Mo. Rev. Stat. § 250.090
Revenue bonds issued under authority of this chapter shall be payable solely from the revenues derived and to be derived from the operation of the sewerage system or combined waterworks and sewerage system acquired, constructed, improved or extended in whole or in part from the proceeds of such bonds. No revenue bonds issued pursuant to this chapter shall constitute an indebtedness of the city, town or village or sewer district within the meaning of any constitutional, statutory or charter restriction, limitation or provision. The face of each bond shall state in substance that the bond has been issued under the provisions of this chapter, that the taxing power of the city, town or village or sewer district issuing the bond is not pledged to the payment thereof either as to principal or interest and that the bond and the interest thereon are payable solely from the revenues of the sewerage system or combined waterworks and sewerage system for the benefit of which the bond was issued.
§ 250.090, RSMo