Wash. Rev. Code § 54.12.090
The commission shall elect from its members, a president and secretary, and shall, by resolution, adopt rules governing the transaction of district business, and adopt an official seal. All proceedings of the commission shall be by motion or resolution, recorded in its minute books, which shall be public records.
A majority of the members shall constitute a quorum of the commission for the transaction of business. The concurrence of a majority of the whole commission in office at the time shall be necessary for the passage of any resolution, and no business shall be transacted, except in usual and ordinary course, unless there are in office at least a majority of the full number of commissioners as fixed by law.
The commission may create and fill such positions and fix salaries and bonds thereof as it may provide by resolution.
RCW 54.12.090