70 ILCS 200/255-65
Board members shall be elected biennially by the electors of the metropolitan area in each odd numbered year beginning with 1981 on the day fixed by the general election law. The 3 members elected in 1974 shall serve for a term of 4 years and their successors to be elected in 1978 shall serve for a period of 6 years and until their successors are elected and qualified under the consolidated schedule of election in 1985. The 4 members to be elected in 1976 shall serve until their successors are elected and qualified at the regular elections in 1981. Their successors shall serve for a term of 6 years. The successors of the 4 members elected in 1972 to serve for a term of 6 years shall serve for a term of 4 years and until their successors are elected in 1983. Their successors shall serve for a term of 6 years. Such members elected after 1983 shall serve for a term of 6 years. In each election after 1972 a number of members shall be elected equal to the number of members whose terms are then expiring. In elections after 1972 there shall also be elected members to fill any vacancies with unexpired terms of at least 2 years, whether the vacancies are temporarily filled by appointment or not. The election of members to fill each vacancy shall be by separate vote, but the ballot for such vote may be on the same ballot as for the regular election of members.
70 ILCS 200/255-65