Wash. Rev. Code § 79.44.070
When any assessing district has made or caused to be made an assessment against such leasehold, contractual, or possessory interest for any such local improvement, the treasurer of that assessing district shall immediately give notice to the chief administrative officer of the agency having jurisdiction over the lands. The assessment shall become a lien against the leasehold, contractual, or possessory interest in the same manner as the assessments on other property, and its collection may be enforced against such interests as provided by law for the enforcement of other local improvement assessments: PROVIDED, That the assessment shall not be made payable in installments unless the owner of such leasehold, contractual, or possessory interest shall first file with such treasurer a satisfactory bond guaranteeing the payment of such installments as they become due.
RCW 79.44.070