Wash. Rev. Code § 91.08.340
Any person interested in any property assessed and desiring to object to the assessment thereon, shall file his or her objections to such report at any time before the day set for hearing said roll, and serve a copy thereof upon the prosecuting attorney. As to all property to the assessment upon which no objections are filed and served, as herein provided, default may be entered and the assessment confirmed by the court. On the hearing of objections the report of the commissioners shall be competent evidence to support the assessment, but either party may introduce such other evidence as may tend to establish the right of the matter. The hearing shall be conducted as in other cases at law tried by the court without a jury; and if it shall appear that the property of the objector is assessed more or less than it will be benefited, or more or less than its proportionate share of the cost of the condemnation and improvement, the court shall so find, and it shall also find the amount in which said property ought to be assessed and correct the assessment accordingly. Judgment shall be entered confirming the assessment roll as originally filed or as corrected, as the case may require.
RCW 91.08.340
Civil procedure: Title 4 RCW.