(1) Any county or city required to plan under the act is authorized to require, after reasonable notice to the public and a public hearing, property owners to provide their portion of reasonable relocation assistance to low-income tenants displaced by certain changes to residential property. The changes include demolition, substantial rehabilitation (whether due to code enforcement or any other reason), change of use and removal of use restrictions in an assisted-housing development.

(2) As used in this section, "assisted housing development" means a multifamily rental housing development that either receives government assistance and is defined as federally assisted housing in RCW 59.28.020, or that receives other federal, state, or local government assistance and is subject to use restrictions.

(3) The regulations implementing the relocation assistance program shall be governed by the provisions of RCW 59.18.440.

(4) "Low-income tenants" means tenants whose combined total income per dwelling unit is at or below fifty percent of the median income, adjusted for family size, in the county where the tenants reside.

(5) For purposes of determining eligibility, the department must annually inform counties and cities of the appropriate dollar limits to use for median income, adjusted for family size, in different areas within the state. In deciding on these limits, the department will refer to the county-by-county family income figures published annually by the federal department of Housing and Urban Development. As soon as the federal figures become available each year, the department will review them and advise counties and cities promptly of the appropriate dollar limits and their effective dates.