Ala. Code § 11-102-1
Except as otherwise provided in this chapter or as otherwise prohibited by law, any county or incorporated municipality of the State of Alabama may enter into a written contract with any one or more counties or incorporated municipalities for the joint exercise of any power or service that state or local law authorizes each of the contracting entities to exercise individually. For purposes of this chapter, it is sufficient if each of the contracting entities has the authority to exercise or perform the power or service which is the subject of the contract regardless of the manner in which the power or service shall be exercised or performed, provided that at least one of the contracting parties has the authority to exercise the power or service in the manner agreed upon by the parties. The joint contract may provide for the power or service to be exercised by one or more entities on behalf of the others or jointly by the entities.
Ala. Code § 11-102-1 (1975)