Within 60 days after January 1, 1989 (the effective date of Article I of Public Act 85-1314), the Mayor of the City of Benton, with the advice and consent of the Benton City Council, shall appoint 3 members of the Board for initial terms expiring June 1, 1990; 3 members for initial terms expiring June 1, 1991; and 3 members for initial terms expiring June 1, 1992. The successors of the initial members shall be appointed in like manner for 3 year terms from the date of appointment, except in case of an appointment to fill a vacancy.
70 ILCS 200/15-20