Wash. Rev. Code § 35.43.150
Notice of the hearing upon a resolution declaring the intention of the legislative authority of a city or town to order an improvement shall be given by mail at least fifteen days before the day fixed for hearing to the owners or reputed owners of all lots, tracts, and parcels of land or other property to be specially benefited by the proposed improvement, as shown on the rolls of the county assessor, directed to the address thereon shown.
The notice shall set forth the nature of the proposed improvement, the estimated cost, a statement that actual assessments may vary from assessment estimates so long as they do not exceed a figure equal to the increased true and fair value the improvement, or street lighting, adds to the property, and the estimated benefits of the particular lot, tract, or parcel.
RCW 35.43.150