70 ILCS 3715/12
Any ordinance or resolution authorizing the issuance of revenue bonds under this Act may in the discretion of the authority provide that the bonds be secured by a trust agreement or depository agreement by and between the authority and a corporate trustee, which may be a trust company, or a bank having the powers of a trust company, within the state of Illinois, containing such provisions for directing and supervising the rights and remedies of the bondholders as may be deemed reasonable and proper, including the terms upon which the trustee under such trust agreement or depository agreement and the bondholders, or either of them, may enforce their rights; but no such trust agreement or depository agreement shall convey, mortgage or create any lien upon the waterworks properties of such authority.
70 ILCS 3715/12