65 ILCS 5/7-3-1
Within one year of the organization of any municipality under the provisions of Divisions 2 and 3 of Article 2 of this Code, any territory which has been included therein may be disconnected from such municipality if the territory sought to be disconnected is (1) upon the border, but within the boundary of the municipality, (2) contains 20 or more acres, (3) if disconnected will not result in the isolation of any part of the municipality from the remainder of the municipality, and (4) if disconnected will not be a territory wholly bounded by one or more municipalities or wholly bounded by one or more municipalities and a river or lake, (5) if disconnected, the growth prospects and plan and zoning ordinances, if any, of such municipality will not be unreasonably disrupted, (6) 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, (7) if disconnected the municipality will not be unduly harmed through loss of tax revenue in the future. The procedure for disconnection shall be as follows:
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 within one year of the organization of any municipality under the provisions of Divisions 2 and 3 of Article 2 of this Code. The petition shall set forth the description of the territory to be detached from such municipality, shall allege the pertinent facts in support of the disconnection of such territory and shall pray the court to detach the territory from the municipality.
65 ILCS 5/7-3-1