Wash. Rev. Code § 17.10.120
In any case where a regional noxious weed control board is created, the county noxious weed control boards comprising the regional board shall still remain in existence and shall retain all powers and duties provided for the boards under this chapter.
The regional noxious weed control board is comprised of the voting members and the nonvoting members of the component counties noxious weed control boards or county legislative authorities who shall, respectively, be the voting and nonvoting members of the regional board: PROVIDED, That each county shall have an equal number of voting members. The board may appoint other nonvoting members as deemed necessary. A majority of the voting members of the board constitutes a quorum for the transaction of business and is necessary for any action taken by the board. The board shall elect a chair from its members and other officers as may be necessary. Members of the regional board serve without salary but shall be compensated for actual and necessary expenses incurred in the performance of their official duties.
RCW 17.10.120