60 ILCS 1/205-50
If a city, village, or incorporated town is located within the boundaries of a township availing itself of the provisions of this Article that does not own or operate a waterworks system or a sewerage system within the city, village, or incorporated town or within any particular locality of the city, village, or incorporated town, and if the city, village, or incorporated town adopts an ordinance requesting the township to supply water or sewerage service, or both, for public and domestic use within the city, village, or incorporated town or within the particular locality of the city, village, or incorporated town, then the township may construct, acquire, extend, improve, operate, and maintain its waterworks system or sewerage system, or both, within the corporate limits of the city, village, or incorporated town for the purpose of serving the inhabitants of the city, village, or incorporated town or of the particular locality.
60 ILCS 1/205-50