WAT § 47352

The sale shall be made for cash, except the treasurer may receive from any purchaser, at their face value in lieu cash, bonds of the district or their interest coupons, issued on the assessment and then matured or to mature within 60 days after the sale. Any bond or coupon received in payment for property sold by the county treasurer shall be canceled and filed by the county treasurer in the office of the treasurer of the district. If the entire amount of the bond or coupon tendered in payment is not required to complete payment of the purchase money, the county treasurer shall endorse thereon as paid the amount of the purchase money credited thereon.