70 ILCS 1815/4

(70 ILCS 1815/4) (from Ch. 19, par. 804) Sec. 4. All property of every kind owned by the Port District shall be exempt from taxation, provided that a tax may be levied upon a lessee of the Port District by reason of the value of a leasehold estate separate and apart from the fee simple title, or upon such improvements as are constructed and owned by others than the Port District. (Source: P.A. 77-1799.)