Missouri constitution
Article VI: local government
Section 27

(1) Revenue producing water, sewer, gas or electric light works, heating or power plants;
(2) Plants to be leased or otherwise disposed of pursuant to law to private persons or corporations for manufacturing and industrial development purposes, including the real estate, buildings, fixtures and machinery; or
(3) Airports. The project shall be owned by the municipality or by the cooperating municipalities or political subdivisions or the joint board or commission, either exclusively or jointly or by participation with cooperatives or municipally owned or public utilities, the cost of operation and maintenance and the principal and interest of the bonds to be payable solely from the revenues derived by the municipality or by the cooperating municipalities or political subdivisions or the joint board or commission from the operation of the utility or the lease or operation of the project. The bonds shall not constitute an indebtedness of the state, or of any political subdivision thereof, and neither the full faith and credit nor the taxing power of the state or of any political subdivision thereof is pledged to the payment of or the interest on such bonds. Nothing in this section shall affect the ability of the public service commission to regulate investor-owned utilities.