70 ILCS 3010/1
When used in this Act:
"Sewerage system" means and includes any or all of the following: a sewage treatment plant or plants, collecting, intercepting and outlet sewers, force mains, conduits, lateral sewers and extensions, pumping stations, ejector stations, and all other appurtenances, extensions, or improvements necessary or useful and convenient for the collection, treatment, and disposal, in a sanitary manner, of sewage and industrial wastes. The term also includes the disconnection of storm water drains and constructing outlets therefor, where, in any case, such work is necessary to relieve existing sanitary sewers of storm water loads, in order to permit the efficient operation of such sanitary sewers for collection, treatment, and disposal of sewage and industrial wastes.
"Sanitary district" means a sanitary district organized and created under any of the laws of the State of Illinois having a population of less than 500,000 and also means any drainage district which comes within the terms of "An Act relating to drainage districts that collect and convey sewage and other wastes through long, continued and common usage of district drainage facilities", enacted by the 73rd General Assembly.
"Board of trustees" means the board of trustees of a sanitary district or the commissioners of a drainage district.
"Municipality" means a city, village, or incorporated town in the State of Illinois having a population of less than 500,000.
"Corporate authorities" means the city council or similar body of cities and the board of trustees or similar body of villages or incorporated towns.
70 ILCS 3010/1