Sec. 20. BOARD OF TRUSTEES FOR VOLUNTEER FIRE DEPARTMENT. (a) In each municipality to which this Act applies and that has a fire department consisting exclusively of volunteers, the fire fighters' retirement system is governed by a board of trustees consisting of:

(1) the mayor of the municipality or the mayor's designated representative;

(2) the municipal treasurer or, if there is no officer denominated as treasurer, the person who performs the duties of municipal treasurer; and

(3) three members of the retirement system elected by participating members as provided by Subsection (b) of this section.

(b) During each period that begins on December 1 of one year and ends on January 31 of the following year, the participating members of a fire fighters' retirement system in a municipality subject to this section shall elect by secret ballot and certify to the governing body of the municipality a member to the board of trustees to serve a term of approximately three years that expires on the day before the date of the first board meeting that occurs after the election of a successor. To be elected a member of a board of trustees under this subsection, a person must be a member of the retirement system and receive a majority of the votes cast in the election, and at least 50 percent of all participating members of the retirement system must vote in the election.

(c) The municipal treasurer is the secretary-treasurer of a board of trustees established under this section. A board of trustees established under this section annually shall elect a chairman and a vice-chairman to preside in the absence or disability of the chairman.