Wash. Rev. Code § 85.15.110
The county clerk shall charge the same filing fees for petitions for review as in civil actions. At the time of the filing of such a petition with the clerk, the appellant shall execute and file a bond in the penal sum of two hundred dollars, with at least two sureties, to be approved by the judge of the court, conditioned upon his or her prosecuting his or her appeal without delay and to guarantee all costs which may be assessed against him or her by reason of such review. The court shall, on motion of either party to the cause, with notice to the other party, set the cause for trial at the earliest time available to the court, fixing a date for hearing and trial without a jury. The cause shall have preference over all civil actions pending in the court except eminent domain and forcible entry and detainer proceedings.
RCW 85.15.110