Wash. Rev. Code § 36.89.065
The county shall have a lien for delinquent charges, including interest, penalties, and costs of foreclosure thereon, against any property against which they were levied for the purposes authorized by this chapter, which lien shall be superior to all other liens and encumbrances except general taxes and local and special assessments. Such lien shall be effective upon the charges becoming delinquent and shall be enforced and foreclosed in the same manner as provided for sewerage liens of cities and towns by RCW 35.67.200 through 35.67.290. However, a county may, by resolution or ordinance, adopt all or any part of the alternative interest rate, lien, and foreclosure procedures as set forth in RCW 36.89.092 through 36.89.094 or 36.94.150, or chapters 84.56, 84.60, and 84.64 RCW.
RCW 36.89.065