92 Ill. Adm. Code 454.620
Intervention
Section 454
Section 454.620 Intervention
a) Any person may intervene by petition in a proceeding involving
a petition for approval of a rate change or in a proceeding involving a
complaint of unreasonable or unjust rates.
b) A petition for leave to intervene must set forth the grounds
of the proposed intervention, the position and interest of the petitioner in
the proceeding, and whether petitioner's position is in support of or
opposition to the relief sought. If the proceeding be by formal complaint and
affirmative relief is sought by petitioner, the petition should conform to the
requirements for a formal complaint.
c) A petition for leave to intervene in any proceeding should be
filed prior to or at the time the proceeding is called for hearing, but not
after, except for good cause shown.
d) When tendered at the hearing, sufficient copies of a petition
for leave to intervene must be provided for distribution as motion papers to
the parties represented at the hearing. If leave be granted at the hearing,
one additional copy must be furnished for the use of the Department. When a
petition for leave to intervene is not tendered at the hearing, the original
copy of the petition shall be submitted to the Department together with a
certificate that service in accordance with Section 454.110 has been made by
petitioner. Any reply in opposition to a petition for leave to intervene not
tendered at the hearing must be filed within ten days after service.
e) Leave will not be granted except on averments reasonably
pertinent to the issues already presented and which do not unduly broaden
them. If leave is granted, the petitioner thereby becomes an intervener and a
party to the proceeding.