65 ILCS 5/9-2-139
The costs and expenses of maintaining the board of local improvements, for paying salaries of the members of the board, and the expense of making and levying special assessments or special taxes and of letting and executing contracts, and also the entire cost and expense attending the making and return of the assessment rolls and the necessary estimates, examinations, advertisements, and like matters, connected with the proceedings provided for in this Division 2, including the court costs and the fees to commissioners in condemnation proceedings, which are to be taxed as provided in this Division 2, shall be paid by the municipality out of its general corporate fund.
However, in municipalities having a population of less than 500,000, the municipality, in the ordinance providing for the prescribed assessment, may provide that a certain sum, not to exceed 6% of the amount of this assessment, shall be applied toward the payment of the specified and other costs of making and collecting this assessment. In municipalities having a population of less than 500,000, the estimate of cost of the improvement may also provide an item setting forth a reserve for deficiency in interest not to exceed 6% of the amount of the assessment.
The limitation in the preceding paragraph shall not apply to the costs of engineering and inspection connected with any local improvement, but these costs in municipalities having a population of less than 500,000 may be included in the cost of the improvement to be defrayed by special assessment or special tax.
In municipalities having a population of 500,000 or more, the municipality, in the ordinance providing for the prescribed assessment, may provide that a certain sum not to exceed 5% of the amount of this assessment, as finally determined after the completion of the improvement in accordance with Sections 9-2-114 through 9-2-116, shall be applied (but only by way of reimbursement of the general corporate fund as hereinafter in this Section provided) toward the payment of the cost of making, levying, and collecting the special assessment or special tax, and of letting and executing contracts, advertising, clerical hire, engineering and inspection, court costs and fees of commissioners in condemnation proceedings incurred in the proceeding and deficiency in interest in the matter of the special assessment or special tax. If the part of the assessment levied on account of the expenses specified in this paragraph, exceeds 5% of the entire assessment as finally determined in accordance with Sections 9-2-114 through 9-2-116, but does not exceed 5% of the assessment as originally levied and filed in court, that excess shall not constitute any objection to a judgment of confirmation of the assessment. But no larger sum on account of the expenses specified in this paragraph than 5% of the assessment as finally determined in accordance with Sections 9-2-114 through 9-2-116, shall be treated as a part of the cost of the improvement to be certified by the board of local improvements in accordance with Sections 9-2-114 through 9-2-116, and if the part of the assessment originally levied on account of the expenses specified in this paragraph exceeds 5% of the entire assessment as finally determined in accordance with that Section, any such excess shall be treated as a part of the excess to be abated in accordance with the provisions of Sections 9-2-114 through 9-2-116.
Such a deficiency in interest, if any, shall be first paid out of the fund so created by this 5% so added as in this Section authorized. The application of this fund toward the payment of the expenses specified in the preceding paragraph shall be only by paying over and transferring the balance of the fund after the payment of such a deficiency in interest, to the general corporate fund of the municipality for reimbursement for expenses of the improvement for which the assessment is levied, theretofore paid out of that general corporate fund.
65 ILCS 5/9-2-139