The members of a hospital authority shall be residents of the participating units comprising the authority. The requirement of residence shall not apply to authorities activated under subsection (d) of Code Section 31-7-72, provided they are selected from within the area of service and within 12 miles of the hospital location or within 12 miles of the sponsoring county or municipality, whichever is farther. The members shall elect one of their number as chair and another as vice chair and shall also elect a secretary-treasurer, who need not be a member. The members shall receive no compensation for their services, either as members or as employees of the authority but may be reimbursed for their actual expenses incurred in the performance of their duties or, in the alternative, the members may elect to be reimbursed for such expenses on a per diem basis in an amount not to exceed $100.00 per meeting and the total amount not to exceed $100.00 per month. The authority shall make rules and regulations for its governance and may delegate to one or more of its members, officers, agents, or employees such powers and duties as may be deemed necessary and proper.