70 ILCS 1905/9: Quorum.

Four (4) members of the Board of Commissioners shall constitute a quorum for the transaction of the business thereof. The concurring vote of four (4) members of the Board of Commissioners shall be required for the exercise of any of the powers granted by this Act. The Chairman, if present, shall be entitled to vote on all matters to be passed upon at a meeting of the Board of Commissioners. All records of the Authority shall be open to public inspection at all reasonable hours.