Wash. Rev. Code § 85.08.420
Upon the approval of said roll the county auditor shall immediately prepare a completed assessment roll which shall contain, first, a map of the district showing each separate description of property assessed; second, an index of the schedule of apportionments; third, an index of the record of the proceedings had in connection with the improvement; fourth, a copy of the resolution of the board of county commissioners fixing the method of payment of assessments; fifth, the warrant of the auditor authorizing the county treasurer to collect assessments; and sixth, the approved schedule of apportionments of assessments; and shall charge the county treasurer with the total amount of assessment and turn the rollover to the treasurer, for collection in accordance with the resolution of the board of county commissioners fixing the method of payment of assessments. As soon as the assessment roll has been turned over to the treasurer for collection, he or she shall publish a notice in the official newspaper of the county for once a week for at least two consecutive weeks, that the said roll is in his or her hands for collection and that any assessment thereon or any portion of any such assessment may be paid at any time on or before a date stated in such notice, which date shall be thirty days after the date of the first publication, without interest, and the treasurer shall accept such payment as in said notice provided. Upon the expiration of such thirty-day period the county treasurer shall certify to the county auditor the total amount of assessments so collected by him or her and the total amount of assessments remaining unpaid upon said roll.
RCW 85.08.420