Washington Revised Code Title 42. Public Officers and Agencies § 42.04.070. Compensation for unofficial services

That the directors, trustees and commissioners of state institutions in this state, serving as such without any compensation, shall not be precluded by reason of holding such offices from receiving compensation for services not official rendered without being procured or brought about by use of such official position, or by reason thereof, but such officers shall be allowed to receive such reasonable compensation for services not official or connected with their respective offices as they would otherwise be allowed were they not such officers.