The board shall approve all disbursements except those for amounts owing under contracts previously approved by the board, those for which by prompt payment the district shall receive a discount or other advantage, and those made from the imprest funds and the trust fund by the superintendent.
As operating procedure, the board shall receive at least monthly from the superintendent lists of bills for payment from district funds, which lists shall be supported by invoices and vouchers properly certified and approved with respect to materials or services received or expenses incurred. The president and the secretary of the board shall sign each listing and forward a copy of each to the treasurer of the district as authorization for payment.
Current practice codified 1988
RCW 28A.66, generally