Ill. Admin. Code tit. 35, § 845.280
1) Discovery of a typographical or calculation error;
4) Promulgation of new statutes or regulations affecting the permit.
d) The Agency may make minor modifications to a permit without following the public notice procedures of Section 845.260. Minor modifications may only:
e) An application for renewal of a permit must be filed with the Agency at least 180 days before the expiration date of the existing permit unless the Agency grants a waiver of this requirement. The Agency may grant a waiver of the 180-day requirement only if: