It is the purpose of this chapter to permit public agencies of the State or any adjoining state, including but not limited to municipalities, counties and school administrative units, and federal agencies and Indian tribes and their political subdivisions to make the most efficient use of their powers by enabling them to cooperate on a basis of mutual advantage and thereby to provide services and facilities within the State in a manner and pursuant to forms of governmental organization that will accord best with geographic, economic, population and other factors influencing the needs and development of communities. [PL 2009, c. 636, Pt. D, §1 (AMD).]