Within thirty days after adoption of the resolutions for creation of a joint public agency by the proposed participating public agencies, the board shall file with the Secretary of State a statement signed by the representatives setting forth (1) the names of all the proposed participating public agencies, (2) a certified copy of each of the resolutions of the participating public agencies determining the need for such a joint public agency, (3) proof of publication as required in subsection (1) of section 13-2509, (4) a brief description of the nature of the joint public agency’s activities, and (5) the name of the joint public agency.