(c) Service of the Petition or Application. The circuit clerk must serve a copy of the petition for review, or an application or cross-application to enforce an agency order, on each respondent as prescribed by Rule 3(d), unless a different manner of service is prescribed by statute. At the time of filing, the petitioner must:
(d) Intervention. Unless a statute provides another method, a person who wants to intervene in a proceeding under this rule must file a motion for leave to intervene with the circuit clerk and serve a copy on all parties. The motion — or other notice of intervention authorized by statute — must be filed within 30 days after the petition for review is filed and must contain a concise statement of the interest of the moving party and the grounds for intervention.