Wash. Rev. Code § 35.54.080
For the purpose of protecting the guaranty fund, so much of the guaranty fund as is necessary may be used to purchase certificates of delinquency for general taxes on property subject to local improvement assessments which underlie the bonds, coupons, or warrants guaranteed by the fund, or to purchase such property at county tax foreclosures, or from the county after foreclosure.
The city or town, as trustee of the fund, may foreclose the lien of general tax certificates of delinquency and purchase the property at foreclosure sale; when doing so the court costs, costs of publication, expense for clerical work and other expenses incidental thereto shall be charged to and paid from the local improvement guaranty fund.
After acquiring title to property by purchase at general tax foreclosure sale or from the county after foreclosure, a city or town may lease it or sell it at public or private sale at such price on such terms as may be determined by resolution of the council. All proceeds shall belong to and be paid into the local improvement guaranty fund.
RCW 35.54.080