Under no circumstances shall any bonds, notes, or certificates issued by the district or any other obligation of the district be or become an indebtedness or obligation of the State of Illinois or of any other political subdivision of or municipality within the State, nor shall any bond, note, certificate, or obligation be or become an indebtedness of the district within the purview of any constitutional limitation or provision. It shall be plainly stated on the face of each bond, note, and certificate that it does not constitute an indebtedness or obligation but is payable solely from the revenues or income of the district.
70 ILCS 1832/75