70 ILCS 3010/8

Every sanitary district which issues bonds under this Act shall install and maintain a proper system of accounts showing the amount of revenue received from the sewerage system and the application of that revenue. At least once each year the sanitary district shall have the accounts properly audited. A report of that audit shall be open for inspection at all proper times to any taxpayer, sewerage system user, or the holder of any bond issued under this Act, or their respective representatives.