A notice, stating the time and place when and where such petition shall be presented to the court, or the judge thereof, together with a copy of such petition, shall be served on each and every person named therein as owner, or otherwise interested therein, at least ten days previous to the time designated in such notice for the presentation of such petition. Such notice shall be signed by the prosecuting attorney of the county wherein the real estate sought to be taken is situated, and may be served in the same manner as summons in a civil action in such superior court is authorized by law to be served.
RCW 8.16.030
Publication of notice in eminent domain proceedings: RCW 4.28.120.