When the legislative body of a community first adopts a resolution as provided for in § 45-31-10, the mayor or the president of the town council shall appoint five (5) resident electors of the community as members of the agency subject to the approval of the legislative body; provided, however, that if authorized by resolution of the legislative body at any time, the mayor or president of the town council shall appoint two (2) additional resident electors of the community as members of the agency, subject to the approval of the legislative body, for a total of seven (7) members. No member of the agency may be an elected officer or an employee of the community. The powers of the agency shall be vested in the members of the agency then in office. Members shall receive their actual and necessary expenses, including travel expenses, and may receive other compensation as the legislative body may prescribe. The redevelopment agency in the city of Providence shall consist of the mayor, ex officio, and seven (7) members. Five (5) of the members shall be resident electors of the city of Providence and appointed by the mayor; and shall serve for the term designated in § 45-31-13; and shall not be an elected officer or employee of the city of Providence. Two (2) members shall be members of the city council elected by that council from its members to serve for a term ending the first Monday in January, 1975; and shall thereafter be elected for a term of four (4) years. The powers of the agency shall be vested in the members then in office. Members shall receive their actual and necessary expenses, including travel expenses, and may receive other compensation as the legislative body may prescribe. Provided, further that the redevelopment agency in the town of Burrillville shall consist of seven (7) members, five (5) members of which shall be regular voting members whose tenure shall be in accordance with this section and two (2) members of which shall serve as alternate members whose term of appointment shall be two (2) years. Provided, further that the redevelopment agency in the town of Bristol shall consist of eight (8) members who are residents of the community, five (5) members of which shall be regular voting members whose tenure shall be in accordance with this section and three (3) members of which shall serve as alternate members whose term of appointment shall be two (2) years. Alternate members shall be designated as first alternate, second alternate, and third alternate and shall be allowed to participate in all agency affairs except that alternate members shall only be allowed to vote in their respective order as first, second, and third alternate in the event a regular voting member is unable to vote for any reason whatsoever.