Payments by a public agency to the municipality for waste collection, transportation, treatment and sewage disposal services and facilities may be made from the income of the public agency’s waterworks system or water supply system or its sewerage system, treatment facilities or sewage disposal system or of both such systems or of its combined waterworks, water supply, treatment facilities, sewerage and sewage disposal systems, as may be prescribed in the contract between the municipality and the public agency, or as otherwise authorized by law. Such payments shall constitute an operating expense of the system or systems whose revenues are thus to be applied. Payments to be made under the contract by the public agency from the income of its waterworks system, water supply system, treatment facility, sewerage system or sewage disposal system or both such systems or its combined waterworks, water supply, treatment facility, sewerage and sewage disposal systems shall be subordinate to amounts required to be paid from the net revenues of such systems for principal of and interest on bonds of the public agency which are outstanding at the time of the making of the contract and which are payable solely from such net revenues unless the ordinance or resolution authorizing such outstanding bonds of the public agency expressly reserves the right to accord such contract payments a priority over such public agency’s bond requirements. No provision of Sections 21-27-161 through 21-27-191 shall be construed to prohibit any public agency, otherwise permitted by law to issue bonds, from issuing bonds in the manner provided by law for the construction, renovation, repair or development of waste disposal facilities within the jurisdictional limits of the public agency. Except to the extent provided in Section 21-27-175, neither the municipality nor the holder of any bonds of the municipality shall have the right to demand payment of the public agency’s obligation out of any funds raised or to be raised by taxation, but such contracts shall constitute an obligation of the public agency and shall be binding upon such public agency according to its terms and shall continue in effect until all bonds specified therein and refunding bonds issued in lieu of such bonds and all other obligations thereunder shall have been paid. Payments made or to be made to a municipality by a public agency or other person pursuant to a contract for waste collection, transportation, treatment and sewage disposal services and facilities shall be determined by the method specified in the contract and shall not be subject to approval or review by the public service commission.