2200.21(a)

"When allowed." A petition for leave to intervene may be filed at any time prior to ten days before commencement of the hearing. A petition filed less than ten days prior to the commencement of the hearing will be denied unless good cause is shown for not timely filing the petition. A petition shall be served on all parties in accordance with 2200.7.

2200.21(b)

"Requirements of petition." The petition shall set forth the interest of the petitioner in the proceeding and show that the participation of the petitioner will assist in the determination of the issues in question, and that the intervention will not unduly delay the proceeding.

2200.21(c)

"Granting of petition." The Commission or Judge may grant a petition for intervention to such an extent and upon such terms as the Commission or the Judge shall determine.