65 ILCS 5/9-2-16
The petition required in Section 9-2-15 shall contain a reasonably accurate description of lots, blocks, tracts, and parcels of land which are to be taken or damaged; provided that in counties in which a property index number system has been established in accordance with Section 9-45 of the Property Tax Code, the index number shall be given in addition to the legal description. There shall be filed with or attached to the petition a copy of the specified condemnation ordinance, certified by the clerk, under the corporate seal. Failure to file such a copy shall not affect the jurisdiction of the court to proceed in that cause and to act upon the petition, but if it appears in the cause that a copy of the ordinance has not been attached to or filed with the petition before the report of the commissioners is filed, as provided in Section 9-2-18, then, upon motion of any person whose real estate is to be taken, or to be assessed, the entire petition and proceedings shall be dismissed.
Upon the filing of the petition, the court shall enter an order designating 2 competent persons as commissioners, to act with the superintendent of special assessments where that officer is provided for by this Code, and in other cases to act with the president of the board of local improvements. These 3 commissioners shall investigate and report to the court the just compensation to be made to the respective owners of private or public property which is to be taken or damaged for the specified improvement, and also what real estate will be benefited by that improvement, and the amount of those benefits to each parcel. Neither of the persons designated by the court shall be an employee of the petitioning municipality and both shall be disinterested persons. They shall be allowed a fee for their services which shall be fixed by the court in advance. The amounts so allowed may be reviewed by the court upon motion, and may be taxed as costs and included in the amount to be assessed, except that in cities having a population of 500,000 or more, the commissioners' fees shall be either paid by the city out of its general fund or included among the expenses to be defrayed out of the sum not to exceed 5% of the amount of the assessment, for which provision is made in Section 9-2-139. These 3 commissioners shall be duly sworn to make a true and just assessment of the cost of the improvement according to law. The concurrence of any 2 in a report shall be sufficient.
65 ILCS 5/9-2-16