70 ILCS 1801/115
Regular meetings of the Board shall be held at least once in each calendar month, the time and place of the meetings to be fixed by the Board. Five members of the Board shall constitute a quorum for the transaction of business. All action of the Board shall be by ordinance or resolution and the affirmative vote of at least 5 members shall be necessary for the adoption of any ordinance or resolution. All such ordinances and resolutions before taking effect shall be approved by the chairperson of the Board, and if he or she approves, the chairperson shall sign the same, and if the chairperson does not approve, the chairperson shall return to the Board with his or her objections in writing at the next regular meeting of the Board occurring after the passage. But in the case the chairperson fails to return any ordinance or resolution with his or her objections within the prescribed time, the chairperson shall be deemed to have approved the ordinance, and it shall take effect accordingly. Upon the return of any ordinance or resolution by the chairperson with his or her objections, the vote shall be reconsidered by the Board, and if, upon reconsideration of the ordinance or resolution, it is passed by the affirmative vote of at least 5 members, it shall go into effect notwithstanding the veto of the chairperson. All ordinances, resolutions, and proceedings of the District and all documents and records in its possession shall be public records, and open to public inspection, except for documents and records that are kept or prepared by the Board for use in negotiations, legal actions, or proceedings to which the District is a party.
70 ILCS 1801/115