Wash. Rev. Code § 35.55.070
When such assessment roll has been prepared it shall be filed in the office of the city clerk and thereupon the city clerk shall give notice by publication in at least three issues of the official paper that such roll is on file in his or her office and that at a date mentioned in said notice, which shall be at least twenty days after the date of the first publication thereof, the city council will sit as a board of equalization to equalize said roll and to hear, consider and determine protests and objections against the same.
At the time specified in the notice, the city council shall sit as a board of equalization to equalize the roll and they may adjourn the sitting from time to time until the equalization of such roll is completed. The city council as board of equalization may hear, consider and determine objections and protests against any assessment and may make such alterations and modifications in the assessment roll as justice and equity may require.
RCW 35.55.070