70 ILCS 2605/4.1a
The person appointed as treasurer for the district pursuant to Section 4 of this Act must devote his full time to performance of the duties of that office and may hold no other position in public or private employment. The treasurer may have no financial interest, direct or indirect, in any financial institution designated as a depository for district funds.
The treasurer shall invest and reinvest money in the treasury of the district which is not needed for expenditures to be made within 30 days of the investment, in obligations authorized under Section 2 of "An Act relating to certain investments of public funds by public agencies", approved July 23, 1943, as now or hereafter amended. Any such securities may be purchased at the offering or market price thereof at the time of such purchase.
70 ILCS 2605/4.1a