for submission of an EIR is contained in s. 23.11(5), Stats. The PER requirement is contained in ch. NR 150, Wis. Adm. Code, and in guidelines issued February 1976, pursuant to executive order no. 26, for the purpose of implementing s. 1.11, Stats. (Wisconsin Environmental Policy Act).