70 ILCS 2405/16.12
Any district issuing revenue bonds under this Act of a waterworks shall install and maintain a proper system of accounts, showing the amount of revenue received and its application. At least once a year the district shall have the accounts properly audited by a competent auditor. The report of that audit shall be open for inspection at all proper times to any taxpayer, user, or any holder of bonds issued under this Act, or to anyone acting for and on behalf of the taxpayer, user, or bondholder. The treasurer of the district shall be custodian and ex-officio collector of the funds derived from income received from a waterworks purchased or constructed under the provisions of this Act. He shall give proper bond for the faithful discharge of his duties as such custodian, and this bond shall be fixed and approved by the trustees.
All of the funds received as income from a waterworks purchased or constructed in whole or in part under the provisions of this Act, and all of the funds received from the sale of revenue bonds shall be kept separate and apart from the other funds of the district.
70 ILCS 2405/16.12