All property of every kind belonging to the Mid-America Intermodal Authority Port District shall be exempt from taxation, provided that a tax may be levied upon a lessee of the district by reason of the value of a leasehold estate separate and apart from the fee or upon any improvements that are constructed and owned by others than the district.
     All property of the Mid-America Intermodal Authority Port District shall be construed as constituting public grounds owned by a municipal corporation and used exclusively for public purposes within the tax exemption provisions of Sections 15-10, 15-15, 15-20, 15-30, 15-75, 15-140, 15-155, and 15-160 of the Property Tax Code.