Wash. Rev. Code § 39.110.100
(1)
(a) An authority may enter into financing documents with borrowers regarding bonds issued by the authority that may provide for the payment by each borrower of amounts sufficient, together with other revenues available to the authority, if any, to:
(2) All money received by or on behalf of the authority with respect to this issuance of its bonds must be trust funds to be held and applied solely as provided in this chapter. The authority, in lieu of receiving and applying the moneys itself, may enter into trust agreement or indenture with one or more banks or trust companies having the power and authority to conduct trust business in the state to:
(a) Perform all or any part of the obligations of the authority with respect to:
[ 2012 c 193 s 12.]