Mich. Comp. Laws § 324.4311: Waterworks systems, sewers, or disposal plants; agreements between local units of government and municipalities as to bonds.

Sec. 4311.

If considered expedient for the safety and health of the people, local units of government may enter into agreement with each other to raise money and issue bonds to erect and maintain waterworks systems, intercepting sewers, sewage treatment plants, or garbage or refuse transfer, processing, or disposal systems.