(1) Any party may file a written petition for administrative review of an initial order issued under WAC 246-11-430 or 246-11-540 stating the specific grounds upon which exception is taken and the relief requested.

(2) Petitions for administrative review must be served upon the opposing party and filed with the adjudicative clerk's office within twenty-one days of service of the initial order.

(3) The opposing party may file a response to a petition for administrative review as provided in this section. The response must be filed at the place specified in subsection (2) of this section. The party filing the response shall serve a copy of the response upon the party requesting administrative review. If the initial order was entered pursuant to WAC 246-11-430, the response will be filed within ten days of service of the petition. In all other matters, the response will be filed within twenty days of service of the petition.