(a) All initial appointments of commissioners shall be made within 30 days after the establishment of the Authority. The Authority is considered established when the proposition is approved by the voters under Section 20. Each appointment shall be in writing and a certificate of appointment signed by the appointing officer shall be filed and made a matter of record in the office of the county recorder. A commissioner shall be appointed for a term of 2 years and shall qualify within 10 days after appointment by acceptance and the taking of an oath or affirmation to faithfully perform the duties of office. Members initially appointed to the board of commissioners shall serve from the date of their appointment until June 30 of the first or second year after the date of their appointment and shall draw lots to determine the terms for which each shall be appointed. Lots shall be drawn so that 4 commissioners from the metropolitan area shall serve in each of 2 classes. Thereafter, commissioners shall be appointed for terms of 2 years beginning on July 1 of the year of appointment. However, a commissioner who is also an elected officer shall have a term of office that runs concurrent and consistent with the elective office.
     (b) Within 45 days after any vacancy occurs on the board by death, resignation, change of residence to outside the metropolitan area, or any other cause, a successor shall be appointed, in the same manner as the commissioner whose office became vacant, for the unexpired remainder of the term. Commissioners and officers of the board shall serve until a successor is appointed and qualifies. A vacancy exists when a commissioner who is also an elected officer leaves elective office. A former city or county elected officer is ineligible to serve as a commissioner for 2 years after leaving elective office.