505 ILCS 5/9

If the proposed agricultural area includes real estate within a 1 1/2 mile radius from the corporate limits of any municipality, the county board shall notify the municipal authorities of such affected municipality of this proposed area. Such municipal authorities may object to the proposal if such objection is presented to the county board within 30 days of the receipt of the proposal by the municipal authorities. Upon receipt of such objection by the county board, the proposed area shall be modified to exclude the real estate within the 1 1/2 mile radius of the corporate limits of such municipality. If no objection is received within the specified time period, the affected real estate shall be included in the agricultural area.