70 ILCS 2905/2-11
Notwithstanding any other provision of law, the board of commissioners of a sanitary district may, by ordinance, annex property within any unit of local government, including a home rule unit, if the property is contiguous to the corporate limits of the sanitary district and served by the sanitary district. The ordinance must describe the property to be annexed. A copy of the ordinance with an accurate map of the annexed property, certified as correct by either the clerk or the executive director of the district, shall be filed with the county clerk of the county in which the annexed property is located or the county clerk of the county in which the predecessor district was organized. For the purposes of this Act, property is served by a sanitary district if (i) the property is served by any work or improvements of the sanitary district either then existing or then authorized by the sanitary district; or (ii) the property is within the boundaries of any work or improvements of such sanitary district including but not limited to levees, flood walls, and embankments that protect or reduce the risk to the property from overflow from any river, tributary stream, or water-course. Upon annexation into the corporate limits of the sanitary district under this Section, the property shall be subject to all powers and rights of the district and its board of commissioners for all purposes, including but not limited to taxation, and subject to all ordinances of the district as though the property had been within the corporate limits when the district was organized under this Act.
70 ILCS 2905/2-11