65 ILCS 5/7-3-6
The owner or owners of record of any area of land consisting of one or more tracts, lying within the corporate limits of any municipality may have such territory disconnected which (1) contains 20 or more acres; (2) is located on the border of the municipality; (3) if disconnected, will not result in the isolation of any part of the municipality from the remainder of the municipality; (4) if disconnected, the growth prospects and plan and zoning ordinances, if any, of such municipality will not be unreasonably disrupted; (5) if disconnected, no substantial disruption will result to existing municipal service facilities, such as, but not limited to, sewer systems, street lighting, water mains, garbage collection, and fire protection; (6) if disconnected, the municipality will not be unduly harmed through loss of tax revenue in the future; and (7) does not contain any territory designated as part of a redevelopment project area as that term is defined in subsection (p) of Section 11-74.4-3 of this Code or any territory otherwise subject to tax increment financing by the municipality. Item (7) applies to petitions and actions pending on the effective date of this amendatory Act of the 100th General Assembly as well as petitions and actions commenced on or after that date. The procedure for disconnection shall be as follows: The owner or owners of record of any such area of land shall file a petition in the circuit court of the county where the land is situated, alleging facts in support of the disconnection. The municipality from which disconnection is sought shall be made a defendant, and it, or any taxpayer residing in that municipality, may appear and defend against the petition. If the court finds that the allegations of the petition are true and that the area of land is entitled to disconnection it shall order the specified land disconnected from the designated municipality. If the circuit court finds that the allegations contained in the petition are not true, the court shall enter an order dismissing the petition.
An area of land, or any part thereof, disconnected under the provisions of this Section from a municipality which was incorporated at least 2 years prior to the date of the filing of such petition for disconnection shall not be subdivided into lots and blocks within one year from the date of such disconnecting. A plat of any such proposed subdivision shall not be accepted for recording or registration within such one year period, unless the land comprising such proposed subdivision shall have been thereafter incorporated into a municipality.
65 ILCS 5/7-3-6