A person may initiate an adjusted standard proceeding by filing a petition that meets the requirements of Section 104.406 of this Part. A petition for an adjusted standard (petition) may be filed either jointly with the Agency or singly under the filing requirements of 35 Ill. Adm. Code 101. If filed singly, the petitioner must also serve the petition upon the Agency in accordance with 35 Ill. Adm. Code 101. Additionally, a person may file a petition and request the Agency to join as a co-petitioner as set forth in Section 104.404.
Ill. Admin. Code tit. 35, § 104.402