Members of the board shall hold office until their respective successors have been elected and qualified. In case of resignation, death, conviction of a felony or ceasing to reside in the metropolitan area or other reason established by law, the member's office shall become vacant. Each vacancy may be filled until the next regular election of members by appointment by a majority vote of the remaining members of the Board of a person resident in the metropolitan area.
70 ILCS 200/255-85