Wash. Rev. Code § 46.29.560
Such deposit shall be held by the department to satisfy, in accordance with the provisions of this chapter, any execution on a judgment issued against such person making the deposit, for damages, including damages for care and loss of services, because of bodily injury to or death of any person, or for damages because of injury to or destruction of property, including the loss of use thereof, resulting from the ownership, maintenance, use, or operation of a vehicle of a type subject to registration under the laws of this state after such deposit was made. Money or securities so deposited shall not be subject to attachment or execution unless such attachment or execution shall arise out of a suit for damages as aforesaid. Any interest or other income accruing to such money or securities, so deposited, shall be paid to the depositor, or his or her order, as received.
RCW 46.29.560