70 ILCS 2805/16
The board of trustees may levy and collect other taxes for corporate purposes upon property within the territorial limits of the sanitary district the aggregate amount of which for each year may not exceed .25% of value, as equalized or assessed by the Department of Revenue, except that if a higher rate has been established by referendum before August 4, 1965, it shall continue. If the board desires to levy such taxes at a rate in excess of .25% but not in excess of .5% of the value of all taxable property within the district as equalized or assessed by the Department of Revenue they shall order the question to be submitted at a referendum to be held within the district. The board shall certify the question to the proper election officials who shall submit the question at an election in accordance with the general election law. The right to levy an additional tax, authorized by the legal voters, may at any time after one or more tax levies thereunder, be terminated by a majority vote of the electors of the sanitary district at a referendum held in accordance with the general election law. The trustees of any such district shall cause the submission of the proposition to terminate the additional taxing power when petitioned so to do by not less than 10% of the legal voters of the district.
In addition to the other taxes authorized by this Section, the board of trustees may levy and collect, without referendum, a tax for the purpose of paying the costs of operation 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 is not subject to the rate limitations imposed by this Section but may be extended at a rate not to exceed .03% of the value of all taxable property within the district as equalized or assessed by the Department of Revenue.
Such tax may be extended at a rate in excess of .03% but not to exceed .05%, providing the question of levying such increase has first been submitted to the voters of such district at a referendum held in accordance with the general election law and has been approved by a majority of such voters voting on the question.
70 ILCS 2805/16