65 ILCS 5/9-3-9
On the date set for consideration and passage of the ordinance, the corporate authorities shall convene, consider the ordinance, examine the certificates submitted with the ordinance in relation to the area benefited and consider all protests that have been filed against the construction of the improvement. The corporate authorities before adoption of the ordinance shall consider the forfeitures and the valuations shown in the certificates of the respective lots, tracts and parcels of real estate within the boundaries of the area probably benefited. If lots, tracts and parcels of real estate representing 25% or more of such value as shown in the certificate in sub-section (3) of Section 9-3-5 of the lots, tracts and parcels of real estate within the boundaries of the area probably benefited have been forfeited to the State for the non-payment of taxes, either general taxes or special assessments, or both, then the corporate authorities shall not adopt the ordinance and shall proceed no further with the improvement and the same improvement shall not again be initiated for a period of one year. Further, if 50% or more in number of the lots, tracts and parcels of real estate within the above described boundaries represent vacant property and the owners of 50% or more in number of the lots, tracts and parcels, of real estate file written objections, the corporate authorities shall proceed no further with the improvement and the same improvement shall not again be initiated for a period of one year, or if the estimated cost of the improvement exceeds the assessed full, fair cash value of the real estate located within the boundaries of the district probably benefited, as shown by the county assessor's certificate, then the corporate authorities shall proceed no further with the improvement and the same improvement shall not be again initiated for a period of one year. If, however, there is less than 25% of the real estate within the area forfeited for non-payment of general taxes or special assessments, or both, and there are less than 50% in number of the lots, tracts and parcels of real estate within the area vacant, or if 50% or more in number of the lots, tracts and parcels of real estate within said area are vacant but the owners of less than 50% of the lots, tracts and parcels of real estate file objections, and the total estimated cost of the improvement does not exceed the assessed full, fair cash value of the real estate located within the area designated as probably benefited, then the corporate authorities shall be authorized to proceed with the improvement and adopt the ordinance authorizing and directing the construction thereof.
The corporate authorities shall adjourn from time to time for consideration of the passage of the ordinance, but not for longer than a period of 90 days from the date set for hearing thereon. If within 90 days after the date set for the hearing and consideration of the ordinance such ordinance is not passed, then such ordinance shall not be passed unless the improvement is again initiated and a new date set for hearing and consideration of the ordinance and notice of the date published and posted as provided in this Division 3.
65 ILCS 5/9-3-9