70 ILCS 2405/23
Additional contiguous territory may be added to any sanitary district organized under this Act in the manner following:
Ten per cent or more of the legal voters resident within the limits of such proposed addition to such sanitary district may petition the circuit court for the county in which the original petition for the formation of said sanitary district was filed, to cause the question to be submitted to the legal voters of such proposed additional territory whether such proposed additional territory shall become a part of any contiguous sanitary district organized under this Act and whether such additional territory and the taxpayers thereof shall assume a proportionate share of the bonded indebtedness, if any, of such sanitary district. Such petition shall be addressed to the court and shall contain a definite description of the boundaries of the territory sought to be added. Provided that no territory disqualified in Section 1 of this Act shall be included.
Upon filing such petition in the office of the circuit clerk of the county in which the original petition for the organization of such sanitary district was filed it shall be the duty of the court to consider the boundaries of such proposed additional territory. The decision of the court is appealable as in other civil cases.
Notice shall be given by the court of the time and place when and where all persons interested will be heard substantially as provided in and by Section 1 of this Act. The court shall certify the proposition to the proper election officials, who shall submit the proposition to the voters at an election in accordance with the general election law. The proposition shall be in substantially the following form:
------------------------------------------------------------------------ For joining sanitary district and assuming a proportionate share of bonded indebtedness, if any. ------------------------------------------------------------------------ Against joining sanitary district and assuming a proportionate share of bonded indebtedness, if any. ------------------------------------------------------------------------
If a majority of the votes on the proposition shall be in favor of becoming a part of such sanitary district and if the trustees of such sanitary district accept the proposed additional territory by ordinance annexing the same, the court shall enter an appropriate order of record in the court, and such additional territory shall thenceforth be deemed an integral part of such sanitary district. Any such additional contiguous territory may be annexed to such sanitary district upon petition addressed to such court, signed by a majority of the owners of lands constituting such territory who, in the case of natural persons, shall have arrived at lawful age and who represent a majority in area of such territory, which said petition shall contain a definite description of the boundaries of such territory and shall set forth the willingness of the petitioners that such territory and the taxpayers thereof assume a proportionate share of the bonded indebtedness, if any, of such sanitary district. Upon the filing of such petition and notice of and hearing and decision upon the same by the court, all as hereinbefore provided, the court shall enter an order containing his or their findings and decision as to the boundaries of the territory to be annexed; and thereupon, if the trustees of such sanitary district shall pass an ordinance annexing the territory described in such order to said sanitary district, said court shall enter an appropriate order as hereinabove provided, and such additional territory shall thenceforth be deemed an integral part of such sanitary district.
70 ILCS 2405/23