Wash. Rev. Code § 85.05.110
A summons stating briefly the objects of the petition and containing a description of the land, real estate, premises or property sought to be appropriated, and those which it is claimed will be benefited by the improvement, and stating the court wherein the petition is filed, the date of the filing thereof and when the defendants are required to appear (which shall be ten days, exclusive of the day of service, if served within the county in which the petition is pending, and if in any other county, then twenty days after such service, and if served by publication, then within thirty days from the date of the first publication), shall be served on each and every person named therein as owner, encumbrancer, tenant or otherwise interested therein. The summons must be subscribed by the commissioners, or their attorney, running in the name of the state of Washington and directed to the defendants; and service thereof shall be made by delivering a copy of such summons to each of the persons or parties so named therein, if a resident of the state, or in case of the absence of such person or party from his or her usual place of abode, by leaving a copy of the notice at his or her usual place of abode; or in case of a foreign corporation, at its principal place of business in this state with some person of more than sixteen years of age; in case of domestic corporations service shall be made upon the president, secretary or other director or trustee of the corporation; in case of persons under eighteen years of age, on their guardians, or in case no guardian shall have been appointed, then on the person who has the care and custody of the person; in case of idiots, lunatics or insane persons, on their guardian, or in case no guardian shall have been appointed, then on the person in whose care or charge they are found. *In case the land, real estate, premises or other property sought to be appropriated, or which it is claimed will be benefited by the improvement, is state, tide, school or county land, the summons shall be served on the auditor of the county in which the land, real estate, premises or other property sought to be appropriated, or which it is claimed will be benefited, is situated. In all cases where the owner or person claiming an interest in the real or other property is a nonresident of this state, or where the residence of the owner or person is unknown, and an affidavit of one or more of the commissioners of the district shall be filed that owner or person is a nonresident of this state, or that after diligent inquiry his residence is unknown or cannot be ascertained by such deponent, service may be made by publication thereof in a newspaper of general circulation in the county where such lands are situated once a week for three successive weeks. The publication shall be deemed service upon each nonresident person or persons whose residence is unknown. The summons may be served by any competent person eighteen years of age or over. Due proof of service of the summons by affidavit of the person serving the same, or by the printer's affidavit of publication, shall be filed with the clerk of the court before the court shall proceed to hear the matter. Want of service of the notice shall render the subsequent proceedings void as to the person not served; but all persons or parties having been served with summons as herein provided, either by publication or otherwise, shall be bound by the subsequent proceedings. In all cases not otherwise provided for, service of notice, order and other papers in the proceeding authorized by this chapter may be made as the superior court, or the judge thereof, may direct: PROVIDED, That personal service upon any party outside of this state shall be of like effect as service by publication.
RCW 85.05.110
*Reviser's note: Subsequent legislation provides for service of summons on budget director (now director of financial management; chapter 43.41 RCW), see chapter 79.44 RCW; see also note following RCW 85.06.110.
Severability-1971 ex.s. c 292: See note following RCW 26.28.010.