Wash. Rev. Code § 81.04.240
If the public service company subject to regulation by the commission as to rates and service does not comply with the order of the commission for the payment of damages or overcharges within the time limited in the order, action may be brought in any superior court where service may be had upon the company to recover the amount of damages or overcharges with interest. The commission shall certify and file its record in the case, including all exhibits, with the clerk of the court within thirty days after the action is started. The action must be heard on the evidence and exhibits introduced before and certified by the commission.
If the complainant prevails in the action, the court shall enter judgment for the amount of damages or overcharges with interest and award the complainant reasonable attorney's fees, and the cost of preparing and certifying the record for the benefit of and to be paid to the commission by complainant, and deposited by the commission in the public service revolving fund, the sums to be fixed and collected as a part of the costs of the action.
If the order of the commission is found contrary to law or erroneous by the rejection of testimony properly offered, the court shall remand the cause to the commission with instructions to receive the testimony so proffered and rejected and enter a new order based upon the evidence theretofore taken and such as it is directed to receive.
The court may remand any action it reverses to the commission for further action.
Appeals to the supreme court shall lie as in other civil cases. Action to recover damages or overcharges must be filed in the superior court within one year from the date of the order of the commission.
The procedure provided in this section is exclusive, and neither the supreme court nor any superior court has jurisdiction except as provided.
RCW 81.04.240