Each authority shall be governed by a board of directors. All powers of the authority shall be exercised by the board or pursuant to its authorization. The board shall consist of seven directors who shall be elected by the governing body of the city for staggered terms as hereinafter provided. The governing body of the city shall specify for which term each director is elected. The initial terms of office of two directors shall be two years each. The initial terms of office of two directors shall be four years each. The initial terms of office of three directors shall be six years. Thereafter, the term of office of each such director shall be six years. If at the expiration of any term of office of any director, a successor thereto shall not have been elected, then the director whose term of office shall have expired shall continue to hold office until his or her successor shall be so elected. If at any time there should be a vacancy on the board, a successor director to serve for the unexpired term applicable to such vacancy shall be elected by the governing body of the city. No officer or employee of the state or of any county or municipality shall, during his or her tenure as such officer, be eligible to serve as a director. Each director shall be a duly qualified elector of the city. Directors shall be eligible for re-election. Each director shall be reimbursed for expenses actually incurred by him or her in and about the performance of his or her duties. Any director of the authority may be impeached and removed from office in the same manner and on the same grounds provided in Section 175 of the Constitution of Alabama and the general laws of the state for impeachment and removal of the officers mentioned in Section 175.