Within 60 days after September 17, 1984 (the effective date of Article 5 of Public Act 83-1456), the Mayor of Skokie shall appoint 3 members of the Board, one member to be appointed for a term of one year, one member to be appointed for a term of 2 years, and one member to be appointed for a term of 3 years; and the Township Supervisor of Niles Township shall appoint 3 members of the Board, one member to be appointed for a term of one year, one member to be appointed for a term of 2 years, and one member to be appointed for a term of 3 years; such terms commencing on the date each is appointed. Within 90 days after September 17, 1984, the 6 members of the Board so appointed shall appoint the remaining 3 members of the Board, one member to be appointed for a term of one year, one member to be appointed for a term of 2 years, and one member to be appointed for a term of 3 years; such terms commencing on the date each is appointed. After September 1, 1990, upon the expiration of the terms of the remaining 3 members of the Board (formerly appointed by the other 6 members), their successors shall thereafter be appointed by the Mayor of Skokie. After September 1, 1990, all appointments made by the Mayor of Skokie shall be made with the advice and consent of the corporate authorities of Skokie, and all appointments made by the Township Supervisor of Niles Township shall be made with the advice and consent of the corporate authorities of Niles Township. At the expiration of the term of any member, his successor shall be appointed in like manner. All successors shall hold office for a term of 3 years from the date of appointment, except in case of an appointment to fill a vacancy.