The members of the board of directors of any authority created or operated in Mobile County pursuant to Sections 11-88-1 to 11-88-21, inclusive, which operates a public water system, a public sewer system, or a fire protection facility that serves 6,500 or more customers, in addition to any other compensation and if authorized by resolution of the board of directors of the authority, shall be compensated for performance of their duties as follows:
Ala. Code § 45-49-251 (1975)