The governing body of each of the municipalities participating in the creation of such agency shall by appropriate action by ordinance or resolution determine that there is a need for such agency and set forth the names of the proposed participating municipalities of the agency. Such an action may be taken by a municipality's governing body on its own motion upon determining, in its discretion, that a need exists for an agency. In determining whether such a need exists, a governing body may take into consideration the present and future needs of the municipality with respect to the commodities and services which an agency may provide, the adequacy and suitability of the supplies of such commodities and services to meet such needs, and economic or other advantages or efficiencies which may be realized by cooperative action through an agency. Upon the adoption of an ordinance or passage of a resolution as provided in this section, the mayor, in the case of a city, the chairperson of the board of trustees, in the case of a village, or the chairperson of the governing body, of each of the proposed participating municipalities, with the approval of the respective governing body, shall appoint a director who shall be an elector of the municipality for which he or she acts as director. The directors shall constitute the board in which shall be vested all powers of the agency.