65 ILCS 5/11-142-3

In addition to all other taxes now or hereafter authorized, the corporate authorities of each municipality may levy and collect, without referendum, a tax for the purpose of paying the expenses of the chlorination of sewage, or other means of disinfection or additional treatment as may be required by water quality standards approved or adopted by the Pollution Control Board or by the court, which tax may be extended at a rate not to exceed .02% of the value of all taxable property within the municipality as equalized or assessed by the Department of Revenue.