70 ILCS 200/155-40
If a majority of the voters of said metropolitan area approve the issuance of bonds as provided in Section 155-35, the Authority shall have power to issue general obligation bonds, pledge its full faith and credit to the payment thereof and levy taxes sufficient to pay for the annual principal and interest charges on such bonds. Such bonds may bear such date or dates, may mature at such time or times not exceeding 40 years from their respective date, may bear interest at such rate or rates, may be in such form, may carry such conversion, registration and exchange privileges, may be subject to defeasance upon such terms, may be executed in such manner, may be payable at such place or places, may be made subject to redemption in such manner and upon such terms, with or without premium as is stated on the face thereof, may be sold by negotiated sale or pursuant to advertisement and sealed bid, and may contain such terms and covenants, all as may be provided by the Authority.
Such taxes proposed by the Authority to be levied upon the taxable property within the metropolitan area shall be levied by ordinance and be unlimited as to rate and amount. A certified copy of such levy ordinance shall be filed with the county clerk, and thereupon the county clerk shall extend such tax in each year as provided in such ordinance and in accordance with law.
70 ILCS 200/155-40