Ill. Admin. Code tit. 35, § 831.105
b) All permit applications must be signed by the operator and the property owner, if different from the operator, or the duly authorized agent(s) of the operator or property owner, accompanied by an oath or affidavit attesting to the agent's authority to sign the application, if applicable, and notarized. The following persons are considered duly authorized agents of the operator and the property owner: