Ill. Admin. Code tit. 35, § 166.235 – Intervention

a) A person desiring to intervene shall file with the Hearing Officer a petition to intervene, accompanied by any pleadings or motions the person may wish to file at the same time. The petition shall be served on all parties at least 15 days prior to the hearing, unless a different time period is allowed by the Hearing Officer, but in no case shall intervention be allowed less than seven days prior to the hearing.
b) Intervention shall be allowed when:
1. 1) The petitioner can show an interest which may not be adequately represented by the parties to the proceedings; or
2. 2) The petition may adversely affected by the Agency's final administrative decision; or
3. 3) The petition is another agency or department of the United States or the State of Illinois which has an interest in the subject of the hearing before the Agency.
c) Any party may object to the petition to intervene by filing a notice of objection with the Hearing Officer within seven (7) days of service of the petition. The notice shall state the party's reasons for objecting and shall be served upon all parties and the persons petitioning to intervene.
d) In determining whether to allow intervention, the Hearing Officer shall consider whether there are other remedies available to the petitioner and whether the intervention will:
1. 1) Unduly delay the hearing;
2. 2) Be unduly burdensome to any party;
3. 3) Enlarge the scope of the proceedings;
4. 4) Insert new issues into the proceedings.
e) The intervenor shall have the right to present evidence and cross-examine witnesses only with respect to those issues which are within the scope of the intervention.