40 ILCS 5/19-104
It shall be lawful for any such city to levy a tax upon all taxable property in such city of not more than .0009 per cent of the value, as equalized or assessed by the Department of Revenue, of all taxable property in such city, for the purpose of providing revenue for the pension fund herein provided for.
For such purpose, the city council of such city shall levy such a tax annually upon all taxable property in such city at the aforementioned rate. The tax shall be levied and collected in like manner with the general taxes of such city, beginning with the first such levy made subsequent to January 1, 1946, and shall be in addition to all other taxes which such city is now or may hereafter be authorized to levy on the aggregate valuation of all taxable property within such city, and shall be exclusive of and in addition to the amount of tax such city is now or may hereafter be authorized to levy for general purposes under and by virtue of any law or laws which limit the amount of tax which such city may levy for general purposes. The County Clerk of the county in which such city is located, in reducing tax levies under the provisions of any Act concerning the levy and extension of taxes, shall not consider any such tax levied pursuant to this Division as part of the general tax levy for city purposes, and shall not include the same in any limitation of the per cent of the assessed valuation upon which taxes are required to be extended.
The amount of the tax to be levied in each year shall be certified to the city council of such city by the board of trustees of said pension fund.
As soon as any revenue derived from the tax shall be collected, the same shall be paid to the city treasurer of such city and shall be held by such city treasurer for the benefit of the pension fund herein provided for, and all such revenue shall be paid into the pension fund.
If the funds available for the purposes of this Division shall be insufficient during any year to meet the requirements of this Division, such city may issue tax anticipation warrants, as provided by law against the tax levy herein provided for, for the current fiscal year.
40 ILCS 5/19-104