35 Ill. Adm. Code 310.421
Final Action
Section 310
Section 310.421 Final Action
a) If the Agency denies a pretreatment permit, it must send the
applicant a written statement of the reasons for denial, as provided by Section
39(a) of the Act [415 ILCS 5/39(a)].
b) The date of the Agency's final action must be the date the
pretreatment permit or statement of reasons for denial is mailed to the
applicant.