Intervention

(1) Any employer, employee, or employee organization, or person not initially a party who may be substantially and specifically affected desiring to intervene in any proceeding shall file with the Department a written motion, or may move orally at the hearing, on the record, stating the grounds upon which such employee, employer or employee organization or person claims to be interested. Such written motion shall be filed at or prior to the first day of hearing in any proceeding, except for good cause shown. (2) At the discretion of the Department, any employer, employee, employee organization, or other entity may be allowed to intervene. (3) Any intervenor shall have the rights of a party to present evidence at any proceeding, subject to the discretion and limitations imposed by the Department, which shall consider the potential for delay and unnecessary duplication of evidence.