65 ILCS 5/11-139-1
When used in this Division 139, "waterworks" means and includes a waterworks system in its entirety or any integral part thereof, including mains, hydrants, meters, values, standpipes, storage tanks, pump tanks, intakes, wells, impounding reservoirs, pumps, machinery, purification plants, softening apparatus, and all other elements, useful in connection with a water supply or water distribution system.
"Sewerage system" means and includes any or all of the following: a sewerage treatment plant or plants, collecting, intercepting and outlet sewers, lateral sewers, and drains, including combined and separate storm water and sanitary drains, force mains, conduits, pumping stations, ejector stations and all other appurtenances, extensions and improvements necessary, useful, or convenient for the collection, treatment, and disposal in a sanitary manner of sewage and industrial wastes.
"Combined waterworks and sewerage system" means and includes a waterworks and sewerage system, which the municipality determines by ordinance to operate in combination.
65 ILCS 5/11-139-1