The Director of Public Service shall be the head of the Department of Public Service. The Mayor, in addition to his other duties, shall be, and shall perform the duties of the Director of Public Service, until such time as Council may determine that it is in the best interest of the Municipality to appoint some other person to that office. Upon making such determination, the Council shall declare the office of Director of Public Service vacant, and the Director of Public Service shall then be appointed by the Mayor.