65 ILCS 5/7-1-18.5: Maintenance of sanitary sewers.

A municipality located in a county with a population of 3,000,000 or more to which territory is annexed after the effective date of this amendatory Act of the 92nd General Assembly is responsible for the operation and maintenance of any existing sanitary sewerage system serving the annexed territory, unless the sanitary sewerage system is under the jurisdiction of another unit of local government other than the Metropolitan Water Reclamation District.