Wash. Rev. Code § 35.57.050
The board of directors of the public facilities district shall adopt a resolution that may be amended from time to time that shall establish the basic requirements governing methods and amounts of reimbursement payable to such district officials and employees for travel and other business expenses incurred on behalf of the district. The resolution shall, among other things, establish procedures for approving such expenses; the form of the travel and expense voucher; and requirements governing the use of credit cards issued in the name of the district. The resolution may also establish procedures for payment of per diem to board members. The state auditor shall, as provided by general law, cooperate with the public facilities district in establishing adequate procedures for regulating and auditing the reimbursement of all such expenses.
RCW 35.57.050