Wash. Rev. Code § 28B.07.330
Bonds may be issued by the authority to refund other outstanding bonds issued pursuant to this chapter, at or prior to the maturity thereof, and to pay any redemption premium with respect thereto. Bonds issued for such refunding purposes may be combined with bonds issued for the origination or purchase of educational loans. Pending the application of the proceeds of the refunding bonds to the redemption of the bonds to be redeemed, the authority may enter into an agreement or agreements with a corporate trustee with respect to the interim investment of the proceeds and the application of the proceeds and the earnings on the proceeds to the payment of the principal of and interest on, and the redemption of the bonds to be redeemed.
RCW 28B.07.330
Policy-Purpose-2007 c 36: See note following RCW 28B.07.300.