Wash. Rev. Code § 80.04.170
Any complainant or any public service company affected by any findings or order of the commission, and deeming such findings or order to be contrary to law, may, within thirty days after the service of the findings or order upon him or her or it, apply to the superior court of Thurston county for a writ of review, for the purpose of having the reasonableness and lawfulness of such findings or order inquired into and determined. Such writ shall be made returnable not later than thirty days from and after the date of the issuance thereof, unless upon notice to all parties affected further time be allowed by the court, and shall direct the commission to certify its record in the case to the court. Such cause shall be heard by the court without the intervention of a jury on the evidence and exhibits introduced before the commission and certified to by it. Upon such hearing, the superior court shall enter judgment either affirming or setting aside or remanding for further action the findings or order of the commission under review. The reasonable cost of preparing the transcript of testimony taken before the commission shall be assessable as part of the statutory court costs, and the amount thereof, if collected by the commission, shall be deposited in the public service revolving fund. In case such findings or order be set aside, or reversed and remanded, the court shall make specific findings based upon evidence in the record indicating clearly all respects in which the commission's findings or order are erroneous.
RCW 80.04.170