35 ILCS 200/2-10
Before August 1, 2002 and every 10 years thereafter, the supervisor of assessments shall prepare maps, by county, of the townships, indicating the number of inhabitants and the equalized assessed valuation of each township for the preceding year, within the counties under township organization, and shall distribute a copy of that map to the county board and to each township supervisor, board of trustees, sitting township or multi-township assessor, and to the Department. The map shall contain suggested multi-township assessment districts for purposes of assessment. Upon receipt of the maps, the boards of trustees shall determine separately, by majority vote, if the suggested multi-township districts are acceptable.
The township boards of trustees may meet as a body to discuss the suggested districts of which they would be a part. Upon request of the township supervisor of any township, the township supervisor of the township containing the most population shall call the meeting, designating the time and place, and shall act as temporary chairperson of the meeting until a permanent chairperson is chosen from among the township officials included in the call to the meeting. The township assessors and supervisor of assessments may participate in the meeting. Notice of the meeting shall be given in the same manner as notice is required for township meetings in the Township Code. The meeting shall be open to the public and may be recessed from time to time.
If a multi-township assessment district is not acceptable to any board of trustees, they shall so determine and further determine an alternative multi-township assessment district. The suggested or alternative multi-township assessment district shall contain at least 2 townships and 1,000 or more inhabitants, shall contain no less than the total area of any one township, shall be contiguous to at least one other township in the multi-township assessment district, and shall be located within one county. For purposes of this Section only, townships are contiguous if they share a common boundary line or meet at any point. This amendatory Act of 1996 is not a new enactment, but is declarative of existing law.
Before September 15, 2002 and every 10 years thereafter, the respective boards of town trustees shall notify the supervisor of assessments and the Department whether they have accepted the suggested multi-township assessment district or whether they have adopted an alternative district, and, in the latter case, they shall include in the notification a description or map, by township, of the alternative district. Before October 1, 2002 and every 10 years thereafter, the supervisor of assessments shall determine whether any suggested or alternative multi-township assessment district meets the conditions of this Section and Section 2-5. If any township board of trustees fails to so notify the supervisor of assessments and the Department as provided in this Section, the township shall be part of the original suggested multi-township assessment district. In any dispute between 2 or more townships as to inclusion or exclusion of a township in any one multi-township assessment district, the county board shall hold a public hearing in the county seat and, as soon as practicable thereafter, make a final determination as to the composition of the district. It shall notify the Department of the final determination before November 15, 2002 and every 10 years thereafter. The Department shall promulgate the multi-township assessment districts, file the same with the Secretary of State as provided in the Illinois Administrative Procedure Act and so notify the township supervisors, boards of trustees and county clerks of the townships and counties subject to this Section and Section 2-5. If the Department's promulgation removes a township from a prior multi-township assessment district, that township shall, within 30 days after the effective date of the removal, receive a distribution of a portion of the assets of the prior multi-township assessment district according to the ratio of the total equalized assessed valuation of all the taxable property in the township to the total equalized assessed valuation of all the taxable property in the prior multi-township assessment district. If a township is removed from one multi-township assessment district and made a part of another multi-township assessment district, the district from which the township is removed shall, within 30 days after the effective date of the removal, cause the township's distribution under this paragraph to be paid directly to the district of which the township is made a part. A township receiving such a distribution (or a multi-township assessment district receiving such a distribution on behalf of a township that is made a part of that district) shall use the proceeds from the distribution only in connection with assessing real estate in the township for tax purposes.
35 ILCS 200/2-10