70 ILCS 1837/115
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. Four 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 4 members shall be necessary for the adoption of any ordinance or resolution. Before taking effect, all ordinances and resolutions shall be approved by the chairperson of the Board by signing the ordinance or resolution. If the chairperson does not approve of the ordinance or resolution, then the chairperson shall return it to the Board with written objections at the next regular meeting of the Board after the passage of the ordinance or resolution. If the chairperson fails to return any ordinance or resolution with his or her objections by the time set forth in this Section, then the chairperson shall be deemed to have approved the ordinance or resolution and it shall take effect accordingly. Upon the return of any ordinance or resolution by the chairperson with his or her objections, the vote by which the same was passed shall be reconsidered by the Board, and if upon reconsideration the ordinance or resolution 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 as are kept or prepared by the Board for use in negotiations, legal actions, or proceedings to which the District is a party.
70 ILCS 1837/115