70 ILCS 2805/32a.4a
The corporate authorities of any sanitary district may enter into an agreement with one or more of the owners of record of land in any territory which may be annexed to such sanitary district as provided in this Act. Such agreement may provide for the annexation of such territory to the sanitary district, subject to the provisions of this Act, and any other matter not inconsistent with the provisions of this Act, nor forbidden by law. Such agreement shall be valid and binding for a period not to exceed 20 years from the date of execution thereof.
Any action taken by the corporate authorities during the period such agreement is in effect, which, if it applied to the land which is the subject of the agreement, would be a breach of such agreement, shall not apply to such land without an amendment of such agreement.
Any such agreement executed after the effective date of this amendatory Act of 1983 and all amendments of annexation agreements, shall be entered into in the following manner. The corporate authorities shall fix a time for and hold a public hearing upon the proposed annexation agreement or amendment, and shall give notice of the proposed agreement or amendment not more than 30 nor less than 15 days before the date fixed for the hearing. This notice shall be published at least once in one or more newspapers published within the sanitary district or, if there is no newspaper published in the district, in a newspaper published in the county and having general circulation in the district. After such hearing the agreement or amendment may be modified before execution thereof. The annexation agreement or amendment shall be executed by the president of the board of trustees only after such hearing and upon the adoption of a resolution directing such execution, which resolution must be passed by a vote of two-thirds of the corporate authorities then holding office.
Any annexation agreement executed pursuant to this Section shall be binding upon the successor owners of record of the land which is the subject of the agreement and upon successor corporate authorities of the sanitary district and successor sanitary districts. Any party to such agreement may by civil action, mandamus or other proceeding, enforce and compel performance of the agreement.
Any annexation agreement executed prior to the effective date of this amendatory Act of the 91st General Assembly which was executed pursuant to a two-thirds vote of the corporate authorities and which contains provisions not inconsistent with this Section is hereby declared valid and enforceable as to such provisions for the effective period of such agreement, or for 20 years from the date of execution thereof, whichever is shorter.
The effective term of any Annexation Agreement executed prior to the effective date of this amendatory Act of the 91st General Assembly may be extended at any time prior to the original expiration date to a date which is not later than 20 years from the date of execution of the original Annexation Agreement.
70 ILCS 2805/32a.4a