(1) The authority and any municipality or Indian tribe may contract for the furnishing of water, sewage disposal, or waste management services or a combination of such services by the authority to the municipality or Indian tribe. The charges or rates specified in a contract under this subsection are subject to change by the authority, if necessary to meet its obligations. The charges or rates to a municipality that is not a constituent municipality or to an Indian tribe may be greater than those to constituent municipalities.

    (2) The authority and any other public corporation may contract for the furnishing of water, sewage disposal, or solid waste management system services or a combination of such services by the other public corporation to the authority or may contract for the use by the authority of any of the facilities of the water supply system; sewage disposal system, including sewers; or solid waste management system or a combination of systems of the other public corporation. Any lump sum payment for such a use may be considered as a part of the cost of the authority system and may be financed the same as other capital costs are financed under this act.

    (3) Each contract authorized in this section shall be for a period not exceeding 40 years. Each contract with a municipality authorized in this section is a general obligation of the municipality.