Ala. Code § 45-35A-54.10: Board of Commissioners - Conduct of Meetings.

The president of the board, when present, shall preside at all meetings of the board, but shall have no veto power. Three members of the board shall constitute a quorum for the transaction of all business to be done by the board, and for the exercise of any power conferred upon it; and the affirmative vote of three members of the board shall be necessary and sufficient for the passage of any resolution, bylaw, or ordinance, or for the transaction of any business of any sort by the board, or for the exercise of any of the powers conferred upon it by the terms of this part, or that may hereafter be conferred upon it.