70 ILCS 3705/18

Any ordinance authorizing the issuance of revenue bonds under this Act may in the discretion of the district provide that the bonds be secured by a trust agreement or depositary agreement by and between the district 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 deemed reasonable and proper, including the terms upon which the trustee and the bondholders, or either of them, may enforce their rights, but no such trust agreement or depositary agreement shall convey, mortgage or create any lien upon the waterworks properties of such district.