Section 65 ILCS 5/9-3-5 - Plans, specifications and costUpon the adoption of a resolution determining to make the improvement by the corporate authorities, the committee on local improvements shall proceed with the preparation of plans, specifications and estimate of cost of the improvement. Upon completion, the plans, specifications and estimate of cost, shall be filed in the office of the recording officer of such municipality. The plans and specifications shall be in sufficient detail to enable a competent engineer to direct construction thereof, and in sufficient detail to advise any person interested of the general nature, character and type of the improvement. The estimate of cost shall set forth in one item the estimated amount to be paid the contractor. A second item shall include the cost of making and collecting the assessment, engineering inspection, attorneys' fees and other costs, which second item shall in no event exceed 12% of the estimated contract price as set out in the first item above mentioned. The plans, specifications and estimate of cost shall be accompanied by:
(1) A certificate executed by the members of the committee on local improvements setting forth the boundaries of the area probably benefited by such improvement. The establishment of the boundaries of the area probably benefited shall have no relation to the levy of an assessment against property benefited. Such boundaries are to be used merely for the determination of an area in which protests may be filed against the construction of the improvement. Assessments shall be levied against all property benefited regardless of whether or not such property is located within the boundaries of the area;(2) A certificate executed by the County Clerk setting forth the lots, tracts and parcels of real estate that have been forfeited for delinquent taxes either for general taxes or special taxes, or both, within the boundaries of the area as set forth in the certificate required by subdivision (1) of this section;(3) A certificate executed by the assessing officer of the county to show the assessed valuation of each lot, tract and parcel of real estate located within the boundaries of the area set forth in the certificate required under subdivision (1) of this section;(4) A certificate executed by any officer of the municipality setting forth the names and addresses of all persons owning lots, tracts and parcels of real estate within the boundaries of the area probably benefited by such improvement as shown on the tax collector's records for the last year in which taxes were levied.