65 ILCS 5/11-140-2

The corporate authorities of such municipality may maintain and keep in repair the outlet sewers, purification plants, reservoirs, pumping works, and machinery provided for in Section 11-140-1. The cost of the maintenance and repair shall be borne by special assessment or by special taxation upon the property specified in Section 11-140-1. No lot, block, or parcel of land shall be assessed more than once in any one year for such maintenance and repair.