(1) In any adjudicative proceeding all parties shall be served with a notice of hearing within the time required by law governing the respective agency or proceeding. If there is no requirement under other law, all parties shall be served with a notice of hearing not less than seven days before the date set for the hearing. The notice shall include the information specified in RCW 34.05.434. If the hearing is to be conducted by teleconference call, the notice shall so state.

(2) The notice shall state that if a limited-English-speaking or hearing impaired party or witness needs an interpreter, a qualified interpreter will be appointed and there will be no cost to the party or witness. The notice shall include a form for a party to indicate whether the party needs an interpreter and to identify the primary language or hearing impaired status of the party.

(3) Defects in the notice may not be waived unless:

(a) The presiding officer determines that the waiver has been made knowingly, voluntarily and intelligently;

(b) The party's representative, if any, consents; and

(c) If a party is an impaired person, the waiver is requested through the use of a qualified interpreter.