70 ILCS 2605/28
Any territory within the sanitary district may be disconnected therefrom if the territory sought to be disconnected, (1) is upon the border, but within the boundary of the sanitary district, (2) contains 20 or more acres, (3) if disconnected will not result in the isolation of any part of the sanitary district from the remainder of the sanitary district, and (4) if the sanitary district has not extended sewerage or drainage facilities to such territory or has not provided sewage treatment plant facilities for the area in the following manner:
A written petition directed to the circuit court of the county in which the territory proposed to be disconnected is located and if such territory is located in more than one county then to the circuit court of the county in which the greater part of such territory may be located, which petition shall be signed by a majority of the electors, if any, residing within the territory and also signed by a majority of the owners of record of land in such territory, and also representing a majority of the area of land in such territory, shall be filed with the clerk of the court. The petition shall set forth the description of the territory to be detached from the sanitary district, shall allege the pertinent facts in support of the disconnection of such territory and shall pray that the court detach the territory from the sanitary district.
Upon the filing of the petition, the court shall set the same for public hearing which date of public hearing shall be within 30 days of the date of the filing of the petition, and the court shall give at least 10 days notice of such hearing by publishing notice thereof once in a newspaper having a general circulation within the sanitary district the date of such publication to be not less than 10 days prior to the date set for the public hearing. The notice shall refer to the petition filed with the court, shall describe the territory proposed to be disconnected, shall indicate the prayer of the petition and the date, time and place at which the public hearing will be held and shall further indicate that the sanitary district and any person residing in or owning property in the territory or in the sanitary district from which such territory is sought to be disconnected shall have an opportunity to be heard on the prayer of the petition. Notice of the filing of the petition, the substance of which shall be as hereinabove prescribed for the published notice shall also be mailed to the president of the board of trustees of the sanitary district.
The public hearing may be continued from time to time by the court. After such public hearing and having heard all persons desiring to be heard who reside in or own property in the territory involved or in the sanitary district from which such territory is sought to be disconnected, including the sanitary district, if the court finds that the allegations of the petition are true, the court shall grant the prayer of the petition and shall enter an order disconnecting the territory from the sanitary district, which order shall be filed of record and the clerk of the court shall cause to be delivered a certified copy of such order to the clerk of the sanitary district from which such territory has been detached and to the county clerk. If the court finds that the allegations contained in the petition are not true then the court shall enter an order dismissing the same.
However, the disconnection of any territory from the sanitary district shall not exempt such territory from taxation for the purpose of paying any indebtedness incurred by the corporate authorities of the sanitary district prior to the time of filing of the petition for disconnection and during the time that such territory was a part of the sanitary district which is payable from general property taxes income. Such territory shall be assessed and taxed to pay such indebtedness until such indebtedness is completely paid, the same as though the territory had not been disconnected.
70 ILCS 2605/28