70 ILCS 5/13
Every Authority created under this Act is hereby empowered to levy and collect a general tax on all of the taxable property within the corporate limits of such Authority for the purpose of paying the cost of operating and maintaining any public airport or public airport facility of the Authority, and any other corporate expenses of the Authority. However, a tax levy imposed by a Metropolitan Airport Authority does not apply to any township, municipality, or unincorporated territory that has been statutorily removed from the jurisdiction of the Authority, has opted out of the Authority, or is currently being taxed by another airport authority. The aggregate amount of such tax for one year, exclusive of the amount levied for bonded indebtedness or interest thereon, shall not exceed the rate of .075% upon the aggregate valuation of all taxable property within the Authority, as equalized or assessed by the Department of Revenue. If there is in effect in the Authority a maximum tax rate established pursuant to Section 2.1a or 13.1, the aggregate amount of such tax for one year, exclusive of the amount levied for bonded indebtedness or interest thereon, shall not exceed the maximum tax rate so established, and in no event shall such maximum tax rate exceed the rate of .075% as hereinbefore set forth.
The Board of Commissioners of any Airport Authority shall establish the beginning and ending of its fiscal year and annually within the first quarter of the fiscal year shall adopt an appropriation ordinance appropriating such sums of money as are deemed necessary to pay the costs of operating and maintaining any public airport or airports located within the corporate limits of the Authority and under the jurisdiction thereof and other expenses of the Authority and specifying the purpose of each appropriation made.
An appropriation ordinance adopted by an Authority created under this Act in a county with a population between 700,000 and 3,000,000 shall be immediately presented to the county board chairman. The chairman of the county board has the power to veto or reduce any line item in the ordinance as provided in Section 5-1014.5 of the Counties Code.
After the adoption of the appropriation ordinance and on or before the second Tuesday in August of each year, the board of commissioners shall ascertain the total amount of the appropriations legally made which are to be provided for from the tax levy for that year. Then, by an ordinance specifying in detail the purposes for which such appropriations have been made and the amounts appropriated for such purposes, the board of commissioners shall levy not to exceed the total amount so ascertained upon all the property subject to taxation within the authority as the same is assessed and equalized for state and county purposes for the current year.
The limits of the tax rate and the authority to levy as set forth in this Section do not include the rate of or authority to levy taxes required for lease payments to any Public Building Commission. The tax rate necessary and the authority to levy taxes for such lease payments are in addition to such limits and are without limitation as to rate or amount.
70 ILCS 5/13