Section 4. The affairs of an authority shall be managed by an administrator who shall be appointed by and serve at the pleasure of the advisory board of the authority established pursuant to section five; provided, however, that the administrator shall not be appointed until after the board has provided the notification required by clause (c) of section fourteen; and provided, further, that the administrator shall not hold any elective office, except that of town meeting member, in any city or town within the jurisdiction of such authority. The administrator shall be the chief executive officer of the authority and shall receive such annual salary as shall be determined by said advisory board. Upon his appointment, the administrator shall give the state treasurer a bond for the faithful performance of his official duties in such penal sum and with such sureties as may be approved by the advisory board.