70 ILCS 2605/13
The board of trustees has power to defray the expenses of any improvement made by it in the execution of the powers hereby granted to such incorporation, by special assessment or by general taxation, or partly by special assessment and partly by general taxation, as they shall by ordinance prescribe. It shall constitute no objection to any special assessment, that the improvement for which the same is levied is partly outside the limits of such incorporation, but no special assessment shall be made upon property situated outside of such sanitary district, and in no case shall any property be assessed more than it will be benefited by the improvement for which the assessment is levied. The proceedings for making, levying, collecting and enforcing of any special assessment levied hereunder, shall be the same, as nearly as may be, as is prescribed by Article 9, Division 2, or Article 9, Division 3, of the "Illinois Municipal Code", approved May 29, 1961, subject to any restrictions appearing in such divisions. However, once an improvement is begun under the procedures of one of these Divisions it must be completed pursuant to the procedure of that Division. Whenever in the referred to Act the words "city council" or "corporate authorities" are used, the same shall apply to the board of trustees constituted by this Act, and the words applying to the municipality or its officers in that Article shall be held to apply to the corporation hereby created and to its officers.
70 ILCS 2605/13