50 ILCS 405/1.16

The limitation prescribed in Section 1 of this Act shall not apply to any indebtedness of any sanitary district incorporated under "An Act to create sanitary districts and to provide for sewage disposal", approved June 22, 1917, as amended, for the purpose of constructing, altering, improving or repairing a waterworks or a sewer system, including a plant for the treatment and disposal of sewage.