(1) An agency shall maintain an official record of each adjudicative proceeding under this chapter.

(2) The agency record shall include:

(a) Notices of all proceedings;

(b) Any prehearing order;

(c) Any motions, pleadings, briefs, petitions, requests, and intermediate rulings;

(d) Evidence received or considered;

(e) A statement of matters officially noticed;

(f) Proffers of proof and objections and rulings thereon;

(g) Proposed findings, requested orders, and exceptions;

(h) The recording prepared for the presiding officer at the hearing, together with any transcript of all or part of the hearing considered before final disposition of the proceeding;

(i) Any final order, initial order, or order on reconsideration;

(j) Staff memoranda or data submitted to the presiding officer, unless prepared and submitted by personal assistants and not inconsistent with RCW 34.05.455; and

(k) Matters placed on the record after an ex parte communication.

(3) Except to the extent that this chapter or another statute provides otherwise, the agency record constitutes the exclusive basis for agency action in adjudicative proceedings under this chapter and for judicial review of adjudicative proceedings.